Method for producing filtration media having a chemical reagent

The present invention relates to a fluid or air filter using a solid filtration medium containing a chemical reagent for removing odors.

It is well known to use activated materials such as activated carbon in the air stream for deodorization. Conventional carbon-based adsorbents have been found to have a wide range of efficacy against odors. However, such an activated carbon adsorption technique that removes odor from the air flow is effective only for a relatively short period of time, is not very effective when the odor concentration is low, and the performance deteriorates sharply at high relative humidity. Occasionally, a relatively high differential pressure may occur over the activated carbon filtration medium. The odor is adsorbed on the pores of the activated carbon. The odor adsorbed in this way may be desorbed to varying degrees depending on conditions such as temperature changes, supersaturation of the adsorption surface, and preferentially adsorbed gas or vapor. This action occurs more or less in all adsorbents as a result of the formation of atypical desorbed odor complexes of the adsorbed odor. As a result, a relatively large amount of activated carbon is required for such a filter device, but even with a relatively large amount of activated carbon, the problem of relatively large differential pressure remains unsolved.

It is known to use activated alumina as a support for gas filters. Activated alumina is coated or impregnated with reagents in a variety of complex methods. A major problem with impregnating activated alumina is that alumina is economically impregnated with effective chemicals without destroying the impregnated material or support while maintaining the desired degree of activity and wear resistance. Is. A material that is particularly difficult to impregnate activated alumina with while maintaining sufficient strength and desired performance is alkali metal permanganate, especially potassium permanganate. However, permanganate ions have a fast reaction rate and a wide reaction profile for inorganic and organic moieties and have therefore long been used in dry support form for deodorization in liquid cleaning applications. In addition, permanganate ions have a history of being proven to have performance against a wide range of odors. Permanganate ions are strong oxidants capable of reacting with aldehydes, reduced sulfur compounds, unsaturated hydrocarbons, alcohols, phenols, amines, hydrogen sulfide, sulfur dioxide and the like. Therefore, there is a need for a filtration medium with a support material impregnated with permanganate.

Early development to produce activated alumina forms containing oxidants such as permanganate that was satisfactory was to pellet the alumina starting material and exhaust the alumina pellets to fill the pellet holes. It is emptied so that the alumina mold can be effectively impregnated with the oxidizing agent. The impregnation of the alumina mold was usually performed by spraying the impregnation solution on the mold. After impregnating with the oxidizing agent, the alumina mold is dried to remove the separated water. A problem in trying to adapt the currently used commercial methods for the production of permanganate-impregnated alumina composites is to obtain the desired uniform distribution of oxidant in alumina. It can be difficult. Further, economically forming a filtration medium having a desired permanganate concentration, a desired pellet size or shape and a desired physical strength remains a challenge.

<p> The present invention preferably provides an alumina-based impregnated pellet and a method for producing the pellet, wherein the pellet is impregnated with at least one oxidant containing permanganate for use in treating fluid flow. doing. Permanganate is used in bulk, impregnated with alumina-based particles, pellets, tablets or other medium with the desired shape at a cost-effective concentration and placed in a filter cartridge. It is attached to foam, synthetic fibers and fiberglass mechanically or by adhesion, or is contacted with the fluid stream in other ways known to those skilled in the art to remove odors from the fluid stream. At least some of the permanganates are placed in an impregnated solution in the form of a low cost permanganate source such as potassium permanganate. Water and various salts are also introduced into the impregnating solution, Na⁺, Li⁺, K⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl^-, SO₄^2-, BO₃^2-, PO₄^3-, NO₃^-And ions and ionic compounds such as these are added to improve the solubility of the permanganate in the impregnating solution, yet another deodorant is added and / or the formed tablet, pellet or other form of medium. Improves hardness or physical strength of. Preferably, alumina-based pellets or tablets are prepared by mixing an impregnated solution containing potassium permanganate with activated alumina, impregnating the impregnated solution, and forming the desired shape.</p><p> Other features of the invention will become apparent from the accompanying drawings and the following detailed description relating to the claims.</p><p> With reference to the accompanying drawings, one aspect of the filtration medium cartridge and test data of the filtration medium containing the reagents are disclosed, but the other cartridges, cassettes, substrates and compositions of the filtration medium and the filtration medium are contained or supported. It should be understood that the present invention is not limited to the above aspects, as other means of doing so will be known to those skilled in the art by reading the disclosed contents of the present invention.</p>

<figref num="1">It is a table of test data obtained in Examples showing the performance characteristics of some aspects of the filtration medium according to the invention compared to the prior art.</figref><figref num="2">NaNO₃It is a graph of the selected data of the selected aspect of the present invention including.</figref><figref num="3">Na₃PO₄It is a graph of the selected data of the selected aspect of the present invention including.</figref><figref num="4">It is a perspective view of the aspect of the filter cassette which has a shape to be installed in a gas stream.</figref>

The present invention relates to chemical reagents for removing odors from fluids, especially air, in a closed environment. Odor removal is known in the art for the filtration medium contained in the filter cartridge, or other medium holding means or supporting material in which the filtration medium is attached to a substrate such as foam, synthetic fiber and fiberglass by mechanical or adhesive. It is carried out by passing the fluid through a means for bringing the fluid into contact with a filtration medium or the like to oxidize the odor. Permanganate oxidizes odors emitted from hydrogen sulfide, organic matter, etc., i.e., these sulfides and organic matter are quickly and efficiently converted to odorless oxides, so that permanganate is filtered through the filter. Incorporated in the medium. The filtration medium contains an activated hydrophilic substrate impregnated with permanganate. Substrates include silica alumina, gels, activated bauxite and activated clay. The substrate preferably contains activated alumina. Permanganate is known to oxidize most of the odors of tobacco, human body and cooking odors to carbon dioxide, water or some other odorless oxides. A certain amount of water contained in the base material is necessary for causing an oxidation reaction. In the absence of water, permanganate cannot be ionized to release active permanganate ions. This is the reason why the filtration medium contains a hydrophilic substrate, preferably alumina.

The substrate is preferably rich in pellets, tablets or other forms of alumina known in the art. Provided are a medium and a method of making a medium in which the medium is impregnated with at least one oxidizing agent containing a permanganate for use in treating a fluid, preferably an air stream or the like. The permanganate is impregnated into a pellet, tablet or other form of medium at the desired concentration in an inexpensive manner to form a filtration medium with the desired hardness, which is placed in the fluid stream and placed on it. Remove the odor contained. Permanganate is Na⁺, Li⁺, K⁺, NH₄⁺, Mg²⁺And / or Ca²⁺It is preferable to impregnate the substrate in the form of permanganate.

It is advantageous that the activated alumina substrate is substantially uniformly impregnated with the metal permanganate. In the method of producing a filtration medium, the first activated alumina support is provided. Activated alumina is commercially available in the form of microparticles. By providing activated alumina in the form of microparticulates with a predetermined particle size distribution, it is possible not only to obtain pellets, tablets or other shapes of media with improved strength and other physical properties, but also more. The final alumina-containing medium impregnated uniformly is obtained. It is preferable that the activated alumina can be rehydrated. The activated alumina is then mixed with an impregnating solution containing the metal permanganate, which results in the alumina containing a substantially uniformly distributed permanganate. When forming the medium by compression, the permanganate-containing alumina is partially cured under thermal and humidity conditions to form an agglomerated mass. The addition of water involved in hydration and solubilization is necessary to maintain the permanganate in solution as the insoluble permanganate does not react. When the medium is formed by compression, the permanganate-impregnated particles are partially hydrated due to the lack of chemical bonds required to provide the formed medium with the desired strength properties and wear resistance. If the material is reformed, it is necessary that the curing does not proceed to the end. When the medium is formed by compression, the partially cured agglomerates are preferably granulated into particles with a particle size of 40-80 mesh and compressed into the desired shape. Curing is complete once the medium is formed. Hydration and curing is performed before and / or during pelletization to obtain the desired strength properties and vent capacity.

The permanganate may be impregnated in alumina at any stage before pelleting, during pelleting, or after pelleting, and this impregnation may result in activation of the alumina, preferably in the form of microparticles. This is performed by mixing the obtained alumina with the permanganate-containing impregnating solution by a method in which the permanganate is distributed substantially uniformly on the alumina base material. This mixing is typically done by mechanically mixing the alumina substrate with a solution containing permanganate and water. Permanganate is absorbed by the alumina substrate. The amount of permanganate absorbed by the alumina substrate can be predicted from the concentration of permanganate in the solution. When the permanganate solution is brought into contact with a solid material such as alumina, the amount of permanganate absorbed is proportional to the concentration of permanganate in the solution. Therefore, the higher the solubility of the permanganate in the solution, the higher the concentration of the permanganate in the final medium, which in turn increases the oxidizing ability. However, if the permanganate source is cheaper, the solubility of the permanganate potassium salt in water is only about 4% (wt / v) at room temperature, and the permanganate source is expensive. If so, the solubility of the potassium salt of permanganate in water is as high as about 40% (wt / v) at room temperature. The impregnated solution of the present invention preferably contains permanganate in the solution at a concentration of at least 20% (wt / v), preferably at a higher concentration.

Na⁺, Li⁺, K⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl^-, SO₄^2-, BO₃^2-, CO₃^2-, PO₄^3-, NO₃^-And when one or more of the ions and ionic compounds, such as combinations thereof, are introduced into a solution containing potassium permanganate, various permanganates are formed in the solution, thus improving the solubility of the permanganate in the solution. To do. However, the important thing to note is Mg²⁺Or Ca²⁺As carbonate or bicarbonate as CO₃^2-With or with Mg²⁺Or Ca²⁺As Sulfate or Bisulfate SO₄^2-With or with Mg²⁺Or Ca²⁺The phosphate or other as PO₄^3-When added with MgCO₃, CaCO₃, Mg₃(PO₄)₂, Ca₃(PO₄)₂, DDL₃Or CaSO₃These combinations should be avoided as they cause unwanted precipitates such as. Therefore, H₂O, KMnO₄And Na⁺, Li⁺, K⁺, NH₄⁺, Cl^-, SO₄^2-, BO₃^2-, CO₃^2-, PO₄^3-, NO₃^-And a group consisting of these combinations or Na⁺, Li⁺, K⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl^-, BO₃^2-, NO₃^-And by mixing at least one salt-added ion or ionic compound selected from the group consisting of these combinations, an impregnated solution having improved solubility of permanganate is obtained. For example, by introducing a sodium cation into a solution containing potassium permanganate, a sodium permanganate salt is formed in the solution, and the solubility of the permanganate in the solution is improved. Sodium permanganate salt is much more water-containing than potassium permanganate salt. Sodium permanganate is more than twice as expensive as potassium permanganate on a dry basis, so by introducing sodium cations from sodium nitrate, sodium carbonate, sodium bicarbonate, sodium chloride, etc., potassium permanganate A more economically concentrated permanganate solution can be obtained than when the above is used alone. The solution may contain a base or acid that is added to adjust the pH to provide the solubility and / or oxidation potential of the permanganate. The base material, preferably activated alumina, is impregnated with this permanganate solution.

More than adding permanganate in the form of sodium permanganate, calcium permanganate or magnesium permanganate to the impregnated solution by introducing cations such as sodium, calcium or magnesium into the potassium permanganate-containing solution. It is possible to realize a filtration medium having effective oxidizing ability at low cost. Improving the solubility of permanganate by introducing one or more ions or ionic compounds can increase the concentration of components having an oxidizing function in the pellet, improve the efficiency of the medium, and reduce the odor. It is possible to increase the amount of time a filter with the filtration medium of the invention before break through is in operation. An economical fluid filter for continuously removing odors thus avoiding the problem of low solubility in cheaper permanganates, i.e. solutions impregnating alumina-based pellets of potassium permanganate. However, it is provided without incurring the additional costs associated with adding sodium permanganate, calcium permanganate or magnesium permanganate alone, while providing a structurally reliable filtration medium.

Nitrate is an oxidant known to be effective in reducing odor. It is advantageous for the impregnating solution to contain at least one alkali metal permanganate and water soluble nitrate, the composition of which comprises approximately 0.5-95.5 weight percent permanganate and 0.5-95.5 weight percent nitrate. .. In a preferred embodiment, the composition of the impregnating solution comprises water saturated with the reactants, in which the reactants are composed of about 20-75% by weight of alkali metal permanganate and about 25-80% by weight of water-soluble nitrate. Most preferably, the reactants include about 33% by weight of permanganate and 67% by weight of nitrate. In these two preferred embodiments, the permanganate is preferably added to the impregnating solution as potassium permanganate and the nitrate is added in the form of sodium nitrate.

In a preferred embodiment, the method of adding sodium ions to improve the solubility of the permanganate in the impregnating solution comprises adding sodium in the form of sodium nitrate to the impregnating solution containing potassium permanganate. The combination of potassium permanganate and sodium nitrate acts synergistically to remove odors from the gas stream. Potassium permanganate is usually soluble in water under saturation conditions of about 4 percent at room temperature, and sodium permanganate is more than 40 percent soluble at room temperature. However, the solubility of potassium permanganate can be increased to 12 percent (wt / v) or higher, and even to 20 percent (wt / v) or higher, with the addition of sodium nitrate. In addition to improving the solubility of the permanganate in the impregnating solution, the nitrate is impregnated into the alumina substrate. Therefore, by adding potassium permanganate and sodium nitrate, an impregnated solution containing a large amount of permanganate can be obtained as compared with the case where potassium permanganate is introduced alone, and a second oxidation can be obtained. Agents and nitrates are provided. This increased solubility and the addition of nitrates provide a highly effective and efficient oxidant solution for impregnation into the filtration medium. It is important to note here that the addition of permanganate to the impregnating solution is carried out by permanganate and permanganates such as sodium permanganate, which is within the scope of the present invention. .. Permanganate and nitrate are preferably maintained in a ratio of at least 1: 1-about 4: 1 in the impregnating solution. It is advantageous for the permanganate to be added to the impregnating solution until saturated. In one embodiment of the impregnating solution, the solution is about 0.5-20 weight percent potassium permanganate and about 0. It is advantageous to include 5-42 weight percent sodium nitrate and about 48-99 weight percent water. In another aspect, the aqueous composition comprises about 4-about 16 weight percent potassium permanganate, about 8-about 33 weight percent sodium nitrate, and about 59-88 weight percent water. .. In yet another embodiment, the impregnating solution contains a large amount of sodium nitrate in an aqueous solution of a pH adjusted to maximize the solubility and reactivity of potassium permanganate in it, which solution is permanganic acid. It is saturated with salt. Of course, other permanganate salts, such as sodium permanganate, may be added to the impregnating solution along with potassium permanganate, which is also within the scope of the present invention.

Sodium phosphate and the combination of sodium phosphate and sodium nitrate are also known to be effective in increasing the solubility of the permanganate introduced into the impregnation solution in the form of potassium permanganate. A certain amount of sodium bicarbonate is also known as an effective solubilizer for permanganate. Impregnated solutions containing certain amounts of potassium permanganate and / or a combination of sodium phosphate and sodium nitrate and sodium bicarbonate are also known to be effective. Not surprisingly, Na added with an amount of permanganate in the impregnating solution⁺, Li⁺, K⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl^-, SO₄^2-, BO₃^2-, PO₄^3-, NO₃^-And the ions and ionic compounds selected from the group consisting of combinations thereof are within the scope of the present invention.

The impregnating solution is used to impregnate a substrate or support, such as activated alumina such as alumina trihydrate. One method provides commercially available granular activated alumina capable of at least partial rehydration. The granular activated alumina is then mixed with an impregnating solution containing a permanganate and preferably a sodium salt to give a composite mixture containing the alumina material in which the permanganate is substantially uniformly distributed. This composite mixture is rehydrated and partially cured to give the alumina-containing medium the desired strength and wear resistance, which is detrimental to the reactivity of the pellet with the odorous components in the fluid passing through it. The medium is formed without filling the pores of the base material to the extent that it does not become. Alumina impregnated with the impregnating solution is pelleted or molded into the desired shape by any suitable method known to those of skill in the art. For example, impregnated alumina can be extruded and agglomerated by compression (as is done in briquette production) or tumbling. In the pelleting method, alumina is tumbled with the impregnating solution so that rounded pellets are produced. Pellets of rounded filtration medium are preferred. Because this geometry reduces the resistance to the fluid flow and also increases the substantially exposed surface area in contact with the fluid flow, thus reducing the pressure drop across the filtration medium due to the fast-paced reaction. The rounded shape is even more wear resistant, minimizing pellet wear. A preferred method of pelletization is to compress the particles in a compression molding machine. This method is advantageous when serving tablets in situations where reaction surface area is important, with tablets with rounded or oval shapes such as spherical, saddle-shaped, Raschich rings, cross-partitioning rings, pole rings, cascade rings, etc. Similarly, it can be formed by a compression molding machine. The compression molding machine preferably has a compression ratio of about 2-5, more preferably about 3.15-3. It is set to be 40. After pelletization, the partially hydrated pellets are left or heated in a moist atmosphere to complete the hydration reaction and complete with unbound water or replenished water in the compressed pellets. The desired physical and chemical properties are obtained in the resulting medium.

Another step is the preparation of an impregnated solution containing permanganate. NO₃^-, Na⁺, Li⁺, K⁺, Cl^-, SO₄^2-, BO₃^2-, CO₃^2-, PO₄^3-, SO₃^2-, NH₄⁺, Mg²⁺And Ca²⁺Prepare one or more aqueous impregnated solutions of ions or ionic compounds such as, and stir while adding potassium permanganate until the solution is saturated. However, the important thing to note here is Mg.²⁺Or Ca²⁺As carbonate or bicarbonate as CO₃^2-With or with Mg²⁺Or Ca²⁺As Sulfate or Bisulfate SO₄^2-With or with Mg²⁺Or Ca²⁺The phosphate or other as PO₄^3-When added with MgCO₃, CaCO₃, Mg₃(PO₄)₂, Ca₃(PO₄)₂, DDL₃Or CaSO₃These combinations should be avoided as they cause unwanted precipitates such as. You may also add some amount of other permanganate. Sufficient amounts of ions or ionic compounds are present in the solution, preferably at room temperature, at least 12 g per 100 ml, more preferably 40 g per 100 ml of permanganate in solution. The temperature of the solution is maintained above 30 ° C, preferably in the range of about 90-95 ° C, further improving the solubility of the permanganate in the solution. Other reagents can be added to impart additional odor removing ability.

The base material is impregnated with the impregnated solution by mixing the impregnated solution and the activated alumina base material in a tumbling mill in which the injection nozzle introduces the impregnated solution. The agglomeration effect of the impregnating solution causes the substrate to agglomerate into spherical or oval pellets. The feed rate of the substrate and impregnating solution and the rotation speed of the tumbling mill are adjusted to produce pellets of the desired size. Alternatively, the medium may be molded by a compression molding machine. When the medium is compression molded, the impregnated solution and activated alumina are mixed and partially cured in a heated moist environment with agglomerated masses. The agglomerates are preferably granulated to a particle size of about 40-80 mesh and compressed into the desired shape. Curing is then terminated when a medium of the desired strength is formed. The medium may also be formed by other methods known in the art that allow curing to be performed before, during and / or after forming pellets, tablets or other shaped media.

The medium containing the impregnated alumina may then be cured to ensure that the desired density and strength are obtained. The degree of curing (before, during or after formation of the medium) depends on the desired properties such as the strength and pore volume of the medium. A sufficient set of conditions for curing the formed medium is to cure at about 55-60 ° C under wet conditions, up to 99.9 ° C for about 4 hours. By hydrating the medium while removing all unbound water during the curing step, a medium with wear resistance is obtained. However, hydration is not always necessary and therefore the humidity during the curing step may be reduced.

By this method, a permanganate-alumina composite filtration medium in which the oxidizing agent composed of permanganate is substantially uniformly distributed in the oxidation medium is obtained.

Example 1 15g KMnO tablet-shaped gas phase medium₄, 15g LVDS₃And 10g NaNO₃Was put in a solution tank to prepare. 100 g of activated alumina (AA) was placed in a dry powder mixer. Put 100g of water in a solution tank and heat to 90-95oC to KMnO₄, LVDS₃And NaNO₃Was dissolved to form an ionic solution. AA was mixed with the ionic solution and cured at about 50 ° C until the water content was about 26-32 percent. The cured mixture was granulated into uniform particles while maintaining a moisture content of about 26-32 percent. The resulting particles were immediately placed in a compression molding machine with a compression ratio set to 3.15-3.40. The particles were compressed into tablets. The resulting tablets were cured in a humidifying oven at about 50-60 ° C until the tablets contained about 15-20 percent free water by weight.

Example 2-15 NaNO as shown in the table in Figure 1₃Change the amount of and Na₃PO₄Was introduced into a solution tank to prepare a tablet according to the method of Example 1.

The pellets made in Examples 1-15 were tested according to the following procedure to measure hardness,% wear, water content and optionally water leaching and gas capacity.

The hardness of the pellets formed in Examples 1-15 was measured using a YPD200C hardness tester. The hardness tester uses a motor that transmits the force to press the tablet, amplifies the pressure signal on the sensor bridge, and this signal is used to calculate the hardness value via the A / D transfer circuit. To. Ten samples of granular or pelletized medium were randomly removed from the medium of each example as individual batches and tested for their hardness. Each batch was placed in turn in the center of the reference plate and the "Start" key was pressed. The displayed value when the tablet of the batch is crushed is the hardness of each example. This was repeated in the tablet batch of each example, and the results are shown in the table of FIG.

The wear of the pellets formed in Examples 1-15 was measured using a device for measuring the brittleness of the drug tablet, which measures the resistance of the granular or pelletized medium to wear. A wheel cavity hub containing a tablet whose mass was measured from each example was rotated at a specific speed for a predetermined number of cycles. After rotating in a predetermined number of cycles, the medium was separated from the smaller pieces and the mass of the medium was measured again. The difference in mass indicates the wear resistance of the medium. The tablets of each example were tested individually.

Twenty samples of granular or pelletized medium were randomly removed from the medium of each example as individual batches and resistance to wear was measured. Weigh the batch from each example to an accuracy of 0.0001 g and W₁Recorded as. Each batch was handled roughly and placed individually in the wheel hub to avoid breaking the medium. The tablet brittleness measuring device was switched on and the wheel cavity hub containing the batch was rotated at 25 RPM. After 100 revolutions, the wheel hub automatically stopped spinning, the hub was opened and the intact tablet was removed. Dust was blown off the surface of these intact tablets. Weigh these intact tablets to an accuracy of 0.0001g and W₂Recorded as. A small piece of all observed broken media also W₂Included in. The wear of each batch of tablets from each sample was calculated from the following formula.

<maths num="1"><img file="JP5114497B2_D0001.tif" /></maths>

The water content of the pellets formed in Examples 1-15 was measured by a weighing-drying method in which the sample was dried until its mass became constant. At the beginning of the measurement, a moisture analyzer was used to weigh the sample, and immediately after that, the sample was heated with an integral halogen heating module to vaporize the moisture. During the drying process, the moisture analyzer continuously weighed the sample. When drying was complete, moisture was determined by the difference in weight measured before and after drying. Batch samples were randomly removed from the media of each example. Each batch was placed individually in a moisture analyzer, the setup key was pressed and the temperature was set to 105 ° C to dry the sample. Press the setup key and select the standard drying mode. Press the Tare / Zero key to set the scale to zero (tare the) I made it to balance). The heating module was opened and the batch sample was placed on the sample pan. The wet weight (WW) of the batch sample was shown on the screen and recorded. For best results, the wet weight of the batch sample was between about 5 g and 8 g and the samples were evenly distributed on the sample pan. The heating module was closed and the analyzer automatically started the drying and measuring process. After the batch sample weight became constant, the dry weight (DW) was recorded and the water content (MC) was automatically calculated according to the following formula.

<maths num="2"><img file="JP5114497B2_D0002.tif" /></maths>

The heating module was opened and the next batch sample was analyzed.

Several examples were selected from Examples 1-15, and the amount of water leaching of the pellets formed in these examples was measured by randomly sampling 10 g of the pellets of these examples. Each sample was placed individually in a 250 ml conical beaker, into which water was introduced at a flow rate of 350 ml / min. The time spent in each beaker until the water became clear was recorded in minutes. The pellets were analyzed to determine if they were suitable for gas volume testing. In this analysis, it is first determined whether these pellets are strong enough to remain perfect in the aquarium, then the pellets from each sample are crushed to allow sufficient water penetration into the pellets. Determine if there is any purple color left in the pellet to indicate that it is not.

The gas capacity of the pellets from the selected examples is a variety of unused freshly impregnated or used granules or pellets when exposed to a gas stream containing high concentrations of contaminants under laboratory test conditions. It was measured by assessing the removal capacity of the medium. Breakthrough capacity is the emission of gaseous contaminants through a sample of a known amount of granular or pelletized medium in a preheated humidified air stream containing 1% by volume of contaminants under certain conditions. It was measured by passing it through until the concentration of was reached 50 ppm. The air used is preheated, humidified, oil-free, clean, compressed air. Contaminated gas is H in nitrogen₂S, Cl₂, SO₂, NH₃It contained 5% of pollutants such as. The medium was randomly sampled from the pellets of each selected example and tested. The apparent density of each sample was measured. Pollutant and air flow velocity is 1450 cm via a 1 inch diameter adsorption tube³The total flow rate of / min was adjusted to generate 1.0% (vol./vol.) Pollutant gas flow. The suction tube was washed and dried, and the tare was measured (tared) with an approximate number of up to 1.0 mg. 116 ml of the medium sampled from one example was placed in the suction tube while tapping the suction tube to ensure that the medium settles in the tube with minimal gaps formed by the medium. The suction tube contained 116 ml of medium and a bed with a depth of about 22.9 cm was formed. The tare was measured with the weight of the suction tube filled with the medium as an approximate number up to 1.0 mg. The filled tubing was then transferred to the test system, connected to the test equipment, and the contaminated gas entered the bottom of the tubing and passed through a filtration medium where it was analyzed with Honeywell Zellweger Analytics' SPM (Single Point Monitor). When a 50 ppm leak point was indicated, the time elapsed from the start to the 50 ppm leak point was recorded. This was repeated for each sample of each selected example, and the gas capacity of each sample of each selected example was calculated according to the following formula.

<maths num="3"><img file="JP5114497B2_D0003.tif" /></maths>

here, K is H₂1.52 for S, SO₂In the case of 2.86, Cl₂In the case of 3.17, CH₃For SH 2.15, NH₃In case of 0.76, NO₂2.05 for, 1.39 for NO, C represents the concentration (percentage of volume) of polluted gas in the air stream. F represents the total flow rate (cc / min) T_{b b}Represents the time (minutes) to the leak point of 50 ppm. V represents the volume (CC) of the column formed by the medium in the adsorption tube.

The results of Examples 1-15 are shown in the table of FIG. It is important to note here that these examples are merely selected embodiments of the invention and do not serve to limit the concentration of ions introduced into the impregnating solution or any other difference thereof. Ions or ionic compounds and their concentrations are also within the scope of the present invention. For example, a part of the permanganate may be introduced into the impregnated solution as sodium permanganate or permanganate, which is also within the scope of the present invention.

NaNO₃Also Na₃PO₄Example 15 which does not include the above is an example of the prior art, and serves as a reference for comparison with the example of the filtration medium of the present invention produced by the production method of the present invention. As shown in FIG. 1, the average gas capacity of the medium of the selected example was about 0.0345 g / cc, and the gas capacity of the prior art was only about 0.0248 g / cc. Some embodiments have a gas capacity of 33% or more relative to the medium of the prior art and mechanically or on substrates such as gas filter cartridges, loose states, foams, wires, synthetic fibers and fiberglass. A medium that is brought into contact with the fluid stream by an adhesively attached medium or other means known to those of skill with the same volume of filtration medium should be filtered in one-third the time compared to conventional ones. Can be done. In addition, hardness and wear are acceptable in most aspects, many of which are improved over prior art.

Figures 2 and 3 show NaNO₃And Na₃PO₄The effect on gas capacity and hardness is shown graphically as a function of the concentration of. Figure 2 shows KMnO₄Is 15g and LVDS₃Is 15g and NaCO as in Examples 1, 6, 7 and 10₃The gas capacity of the pellets when the amount of is changed is shown. NaNO₃The optimum amount of is about 2-8 g, and 5 g is advantageous, as the volume and hardness curves reach the desired levels within these ranges. The tablet of Example 7 in Table 1 is 15 g of KMnO.₄, 15g LVDS₃And 5g NaNO₃Including 0.046gH₂It shows a gas capacity of S / cc and a hardness of 61 g, which is NaNO.₃It is significantly increased as compared with Example 10 which does not include. However, NaNO₃If the amount of is less than 2 g, the desired pellet properties are obtained, which is also within the scope of the present invention.

Figure 3 shows Na₃PO₄The effect on gas capacity and hardness is shown graphically as a function of the concentration of. Figure 3 shows KMnO₄Is 15g and LVDS₃Is 15g and Na as in Examples 5, 10 and 14₃PO₄The gas capacity of the pellets in which the amount of the pellets is changed is shown. LVDS₃The optimum amount of is about 0.1-4 g, and 2 g is advantageous, as the volume and hardness curves reach the desired levels within these ranges. The tablet of Example 14 in Table 1 is 15 g of KMnO.₄, 15g LVDS₃And 2g of LVDS₃Including 0.046gH₂It shows a gas capacity of S / cc and a hardness of 55 g, which is LVDS.₃It is significantly increased as compared with Example 10 which does not include. However, LVDS₃If the amount of is less than 0.1 g, the desired pellet properties are obtained, which is also within the scope of the present invention.

The filtration medium of the present invention is placed in cassettes or containers such as porous cartridges filled with loosely packed oxidant pellets as shown in FIG. FIG. 4 shows a V-shaped cartridge filter cassette 100. Not surprisingly, this cartridge is an example of a filter container containing a filtration medium containing chemical reagents, and other containers known in the art can also be used to contain the medium of the invention. Is. For example, a medium containing the chemical reagents of the present invention may be attached to a substrate such as a loose state, foam, wire, synthetic fiber and fiberglass mechanically or by adhesion, or has a filtration medium of the same volume. The fluid flow may be contacted by other means known to those skilled in the art. The filter cassette 100 is an example of a medium container for processing airflow, having a pair of rectangular side panels 102, and a set of filter medium containers 101 extending between them. Each filtration medium container 101 is formed by an opposing rectangular end plate 114, a rear end plate (not shown) and a pair of opposing rectangular medium screens 124. The set of filtration medium containers 101 has a V-shape due to the outermost end plate 114 of the sealed side of the cassette 100 extending between the corners of the side panel 102. The closed side of the filter cassette 100 is substantially smooth, flat, and has a uniform surface, formed by a front plate 114 and a closed edge 126 of the side panel. The end plate 114 and the side panel edge 126 optionally have a recess 103 extending between the closed edges of the side panel 102, substantially parallel to the outer longitudinal edge of the end plate 114. It is preferable that they are in close proximity. The seal 112 is inserted into the recess 103. The seal 112 is preferably a butterfly seal or a gel seal. The friction reducing means 122 on the outer edge of the end plate 114 is optional and is substantially perpendicular to the rectangular side panel 102 that engages the housing or rack guide in FIG. Has a groove on the outer surface Shown as a clip. The guide notch 110 on the side edge of the side panel 102 is located on a side other than the closed and non-sealed sides with the front and rear plates, respectively. The side panel 102 has a recess 108 in which at least one strip-shaped gasket extending between the outer edges of the side panel 102, optionally substantially parallel to the sealing surface of the cassette 100, is located. Preferably, a gasket such as a compression gasket is located in each recess. Optionally, each rectangular side panel 102 has at least one friction reducing means 120 on sides other than the closed and non-sealed sides. In the illustrated embodiment, each side panel 102 has a finger hole 104 near a corner adjacent to the non-sealed surface of the cassette 100. Further, in this figure, a notch 106 adjacent to a part of the finger hole 104 and surrounding the finger hole 104 is provided in the panel 106 again.