Air filtration arrangements having fluted media constructions and methods

【0001】

This application is in the name of Donaldson Company, Inc., a company in the United States and has a residence in the United States, and was filed as a PCT international patent application on August 10, 2001, with all countries except the United States as designated countries. It claims priority under US application Nos. 60 / 230,138 filed on September 5, 2000 and US application No. 09 / 871,590 filed on May 31, 2001.

【0002】

(Field of Invention) The present invention relates to a filter structure and a filter method. More specifically, the present invention relates to a device for removing (filtering) particulate matter from a gas stream, such as an air stream. The present invention also relates to methods for achieving the desired removal of particulate matter from such a stream of gas streams.

【0003】

The invention is currently under development by Donaldson Company Inc. of Minneapolis, Minnesota, the assignee of the invention. This disclosure relates to ongoing technological development, in part relating to the subject matter characterized in US Pat. Nos.: B2 4,720,292; Design 416,308; 5,613,992; 4,020,783; and 5,112,372. Each of the patents identified in the preamble is also owned by Donaldson, Inc. of Minneapolis, Minnesota, and the full disclosure of each is incorporated herein by reference.

【0004】

The present invention also relates to a filter comprising a substrate having a fine fiber layer made of a polymeric material that can be manufactured with increased environmental stability against heat, humidity, reactive materials and mechanical stresses. Such materials can be used in forming fine fibers such as microfiber and nanofiber materials with increased stability and strength. As the size of the fiber decreases, the survivability of the material is gradually becoming a problem. Such fine fibers are useful in various applications. In one application, this fine fiber technique can be used to create a filter structure. The present invention relates to polymers, polymer compositions, fibers, filters, filter structures, and filter methods. Applications of the present invention particularly relate to removing (filtering) particles from a fluid stream, such as an air stream or a liquid (eg, non-aqueous or aqueous) stream. The technique described relates to a structure having one or more fine fiber layers in a filter medium (media / medium). The size of the composition and fiber is selected according to the combination of properties and persistence.

【0005】

(Background of the Invention) A gas stream often contains particulate matter within it. In many cases, it is desirable to remove some or all of the particulate matter from the gas stream. For example, the intake flow to an engine for an engine-operated vehicle or power generation equipment, the gas flow directed to a gas turbine, and the air flow to various combustion furnaces often contain particulate matter within them. When particulate matter reaches the internal mechanisms of the various mechanisms involved, it can cause considerable damage to those mechanisms. It is often necessary to remove particulate matter from the gas stream upstream of the engine, turbine, furnace, or other equipment involved.

【0006】

The present invention is a polymer with improved properties that can be used in a variety of applications including the formation of permeable structures such as fibers, microfibers, nanofibers, fiber webs, fiber mats, films, coatings and films. Regarding the composition. The polymeric materials of the present invention can impart the ability to withstand the effects of humidity, heat, airflow, chemicals, and deterioration due to mechanical stress or impact on polymeric materials in various physical shapes or forms. A composition having possible physical properties.

【0007】

Various materials, including glass fibers, metals, ceramics, and polymer compositions, are used to form fine fiber filter media. Various fiber forming methods or techniques are used in the production of small diameter microfibers and nanofibers. One method involves passing the material through a fine capillary or opening as a molten material or in a solution that is to be evaporated later. Fibers can also be formed by using "spinnerets" that are common in the production of synthetic fibers such as nylon. Electrostatic spinning is also known. Such techniques include the use of hypodermic needles, nozzles, capillaries, or movable emitters. These structures result in a polymer solution that is later attracted to the collection zone by a high voltage electrostatic field. As the material is pulled away from the emitter and accelerated in the electrostatic zone, the fiber becomes very thin and solvent evaporation can form the fiber structure.

【0008】

High humidity from 10% to 90%, up to 100% RH, at high temperatures from 100 ° F to 250 ° F, often 140 ° F to 240 ° F, up to 300 ° F, as more demanding applications are possible with filter media. Filters micron and submicron particles (in the range of about 0.01 micron to over 10 microns) at high flow rates, both gas and liquid, and is greasy and non-abrasive, reactive and non-reactive. Significantly improved materials are needed to withstand the harsh conditions of removing certain microparticles from the flow of fluid.

【0009】

Therefore, polymer materials, microfiber and nanofiber materials, and filter structures that provide improved properties are required to filter flows containing micron and submicron particulate matter at high temperatures, high humidity, and high flow rates. Has been done.

【0010】

Various air filters or gas filter devices have been developed for the removal of fine particles. However, in general, improvements are still required.

【0011】

(Overview of the Invention) The present specification provides general techniques for designing and applying an air cleaner device. This technique includes preferred filter element design, as well as preferred methods of application and filtering.

【0012】

In general, a preferred application relates to utilizing a Z-shaped medium containing a composite of a substrate and a fine fiber in an air filter.

【0013】

The filter medium comprises at least a microfiber web layer or a nanofiber web layer that is combined with a substrate material in a mechanically stable filter structure. Together, these layers provide excellent filter efficiency in capturing a large number of particles with minimal flow limits as fluids such as gases and liquids pass through the filter medium. The substrate can be positioned upstream, downstream, or inner layer of the fluid flow. The fiber can be positioned upstream, downstream, or on both sides of the filter substrate, regardless of the geometry of the filter. The fibers are generally located upstream. However, in certain applications, it may be useful to place it downstream. A double-sided structure is useful in certain applications. In various industries, a great deal of interest in recent years has been directed to the use of filters, i.e. filter media for the removal of unwanted particles from fluids such as gases and liquids. A typical filter process removes particulates from fluids, including air streams and other vapor streams, or from liquid streams such as hydraulic fluids, lubricants, fuels, water streams, or other fluids. Such a filter process requires that the microfiber and substrate material have mechanical strength, chemical and physical stability. Filter media can be exposed to a wide range of temperature conditions, humidity, mechanical vibrations and shocks, reactive and non-reactive abrasive or non-abrasive particles mixed into the fluid flow. During normal operation, the filter is generally exposed to ambient or near ambient or slightly higher temperatures of air. Filters can be exposed to higher temperatures when the engine malfunctions or when the engine shuts down after prolonged use. If the engine is not running, the air will not pass through the filter. The filter quickly cools below the hood temperature. Further, the filter medium has a self-cleaning ability to expose the filter medium to a reverse pressure pulse (reversing the flow of fluid for a single hour to remove the surface coating of the fine particles), or removes mixed fine particles from the surface of the filter medium. Often requires other cleaning mechanisms that can. Such reverse cleaning can significantly improve (ie) reduce the pressure drop after pulse cleaning. Particle capture efficiency is generally not improved after pulse cleaning, but pulse cleaning reduces the pressure drop and saves energy for filter operation. Such filters can be removed during use and cleaned in an aqueous or non-aqueous cleaning composition. Such media are often produced by spinning fine fibers and then forming a web of entangled microfibers on a porous substrate. In the spinning process, the fibers can form physical bonds between the fibers, thereby entwining the fiber mat with the integral layer. Such materials can then be made into desired filter forms such as cartridges, flat discs, canisters, panels, bags, pouches and the like. Within such a structure, the medium can be fully pleated, rolled, or otherwise positioned onto the substrate structure. It can be made into a desired filter form such as a desk, canister, panel, bag, pouch or the like. Within such a structure, the medium can be fully pleated, rolled, or otherwise positioned onto the substrate structure. It can be made into a desired filter form such as a desk, canister, panel, bag, pouch or the like. Within such a structure, the medium can be fully pleated, rolled, or otherwise positioned onto the substrate structure.

【0014】

The filter structure described herein can be used in a wide variety of applications including, for example, dust collectors, air compressors, on-road and off-road engines, gas turbine systems, generators such as fuel cells, and the like. it can.

【0015】

(Detailed description of the invention) A.<u style="single">Microfiber or fine fiber polymer material</u>The present invention provides improved polymeric materials. The physical and chemical stability of this polymer is improved. Polymer fine fibers (microfibers and nanofibers) can be made into useful product forms. The diameter of the fiber can be about 0.001-10 microns, about 0.005-5 microns, about 0.01-0.5 microns. Nanofibers are fibers with a diameter of less than 200 nanometers, i.e. less than 0.2 microns. Microfibers are fibers that are larger than 0.2 microns in diameter but less than 10 microns in diameter.

【0016】

This fine fiber can be made in the form of an improved multi-layer precision filter medium (media / medium) structure. The fine fiber layer of the present invention includes a random distribution of fine fibers that can be coupled to form an intertwined net. As a result of the fine fiber blocking the passage of fine particles, high filter performance can be obtained. Structural properties such as rigidity, strength and permeability are obtained by the substrate to which the fine fibers are bonded. An intertwined network of fine fibers has, as an important feature, fine fibers in the form of microfibers or nanofibers and a relatively small space between the fibers. Such interfiber spaces in the layers generally range from about 0.01 micron to about 25 microns, or often from about 0.1 micron to about 10 microns, between fibers. Filter products include fine fiber layers on appropriately selected substrates such as synthetic layers, natural layers, or mixed natural / synthetic substrates. Fine fibers increase the thickness by less than 5 microns, often less than 3 microns. According to the fine fiber in a particular application, the thickness of the entire filter medium in which the substrate is added to the fine fiber is increased by the diameter of about 1 to 10 or 1 to 5 fine fibers. During use, the filter can stop the influx of particles from moving to the substrate or passing through the fine fiber layer, providing a sufficient surface load of the captured particles. The particles containing dust or other inflowing fine particles quickly form a dust cake on the surface of the fine fiber, and the initial efficiency and overall efficiency for removing the fine particles are maintained high. Filter media containing fine fibers have very high dust capacities, even for relatively fine contaminants with a particle size of about 0.01 to about 1 micron.

【0017】

The polymeric materials disclosed herein are resistant to heat, humidity, high flow rates, reverse pulse cleaning, operational wear, submicron particles, cleaning of filters in use, and other undesired effects of harsh conditions. The sex was greatly improved. Improved microfiber and nanofiber performance is obtained by improving the properties of the polymeric material that forms the microfiber or nanofiber. Further, the filter medium of the present invention using the improved polymer material of the present invention is highly efficient, low flow rate limitation, high durability in the presence of abrasive fine particles and a smooth outer surface free of loose fibers or fibrils. It provides several advantageous features, including (stress related or environmental related). The overall structure of the filter material provides an overall thinner medium, with a larger medium area per unit volume, slower passage through the medium, higher medium efficiency, and lower flow restrictions.

【0018】

The polymer can be an addition polymer, a condensed polymer, or a mixture or blend thereof. A preferred embodiment of the present invention is a first polymer and a second polymer different from this (different in polymer type, molecular weight, or physical properties), prepared or treated at high temperatures. It is a polymer blend containing. Polymer blends can be reacted to form a single species, or physically bonded by an annealing process, thereby resulting in a blended composition. Annealing means physical changes such as crystallinity, stress relaxation, and orientation. The preferred materials are chemically reacted into a single polymer species so that differential scanning calorimetry analysis reveals a single polymer material. Such materials, when combined with preferred additive materials, provide the surface of additives that provide other relevant improved stability when exposed to harsh operating conditions of oleophobic, hydrophobic, or hot and humid conditions. A coating can be formed on the surface of the microfiber. The diameter of fine fibers in this class of material can range from 0.001 micron to 10 micron. Useful sizes include 0.001 to 2 microns, 0.005 to 5 microns, and 0.01 to 5 microns, depending on the bond, substrate, and application. Such microfibers are smooth, including a separate layer of additive material or an outer coating of additive material that partially dissolves on the polymer surface and / or becomes alloyed with the polymer surface. Can have a unique surface. Preferred materials used in blended polymer systems include nylon 6, nylon 66, nylon 6-10, nylon (6-66-610) copolymers, and other linear, generally aliphatic nylon compositions. .. The molecular weight of the preferred nylon copolymer resin (SVP-651) was analyzed by end group titration (JEWalz and GB). Taylor, determination of the molecular weight of nylon, Anal.Chem.Vol.19, Number 7, pp. 448-450 (1947)). The number average molecular weight (Mn) was between 21,500 and 24,800. The composition was evaluated by phase diagrams of three component nylons, namely nylon 6 at about 45%, nylon 66 at about 20%, and nylon 610 at about 25% (page 286, Nylon Plastics Handbook, Melvin Kohan). , Hanser Publisher, New York (1995)).

【0019】

The reported physical properties of the SVP651 resin are as follows.

【0020】

[table 1]<img file="JP2004508169A_D0001.tif" /> 【0021】

For such polymer systems, polyvinyl alcohol with a degree of hydrolysis of 87-99.9 +% can be used. These are preferably crosslinked. Most preferably, they are crosslinked and bonded to a significant amount of oleophobic and hydrophobic additive material.

【0022】

Another preferred embodiment of the invention comprises a single polymeric material bound to the additive composition so as to improve the life or operational properties of the fiber. Preferred polymers useful in this aspect of the invention include nylon polymers, polyvinylidene chloride polymers, polyvinylidene fluoride polymers, polyvinyl alcohol polymers, especially when combined with highly oleophilic and hydrophobic additives. These listed materials can be included to obtain microfibers or nanofibers in which the additive material is formed as a coating on the surface of the fine fiber. Again, similar nylons, similar blends of polyvinyl chloride polymers, and blends of polyvinylidene chloride polymers are useful in the present invention. Further, polymer blends or alloys of different polymers are also contemplated by the present invention. In this regard, a mixture of compatible polymers is useful in forming the microfiber materials of the present invention. Additive compositions such as fluorine-based surfactants, nonionic surfactants, and low molecular weight resins (eg) tertiary butylphenol resins having a molecular weight of less than about 3000 can be used. This resin is characterized in that phenol nuclei are oligomerically bonded to each other in the absence of a methylene crosslinked group. The positions of the hydroxyl and tertiary butyl groups can be randomly positioned around the ring. Bonds between phenolic nuclei always occur next to hydroxyl groups and are not random. Similarly, the polymeric material can be combined with an alcohol-soluble non-linear polymeric resin formed from bisphenol A. Similar to the tertiary butylphenol resin described above, such materials are formed using oligomeric bonds that directly bond aromatic rings in the absence of any cross-linking groups such as alkylene groups and methylene groups. Is.

【0023】

The highly preferred polymer system of the present invention is sufficient for the substrate as it can tightly bond to the cellulosic substrate when in contact with it and withstand reverse pulse cleaning and other layer peeling due to mechanical stress. It has adhesive properties that allow it to adhere with strength. In such a form, the polymeric material must remain adhered to the substrate while receiving a pulse clean input that is substantially equal to typical filter conditions except that it is in the opposite direction on the filter structure. Such adhesion can be achieved by solvent effects during fiber formation when the fibers come into contact with the substrate, or by post-treatment of the fibers on the substrate with heat or pressure. However, polymer properties determine adhesion such as certain chemical interactions such as hydrogen bonds, contact between the polymer and the substrate that occur at temperatures above or below Tg, and polymer formation with additives. It is considered to play an important role. Polymers that are plasticized with solvent or water vapor during adhesion can increase adhesion.

【0024】

An important aspect of the present invention is the effective utilization of such microfiber or nanofiber materials formed in the filter structure. In such a structure, the fine fiber material of the present invention is formed and adhered on a filter substrate. Span-bonded fabrics, synthetic non-wovens, non-wovens made from cellulose-based, synthetic, and fiberglass blends, non-woven and woven fabrics, plastic screens such as extruded and perforated materials, Substrate of natural and synthetic fibers such as UF and MF membranes of organic polymers can be used. A filter structure in which a sheet-like substrate or cellulosic non-woven web is placed in a fluid stream, including an air stream or a liquid stream, to remove particles suspended or mixed in the stream from the stream. Can be formed into. The shape and structure of the filter material depends on the design engineer. One important parameter of the post-formation filter element is resistance to the effects of heat, humidity, or both. One aspect of the filter medium of the present invention is to test whether it can withstand long-term immersion in warm water. Immersion tests are used to determine if fine fibers can withstand hot and humid conditions and to clean filter elements in aqueous solutions that may contain a significant proportion of strong cleaning surfactants and strong alkaline materials. It can provide valuable information as to whether it can be tolerated. The fine fiber material of the present invention preferably can withstand immersion in warm water while retaining at least 30%, preferably 50%, of the fine fibers formed on the surface of the substrate. By retaining at least 30%, preferably 50% fine fiber, sufficient fiber efficiency can be maintained without loss of filter capacity or increase in back pressure. Most preferably, it is kept at least 75%. The thickness of a typical fine fiber filter layer is about 1 to 100 times the diameter of the fiber, and its basis weight is about 0.01 to 240 μg · cm.^-2To.

【0025】

Fluid streams, such as air and gas streams, often contain particulate matter within them. Some or all of the particulate matter needs to be removed from the fluid stream. For example, intake flow to the cabin of a motor-operated vehicle, air in a computer disk drive, HVAC air, ventilation of an aircraft cabin, filter bag, barrier fabric, clean room ventilation and construction using woven fabric, motor operation. The flow of air to a vehicle engine or power generator, the flow of gas towards a gas turbine, and the flow of air to various combustion furnaces often contain particulate matter within them. For cabin air filters, it is desirable to remove particulate matter so that passengers are comfortable and / or from an aesthetic point of view. With respect to the intake flow of air and gas to engines, gas turbines, and combustion furnaces, it is possible to remove particulate matter as fine particles can cause considerable damage to the internal mechanisms of the various mechanisms involved. desirable. In other cases, the gas or exhaust gas produced by an industrial process or engine may contain particulate matter within it. Such gases can or should be discharged into the atmosphere through various downstream devices, but prior to that, it would be desirable to substantially remove particulate matter from these streams.

【0026】

Some general understanding of the basic principles of air filter design and some of the problems can be understood by considering the following types of filter media: surface loading media and depth media. Each of these types of media has been well researched and widely used. Certain principles relating to these are described, for example, in US Pat. Nos. 5,082,476, 5,238,474, and 5,364,456. The full disclosure of these three patents is incorporated herein by reference.

【0027】

The "life" of a filter is generally determined by the selective critical pressure drop across the filter. The increase in pressure across the filter defines the life at a level determined according to its application or design. Longer life is generally directly related to higher capacity for systems of equal efficiency, as this pressure increase is caused by loading. Efficiency refers to the tendency of the medium to capture fine particles rather than pass them through. In general, the more efficient the filter medium in removing particulates from the gas stream, the faster the filter medium will generally approach the "life" pressure difference (assuming other variables remain constant). ) Will be clear.

【0028】

(Detailed description of drawings) The microfiber or nanofiber of this unit can be formed by an electrostatic spinning process. Figure 1 shows a suitable device for forming fibers. This device includes a reservoir 80 containing a fine fiber-forming polymer solution, a pump 81, and a rotary discharge device or emitter 40 from which the polymer solution is delivered. The emitter 40 generally comprises a rotating union 41, a rotating portion 42 including a plurality of offset holes 44, and a shaft 43 connecting the front portion and the rotating union. The rotating union 41 introduces the polymer solution through the hollow shaft 43 to the front portion 42. The holes 44 are spaced around the perimeter of the front portion 42. Alternatively, the rotating portion 42 can be immersed in the polymer reservoir supplied by the reservoir 80 and pump 81. The rotating portion 42 then obtains a polymeric solution from the reservoir, and as the portion rotates in an electric field, droplets of solution are accelerated by an electrostatic field towards the collection medium 70 discussed below.

【0029】

A substantially planar grid 60 is arranged so as to face the emitter 40, but at intervals from it, on which a collection medium 70 (ie, a substrate or a bonding substrate) is positioned. Air can be drawn through this grid. The collection medium 70 passes around rollers 71 and 72 positioned adjacent to both ends of the grid 60. A high voltage electrostatic potential is maintained between the emitter 40 and the grid 60 by a suitable static voltage power supply 61 and connections 62 and 63, each connected to the grid 60 and the emitter 40, respectively.

【0030】

During use, the polymer solution is delivered from the reservoir 80 to the rotating union 41 or reservoir. The front portion 42 rotates, at which time the liquid exits the hole 44 or is pulled out of the reservoir and moves from the outer edge of the emitter towards the collection medium 70, which is positioned on the grid 60. Specifically, the electrostatic potential between the grid 60 and the emitter 40 charges the material, from which the liquid is discharged as thin fibers and drawn towards the grid 60, where it reaches the substrate 12 or Collected on the effective layer 14. In the case of a molten polymer, the solvent evaporates from the fiber while the fiber is blown onto the grid 60, thus reaching the substrate 12 or the effective layer 14. The fine fiber is coupled to the substrate fiber first encountered on the grid 60. The intensity of the electrostatic field is selected to ensure that a polymeric material is obtained as it accelerates from the emitter to the collected gas 70, which accelerates the material into a very fine microfiber or nanofiber structure. Sufficient for. By increasing or decreasing the advancing speed of the collection medium, the emitted fibers can be deposited less or more on the forming medium, thereby controlling the thickness of each layer deposited on the medium. become. The rotating portion 42 can take various beneficial positions. The rotating portion 42 can be arranged in the rotating plane so that its plane is perpendicular to the surface of the collection medium 70 or is positioned at any angle. The rotating medium can be positioned in a parallel orientation or slightly offset from the parallel orientation.

【0031】

FIG. 2 is a schematic view of a process and an apparatus for forming a fine fiber layer on a sheet-like substrate or medium. In FIG. 2, the sheet-like substrate is unwound at station 20. The sheet-like substrate 20a can then be directed to the splicing station 21 where multiple lengths of the substrate can be spliced for continuous operation. A sheet-like substrate of continuous length is directed to the fine fiber technology station 22 including the spinning technique of FIG. 1, where a spinning device forms fine fibers, and the fine fibers are superposed on a filter layer on the sheet-like substrate. After the fine fiber layer is formed on the sheet-like substrate in the formation zone 22, the fine fiber layer and the substrate are directed to the heat treatment station 23, and appropriate treatment is performed. The sheet substrate and fine fiber layer are then tested on the efficiency monitor 24 and, if necessary, nipped at the nip station 25. The sheet substrate and fine fiber layer are then fed to a suitable winding station where they are wound around a suitable spindle for further processing 26 and 27.

【0032】

FIG. 3 is a scanning electron micrograph showing the relationship between typical dust particles with diameters of about 2 microns and about 5 microns with respect to pore diameter in a typical cellulose medium and a typical fine fiber structure. FIG. 3A shows that the 2 micron particles 31 and the 5 micron particles 32 are among the cellulose media 33 having pore diameters shown to be significantly larger than the typical particle size. In stark contrast, in Figure 3B, the 2 micron particle 31 appears to be approximately equal to or larger than the typical opening between fibers of the fiber web 35, whereas the 5 micron particle 32 is the fine fiber web. Looks larger than any of the 35 openings.

【0033】

The above schematic description of various aspects of the polymeric materials of the invention, the fine fiber materials of the invention, including both microfibers and nanofibers, and the construction of useful filter structures obtained from the fine fiber materials of the invention. It provides an understanding of the general technical principles of action of the present invention. The following specific exemplary materials are examples of materials that can be used to form the fine fiber materials of the present invention, the following materials disclose the best forms. The following exemplary materials were manufactured with the following characteristics and process conditions in mind: Small fibers with a diameter of less than 10 microns by electrospinning are obtained using electrostatic force from a strong electric field that acts as a tensile force to stretch the polymer injection into very fine filaments. Polymer melts can be used in this electrospinning, but fibers smaller than 1 micron are best formed from the polymer solution. As the polymer mass is pulled out to a smaller diameter, the solvent evaporates, contributing to a reduction in fiber size. Solvent selection is extremely important for several reasons. If the solvent dries too quickly, the fibers tend to flatten and increase in diameter. If the solvent dries too slowly, the fibers formed will dissolve in the solvent again. Therefore, it is extremely important to balance the drying rate with the fiber formation. At high production rates, large amounts of exhaust flow help prevent flammable atmospheres and reduce the risk of fire. Non-flammable solvents are useful. In the production environment, the processing equipment needs to be cleaned from time to time. A safe solvent with low toxicity minimizes the exposure of workers to harmful chemicals. Antistatic can be performed at a flow rate of 1.5 ml / min per emitter, a target distance of 8 inches, an emitter voltage of 88 kV, an emitter rpm of 200, and a relative humidity of 45%.

【0034】

The choice of polymer system is important in a given application. For pulse cleaning applications, an extremely thin microfiber layer can help minimize pressure loss and provide an outer surface for trapping and releasing particles. A thin fiber layer with a diameter of less than 2 microns, preferably less than 0.3 microns in diameter is preferred. It is important that the microfiber or nanofiber and the substrate on which the microfiber or nanofiber is deposited are well adhered to each other. When the filter is made of a composite of a substrate and a thin layer of microfibers and nanofibers, such a composite forms an excellent filter medium for self-cleaning applications. Cleaning the surface with a reverse pulse repeats the filter medium to make it as good as new. When a large force is applied to the surface of the fine fiber, the fine fiber having poor adhesion to the substrate may be delaminated by a reverse pulse from the inside of the filter to the microfiber via the substrate. Therefore, good cohesion between microfibers and adhesion between the substrate fiber and the electrospun fiber are crucial for successful use.

【0035】

Products that meet the above requirements can be obtained using fibers made from different polymeric materials. Small fibers with good adhesion are polymers containing polymers such as polyvinylidene chloride, polyvinyl alcohol and various nylons such as nylon 6, nylon 4,6, nylon 6,6, nylon 6,10, and copolymers thereof. And can be made from copolymers. Good fibers can be made from PVDF, but a chlorinated solvent is required to make the fiber diameter sufficiently small. Nylon 6, Nylon 66, and Nylon 6, 10 can be electrospun. However, solvents such as formic acid, m-cresol, trifluoroethanol and hexafluoroisopropanol are difficult to handle or very expensive. Preferred solvents include water, ethanol, isopropanol, acetone, and N-methylpyrrolidone due to their low toxicity. Polymers that are compatible with such solvent systems have been extensively evaluated. We have found that fibers made from PVC, PVDC, polystyrene, polyacrylonitrile, PMMA, PVDF require additional bonding means to obtain structural properties. In addition, the present inventors have excellent adhesiveness to a substrate when a polymer is successfully prepared by dissolving a polymer in water, ethanol, isopropanol, acetone, methanol, or a mixture thereof. It has been found that this creates an excellent filter medium for self-cleaning applications. Self-cleaning via a reverse air pulse or twist is useful when the filter medium is used at very high dust concentrations. In such applications, fibers obtained from alcohol-soluble polyamides and poly (vinyl alcohol) were successfully used. Examples of alcohol-soluble polyamides include Henkel's Macromelt 6238, 6239, and 6900, duPont's Elvamide 8061 and 8063, and Shakespeare Monofilament Company's SVP 637 and 651. Another group of alcohol-soluble polyamides is type 8 nylon, alkoxyalkyl-modified nylon 66 (references, page 447, Nylon Plastics handbook, edited by Melvin Kohan, Hanser Publisher, New York, 1995). Examples of poly (vinyl alcohol) include PV-217 and 224 from Kuraray Co., Ltd. of Japan, and Products and Chemical.

【0036】

The present inventors have found that the filter may be exposed to extreme environmental conditions. Filters in the Saudi Arabian desert can be exposed to temperatures as high as 150 ° F and above. Filters installed in the Gulf of Indonesia or the United States can be exposed to high humidity above 90% RH and temperatures as high as 100 ° F. Also, those filters may be exposed to rain. We have found that filters used under the hood of mobile and construction equipment such as automobiles, trucks, buses and tractors are subject to high temperatures (+ 200 ° F), high relative humidity and other chemical environments. We have found that we may be exposed. The present inventors have developed a test method for evaluating the survivability of a microfiber system under harsh conditions. Immerse the filter medium sample in warm water (140 ° F) for 5 minutes or expose it to high humidity, high temperature, and airflow.

【0037】

B.<u style="single">General Principles for Air Cleaner Design</u>As used herein, the term "air cleaner" is used with respect to a system that functions to remove particulate matter from the flow of airflow. The term "air filter" refers to a system that removes air containing fine particles by passing it through a filter medium. The term "filter medium" or "medium" refers to a material or aggregate of materials through which air passes, in which particles deposit in or on the medium with the passage of air. The term "surface loading medium" or "barrier medium" means that when air passes through a medium, the particulate matter does not enter and deposit in the depth direction of the medium, but the particulate matter is primarily the surface of the medium. Refers to a system that deposits in the media to form a filter cake.

【0038】

As used herein, the term "filter element" generally refers to a portion of an air cleaner that contains a filter medium inside. Generally, the filter element is designed as part of a removable and replaceable, ie maintainable, air cleaner. That is, the filter medium is held by the filter element and can be separated from the rest of the air cleaner, so that the clogged or partially clogged filter element can be removed into a new or cleaned filter element. By replacing it, the air cleaner can be returned to the same condition as new on a regular basis. The air cleaner is preferably designed so that it can be removed and replaced by hand. As used herein, the term "clogging" or a variation thereof means an air cleaner that has been operating for a sufficient period of time so that a significant amount of trapped particles or microparticles are contained on the air cleaner. In many cases, a normally operating filter element is clogged with fine particles, which increases its weight by two or three times (or more) than its original weight.

【0039】

In general, specifications regarding the performance of air cleaner systems are created by the original equipment manufacturer (OEM) of the relevant engine and / or the OEM preference of the relevant truck or other equipment. It includes a wide variety of specifications, one of which is as follows. 1. Engine intake requirement (rated flow) 2. Initial constraint 3. Initial efficiency 4. Average or overall operating constraint 5. Overall efficiency 6. Filter life The engine intake requirement is the engine size, ie maximum, full, or "rated". It is a function of displacement and rpm under load. Generally, this is the product of displacement and rated rpm, modified by volumetric efficiency, which is a factor that reflects turbo efficiency, duct efficiency, and so on. Generally this is a measure of the air volume per unit time required for the engine or other system involved during rated operation or under full load. Intake requirements vary with rpm, but for many typical truck engines, intake requirements are defined at rated rpm, often 1800 rpm or 2100 rpm. This is characterized herein by "rated airflow" or similar terminology. In general, the principles characterized herein are at a wide range of ratings or requirements, including those ranging from, for example, about 3 cubic feet / minute (cfm) up to 10,000 cfm, often in the range of 50-500 cfm. It can be applied to air cleaner devices used with the system specified for operation. Such equipment includes, for example, small engines (motorcycles, mowers, etc.), automobile engines, pickup truck and sports utility vehicle engines, light truck and delivery vehicle engines, buses, long-distance transport trucks, etc. Includes agricultural equipment (eg, tractors), construction equipment, mining equipment, marine engines, various generator engines and, in some cases, gas turbines and air compressors.

【0040】

The overall efficiency of an air cleaner generally reflects the amount of "filterable" solids that enter the air cleaner during use and are retained in the air cleaner. This is typically a weight-based representation of the percentage of solids that enter the air cleaner and are retained in the air cleaner during normal use. This has been evaluated and reported for many systems by using the SAE standard, but the technique is generally practiced in US Pat. No. 5,423,892, column 25, line 60-26, line 59, column 27. Characterized by lines 1-40. A typical standard used is SAE J726, which is incorporated herein by reference.

【0041】

With respect to efficiency, engine and / or equipment manufacturer specifications vary, and in many cases efficiency requirements for overall operation (based on SAE J726 or field trials) are often set to 99.5% or higher, typically. Is set to 99.8% or higher. For a typical vehicle engine with an airflow requirement of 500cfm or higher, it is not uncommon to have an overall average of 99.8% or higher.

【0042】

The initial efficiency is the efficiency of the filter that is measured when the filter is just running. As described in US Pat. No. 5,423,892, column 27, lines 1-40, the initial efficiency of conventional pleated paper (barrier type or surface load) filters is generally well above the overall average efficiency in use. Low. This is because "dust cakes" or contaminants that accumulate on the surface of such filters during operation increase the efficiency of the filters. The initial efficiency is also often specified by the engine manufacturer and / or the vehicle manufacturer. For a typical vehicle engine with an airflow requirement of 500cfm or more, a specification of 98% or more (typically 98.5% or more) is common.

【0043】

There are constraints on the pressure difference across the air cleaner or air cleaner system during operation. Causes of this limitation include the filter medium through which the air passes, the size of the duct through which the air passes, and the structural features in which the air collides with or is directed around it as it flows through the air cleaner and reaches the engine. In the case of air cleaners, their initial constraint limits are often part of the specification and are required by engine and / or equipment manufacturers. This initial constraint is believed to be the pressure difference measured end-to-end of the air cleaner before the system has just run with a clean air filter inside and a heavy load is applied. Typically, a specification for any given system has a maximum initial constraint requirement.

【0044】

In general, engine and equipment manufacturers design equipment with specifications that limit the efficiency of the air cleaner to the maximum. As reported in US Pat. No. 5,423,892, column 2, lines 19-29, and column 6, line 47, column 7, line 3, the limit constraint is pressure for a typical truck engine. The drop is about 20 to 30 inches in the water column, often about 25 inches in the water column, about 20 to 25 inches in the case of an internal combustion engine for automobiles, and typically about 5 inches in the case of gas turbines. Yes, in the case of an industrial ventilation system, the water column is typically about 3 inches.

【0045】

In general, some of the key variables for air cleaner design for developing a system to match the type of specification characterized in the previous section are: 1. Type of filter medium, geometry, and efficiency 2. Shape and structure of air cleaner 3. Size of filter element For example, conventional cellulose fiber media or similar media are generally "barrier" filters. One example is paper media. In general, the operation of such media is due to surface loading, i.e., the surface of the medium acts as a barrier or sieve as air passes through the medium, preventing particulate matter from passing through it. Over time, dust cake accumulates on the surface of the medium, increasing media efficiency. In general, the "tightness" or "porosity" of the fiber structure determines the efficiency of the system, especially the initial efficiency. Over time, the filter cake will work (enhance) efficiently.

【0046】

In general such media are often defined or specified by their transparency. Transparency tests on media are generally characterized in US Pat. No. 5,672,399, column 19, lines 27-39. In general, permeability is the medium surface velocity (air) required to cause a 0.50 inch water column constraint across a flat sheet of referenced material, medium, or complex. Transparency as used herein is to ASTM D737, which is incorporated herein by reference, using, for example, a Frazier Transparency Tester available from Frazier Precision Instrument Co., Inc., Gaithersburg, Md. Evaluated by a compliant Frazier permeability test, or by several similar tests.

【0047】

The permeability of cellulose fiber media used in many types of truck engine filters with a rated airflow of 50 cfm or higher from Donaldson Company is a medium with a permeability of less than about 15 fpm, typically It is about 13 fpm. Generally, in the engine filter market, there are various barrier media (pleated media) with a transparency value of less than about 25 fpm, typically one in the range of 10 to 25 fpm, for such equipment. Has been widely used by various element manufacturers.

【0048】

The principles of efficiency vary depending on the type of medium involved. Cellulose fibers or similar barrier media, for example, generally vary in efficiency by varying the overall general porosity or permeability.

【0049】

C.<u style="single">Typical system; engine intake</u>FIG. 21 typically shows a schematic diagram of the system at 130. System 130 is an example of one type of system in which the arrangement and construction of air cleaners described herein can be used. FIG. 21 schematically shows equipment 131, such as a vehicle with an engine 132 that has a rated airflow requirement of some extent, eg, at least 370 cfm. Equipment 131 can include application to ships such as buses, long-distance trucks, off-road vehicles, tractors, and motorboats. The engine 132 powers the equipment 131 by using a mixture of air and fuel. FIG. 21 shows a state in which the air flow is drawn into the engine 132 in the intake region 133. The optional turbo 134 is shown by imagination as an optional increase in intake air to the engine 132. The air cleaner 135 with the medium pack 136 is upstream of the engine 132 and turbo 134. During operation, air is generally drawn into the air cleaner 135 along arrow 137 and into the medium pack 136. There, particles and contaminants are removed from the air. The purified air flows into the intake port 133 along the arrow 137. From there, air flows into the engine 132 to power the vehicle 131.

【0050】

In engine systems, the temperature under the hood during engine operation is generally at least 120 ° F, often in the range of 140 ° F to 220 ° F or higher, depending on operating conditions. Temperature can adversely affect the operating efficiency of the filter element. Emissions regulations increase restrictions on engine emissions, which can result in further temperature increases. Such media by configuring the filter medium in the form of a complex of a barrier medium and at least a single "fine fiber" layer, and in some cases multiple "fine fiber" layers, as described below. The performance (particularly operating efficiency) of the filter element can be improved as compared with the conventional filter element which is not composed of the complex.

【0051】

D.<u style="single">Example of air cleaner</u>Note Figure 22. FIG. 22 is a perspective view of the first embodiment of the medium pack 140. The preferred medium pack 140 illustrated includes a filter medium 142 and a sealing system 144. In a preferred structure, the filter medium 142 is designed to remove particulates from fluids such as air passing through the filter medium 142, while at the same time the sealing system 144 is on the side wall of the housing or duct, as shown in FIG. On the other hand, the medium pack 140 is designed to be sealed.

【0052】

This medium pack 140 of FIGS. 22-25 is generally described in US Pat. No. 6,190,432 and is incorporated herein by reference.

【0053】

In certain devices, the filter medium 142 is configured to correspond to a linear flow. The linear flow means that the filter medium 142 has a first flow surface 148 (corresponding to the inlet end in the illustrated embodiment) and a second fluid surface 150 facing the first flow surface (in the illustrated embodiment, the outlet). Consists of a structure 146 with (corresponding to the end), the flow of fluid enters the first flow plane 148 along one direction 152 and exits the second flow plane 150 along the same direction 154. Means. When used with an in-line flow housing, fluid generally enters through the housing inlet in one direction, through the first flow plane 148 in the same direction and into the filter structure 146, and in the same direction the second. It exits the filter structure 146 from the flow surface 150 and also exits the housing through the housing outlet in the same direction.

【0054】

In FIG. 22, the first flow surface 148 and the second flow surface 150 are shown in a plane and in parallel. In other embodiments, the first flow surface 148 and the second flow surface 150 may be non-planar, for example conical trapezoidal. Further, the first flow plane 148 and the second flow plane 150 need not be parallel to each other.

【0055】

Generally, the filter structure 146 has a wound structure. That is, the structure 146 will typically include a layer of filter medium that is completely or repeatedly wrapped around the center point. Typically, the winding structure is a coil in which a layer of filter medium is wound a series of times around a center point. In devices that use a winding coil structure, the filter structure 146 becomes a roll of filter medium, typically a transmissive grooved filter medium.

【0056】

Next, pay attention to Fig. 23. FIG. 23 is a schematic perspective view showing the operating principle of a preferred medium that can be used in the filter structures herein. In FIG. 23, the grooved structure of the Z medium is generally shown in 156. The grooved structure 156 preferably includes a corrugated layer 157 having a plurality of grooves 158 and a face sheet 160. In the embodiment of FIG. 22, two sections of the face sheet 160 are shown at 160A (shown above corrugated layer 157) and 160B (shown below corrugated layer 157). Typically, the preferred medium structure 162 used in the apparatus described in the present invention includes a corrugated layer 157 secured to a bottom sheet 160B. When the medium structure 162 is used in a roll structure, the medium is typically rolled by itself so that the bottom sheet 160B covers the top of the corrugated layer 157. The face sheet 160 overlying the top of the corrugated layer is shown as 160A. Face sheets 160A and 160B should be understood as the same sheet 160.

【0057】

When using this type of medium structure 162, the groove chamber 158 is preferably formed such that peaks 164 and troughs 166 are alternately arranged. Trough 166 and peak 164 divide the groove into upper and lower rows. In the particular configuration shown in FIG. 23, the upper groove forms a groove chamber 168 that closes at the downstream end 178, while the groove chamber 170 that closes its upstream end 181 forms the lower row of grooves. The grooved chamber 170 is closed by a first end bead 172 that fills a portion of the upstream end 181 of the groove between the grooved sheet 171 and the second face sheet 160B. Similarly, the second end bead 174 closes the downstream end 178 of the alternating grooves 168.

【0058】

When using a medium configured in the form of medium structure 162, during use, fluids such as unfiltered air enter the groove chamber 168 as indicated by the shaded arrow 176. The upstream end 169 of the groove chamber 168 is open. The unfiltered fluid flow cannot pass through the downstream end 178 of the groove chamber 168 because its downstream end 178 is closed by the second end bead 174. Therefore, the fluid will inevitably travel within the grooved sheet 171 or face sheet 160. As the unfiltered fluid passes through the grooved sheet 171 or face sheet 160, the fluid is cleaned or filtered. The purified fluid is indicated by an unshadowed arrow 180. The fluid then passes through the groove chamber 170 (with its upstream end 181 closed) and out of the grooved structure 156 through the open downstream end 184. In the configuration shown, unfiltered fluid can pass through the grooved sheet 171, upper surface sheet 160A, or lower surface sheet 160B and further into the groove chamber 170.

【0059】

Typically, the medium structure 162 is wound after making so that a roll-shaped structure 146 of the filter medium is formed. When selecting this type of medium for use, the created medium structure 162 includes a corrugated sheet 157 fixed to the bottom sheet 160B with end beads 172 (as shown in FIG. 23, but the top sheet 160A). Without).

【0060】

Note again in Figure 22. FIG. 22 schematically shows the second flow plane 150. There is a portion 182 where a groove is shown that includes an open end 184 and a closed end 178. It should be understood that this section 182 represents the entire flow plane 50. For clarity and simplicity, the groove is not shown in the other remaining part 183 of the flow surface 150. Top, bottom, and side views of the media pack 140 that can be used with the systems and equipment described herein are, by reference, incorporated herein by reference, entitled "Filter Element Having Sealing System," February 26, 1999. It is shown in US Patent Application No. 29/101,193, which was filed on the same day and was assigned to the assignee of the present application.

【0061】

Next, referring to FIG. 24, a filter structure 146 installed in housing 186 (which is part of the intake duct to the engine or turbo of the air cleaner 179) is shown. In the device shown, air flows into housing 186 at 187, flows through the filter structure 146, and exits housing 186 at 188. When a medium structure such as the filter structure 46 of the type shown is used in a duct or housing 186, the seal system 144 ensures that air flows through the medium structure 146 rather than bypassing it. Is required.

【0062】

The particular sealing system 144 illustrated includes a frame structure 190 and a sealing member 192. When using 144 for this type of sealing system, the frame structure 190 provides a support structure or backing capable of compressing the sealing member 192 to form a radial seal 194 with the duct or housing 186.

【0063】

Further referring to FIG. 24, in the particular embodiment illustrated, the frame structure 190 includes a rigid protrusion 196 projecting or extending from at least one portion of the first and second flow planes 148, 150 of the filter structure 146. .. The rigid protrusion 196 extends axially from the second flow surface 150 of the filter structure 146 for the particular device shown in FIG.

【0064】

The illustrated protrusion 196 has a pair of facing surfaces 198, 102 joined by an end tip 104. In a preferred device, by one of the first and second sides 198, 102, the seal 194 can be formed in contact between the selected side 198 or 102 and the appropriate side of the housing or duct. A substrate or backing for the sealing member 192 is provided. When using this type of structure, the protrusion 196 becomes a continuous member forming a closed hoop structure 106 (FIG. 22).

【0065】

When using this type of structure, the housing or duct shall include the protrusion 196 and the protrusion 192, including the seal member 192, so that the seal 194 is formed in contact between the outer surface 102 of the protrusion 196 and the inner surface 110 of the housing or duct. It may be circumscribed to the hoop structure 106.

【0066】

In a particular embodiment shown in FIG. 24, the seal member 192 also engages the end tip 104 of the protrusion 196, which extends from the outer surface 102 over the end tip 104 to the inner surface 198. Will cover.

【0067】

Then referring to FIGS. 22 and 24, the frame 190 has a band, skirt, or hanging lip 107 used to secure the frame 190 to the medium structure 146. The hanging lip 107 hangs or extends downward by a first distance from the cross brace 108.

【0068】

During use of the type of frame 190 described herein, an inward force is applied around the frame 190. The cross brace 108 supports the frame 190. The term "support" means that the cross brace 108 prevents the frame 190 from collapsing radially while a force is applied around the frame 190.

【0069】

The tip portion 104 supports a compressible sealing member 192. The compressible seal member 192 is preferably configured and arranged to be sufficiently compressed to be compressed between the tip portion 104 of the frame 190 and the side wall 110 of the housing or duct. When sufficiently compressed between the tip portion 104 and the side wall 110, a radial seal 194 is formed between the medium pack 140 and the side wall 110.

【0070】

One preferred configuration for the seal member 192 is shown in FIG. The tip portion 104 of the frame 190 may define a wall or support structure and form a radial seal 194 by the compressible seal member 192 so as to be in contact between them. The compression of the compressible sealing member 192 in the sealing system 144 is sufficient to form a radial seal with an insertion pressure of 80 lbs or less, typically 50 lbs or less, for example about 20-40 lbs. It is preferably light enough that it can be conveniently and easily changed by hand.

【0071】

In a preferred embodiment shown in FIG. 25, the seal member 192 has a stepped cross-sectional shape, the outermost dimension of which (diameter in the case of a circle) is from the first end 112 to the second end 113. To achieve the desired seal. Preferred specifications for the profile of the particular device shown in FIG. 25 are: That is, a polyurethane foam material having a plurality of (preferably at least 3), gradually increasing steps configured to engage the side wall 110 to provide a fluid-tight seal.

【0072】

The compressible seal member 192 defines an increasing inner diameter gradient of the surface for engaging the side wall 110. Specifically, in the example shown in FIG. 25, the compressible seal member 192 defines the three steps 114, 115, 116. The cross-sectional dimensions or widths of steps 114, 115, 116 increase from the second end 113 of the compressible sealing member 192 to steps 114, 115, 116. The small diameter of the second end 113 makes it possible to facilitate insertion into the duct or housing. The large diameter of the first end 112 ensures a tight seal.

【0073】

In general, the media pack 140 can be arranged and configured to be press-fitted against the housing 186 or the side wall 110 of the duct. In the particular embodiment shown in FIG. 24, the compressible seal member 192 is compressed between the side wall 110 and the tip portion 104 of the frame 190. After compression, the compressible seal member 192 exerts a force on the side wall 110 when the compressible seal member 192 tries to spread outward and is in its natural state, and the tip portion 104 and the side wall 110 Radial seals 194 are formed between them so as to be in contact with them.

【0074】

Various housings can be used with the media pack 140. In the particular embodiment shown in FIG. 24, the housing 186 includes a body member or a first housing compartment 118 and a removable cover or a second housing compartment 120. In some devices, the first housing compartment 118 is attached to an object such as a truck. The second housing compartment 120 is removably secured to the first housing compartment 118 by a latching device 122.

【0075】

In the embodiment shown in FIG. 24, the second end 150 of the medium pack 140 with the attached frame 190 and the compressible sealing member 192 is inserted into the first housing compartment 118. The media pack 140 is press-fitted into the first housing compartment 118, so that the compressible seal member 192 is compressed to contact them between the tip portion 104 of the frame 190 and the side wall 110 of the first housing compartment 118. A radial seal 194 will be formed between them.

【0076】

During use of the device shown in FIG. 24, the fluid enters the housing assembly 185 from the inlet area 124 of the second housing compartment 120 in the direction indicated by 187. The fluid passes through the filter structure 146. As the fluid passes through the filter structure 146, contaminants are removed from the fluid. The fluid exits the housing assembly 185 in the direction of 188 through the exit area 128. The compressible seal member 192 of the seal system 144 forms a radial seal 194 to prevent contaminated fluid from exiting the housing assembly 185 without first passing through the filter structure 146.

【0077】

FIG. 26 is a perspective view of another embodiment of the medium pack 130. In the structure shown, the medium pack 130 includes a filter medium 132 and a sealing system 134. The filter medium 132 is designed to remove contaminants from fluids such as air passing through the filter medium 132. The sealing system 134 is designed so that the filter medium 134 is sealed in a housing or duct.

【0078】

The structure and geometry of the media pack 130 of FIGS. 26 and 27 are described in US Pat. No. 6,190,432, except for the preferred media developments described in Section H below, which is incorporated herein by reference.

【0079】

In one preferred device, the filter medium 132 is configured with a filter structure 136 having a first flow surface 138 and an opposing second flow surface 140.

【0080】

The filter structure 136 can have various configurations and cross-sectional shapes. In the particular embodiment shown in FIG. 26, the cross section of the filter structure 136 is non-circular. In particular, the embodiment of the filter structure 136 of FIG. 26 has an oblate or "competition track" cross-sectional shape. The "competition track" cross-sectional shape means that the filter structure 136 includes first and second semicircular ends 141, 142 joined by a pair of straight segments 143, 144.

【0081】

In FIG. 26, a portion 146 showing a groove including an open end and a closed end is drawn. It should be understood that this part or section 146 represents the entire flow plane 140 (as well as the first flow plane 138). For the sake of clarity and simplicity, the rest of the flow surface 140, 149, is not grooved. Top and bottom views, as well as side views, of the media pack 130 that can be used in the systems and devices described herein are simultaneous pending applications filed February 26, 1999, entitled "Filter Element Having Sealing System". It is set forth in U.S. Patent Application No. 29 / 101,193, which is also assigned to the assignee of the present application, which is incorporated herein by reference.

【0082】

As in the embodiment of FIG. 22, the medium pack 130 includes a sealing system 134. In a preferred structure, the sealing system 134 includes a frame 148 and a sealing member 150.

【0083】

The frame 148 is non-circular, eg, inverted circular, particularly in the form of a competition track, and is arranged and configured to be attached to the end of the filter medium 132. In particular, the frame 148 has a substantially competitive track-shaped band or skirt or hanging lip 151. The hanging lip 151 hangs or extends downward by a distance from the cross brace 152 and is used to secure the frame 148 to the medium pack 130.

【0084】

During the use of the illustrated device, an inward force is applied around the frame 148. The inward force applied to the semicircular ends 141, 142 can cause the straight segments 143, 144 to bend or bend. The cross brace 152 is provided to provide structural rigidity and support to the straight segments 143, 144. As can be seen from FIG. 26, the particular cross brace 152 illustrated forms a truss system 154 between opposing straight segments 143 and 144. The truss system 154 preferably includes a plurality of rigid struts 156 molded as a single part with the rest of the frame 148.

【0085】

The frame 148 is configured in the same manner as the frame 90. Therefore, the frame 148 includes the tip portion 158 (FIG. 27). In a preferred device, the tip portion 158 acts as an annular seal substrate. In a preferred system, the structure of the compressible seal member 150 is similar to that of the compressible seal member 92 of FIG.

【0086】

The medium pack 130 is preferably installed in a duct or air cleaner housing. In FIG. 27, the illustrated housing is a two-piece housing that includes a cover 160 and a body member 162. The cover 160 defines the air inlet 164. The body member 162 defines the air outlet 166. The housing further includes a pre-cleaner device 167 upstream of the media pack 130, as described in US Pat. Nos. 2,887,177 and 4,162,906, which are incorporated herein by reference. As shown, the pre-cleaner device 167 is in cover 160. The cover 160 includes a dust ejector 168 that ejects dust and debris collected on the pre-cleaner 167.

【0087】

The compressible seal member 150 is compressed between the side wall 170 and the tip portion 158 of the frame 150. As the medium pack 130 is press-fitted, the compressible sealing member 150 is compressed to contact them between the frame 148 (specifically, the tip portion 158 in the particular embodiment illustrated) and the side wall 170. Will be done. After compression, the compressible seal member 150 exerts a force on the side wall 170 as the compressible seal member 150 expands outward and attempts to reach its natural state, resulting in a radial seal 171 along with the side wall 170. To form.

【0088】

Preferred developments for media 132 are described in Section I below.

【0089】

Another filter device is generally shown in FIG. 28 at 174. Filter equipment 174, excluding the preferred media developments described in Section I below, is described in US Pat. No. 5,820.646, which is incorporated herein by reference.

【0090】

The filter device 174 includes a medium pack 176 attached to, held and supported by the panel structure 178. The filter device 174 also includes a housing 180 that includes a body 181 and a removable cover member 182. The panel structure 178 that holds the media pack 176 is sealed within the housing 180, from which it is removable and replaceable.

【0091】

The medium pack 176 includes a grooved filter medium 184 configured as previously described with respect to FIG.

【0092】

E.<u style="single">Typical system; gas turbine intake</u>Figure 29 typically shows the intake port of a gas turbine system at 200. The air flow is indicated by arrow 201 as being drawn into the intake system 200. The intake system 200 includes a plurality of air filter arrangements 202 that are generally held on the tube seat 203. In a preferred system, the tube sheet 203 is configured to hold the filter device 202 at an angle to the vertical axis. The preferred angle is between 5 and 25 °, for example about 7 °. This allows the liquid to be drained from the filter device 202 when the system 200 is not in operation.

【0093】

The air is purified in the air filter arrangement 202, then the air flows downstream along arrow 204 and flows into the gas turbine generator 205, where it is used for power generation.

【0094】

In FIG. 33, an example of an intake port of a microturbine is generally shown by 210. Generally, a micro turbine is a miniaturized version of a gas turbine typically used as a standby generator. In some cases, such a microturbine is about 24 inches x 18 inches, and its electrical output is typically between 30 kW and 100 kW. These systems typically have airflows between 1000cfm and 10,000cfm.

【0095】

FIG. 33 shows a state in which the air flow is drawn into the intake system 211 along the arrow 212. The intake system 211 includes a filter structure 213. As air is drawn through the filter structure 213, the air is cleaned within the air filter arrangement 213 and then flows downstream along arrow 214 into the gas turbine 215. The gas turbine then typically powers a generator, fluid compressor, or fluid pump. The performance of the filter device (as described below) by configuring the filter device in the form of a complex of a barrier medium and at least a single "fine fiber" layer, and in some cases multiple "fine fiber" layers. In particular, operating efficiency) can be increased over prior art filters that are not composed of such media complexes.

【0096】

F.<u style="single">Example of filter device for gas turbine system</u>An example of the air filter arrangement 202 that can be used in the system 200 or the system 210 is shown in FIGS. 30 to 32. An air filter arrangement 202 other than the preferred medium-developed product set forth in Section I is described in U.S. Patent Application No. 09 / 437,867, assigned November 10, 1999, which was assigned by the assignee of the present application. Incorporate by reference to. Generally, the air filter arrangement 202 includes a first or primary filter element 220 (FIGS. 30 and 32) and a second filter element 222 (FIGS. 31 and 32) that acts as a prefilter. The term "pre-filter" means a separator positioned upstream of the primary primary filter element 220 and serves to remove large particles from the gas stream. The primary filter element 220 and the pre-filter element 222 are preferably secured within a sleeve member 224 that is removable and attachable to the aperture 226 of the tube sheet 203. Generally, the airflow is taken into the system 200 and first flows through the pre-filter element 222 and then through the primary filter element 220. After exiting the primary filter element 220, air is directed to the generator 205.

【0097】

In general, the element 220 is composed of a grooved or z-shaped medium 230, as already described with respect to FIGS. 2 and 3. It should be understood that FIG. 30 schematically shows the exit surface 228. That is, a state in which only a part of the surface 228 is grooved is shown. It should be understood that in a typical system, the entire surface 228 is grooved.

【0098】

The filter element 220 has a first end 232 and a second opposite end 234. In the device shown in FIG. 30, the first end 232 corresponds to the upstream end inlet surface 227, while the second end 234 corresponds to the downstream end exit surface 228. The linear flow allows the gas to flow into the first end 232 and out of the second end 234, so that the direction of the airflow towards the first end 232 is the second. It becomes the same flow as the air flow going out from the end 234. The linear flow pattern can reduce the amount of turbulence generated in the gas flow.

【0099】

The medium 230 may be a polyester synthetic medium, a cellulosic medium, or a blend of these types of materials and can be treated with fine fibers.

【0100】

The prefilter element 222 is preferably a pleated structure 236 that includes a plurality of individual pleats 237. The pleats 237 are arranged in a zigzag pattern. The preferred prefiller element 222 has a substantially circular cross section.

【0101】

The pre-filter element 222 is configured to allow linear flow. In other words, the air flows straight through the prefilter element 222, enters the inlet surface 238 and then exits the outlet surface 239 located on the opposite side, but the direction of fluid flow entering the inlet surface 238 is the outlet surface 239. It is in the same direction as the flow of fluid leaving.

【0102】

In one preferred embodiment, there are at least 15 pleats 237, no more than 80 pleats 237, and typically 30-50 pleats 237. The pleated structure 236 is made of a medium 240 bent in the shape of pleats 237 provided around the central core 241. Usable types of medium 240 include glass fiber, or air raid medium. Specific properties of the usable medium 240 are 2.7-3.3 oz / yard 3 (92-112 g / m3) in weight and 0.25-0.40 inches (6.4-10.2) in free thickness (ie, thickness at 0.002 psi compression). Includes a dry raid filter medium made of polyester fibers randomly oriented to form a web with a permeability of at least 400 ft / min (122 m / min).

【0103】

In general, the pre-filter element 222 can be remountably and interchangeably mounted within the sleeve member 224. The sleeve member 224 will be described in more detail below. In some systems, the prefilter element 222 is held within the sleeve member 224 by crushing or compressing the end tip of the medium 240 against the inner wall of the sleeve member 224.

【0104】

A preferred filter device 202 configured according to the principles herein has a sleeve member 224 that is fixed to and circumscribes the primary filter element 220. Generally, the sleeve member 224 functions to hold the primary element 220 in place on the system 200. The preferred sleeve member 224 also holds the prefilter element 222 in place upstream of the primary element 220.

【0105】

As can be seen from FIGS. 30 and 31, the sleeve member 224 preferably has a cross section that matches the cross section of the primary filter element. The sleeve member 224 includes a peripheral wall 244 curved in a shape that provides a peripheral ring 245. The sleeve member 224 is preferably arranged so as to extend relative to the primary filter element 220 by at least 30% of the axial length of the primary filter element 220. In many typical devices, the sleeve member 224 extends by more than 50% of the axial length of the primary filter element 220. In fact, in most preferred devices, the sleeve member 224 extends at least the entire length (ie, 100%) of the axial length of the primary filter element 220. In many typical applications, the sleeve member 224 has a radius of at least 10 inches, typically 15-30 inches, and in some cases 50 inches or less.

【0106】

The sleeve member 224 is preferably configured and arranged with the sealing system so that the primary filter element 220 can be secured to the tube sheet 203 so that air does not bypass the primary element 220. In the illustrated embodiment, the sleeve member 224 includes a seal member pressure flange 246. The flange 246 circumscribes the wall 244 of the sleeve member 224, at least partially and, in many embodiments, completely. The seal member pressure flange 246 acts as a backstop and supports the seal member 248 to generate the seal 250 in contact with them between the flange 246 and the tube sheet 203. The flange 246 extends radially from the wall 244 of the sleeve member 224 and completely circumscribes the seal member 224. The flange 246 extends radially from the wall 244 by a distance sufficient to support the sealing member 248.

【0107】

A patch or retaining clip 252 (FIG. 30) extends beyond the joint 254 to secure the sleeve member 224 to its final shape. The holding clip 252 is preferably permanently fixed to the sleeve member 224, for example by ultrasonic welding.

【0108】

Note Figure 32. It can be seen that the flange 246 supports the sealing member 248 on the axial side surface 256. The sealing member 248 generally includes a circular gasket 258. The gasket 258 is preferably fixed to the flange 246 with an adhesive between the gasket 258 and the side surface 256 of the flange 246. The gasket 258 is positioned on the flange 246 so that the gasket 258 circumscribes the wall 244 and the primary element 220 completely.

【0109】

The device shown also includes a system for clamping the sleeve member 224 to the tube seat 203. In the illustrated embodiment, the clamp system comprises a plurality of latches or clamps 260. If the sleeve member 224 is operably installed on the tube sheet 203, there should be sufficient latch or clamp 260 to form a good and tight seal 250 between the flange 246 and the tube sheet 203. For example, in the device shown, there are four clamps 260. FIG. 32 shows a cross section of the clamp 260. Each of the clamps 260 includes a lever 261 and a nose 262, and a plate 263. The plate 263 includes an aperture for accommodating fasteners such as bolts 264 that secure the clamp 260 to the tube seat 203. The nose 262 acts to apply pressure to the flange 246 to compress the seal member 248 against the tube sheet 203. The lever 261 selectively operates to move the nose 262 toward and away from the tube seat 203. In other embodiments, the clamp 260 can be tightened by hand, such as by using a wingnut.

【0110】

During typical operation, the total pressure drop from end to end of the filter device 202 is about 0.6 to 1.6 inches in the water column. This includes both the primary filter element 220 and the prefilter 222. Typically, the pressure drop with the prefilter 222 alone is about 0.2 to 0.6 inches in the water column, while the pressure drop with the primary element 220 alone is about 0.4 to 1 inch with the water column.

【0111】

Another embodiment of the air filter arrangement 213 that can be used in system 304 or system 302 is shown in FIGS. 34-36. The air filter arrangements, excluding the preferred media developments described in Section I below, are described in U.S. Patent Application No. 09 / 593,257, filed June 13, 2000, which was assigned to the assignee of the present application. Incorporate by reference in the specification.

【0112】

FIG. 35 shows the filter device 213 disassembled and not assembled, and FIG. 14 shows the filter device 213 assembled for use. Generally, the air filter arrangement 213 includes a moisture separator 270, a filter assembly 272, and a filter housing 274. The filter housing 274 is typically secured within the tube sheet 276 during assembly for use. The filter housing 274 is preferably secured within the tube sheet 276 by welding the housing 274 to the tube sheet 276 or by bolting the housing 274 to the tube sheet 276.

【0113】

The access door 278 allows the filter device 213 to be touched during assembly and also allows air to be drawn into the system 302. Generally, the access door 278 is designed and configured to fit into a specific housing of a system, such as system 302 in FIG. 33, and is installed in filter device 213 to allow contact with filter device 213 during assembly. become able to. The access door 278 is also designed and configured to allow air to enter system 210 in FIG.

【0114】

The access door 278 preferably includes an airflow resistance device 280. Generally, the air flow resistance device 280 directs the air flow toward the filter device 213 in a specific direction to reduce the resistance in the system 302. The airflow resistance device 280 also assists in noise attenuation. In the embodiment shown in FIG. 34, the airflow resistance device is depicted as a plurality of louvers 282. The louver 282 also helps protect the system 210 from large objects and moisture from entering the system 302 of FIG. The louver 282 also assists in noise attenuation.

【0115】

Moisture contained in the inflowing air flow can damage the maintainability of the filter assembly 272 and damage the internal mechanics of system 302, which can contribute to corrosion. To address this, the filter device includes a moisture separator 270. Generally, the moisture separator 270 separates and collects moisture from the inflowing air flow before reaching the filter assembly 272. In one embodiment, the moisture separator 270 comprises a plurality of flat screens, such as wire mesh.

【0116】

Generally, the filter assembly 272 removes contaminants from the inflowing airflow 212 of FIG. 33 before entering the internal mechanism of system 302. The filter assembly 272 has a linear flow flowing straight through the filter assembly 272, entering the inlet surface 284 and exiting the oppositely located outlet surface 285, i.e. the flow of fluid entering the inlet surface 284. It is preferably configured so that the direction is the same as the flow of fluid exiting the outlet surface 285.

【0117】

The filter assembly 272 includes a medium pack 286 formed from a cylindrically wound grooved medium 288, as previously described in connection with FIGS. 22 and 23. The medium 288 may be a polyester synthetic medium, a cellulosic medium, or a blend of these types of materials and can be treated with a fine fiber coating or layer. Preferred media developments are described in Section H below.

【0118】

The filter assembly 272 illustrated includes a tensioning mechanism 290. The tensioning mechanism 290 is configured to allow the user to easily remove the filter assembly 272 from the filter housing 274. As shown, the pulling mechanism 290 includes a handle 292 and a holding mechanism 294 (FIG. 34). Typically, the handle 292 is the knob 296. In what is shown in FIG. 34, the holding mechanism 294 includes a bolt 298 attached to the knob 296 and a nut 299 at the other end of the bolt. Alternatively, the tension mechanism and the central part of the filter medium may be one integrated unit.

【0119】

Generally, the filter housing 274 is configured to receive and hold the filter assembly 272 and to facilitate sealing with the filter assembly 272. As shown in FIG. 16, the filter housing 274 includes a transition region 302 angled at least 10 degrees from the outer wall 304, preferably between 10 and 210 degrees, most preferably about 15 degrees. The transition region 302 assists in sealing the filter assembly 272, as described in more detail below.

【0120】

The filter housing 274 further includes a mounting flange 306. The mounting flange 306 secures the filter housing 274 to the tube seat 276 via a fastener device (eg, bolts). Housing 274 also includes stop device 308. The stop device 308 installs the filter assembly 272 inside the housing 274 to prevent the filter assembly 272 from being pushed into the housing 274 more than necessary. The stop device 308 assists in ensuring proper sealing between the filter assembly 272 and the housing 274.

【0121】

The stop device 308 includes a stopper 310. The stopper 310 preferably projects from the outer wall 304 by a sufficient distance so that the filter assembly 272 does not bypass the stopper 310 . In use, the filter assembly 272 is in contact with the top surface 311 of the stopper 310.

【0122】

Filter assembly 272 also includes seal gasket 312. The seal gasket 312 seals the filter assembly 272 inside the filter housing 274 to prevent air from entering system 302 between the filter assembly 272 and the filter housing 274 and to keep the filter assembly 272 in place. Do not detour. This ensures that the air flow effectively passes through the filter assembly 272. In the illustration, the seal gasket 312 extends circumferentially around the radial edge of the filter assembly 272. In one embodiment, the seal gasket 312 comprises closed cell foam and, of course, the seal gasket 312 can include other suitable materials.

【0123】

In use, the seal gasket 312 seals the junction 314 between the filter assembly 272 and the filter housing 274. During installation, the filter assembly 272 is inserted into the housing 274 until the end 315 is in contact with the stopper 310. As the filter assembly 272 is installed, the seal gasket 312 is compressed into the transition region 302 between the filter assembly 272 and the housing 274 to seal the joint 314.

【0124】

During assembly, the filter housing 274 is slid onto the tube seat 276 so that the mounting flange 306 of the filter housing 274 can be mounted against the tube seat 276. The filter assembly 272 is then installed inside the filter housing 274. Slide the filter assembly 272 into the filter housing 274 so that the end 315 of the filter assembly 272 contacts the stopper 310. The seal gasket 312 is partially compressed and the filter assembly 272 is held so that it fits snugly into the filter housing 274.

【0125】

During operation, the filter device 213 is used as follows. That is, the air filtered in system 302 is directed to the intake system 211 along arrow 212. Air flows through the filter assembly 272. Air enters the inlet surface 284, passes through the grooved structure 288, and exits from the outlet surface 285. From there air is taken into the turbine or generator 215.

【0126】

G.<u style="single">Typical system; fuel cell intake</u>The fuel cell intake port is schematically shown in FIG. 37 with 330. As shown in FIG. 37, atmospheric or ambient air 331 enters the filter assembly 332 through inlet 333. Prior to entering filter assembly 332, air 331 is polluted air with various physical (eg, particulate) chemical contaminants. The filter assembly 332 is configured to remove various contaminants from the polluted air, thereby providing clean air 334 leaving the filter assembly 332. The clean air 334 is the air taken into the fuel cell 335 and is used for power generation.

【0127】

Further referring to FIG. 37, the atmosphere 331 enters the filter assembly 332 through the inlet 333 of the housing 336 as dirty air and proceeds to the dirty air side 337 of the filter element 338. As air moves through the filter element 338 to the side of clean air 339, contaminants are removed by the filter element 338, resulting in filtered air 334. The filtered air 334 exits the filter assembly 332 via outlet 340 of housing 336 and is used in equipment 341.

【0128】

The filter assembly 332 also optionally includes a noise suppression element 342 to reduce or suppress the noise or sound level emitted by the equipment 341. The restraint element 342 can be positioned within the housing 336, and in some embodiments the restraint element 342 is defined by the housing 336.

【0129】

Equipment 341 includes a compressor 343 that supplies air to the fuel cell 335 for use in a catalytic reaction. The compressor 343 typically emits noise in the range of 3 to 30,000 hertz, sometimes as high as 50,000 hertz, at a level of 85 to 110 dB per meter. The suppression element 342 reduces the level of sound traveling from upstream to compressor 343 by at least 3 dB, typically at least 6 dB, preferably at least 25 dB.

【0130】

The fuel cell 335 takes in hydrogen fuel 345, releases water and carbon dioxide by-products 346, and generates electricity 347. Generally, a fuel cell is an instrument consisting of two electrodes (anode and cathode) with an electrolyte in between. The hydrogen-containing fuel flows to the anode, where hydrogen electrons are liberated, leaving positively charged ions. Electrons move in an external circuit, in which ions are diffused by the electrolyte. At the cathode, electrons combine with hydrogen ions and oxygen to form by-products of water and carbon dioxide. A common source of oxygen is air. Catalysts are often used to speed up the cathodic reaction. Examples of catalysts often used in fuel cell reactions include nickel, platinum, palladium, cobalt, cesium, neodymium, and other rare earth metals. The reactants in the fuel cell are hydrogen fuel and an oxidizer.

【0131】

Typically, "cryogenic fuel cells" operate at temperatures typically as high as about 70-100 ° C, sometimes as high as 200 ° C. High temperature fuel cells are typically less susceptible to chemical contamination due to their high operating temperature. However, high temperature fuel cells are susceptible to the effects of particulate contamination, sometimes in the form of chemical contamination, and therefore high temperature fuel cells benefit from the filter function described in the present invention. Some types of cryogenic fuel cells are commonly referred to as "PEMs" because they use a proton exchange membrane. Examples of various other types of fuel cells that can be used in combination with the filter assemblies of the present invention include, for example, U.S. Pat. Nos. 6,110,611, 6,117,579, 6,103,415, and 6,083,637. Is incorporated herein by reference. Various fuel cells are available, for example, Ballard Power Systems, Inc. In Vancouver, Canada; International Fuel Cells in Connecticut; Rocky Hill, CT Proton Energy. Systems, Inc .; American Fuel Cell Corp in Massachusetts; Siemans AG in Erlangen, Germany; Energy Partners in Florida, LC; General Motors in Detroit; and Toyota Motor Corporation in Japan.

【0132】

The filter assembly described below removes contaminants from the atmosphere and then uses that air to operate the fuel cell. As described below, the filter assembly is constructed by constructing the filter assembly in the form of a complex of a barrier medium and at least a single "fine fiber" layer, and in some cases multiple "fine fiber" layers. Performance (especially operating efficiency) can be improved. Fine fiber processing is advantageous for improving filter efficiency in most filter geometries and environments. Fine fibers can often withstand certain harsh environments, including both cryogenic and hot fuel cells, where the filter temperature exceeds 120 ° F, extending filter life.

【0133】

H.<u style="single">Example of filter device for fuel cell intake system</u>FIG. 38 shows the filter assembly 350 that can be used in the system of FIG. 37. The filter assembly 350 includes a housing 352 that defines the inlet 354 and the outlet 356. Dirty air enters the filter assembly 350 through inlet 354 and clean air exits through outlet 356.

【0134】

A filter element 358 and a noise suppression element 360 are positioned in the housing 352. The suppression element 360 includes a first resonator 361 and a second resonator 362. The first resonator 361 is configured to attenuate a peak of about 900 Hz and the second resonator 362 is configured to attenuate a peak of about 550 Hz.

【0135】

The filter element 358 of FIG. 38 is generally configured in the same manner as in the case of the filter element structure 40 (FIG. 22). Therefore, it includes media pack 364 of grooved media 366 (as described with respect to FIG. 3) wound around filter element 358.

【0136】

When using the filter element 358 with the in-line flow housing 352, air enters the inlet 354 of the housing 352 in one direction, enters the filter element 358 via the first flow plane 368 in the same direction, and enters the same direction. It exits the filter element 358 via the flow plane 370 of 2 and also exits the housing 352 via the outlet 356 in the same direction.

【0137】

As in the embodiments of FIGS. 22 and 24, the radial seal 372 is formed by compressing the seal gasket 374 between the frame 376 and the internal sealing surface 378 of the housing so that they are in contact with them. ..

【0138】

The filter assembly 350 preferably also includes a portion designed to remove contaminants from the atmosphere by adsorption or absorption. As used herein, terms such as "adsorb", "adsorb", and "adsorbent" shall also include absorption and adsorption mechanisms.

【0139】

The chemically removed portion typically adsorbs or or adsorbs, for example, a desiccant (ie, a material that adsorbs or absorbs water or water vapor), volatile organic compounds and / or acidic and / or basic gases. Includes physical or chemical adsorbent materials, such as materials that absorb. The terms "adsorbent material", "adsorbent material", "adsorbent material", "absorbent material", "absorbent material", "absorbent material", and their modified terms are chemicals by adsorption or absorption. It shall include all materials that remove target contaminants. Suitable adsorbent materials include, for example, activated carbon, activated carbon fiber, impregnated carbon, activated alumina, molecular sieves, ion exchange resins, ion exchange fibers, silica gel, alumina, and silica. Any of these materials may be combined with or coated with materials such as potassium permanganate, calcium carbonate, potassium carbonate, sodium carbonate, calcium sulphate, citric acid, or mixtures thereof, or these materials may be coated. It can be impregnated. In some embodiments, the adsorbent material can be combined with the second material, or the adsorbent material can be impregnated with the second material.

【0140】

The adsorbent material typically comprises particulate or granular material and can be present as granules, beads, fibers, fines, nanostructures, nanotubes, airgels, or ceramic beads or monolithic structures. , Paper medium, can be present as a coating on a base material such as a metal surface. Typically, the adsorbent material, particularly particulate or granular material, is provided as a bed of material.

【0141】

Alternatively, the adsorbent material can be formed in a monolithic or single form, eg, large tablets, granules, beads, or optionally further shaped, such as a pleated or honeycomb structure. At least in some cases, the molded adsorbent material retains substantially its shape during the normal or extended life of the filter assembly. The molded adsorbent material can be formed from a free-flowing particulate matter bound to a solid or liquid binder that is subsequently molded into a non-free-flowing article. The molded adsorbent material can be formed, for example, by a molding, compression molding, or extrusion process. Molded adsorbent articles are taught, for example, in US Pat. Nos. 5,189,092 (Koslow) and 5,331,037 (Koslow), which are incorporated herein by reference.

【0142】

The binder used to provide the molded article may be dry, i.e. in powder and / or granular form, or the binder may be in a liquid, solvated or dispersed state. Binder may be used. Some binders, such as wet-cured urethanes and materials typically referred to as "hot melts," can be attached directly to the adsorbent material by a spraying process. In some embodiments, a temporary liquid binder containing a solvent or dispersant that can be removed during the molding process is used. Suitable binders include, for example, latex, microcrystalline cellulose, polyvinyl alcohol, ethylene-vinyl acetate, starch, carbonylmethyl cellulose, polyvinylpyrrolidone, dicalcium phosphate dihydrate, sodium silicate. The composition of the molded material preferably comprises at least about 70% by weight, typically about 98% by weight or less of the adsorbent material. In some cases, the molded adsorbent contains 85-95% by weight, preferably about 90% by weight, of the adsorbent material. The molded adsorbent typically contains about 2% by weight or more and about 30% by weight or less of the binder.

【0143】

Another embodiment of the adsorbent material suitable for use in the chemically removed moiety is an adsorbent material containing a carrier. For example, a mesh or scrim can be used to hold the adsorbent material and binder. Polyester and other suitable materials can be used as meshes or scrims. Typically, any carrier is no more than about 50% by weight of the adsorbent material, and more often about 20-40% of the total adsorbent weight. The amount of binder in the molded adsorbed material, including the carrier, typically ranges from about 10-50% of the total adsorbent weight, and the amount of adsorbent material typically ranges. It is in the range of about 20-60% of the total adsorbent material.

【0144】

The chemically removed portion may contain a strongly basic material to remove acidic contaminants from the air, or may contain a strongly acidic material to remove basic contaminants from the air. Can, or both can be included. The basic material and the acidic material are preferably removed from each other so as not to cancel each other out. In some embodiments, the adsorbent material itself may be a strongly acidic or strongly basic material. Examples of such materials include materials such as polymer microparticles, activated carbon media, zeolites, clays, silica gels, metal oxides and the like. In other embodiments, strong acid and strong basic materials can be provided as surface coatings for carriers such as granular fine particles, beads, fibers, fine powders, nanotubes, and airgels. Alternatively, or additionally, the acidic and basic material forming the acidic and basic surface can be present over at least a portion of the carrier, for example, adding an acidic or basic material to the carrier material. This can be done by coating or impregnating those materials.

【0145】

Both basic and acidic materials can be present in the chemically removed portion of the filter element, but are spaced apart from each other so that the two types of materials do not react with each other and do not neutralize each other. It is preferable to do so. In some embodiments, the basic material, the acidic material, or both can be spaced apart from the adsorbent material such as activated carbon.

【0146】

Examples of acidic compounds that are often present in the atmosphere and are considered pollutants for fuel cells include sulfur oxides, nitrogen oxides, hydrogen sulfide, hydrogen chloride, volatile organic acids, and non-volatile organic acids. Examples of basic compounds that are often present in the atmosphere and are considered pollutants of fuel cells are ammonia, amines, amides, sodium hydroxide, lithium hydroxide, potassium hydroxide, volatile organic bases, and non-volatile organics. Contains bases.

【0147】

In the case of PEM fuel cells, the cathode reaction is triggered under acidic conditions and therefore the presence of basic contaminants is not desirable. An example of a material preferred for removing basic contaminants, such as ammonia, is a bed of activated carbon granules impregnated with citric acid.

【0148】

A second example of a filter assembly that can be used in the system of FIG. 37 is shown as a filter assembly 380 in FIG. 39 in a fracture section. The filter assembly 380 includes a housing 382 that defines an inlet 384 and an outlet 386. Dirty air enters the filter assembly 380 via inlet 384 and clean air exits through outlet 386. The noise suppression element 388 includes a resonator 390. The filter element 391 is mounted inside the housing 382 and is similar to the filter element 358.

【0149】

The filter assembly 380 also includes an adsorbent element 392. The adsorbent element 392 contains a cylindrical mass of carbon 393 between the ends 394 and 395. In the figure, the mass of carbon 393 is a hollow circular extension 397 of activated carbon held together by a thermoplastic binder. Carbon 393 can be produced, for example, by the teachings of US Pat. Nos. 5,189,092 (Koslow) and 5,331,037 (Koslow). The seal system 396 is positioned at the first end 394 and the cap 398 is positioned at the second end 395.

【0150】

The sealing system 396 provides an airtight seal between the adsorbent element 392 and the baffle 401. The sealing system 396 is designed so that the adsorbent element 392 is sealed against the baffle 401 and that air does not pass through the area between the adsorbent element 392 and the side wall of the housing 382. The sealing system 396 prevents the air flow from flowing away from the carbon 393 of the adsorbent element 392. The sealing system 396 is typically made from a flexible compressible material such as polyurethane.

【0151】

The cap 398 diverts the air out of the filter element 358 so that it enters the adsorbent element 392 through carbon 393 rather than through the cylindrical extension of carbon 393 axially. The air from the filter element 391 collides with the exposed surface 402 of the cap 398 and is sent by another route from its "linear" flow to the flow with radial components. The cap 398 contains an aperture 404 inside it that allows air to pass through the cap 398, so that the air can reach the carbon 393. In addition to controlling the air flow, the cap 398 anchors the absorbent element 392 to the filter element 391.

【0152】

The adsorbent element 392 functions as a chemically removed portion and at the same time functions as an element of the sound suppression element 388. Other arrangement configurations of the adsorbent element and the adsorbent material can also have both a chemically removing property and a sound suppressing property.

【0153】

I.<u style="single">A preferred medium structure for the disclosed filter element</u>The fine fiber filter structure includes a two-layer or multilayer structure, and the filter is one or more combined with or separated by one or more synthetic webs, cellulose webs, or blend type webs. Includes a fine fiber layer. Another preferred motif is a structure that includes fine fibers in a matrix or blend of other fibers.

【0154】

The present inventors have described that the important features of the fiber and the microfiber layer in the filter structure are heat resistance, moisture resistance or moisture resistance, and solvent resistance, especially when the microfiber comes into contact with humidity, moisture, or solvent at high temperature. I think it is related to sex. Furthermore, a second important property of the material of the present invention relates to the adhesion of the material to the substrate structure. The adhesiveness of the microfiber layer is such that the material can be manufactured without the microfiber layer peeling from the substrate, and the microfiber layer combined with the substrate is pleated without causing significant layer peeling. It is an important feature of filter materials so that they can be processed into filter structures that include roll-like materials and other structures. We have developed a manufacturing process that raises the temperature to or near the melting temperature of a polymer material, to a temperature just below it, typically below the lowest melting temperature. It has been found that the heating step significantly improves the adhesiveness between the fibers and the adhesiveness between the fibers and the substrate. At melting temperatures, or higher, fine fibers can have their fibrous structure disjointed. Controlling the heating rate is also extremely important. If the fiber is exposed to its crystallization temperature for an extended period of time, the fibrous structure can also be disintegrated. Careful heat treatment also improves the properties of the polymer, which is brought about by the formation of an external additive layer, where the additive material is transferred to the surface and hydrophobic or oleophobic groups are exposed on the fiber surface. Because it does.

【0155】

Performance criteria allow the material to remain intact for 1 or 3 hours at various operating temperatures, i.e. 140 ° F, 160 ° F, 270 ° F, 300 ° F, depending on the end application. At the same time, the filter efficiency of 30%, 50%, 80%, or 90% is maintained. Another performance criterion is that the material can remain intact for 1 or 3 hours at various operating temperatures, i.e. 140 ° F, 160 ° F, 270 ° F, 300 ° F, depending on the end application. At the same time, 30%, 50%, 80%, or 90% of the effective fine fiber is retained inside the filter layer depending on the final application. Remaining at these temperatures is important in low humidity, high humidity, and water-saturated air. The microfiber and filter materials of the present invention are considered moisture-proof, and the materials can withstand immersion at temperatures above 160 ° F for longer than about 5 minutes while maintaining efficiency. Similarly, the solvent resistance of the microfiber materials and filter materials of the present invention is to withstand contact with solvents such as ethanol, hydrocarbons, working fluids and aromatic solvents for longer than about 5 minutes at 70 ° F. It is obtained from a material that can be produced and at the same time maintains 50% efficiency.

【0156】

The fine fiber materials of the present invention include pulsed clean and non-pulse clean filters for dust collection, gas turbines and engine air suction or introduction systems; gas turbine suction or introduction systems, heavy load engine suction or introduction systems, light vehicle engines. Intake or Introductory Systems; Vehicle Cabin Air; Off-Road Vehicle Cabin Air, Disk Drive Air, Photocopia-Toner Removal; HVAC Filters with Various Filter Applications, including Both Commercial and Residential Filter Applications Can be used. Paper filter elements are a widely used form of surface loading media. Paper elements typically include a dense mat of cellulose, synthetic, or other fibers arranged across a stream of gas containing particulate matter. Paper is generally configured to allow a gas stream to pass through, and also to have a sufficiently fine pore size and appropriate porosity to prevent particles larger than the selected size from passing through the interior. As the gas (fluid) passes through the filter paper, the upstream side of the filter paper operates by diffusing and blocking to capture and retain particles of a size selected from the gas (fluid) flow. The particles are collected as dust cake on the upstream side of the filter paper. Over time, the dust cake also begins to act as a filter, increasing efficiency. This is sometimes referred to as "seasoning," which means higher efficiencies than initial efficiencies.

【0157】

There are at least two types of problems with a simple filter design as described above. The first is a relatively simple defect, that is, the paper breaks and the system fails. Second, particulate matter rapidly accumulates upstream of the filter as a thin dust cake or layer, increasing the pressure drop. Various methods have been used to extend the "life" of surface load filter systems such as paper filters. One method is to provide a medium with a pleated structure so that the surface area of the medium facing the flow of the gas stream is increased compared to a flat structure without pleats. This extends the filter life, but still has significant limitations. For this reason, the surface load medium is used in applications where the speed of passing through the filter medium is relatively slow, generally about 20 to 30 feet or less per minute, and typically about 10 feet or less per minute. Mainly found its use. As used herein, the term "velocity" is the average velocity through a medium (ie, the volume of flow per medium area).

【0158】

In general, as the air velocity through the pleated paper medium increases, the filter life decreases in proportion to the square of the velocity. Therefore, when a pleated paper surface-loaded filter system is used as a particulate filter in a system that requires significant air flow, a filter medium with a relatively large surface area is required. For example, a typical cylindrical pleated paper filter element for long-distance diesel trucks has a diameter of about 9 to 15 inches, a length of about 12 to 24 inches, and a pleated depth of about 1 to 2 inches. .. Therefore, the filter surface area (one side) of the medium is typically 30-300 square feet.

【0159】

In many applications, especially when the flow rate is relatively high, alternative types of filter media, sometimes referred to as "depth" media, are used. A typical depth medium comprises a relatively thick material in which the fibers are entangled. Depth media are generally defined by their porosity, density, or percentage of solids. For example, a medium with a solidity of 2-3% is the depth of a fiber arranged such that about 2-3% of the total volume contains fibrous material (solid content) and the rest is air or gas space. Considered a medium mat.

【0160】

Another useful parameter for defining the depth medium is the fiber diameter. If the percentage of solidity is kept constant but the fiber diameter (size) is reduced, then the pore size or space between fibers is reduced, that is, the filter becomes more efficient and more effectively captures smaller particles. It will be.

【0161】

A typical conventional depth medium filter is a medium with a deep, relatively constant (or uniform) density, i.e., a system in which the solidity of the depth medium is kept substantially constant throughout its thickness. Is. As used herein, "substantially constant" means that there is, if any, relatively small density variation over the depth of the medium. For example, such variability can result from the external engaging surface being slightly compressed by the container in which the filter medium is positioned.

【0162】

Gradient density depth media devices have been developed. Several such devices are described, for example, in US Pat. Nos. 4,082,476, 5,238,474, and 5,364,456. In general, depth medium devices can be designed to provide a "load" of particulate matter over substantially their volume or depth. Therefore, such a device can be designed so that when the full filter reaches its end of life, it will be loaded with a larger amount of particulate matter compared to a surface loading system. However, in general, such devices have sacrificed efficiency because media with relatively low solidity is desirable due to the considerable load. Gradient density systems, such as those described in the patents referenced above, have been designed to provide sufficient efficiency and longer life. In some cases, the surface loading medium is utilized as a "polishing" filter in such equipment.

【0163】

The filter medium structure according to the present invention includes a first layer of a permeable coarse fibrous medium or substrate having a first surface. The first layer of the fine fiber medium is fixed to the first surface of the first layer of the coarsely permeable fibrous medium. The first layer of the coarsely permeable fibrous material preferably comprises fibers having an average diameter of at least 10 microns, typically and preferably about 12 (or 14) to 30 microns. Further, the first layer of the coarsely permeable fibrous material preferably contains a medium having a basis weight of about 200 g / m 2 or less, preferably about 0.50 to 150 g / m2, and most preferably at least 8 g / m2. .. The first layer of the coarsely permeable fibrous medium is at least 0.0005 inches (12 microns) thick, typically 0.0006 to 0.02 (15 to 500 microns) thick, preferably about 0.001 to about 0.001 to thick. It is preferably 0.030 inches (25 to 800 microns).

【0164】

In a preferred device, the first layer of coarsely permeable fibrous material exhibits a permeability of at least 1 m / min when evaluated separately from the rest of the structure by a Frazier permeability test, typically and preferably. Includes materials that exhibit a permeability of approximately 2 to 900 m / min. When discussing efficiency here, unless otherwise stated, it is measured according to ASTM-1215-89 using 0.78 μmonodisperse polystyrene spherical particles at 20 fpm (6.1 m / min), as described herein. It means the efficiency of.

【0165】

The layer of fine fiber material fixed to the first surface of the layer of coarsely permeable fibrous medium is preferably a layer of nanofiber and microfiber medium, the average fiber diameter of this fiber being about 2 microns or less. The fiber diameter is generally and preferably less than about 1 micron, typically and preferably less than 0.5 micron and in the range of about 0.05 to 0.5 micron. Further, the first layer of the fine fiber material fixed to the first surface of the first layer of the coarsely permeable fibrous material has a total thickness of about 30 microns or less, more preferably 20 microns or less. It is most preferably about 10 microns or less, and typically and preferably about 1 to 8 times (more preferably 5 times or less) the average diameter of the fine fibers of this layer.

【0166】

One preferred apparatus according to the invention includes a filter medium as generally defined for the entire filter structure. Some preferred devices for such applications are cylindrical pleated configurations, in which the pleats extend substantially vertically, i.e., extend in the same direction as the vertical axis of the cylindrical pattern. Includes media placed in. In such a device, the medium can be embedded in the end cap, similar to a conventional filter. Such devices can include upstream and downstream liners if desired for typical conventional purposes.

【0167】

In some applications, the media according to the invention can be used with other types of media, eg, with conventional media, to improve overall filter performance or lifetime. For example, the medium according to the invention can be stacked on a conventional medium and used in a stacking configuration, or incorporated into a medium structure containing one or more regions of the conventional medium (integrated feature). )be able to. It can be used upstream of such media for good loading and / or as a high efficiency polishing filter downstream of conventional media.

【0168】

Some devices according to the invention can also be used in liquid filter systems, i.e., in systems in which the particulate matter being filtered is contained in a liquid. Some devices according to the invention can also be used in mist collectors, such as devices for filtering fine mist from air.

【0169】

According to the present invention, a method for filtering is provided. This method generally involves the advantageous use of the media described above for the filter. As can be seen from the following description and examples, the medium according to the invention can be particularly formed and configured to advantageously provide a relatively long life for a relatively efficient system.

【0170】

Various filter designs are shown in patents that disclose and claim various aspects of the filter structure used with the filter material. Engel et al., U.S. Pat. No. 4,720,292, discloses a radial seal design for a filter assembly that has a nearly cylindrical filter element design, which is a cylindrical, radial inward surface. It is sealed by a relatively soft rubbery end cap with. Kahlbaugh et al., US Pat. No. 5,082,476 discloses a filter design using a depth medium containing a foam substrate in which pleated components are bonded to the microfiber material of the present invention. Stifelman et al., US Pat. No. 5,104,537, relates to a filter structure useful for filtering liquid media. The liquid is trapped inside the filter housing, passes outside the filter, enters the internal annular core, and then returns to the structure for effective use. Such filters are very useful for filtering the hydraulic fluid. Engel et al., US Pat. No. 5,613,992 shows a typical diesel engine intake filter structure. This structure obtains air from the outer surface of the housing that may or may not contain mixed moisture. Air can pass through the filter while moisture can move to the bottom of the housing and drain from the housing. Gillingham et al., US Pat. No. 5,820,646, disclose a Z-filter structure, which allows fluid flow to at least one layer of the "Z" -passage filter medium for proper filter performance. Use a specific pleated filter design, including closed passages that need to be passed through. The filter medium formed in the pleated Z form can include the fine fiber medium of the present invention. Glen et al. US Pat. No. 5,853, No. 442 discloses a bag-house structure having a filter element that can include the fine fiber structure of the present invention. Berkhoel et al., U.S. Pat. No. 5,954,849, filters dust from airflow when processing high dust load air, generally after processing a processed product in production and creating a significant dust load in the environmental air. The dust collector structure useful for this is shown. Finally, Gillingham's US Design Patent No. 425,189 discloses a panel filter using a Z-filter design.

【0171】

The following materials were produced using the following electrospinning process conditions.

【0172】

The following materials were spun using a rotating emitter system or capillary needle system. It was found that both produced substantially the same fibrous material.

【0173】

Fibers are commonly manufactured for use in devices. The flow rate was 1.5 mil / min per emitter, a target distance of 8 inches, an emitter voltage of 88 kV, a relative humidity of 45%, and a rotating emitter of 35 rpm.

【0174】<u style="single">Example 1: Effect of fiber size</u>Fine fiber samples were prepared from copolymers of nylon 6, 66, 610 and the molecular weight of the nylon copolymer resin (SVP-651) was analyzed by terminal titration (JEWalz and GB Taylor, determination of the molecular weight of nylon, Anal). .Chem.Vol.19, Number 7, pp. 448-450 (1947)). The number average molecular weight was between 21,500 and 24,800. The composition was estimated by phase diagrams of the melting temperatures of three component nylons, namely nylon 6 about 45%, nylon 66 about 20%, and nylon 610 about 25% (page 286, Nylon Plastics Handbook, edited by Melvin Kohan, Hanser). Publisher, New York (1995)). The reported physical properties of the SVP 651 resin are as follows: [0175]

[Table 2]<img file="JP2004508169A_D0002.tif" />Fibers with diameters of 0.23 micron and 0.45 micron were produced. The sample was immersed in water at room temperature, air-dried, and its efficiency was measured. As can be seen from the graph in FIG. 12, the larger the fiber, the longer the decomposition time and the lower the decomposition level. Without any particular theory, it seems that smaller fibers with larger surface / volume ratios are more likely to decompose due to environmental effects. However, larger fibers do not form an efficient filter medium.

【0176】<u style="single">Example 2: Crosslinking of nylon fiber with phenol resin and epoxy resin</u>In order to improve the chemical resistance of the fiber, chemical cross-linking of nylon fiber was attempted. The above-mentioned copolyamide (nylon 6, 66, 610) was mixed with a phenol resin of Georgia Pacific 5137 and spun into a fiber. The nylon: phenol resin ratio and the melting temperature of the blend are shown below.

【0177】

[Table 3]<img file="JP2004508169A_D0003.tif" /> 【0178】

A comparable fiber could be produced from this blend. The 50:50 blend could not be crosslinked because the fibrous structure was destroyed via heat. Heating the 65:35 blend at a temperature below 90 ° C for 12 hours improved the chemical resistance of the resulting fiber, resulting in less solubility in alcohol. Blends of polyamide with epoxy resins such as Shell's Epon 828 and Epi-Rez 510 can be used.

【0179】<u style="single">Example 3: Surface modification with a fluorinated additive (Scotchgard®) water repellent</u>3M's alcohol miscible Scotchgard® FC-430 and 431 were added to the polyamide and then spun. The added amount was 10% solid content. The addition of Scotchgard did not interfere with fiber formation. On the THC bench, it is shown that finishing with a Scotchgard-like high molecular weight water repellent did not improve water resistance. Samples supplemented with Scotchgard were heated at 300 ° F. for 10 minutes as indicated by the manufacturer.

【0180】<u style="single">Example 4: Modification with a coupling agent</u>The polymer film was cast from the polyamide with a titanium-based coupling from Kenrich Petrochemicals, Inc. This coupling agent includes isopropyltriisostearoyl titanate (KRTTS), neopentyl (diallyl) oxytri (dioctyl) phosphatitanate (LICA12), neopentyl (diallyl) oxy, tri (N-ethylenediamino) ethylzirconate (NZ44). Is included. The casting film was immersed in boiling water. The control sample without the coupling agent quickly lost its strength, while the sample with the coupling agent maintained its shape for up to 10 minutes. Samples to which these coupling agents were added were spun into fibers (0.2 micron fiber).

【0181】<u style="single">Example 5: Modification with low molecular weight p-tert-butylphenol polymer</u>Oligomers of p-tert-butylphenol with molecular weights ranging from 400 to 1100 were purchased from Enzymol International in Columbus, Ohio. These low molecular weight polymers were dissolved in lower alcohols such as ethanol, isopropanol and butanol. These polymers were added to the copolyamides described above and electrospun into 0.2 micron fibers without adverse results. Some polymers and additives interfere with the electrospinning process. Unlike the conventional phenolic resins described in Example 2, the inventors have found that this group of polymers does not interfere with the fiber forming process.

【0182】

The inventors have found that this group of additives protects fine fibers from a moist environment, as seen in the graph. Figures 13-16 show that oligomers provide very good protection at 140 ° F and 100% relative humidity, and their performance is not very good at 160 ° F. This additive was added in an amount of 5% to 15% of the polymer used. We have found that these additives equally effectively prevent the fiber from being exposed to high humidity at 140 ° F. The present inventors have also found that the performance can be improved by exposing the fiber to 150 ° C for a short time.

【0183】

Table 1 shows the effects of temperature and time exposure of the 10% addition polyamide fiber.

【0184】

[Table 4]<img file="JP2004508169A_D0004.tif" /> 【0185】

This was a surprising result. A dramatic improvement in water resistance was seen for this type of additive. To understand how this group of additives works, fine fiber mats were analyzed using a surface analysis technique called ESCA. The 10% additional amount sample shown in Table 1 was analyzed using ESCA at the University of Minnesota, and the results are shown in Table 2.

【0186】

[Table 5]<img file="JP2004508169A_D0005.tif" /> 【0187】

Initially, it seemed unreasonable to find that the surface concentration of the additive was more than twice the bulk concentration. However, the present inventors consider that this can be explained by the molecular weight of the additive. The molecular weight of the additive, which is about 600, is much smaller than the molecular weight of the main fiber-forming polymer. Due to the smaller size of the additives, they can move with the evaporating solvent molecules. Therefore, the surface concentration of the additive can be increased. Further treatment increases the surface concentration of the protective additive. However, when exposed to 150 ° C for 10 minutes, the concentration did not increase. This is thought to indicate that a two-component mixture of copolyamide and oligomer molecules is occurring because the long-chain polymer has time to move around. What is taught by this analysis is that performance can be enhanced by proper selection of post-treatment time and temperature, but too long exposure can have adverse effects.

【0188】

In addition, the flight time (Time of A technique called Flight) SIMS was used to test the surface of microfibers containing such additives. This technique involves colliding electrons with an object and observing what comes from its surface. Samples without additives show that organic nitrogen species can be removed by collision with electrons. This indicates that the polyamide species can be obtained. It also shows the presence of small amounts of impurities such as sodium and silicone. Unheat-treated, additive-containing samples (surface additive concentration 23%) show that the majority of the species are t-butyl fragments, with small but distinct polyamide peaks observed. A high mass peak was also observed with a mass difference of 148 amu, which corresponds to t-butylphenol. For samples treated at 150 ° C for 10 minutes (ESCA analysis surface additive concentration 50%), inspection shows that t-butyl fragments dominate most of the sample, with very small peaks, if any, indicating polyamide. It is only shown. It does not show peaks associated with t-butylphenol and its polymers as a whole. It also shows peaks associated with C2H3O fragments.

【0189】

Time-of-flight SIMS analysis shows that exposed polyamide fibers release broken nitrogen fragments from exposed polymer chains due to ionic impact, creating contaminants on the surface. Additives without heat treatment indicate incomplete coating, which indicates that the additive does not cover part of the surface. The t-butyl oligomer is loosely organized on the surface. When the ion beam hits its surface, the entire molecule can be taken with unstable t-butyl fragments. The heat treated additive promotes a complete coating of the surface. Furthermore, the molecules are closely arranged so that only unstable fragments such as t-butyl or CH = CH-OH are detached and the entire molecule of t-butylphenol is not detached. ESCA and flight time SIMS see different depths of the surface. ESCA sees deeper aspects up to 100 angstroms, while flight time SIMS sees only 10 angstrom depths. These analyzes are in agreement.

【0190】<u style="single">Example 6-Development of surface coated interpolymer</u>Type 8 nylon was first developed to prepare soluble and crosslinkable resins for coating and adhesive applications. This type of polymer is formed by the reaction of polymer 66 with formaldehyde and alcohol in the presence of acid (references Cairns, TL; Foster, HD; Larcher, AW; Schneider, AK; Schereiber, RS JAm. Chem. Soc. 1949, 71, 651). This type of polymer can be electrospun and crosslinked. However, fiber formation from this polymer is inferior to copolyamide and can be difficult to crosslink.

【0191】

To prepare Type 8 nylon, it was placed in a 10 gallon high pressure reactor at the following ratio.

【0192】

[Table 6]<img file="JP2004508169A_D0006.tif" /> 【0193】

The reactor was then run with nitrogen and heated to at least 135 ° C. under pressure. When the desired temperature was reached, a small amount of acid was added as a catalyst. Acid catalysts include trifluoroacetic acid, formic acid, toluenesulfonic acid, maleic acid, maleic anhydride, phthalic acid, phthalic anhydride, phosphoric acid, citric acid, and mixtures thereof. Nafion® polymers can also be used as catalysts. After adding the catalyst, the reaction is allowed to proceed for up to 30 minutes. A viscous homogeneous polymer solution is formed at this stage. After the specified reaction time has elapsed, the contents of the high pressure vessel are transferred to a bath containing a base such as methanol, water, ammonium hydroxide or sodium hydroxide to suppress the reaction. After the solution has been sufficiently quenched, the solution is precipitated in deionized water. Fluffy polymer granules are formed. The polymer granules are then centrifuged and vacuum dried. This polymer dissolves in methanol, ethanol, propanol, butanol, and mixtures thereof, which contain various proportions of water. They also dissolve in blends of different alcohols.

【0194】

The alkoxyalkyl-modified Type 8 polyamide thus formed is soluble in the ethanol / water mixture. The polymer solution is electrospun as described in Barris US Pat. No. 4,650,516. The viscosity of the polymer solution tends to increase over time. It is generally known that the viscosity of a polymer has a great influence on determining the size of a fiber. Therefore, it is difficult to control the process in continuous production on a commercial scale. Moreover, under the same conditions, type 8 polyamides do not form microfibers as efficiently as copolyamides. However, if an acidic catalyst such as toluene sulfonic acid, maleic anhydride, trifluoromethanesulfonic acid, citric acid, or ascorbic acid is added to prepare the solution and the fiber mat is carefully heat-treated after fiber formation, the resulting fiber will be obtained. It has very good chemical resistance (Fig. 13). Care must be taken not to destroy the fibrous structure during the cross-linking stage.

【0195】

We have found surprising results when blending type 8 polyamides (polymer B) with alcohol-soluble copolyamides. Alkoxyalkyl-modified polyamide 66 30% by weight was found to have a synergistic effect by substituting alcohol-soluble copolyamides such as SVP 637 or 651 (Polymer A), Elvamide 8061. The fiber formation of the blend is more efficient than the case of either component alone. Immersion in ethanol and measurement of filter efficiency have shown that better than 98% filter efficiency is maintained, and THC bench tests show results comparable to type 8 polyamide alone. This type of blend shows that the advantages of efficient fiber formation and the excellent filter properties of copolyamides can be obtained along with the advantages of the excellent chemical resistance of crosslinked type 8 polyamides. Alcohol immersion tests strongly show that non-crosslinkable copolyamides contribute to cross-linking and maintain a filter efficiency of 98%.

【0196】

The DSC of the blend of Polymers A and B (see Figures 17-20) is indistinguishable from the DSC of Polymer A alone after heating to 250 ° C and is clear (in a fully crosslinked state). Does not show a good melting temperature. This strongly indicates that the blend of Polymers A and B is a fully integrated polymer due to the cross-linking of Polymer B with Polymer A. This is a completely new kind of polyamide.

【0197】

Similarly, melt blends of poly (ethylene terephthalate) and poly (butylene terephthalate) have similar properties. During the melting process at a temperature higher than the melting temperature of either component, ester group exchange is triggered to form an interpolymer of PET and PBT. Furthermore, the cross-linking temperature of the present inventors is lower than that of any single component. It is unlikely that such group exchange will occur at this low temperature. Therefore, it is considered that the present inventors have found a new type of polyamide by a solution blend of type A and type B polyamides and cross-linking at a temperature lower than the melting point of any of the components.

【0198】

The present inventors have found that even better results can be obtained when 10% by weight of t-butylphenol oligomer (additive 7) is added and heat treatment is performed at a temperature required for the crosslinking temperature. The present inventors have theorized that the hydroxyl functional group of the t-butylphenol oligomer may contribute to the reaction with the functional group of type 8 nylon. What the present inventors have found is that in this component system, fiber formation is good, resistance to high temperature and humidity is improved, and hydrophobicity is provided on the surface of the fine fiber layer.

【0199】

A mixture sample of polymer A and polymer B (sample 6A) and a mixture sample of polymer A, polymer B, and additives (sample 6B) were prepared. Fibers were then formed by electrospinning processes, the fiber mats were exposed to 300 ° F for 10 minutes and the surface composition was evaluated by ESCA surface analysis.

【0200】

The table shows the ESCA analysis of samples 6A and 6B.

【0201】

[Table 7]<img file="JP2004508169A_D0007.tif" /> 【0202】

ESCA provides information on surface composition other than hydrogen concentration. ESCA provides information on carbon, nitrogen, and oxygen. Since the additive 7 does not contain nitrogen, the ratio of the nitrogen-containing polyamide to the nitrogen-free additive can be estimated by comparing the nitrogen concentrations. Additional quantitative information is the O 1s of binding energy between 535eV and 527eV. It is available by testing the spectrum. The C = O bond has a binding energy of around 531 eV, and the CO bond has a binding energy of around 533 eV. By comparing the peak heights of these two peaks, the relative concentration of polyamide can be estimated, with C = O groups accounting for the majority and only CO groups present in addition. Polymer B has CO bonds due to denaturation, and when crosslinked, the CO concentration will decrease. ESCA confirmed that such a reaction actually occurred and showed a relative reduction in CO bonds (Figure 4 shows Polymer A and Polymer B mixed fibers that have not been heat treated, Figure 5). For heat-treated mixed fibers of Polymer A and Polymer B). If the molecule of additive 7 is present on the surface, it can be expected that there will be more CO bonds. This is actually the case as seen in FIGS. 6 and 7 (FIG. 6 relates to a mixed fiber of polymer A, polymer B, and additive 7 in a spun state; FIG. 7 shows polymer A, polymer B, And the heat-treated polymer of Additive 7). FIG. 6 shows that the concentration of CO bonds increases with respect to Example 7. These findings are consistent with the surface concentrations based on the XPS multiplex spectra from FIGS. 8 to 11.

【0203】

It is clear that the t-butyl oligomer molecule migrates towards the surface of the fine fiber, forming a hydrophobic coating of about 50 Å. Type 8 nylon has functional groups such as -CH2OH and -CH2OCH3, which the present inventors expected to react with the -OH group of t-butylphenol. For this reason, the inventors expected that fewer oligomeric molecules would be found on the fiber surface. The present inventors have found that their hypothesis is incorrect and that there is a thin film on the surface of the interpolymer.

【0204】

Samples 6A, 6B and the samples described in Section 5 were repeated on a 160 ° F, 100% RH THC bench. In the section above, the sample was exposed to 140 ° F and 100% RH. Under these conditions, t-butylphenol prevented the terpolymer copolyamide from decomposing. However, when the temperature rises to 160 ° F at 100% RF, the t-butylphenol oligomers cannot adequately protect the underlying terpolymer copolyamide fiber. These samples were compared at 160 ° F and 100% RH.

【0205】

[Table 8]<img file="JP2004508169A_D0008.tif" /> 【0206】

The table shows that Sample 6B helps prevent exposure to high temperatures and humidity.

【0207】

A more significant difference is seen when exposed to water droplets on the fiber mat. When a small drop of DI water is placed on the surface of sample 6A, the water drop immediately spreads throughout the fiber mat and wets the substrate paper. On the other hand, when water droplets are placed on the surface of sample 6B, the water droplets form beads and do not spread on the mat surface. The surface of sample 16 was modified to be hydrophobic by adding an oligomer of pt-butylphenol. This type of product can be used as a water mist eliminator because water droplets do not pass through the surface layer of the fine fiber of sample 6B.

【0208】

Repeated samples of Samples 6A, 6B and Section 5 were placed in a furnace set to a temperature of 310 ° F. The table shows that both samples 6A and 6B remained intact and the sample in section 5 was severely damaged.

【0209】

[Table 9]<img file="JP2004508169A_D0009.tif" /> 【0210】

When the oligomer is added only to the polymer A, the heat resistance of the fine fiber layer is improved, but when the additive 7 is added, there is no clear effect on high temperature exposure.

【0211】

Mixtures of terpolymer copolyamide, alkoxyalkyl-modified nylon 66, and t-butylphenol oligomers are more than a mixture of terpolymer copolyamide and t-butylphenol oligomers, or a mixture of terpolymer copolyamide and alkoxyalkyl-modified nylon 66. It has been clearly shown to provide better products by helping fine fibers in harsh environments with improved productivity. The mixture of these two components is also improved over the single component system.

【0212】<u style="single">Example 7: Compatibility blend of polyamide and bisphenol A polymer</u>New types of polymers can be prepared by oxidative coupling of phenolic rings (Pecora, A; Cyrus, W. US Pat. No. 4,900,671 (1990) and Pecora, A; Cyrus, W .; Johnson, M. USA. Patent No. 5,153,298 (1992)). Of particular interest are polymers made from Bisphenol A, sold by Enzymol Corp. Catalytic oxidation of bisphenol A by soybean peroxidase can be initiated from either side of the two -OH groups of bisphenol A. Unlike linear, bisphenol A-based polycarbonates, this type of bisphenol A polymer forms a highly branched polymer. Due to the highly branched nature of this polymer, the viscosity of the polymer blend can be reduced.

【0213】

The present inventors have found that this type of bisphenol A polymer and polyamide can be solution-blended. The Hansen solubility parameter reported for nylon is 18.6 (page 317, Handbook of Solubility Parameters and other cohesion parameters, edited by A. Barton, CRC Press, Boca Raton Florida, 1985). When calculating the solubility parameter (page 61, Handbook of Solubility Parameters), the calculated solubility parameter is 28.0. Due to the difference in solubility parameters, it cannot be expected that both are miscible with each other. However, the inventors have found that both are completely miscible, resulting in unexpected properties.

【0214】

In an ethanol solution, a 50:50 blend of bisphenol A with a molecular weight of 3,000 and copolyamide was formed. The total concentration in the solution was 10%. With copolyamide alone, the fiber diameter was 0.2 microns. In the case of blending, it became a thick layer of fiber of about 1 micron. Bisphenol A with a molecular weight of 7,000 is not stable when present with copolyamide and tends to precipitate.

【0215】

A DSC in a 50:50 blend indicates that the melting temperature is inadequate. The melting temperature of copolyamide is about 150 ° C, and the bisphenol A resin is a glassy polymer with a Tg of about 100. This blend indicates inadequate clear melting. When the fiber mat is exposed to 100 ° C, the fiber mat disappears. This blend is believed to produce a good filter medium when the upper limit operating temperature is not very high and the pressure drop needs to be low. This polymer system could not be crosslinked in a reasonable manner.

【0216】<u style="single">Example 8: Dual Role as Solvent and Solid in Blending Bisphenol A Polymers</u>A surprising feature of bisphenol A polymer blends is that in the form of a solution the bisphenol A polymer behaves like a solvent and in the form of a solid the polymer functions as a solid. The present inventors have found that the dual role of the bisphenol A polymer is completely unique.

【0217】

The following formulation was performed.

【0218】

[Table 10]<img file="JP2004508169A_D0010.tif" /> 【0219】

The viscosity of this blend was 32.6 centipores according to the Brookfield viscometer. The total polymer concentration was 19.2%. The viscosity of Polymer B at 19.2% exceeds 200 centipores. In a similar solvent, the viscosity of 12% Polymer B alone is about 60 centipores. This is a clear example of how bisphenol A resin behaves like a solvent because the overall viscosity of the solution is lower than expected. The diameter of the resulting fiber was 0.157 microns. If only Polymer B contributed to the fiber formulation, the expected fiber size would be less than 0.1 micron. In other words, Polymer C contributed to the fiber formulation. Thus, no other case is known in which the ingredients play a dramatic dual role. After immersing the sample in ethanol, filter efficiency and fiber size were measured. After immersion in alcohol, the filter efficiency of 85.6% was maintained and the fiber size did not change. This indicates that the polymer C contributed to the cross-linking operation like the polymer solid.

【0220】

Another polymer solution was prepared by the following procedure: [0221]

[Table 11]<img file="JP2004508169A_D0011.tif" />The viscosity of this blend was 90.2 cm pores. This is a very low viscosity for a solid 24%. This also indicates that Polymer C behaves like a solvent in solution. However, when electrospun to make a fiber, the fiber diameter is 0.438 microns. A 15% solution of Polymer B alone is believed to produce fibers of approximately 0.2 microns. In the final state, the contribution of Polymer C increases the fiber size. Again, this example shows that this type of branched polymer acts as a solvent in solution and as a solid in the final state. After immersion in ethanol solution, the filter efficiency of 77.9% was maintained and the fiber size did not change.

【0222】<u style="single">Example 9: Development of a crosslinked polyamide / bisphenol A polymer blend</u>Three different samples were prepared by combining the resin, alcohol, and water and stirring at 60 ° C. for 2 hours. The solution was cooled to room temperature, the catalyst was added to the solution and the mixture was stirred for an additional 15 minutes. Then, the viscosity of the solution was measured and spun into fibers.

【0223】

The table below shows examples of these: [0224]

[Table 12]<img file="JP2004508169A_D0012.tif" />The present inventors have found that this blend efficiently produces fibers, and the mass of the fibers is increased by about 50% as compared with the polymer A formulation. In addition, the resulting polymer microfibers produce fibers with higher chemical resistance. Filters made from these fibers maintain filter efficiencies greater than 90% and no change in fiber diameter, even though only 44% of the solid composition is essentially crosslinkable after alcohol immersion. It was. This three-component polymer composition of copolyamide, alkoxyalkyl-modified nylon 66, and bisphenol A produces a chemically durable material that forms excellent fibers.

【0225】<u style="single">Example 10: Alkoxyalkyl modified copoly of nylon 66 and nylon 46</u><u style="single">Ma</u>The following reactions were carried out in a 10 gallon high pressure reactor and the resulting polymer was analyzed. After reaching the reaction temperature, the catalyst was added and the reaction was carried out for 15 minutes. The polymer solution was then quenched, precipitated, washed and dried.

【0226】

[Table 13]<img file="JP2004508169A_D0013.tif" /> 【0227】

The DSC of the polymer formed of nylon 46 and nylon 66 exhibits a single broad melting temperature that is lower than the melting temperature of modified nylon 46 (241 ° C) or the melting temperature of modified nylon 66 (210 ° C). This indicates that both components are randomly distributed along the polymer chain during the reaction. Therefore, it is considered that the alkoxyalkyl modification gave a random copolymer of nylon 46 and nylon 66. These polymers are soluble in alcohol and also in a mixture of alcohol and water.

【0228】

[Table 14]<img file="JP2004508169A_D0014.tif" /> 【0229】

Both have high crystallinity and do not dissolve in common alcohols.

【0230】

Source: Modern Plastics Encyclopedia 1998<u style="single">Example 11: Development of an interpolymer of copolyamide and an alkoxy-modified nylon 46/66 copolymer, and formation of an electrospun fiber.</u>Samples of Experiments 10B and 10D were made into fibers by the methods described above. Only alkoxyalkyl-modified nylon 46/66 (Polymer D) was successfully electrospun. By blending Polymer D and Polymer A, fibers can be formed more efficiently without sacrificing the crosslinkability of Polymer D, as shown in the table below, to produce larger fibers. You can get the additional benefit of being able to.

【0231】

[Table 15]<img file="JP2004508169A_D0015.tif" /> 【0232】

The fiber mass ratio was calculated by (total length of fiber x cross-sectional area). Retention efficiency retention was measured by immersing the filter sample in ethanol. Fiber size did not change with alcohol immersion.

【0233】<u style="single">Example 12: Crosslinked electrospinning PVA</u>PVA powder was purchased from Aldrich Chemicals. The powder was dissolved in water or a mixture of ethanol and water in 50/50. These were mixed with a cross-linking agent and a toluene sulfonic acid catalyst and electrospun. The resulting fiber mat was crosslinked in a 150 ° C. furnace for 10 minutes and then placed on a THC bench.

【0234】

[Table 16]<img file="JP2004508169A_D0016.tif" /> 【0235】<u style="single">Example 13</u>A conventional cellulose air filter medium was used as a substrate. The substrate has a basis weight of 67 pounds per 3000 square feet and a flavor transmission of 0.5 inches of water pressure drop of 16 feet per minute, a thickness of 0.012 inches and a LEFS efficiency of 41.6. %Met. The fine fiber layer of Example 1 was added to the surface using the process described for a nominal fiber diameter of 0.2 microns. The LEFS efficiency of the obtained complex was 63.7%. After exposure to 140 F air for 1 hour at 100% relative humidity, the substrate-only sample was cooled and dried, resulting in a LEFS efficiency of 36.5%. After 1 hour exposure to 140 F air at 100% relative humidity, the complex sample was cooled and dried, resulting in a LEFS efficiency of 39.7%. Using the formula described, the efficiency of the fine fiber layer retained after 1 hour of exposure was 13% and the number of valid fine fibers retained was 11%.

【0236】<u style="single">Example 14</u>A conventional cellulose air filter medium was used as a substrate. The substrate has a basis weight of 67 pounds per 3000 square feet and a flavor transmission of 0.5 inches of water pressure drop of 16 feet per minute, a thickness of 0.012 inches and a LEFS efficiency of 41.6. %Met. The fine fiber layer of Example 5 was added to the surface using the process described for a nominal fiber diameter of 0.2 microns. The LEFS efficiency of the obtained complex was 96.0%. After 3 hours of exposure to 160 F air at 100% relative humidity, the substrate-only sample was cooled and dried, resulting in a LEFS efficiency of 35.3%. After 3 hours of exposure to 160 F air at 100% relative humidity, the complex sample was cooled and dried, resulting in a LEFS efficiency of 68.0%. Using the formula described, the efficiency of the fine fiber layer retained after 3 hours of exposure was 58% and the number of valid fine fibers retained was 29%.

【0237】<u style="single">Example 15</u>A conventional cellulose air filter medium was used as a substrate. The substrate has a basis weight of 67 pounds per 3000 square feet and a flavor transmission of 0.5 inches of water pressure drop of 16 feet per minute, a thickness of 0.012 inches and a LEFS efficiency of 41.6. %Met. A fine fiber layer of the polymer A and polymer B blend described in Example 6 was applied to the surface using the process described for a nominal fiber diameter of 0.2 microns. The LEFS efficiency of the obtained complex was 92.9%. After 3 hours of exposure to 160 F air at 100% relative humidity, the substrate-only sample was cooled and dried, resulting in a LEFS efficiency of 35.3%. After 3 hours of exposure to 160 F air at 100% relative humidity, the complex sample was cooled and dried, resulting in a LEFS efficiency of 86.0%. Using the formula described, the efficiency of the fine fiber layer retained after 3 hours of exposure was 96% and the number of effective fine fibers retained was 89%.

【0238】<u style="single">Example 16</u>A conventional cellulose air filter medium was used as a substrate. The substrate has a basis weight of 67 pounds per 3000 square feet and a flavor transmission of 0.5 inches of water pressure drop of 16 feet per minute, a thickness of 0.012 inches and a LEFS efficiency of 41.6. %Met. The fine fiber layers of Polymer A, Polymer B, and t-butylphenol oligomers described in Example 6 were added to the surface using the process described for a nominal fiber diameter of 0.2 microns. The LEFS efficiency of the obtained complex was 90.4%. After 3 hours of exposure to 160 F air at 100% relative humidity, the substrate-only sample was cooled and dried, resulting in a LEFS efficiency of 35.3%. After 3 hours of exposure to 160 F air at 100% relative humidity, the complex sample was cooled and dried, resulting in a LEFS efficiency of 87.3%. Using the formula described, the efficiency of the fine fiber layer retained after 3 hours of exposure was 97% and the number of effective fine fibers retained was 92%.

【0239】<u style="single">Example 17</u>A conventional cellulose air filter medium was used as a substrate. The substrate has a basis weight of 67 pounds per 3000 square feet and a flavor transmission of 0.5 inches of water pressure drop of 16 feet per minute, a thickness of 0.012 inches and a LEFS efficiency of 41.6. %Met. A fine fiber layer of PVA and polyacrylic acid crosslinked in Example 12 was added to the surface using the process described for a nominal fiber diameter of 0.2 microns. The LEFS efficiency of the obtained complex was 92.9%. After exposure to 160 F air at 100% relative humidity for 2 hours, the substrate-only sample was cooled and dried, resulting in a LEFS efficiency of 35.3%. After exposure to 160 F air at 100% relative humidity for 2 hours, the complex sample was cooled and dried, resulting in a LEFS efficiency of 83.1%. Using the formula described, the efficiency of the fine fiber layer retained after 2 hours of exposure was 89% and the number of effective fine fibers retained was 76%.

【0240】<u style="single">Example 18</u>The following filter media were prepared by the methods described in Examples 1 to 17.

【0241】

[Table 17]<img file="JP2004508169A_D0017.tif" /> 【0242】

[Table 18]<img file="JP2004508169A_D0018.tif" /> 【0243】

[Table 19]<img file="JP2004508169A_D0019.tif" /> 【0244】

The medium was used for flat sheets, pleated flat panels, pleated round filters, and Zee filters in a flat, corrugated, pleated, corrugated and pleated state.

【0245】<u style="single">Test method</u><u style="single">Hot water immersion test</u>The use of filter efficiency in measuring the number of fine fibers that are effectively and functionally retained in the structure has several advantages over other possible methods such as SEM evaluation.

【0246】

Filter measurements evaluate a few square inches of medium that gives a better average than the small area (typically less than 0.0001 square inches) found in SEM micrographs.

【0247】

Filter measurements quantify the number of fibers that remain functional in the structure. These fibers, which remain intact within the altered structure but are agglomerated or present in another embodiment, are included only with respect to their measured effectiveness and functionality.

【0248】

Nevertheless, for fibrous structures where filter efficiency is not easily measured, other methods can be used to measure the percentage of remaining fiber and can be evaluated against a 50% retention criterion. ..

【0249】

Description: This test accelerates the moisture resistance of the filter medium. This test uses a LEFS test bench to measure changes in filter medium performance when immersed in water. Water temperature is a very important parameter and is selected based on the residual history of the medium during the test, the desire to minimize test time, and the test ability to identify the type of medium. Typical water temperatures are 70 ° F, 140 ° F, or 160 ° F.

【0250】

Procedure: Cut a 4 inch diameter sample from the medium. On a LEFS (see ASTM Standard F1215-89 for a description of the LEFS test) bench operating at 20 FPM, 0.8 μm latex spheres are used as the test contaminant to calculate the particle capture efficiency of the test piece. The sample is then submerged in distilled water for 5 minutes (typically 140 ° F). The sample is then placed on a drying rack and dried at room temperature (typically overnight). Once the sample is dry, retest efficiency on the LEFS bench using the same conditions as for the initial calculation.

【0251】

Repeat the previous steps for fine fiber substrates that do not contain fine fibers.

【0252】

From the above information, the efficiency component due only to the fine fiber and the efficiency loss due to water damage can be calculated. Once the loss efficiency of the fine fiber is determined, the amount of efficiency retained can be calculated.

【0253】

Calculation: Fine fiber layer efficiency: Ei = initial composite efficiency; Es = initial substrate efficiency; Fe = fine fiber layer Fe = 1-EXP (Ln (1-Ei) -Ln (1-Ex)) Fiber layer efficiency: Fi = initial fine fiber layer efficiency; Fx = fine fiber layer efficiency after immersion; Fr = fine fiber retained Fr = Fx / Fi Percentage of fine fiber retained with effective functionality Can also be calculated by% = log (1-Fx) / log (1-Fi).

【0254】

Pass / Fail Criteria:&gt; 50% Efficiency Preservation In most industrial pulse cleaning filter applications, the filter is considered to work well if at least 50% fine fiber efficiency is preserved. ..

【0255】<u style="single">THC bench (temperature, humidity)</u>Description: The purpose of this bench is to evaluate the resistance of fine fiber media to the effects of high temperature and humidity under dynamic flow conditions. The tests are intended to simulate the application of industrial filters, gas turbine intakes, or the extreme operating conditions of a heavy-duty engine air intake environment. At intervals, samples are removed, dried and subjected to LEFS testing. This system is often used to stimulate hot / humid conditions, but can also be used to stimulate hot / cold dry conditions. Temperature -31 ~ 390 ° F Humidity 0 ~ 100% RH (At 100% RH, the maximum temperature is 160 ° F and the maximum continuous duration under these conditions is 16 hours) Flow rate 1 ~ 35 FPM Procedure: Diameter Cut a 4-inch sample from the medium.

【0256】

On a LEFS bench operating at 20 FPM, 0.8 μm latex spheres are used as test contaminants to calculate the particle capture efficiency of the test piece. The sample is then inserted into the THC medium chuck. The test time can be from a few minutes to a few days depending on the test conditions. The sample is then placed on a drying rack and dried at room temperature (typically overnight). Once the sample is dry, retest efficiency on the LEFS bench using the same conditions as for the initial calculation. Repeat the previous steps for fine fiber substrates that do not contain fine fibers. From the above information, the efficiency component due only to the fine fiber and the efficiency loss due to the damage caused by alcohol can be calculated. Once the loss efficiency of the fine fiber is determined, the amount of efficiency retained can be calculated.

【0257】

Pass / Fail Criteria:&gt; 50% Efficiency Preservation In most industrial pulse cleaning filter applications, the filter is considered to work well if at least 50% fine fiber efficiency is preserved. ..

【0258】<u style="single">Alcohol (ethanol) immersion test</u>Description: This test uses a LEFS test bench to measure changes in filter medium performance when immersed in ethanol at room temperature.

【0259】

Procedure: Cut a 4 inch diameter sample from the medium. On a LEFS bench operating at 20 FPM, 0.8 μm latex spheres are used as test contaminants to calculate the particle capture efficiency of the test piece. The sample is then submerged in alcohol for 1 minute.

【0260】

The sample is then placed on a drying rack and dried at room temperature (typically overnight). Once the sample is dry, retest efficiency on the LEFS bench using the same conditions as for the initial calculation. Repeat the previous steps for fine fiber substrates that do not contain fine fibers. From the above information, the efficiency component due only to the fine fiber and the efficiency loss due to the damage caused by alcohol can be calculated. Once the loss efficiency of the fine fiber is determined, the amount of efficiency retained can be calculated.

【0261】

Pass / Fail Criteria:&gt; Retaining 50% Efficiency The specifications, examples, and data described above illustrate the invention. However, many modifications and embodiments can be presented with respect to the disclosed invention. The present invention is embodied within the scope of the claims described above.

[Simple explanation of drawings]

[Figure 1]

It is a figure which shows the typical electrostatic emitter drive device for producing the fine fiber of this invention.

[Figure 2]

FIG. 5 shows an apparatus used to introduce fine fibers onto a filter substrate and further lead to the fine fiber forming technology shown in FIG.

[Fig. 3]

FIG. 5 shows a typical internal structure of a supporting material and another diagram showing a fine fiber material of the present invention compared to small particulate matter, ie 2 and 5 micron particulate matter.

[Fig. 4]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 5]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 6]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 7]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 8]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 9]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 10]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 11]

It is a figure which shows the analysis ESCA spectrum about Example 13.

[Fig. 12]

It is a figure which shows the stability of the 0.23 and 0.45 microfiber material of this invention obtained from Example 5.

[Fig. 13]

FIG. 5 shows improved temperature and humidity stability of the materials of Examples 5 and 6 when compared to non-modified nylon copolymer solvent-soluble polyamides.

[Fig. 14]

FIG. 5 shows improved temperature and humidity stability of the materials of Examples 5 and 6 when compared to non-modified nylon copolymer solvent-soluble polyamides.

[Fig. 15]

FIG. 5 shows improved temperature and humidity stability of the materials of Examples 5 and 6 when compared to non-modified nylon copolymer solvent-soluble polyamides.

[Fig. 16]

FIG. 5 shows improved temperature and humidity stability of the materials of Examples 5 and 6 when compared to non-modified nylon copolymer solvent-soluble polyamides.

[Fig. 17]

A blend of two copolymers, nylon homopolymers and nylon copolymers, which have been heat-treated and then attached to an additive, are crosslinked or otherwise chemically chemically without showing the distinguishing characteristics of the two distinct polymer materials. It is a figure which shows forming a single component material which can be seen as a bonded single phase.

[Fig. 18]

A blend of two copolymers, nylon homopolymers and nylon copolymers, which have been heat-treated and then attached to an additive, are crosslinked or otherwise chemically chemically without showing the distinguishing characteristics of the two distinct polymer materials. It is a figure which shows forming a single component material which can be seen as a bonded single phase.

[Fig. 19]

A blend of two copolymers, nylon homopolymers and nylon copolymers, which have been heat-treated and then attached to an additive, are crosslinked or otherwise chemically chemically without showing the distinguishing characteristics of the two distinct polymer materials. It is a figure which shows forming a single component material which can be seen as a bonded single phase.

[Fig. 20]

A blend of two copolymers, nylon homopolymers and nylon copolymers, which have been heat-treated and then attached to an additive, are crosslinked or otherwise chemically chemically without showing the distinguishing characteristics of the two distinct polymer materials. It is a figure which shows forming a single component material which can be seen as a bonded single phase.

[Fig. 21]

It is the schematic of the engine system which can utilize the air cleaner by the disclosure of this invention.

[Fig. 22]

FIG. 2 is a schematic perspective view of an embodiment of a filter element that can be used in the system shown in FIG.

[Fig. 23]

It is a schematic perspective view of a part of the filter medium (Z medium) that can be used in the apparatus of FIG.

[Fig. 24]

FIG. 2 is a schematic cross-sectional view of the filter element shown in FIG. 22 installed in the housing.

[Fig. 25]

FIG. 6 is an enlarged schematic view of a breakage of one embodiment of a compressible sealing member used in the sealing system for a filter element of FIG.

[Fig. 26]

FIG. 2 is a schematic perspective view of another embodiment of the filter element that can be used in the engine system of FIG.

[Fig. 27]

FIG. 6 is a schematic cross-sectional view of the filter element of FIG. 26 installed in the housing.

[Fig. 28]

FIG. 2 is a schematic exploded perspective view of another embodiment of a filter element and housing that can be used in the engine system of FIG.

[Fig. 29]

It is the schematic of the gas turbine system which can utilize the filter element by the disclosure of this invention.

[Fig. 30]

FIG. 9 is a schematic perspective view of an embodiment of a filter element that can be used in the gas turbine intake system shown in FIG.

[Fig. 31]

It is a rear view of the filter element shown in FIG. 30 installed in a tube sheet, and shows the one having a pre-filter installed upstream of the filter element of FIG. 30.

[Fig. 32]

It is an enlarged schematic fracture sectional view of the air filter arrangement of FIG. 31 obtained along line 12-12 of FIG.

[Fig. 33]

It is the schematic of the intake system for a microturbine system which can utilize the filter element of the disclosure of this invention.

[Fig. 34]

A schematic cross-sectional view of a filter element operably installed to clean the intake air in a gas turbine system, taken along lines 14-14 of Figure 35, showing the assembled state. It is a figure.

[Fig. 35]

It is an exploded side view of the filter device of FIG. 34, and is the figure which shows the state which is not assembled.

[Fig. 36]

FIG. 6 is a schematic cross-sectional view taken along the line showing a filter element sealed in a filter housing.

[Fig. 37]

It is the schematic of the intake port for a fuel cell system which can utilize the filter element disclosed in this specification.

[Fig. 38]

FIG. 3 is a schematic cross-sectional view of a filter assembly that can be used in the fuel cell intake system of FIG. 37.

[Fig. 39]

FIG. 3 is a schematic cross-sectional view of another embodiment of a filter assembly that can be used in a fuel cell system intake.