Process for fabricating a gas storage and dispensing system

Manufacturing method of gas storage and distribution system

<p>10. . .Gas storage and distribution system</p><p>12. . .container</p><p>14. . .Cylindrical wall</p><p>16. . .Physical sorbent material</p><p>18. . .neck</p><p>20. . .Valve head combination</p><p>twenty four. . .Single block body</p><p>26. . .Manual wheel</p><p>26a. . .Coupler</p><p>50. . .Inert gas source</p><p>52. . .Vacuum pump</p><p>60. . .container</p><p>62. . .furnace</p><p>64. . .Inert gas feed line</p><p>66. . .Flow control valve</p><p>68. . .Inert gas exhaust line</p><p>70. . .valve</p><p>72. . .Vacuum line</p><p>74. . .valve</p>

FIG. 1 is a schematic diagram of a storage and release system according to a specific example of the present invention.

FIG. 2 is a schematic diagram of a method system for performing the method of the present invention in a specific example.

Fig. 3 is a schematic flow chart showing specific steps of the method according to the present invention.

Figure 4 is a thermogravimetric analysis (TGA) diagram of an activated carbon sorbent material, which shows the desorption loss of the oxygen-containing group from the sorbent material when heated above 650 ° C.

Cross-references to related applications

This is US Patent Application No. 08 / 809,019, filed on April 11, 1997 under the names of Glenn M. Tom and James V. McManus, "STORAGEAND DELIVERY SYSTEM FOR GASEOUS COMPOUNDS" Partial continuation, U.S. Patent Application No. 08 / 809,019 was filed on October 13, 1995, and stated that the application filed on October 13, 1994, which is a partial continuation of U.S. Patent Application No. 08 / 322,224, has priority International Patent Application No. PCT / US95 / 13040, 35 USC § 371.

BACKGROUND OF THE INVENTION

The present invention generally relates to the manufacture of a storage and distribution system for selectively distributing fluid from a container or storage container, wherein the fluid component is contained in a solid sorbent medium in an adsorption relationship, and is desorbed from the sorbent medium during a dispensing operation freed.

Description of related skills

In many industrial processes and applications, there is a need for a reliable source of process fluids.

Such processes and application areas include semiconductor manufacturing, ion implantation, flat display manufacturing, medical intervention and treatment, water treatment, emergency breathing equipment, welding operations, space conveyors for liquids and gases, and so on.

US Patent No. 5,518,528 issued on May 21, 1996 under the names of Glenn M. Tom and James V. MC Manus describes a gas storage and distribution system for storing and distributing gas. Tom et al.'S patented gas storage and distribution system includes adsorption-desorption devices for storage and distribution of gases, such as hydride gases, halide gases, Group V organometallic compounds, and the like, including: structure and configuration A storage and distribution container for containing a solid-phase physical sorbent medium, and a gas selectively flowing into and out of the container; a solid-phase physical sorbent provided in the storage and distribution container under internal gas pressure Medium; the sorbed gas physically adsorbed on the solid-phase physical sorbent medium; and the distribution combination combined with the storage and distribution container by means of airflow intercommunication, so that the gas is desorbed from the sorbent medium in the container and selected Discharging from the container.

Desorption can be by thermally desorbing the gas to be dispensed, or by providing a pressure differential between the internal volume of the container and an external dispensing location, for example, by applying a vacuum on the storage and distribution container, or by pumping the gas to the dispensing gas It is expected to achieve the use site. As a result of this distribution mode, the pressure of the gas in the storage and distribution container may be at or below atmospheric pressure.

As a result, the patented storage and distribution container of Tom et al. Represents a substantial improvement in the art over previous art using high pressure gas cylinders. Conventional high-pressure gas cylinders are prone to leak from damaged or malfunctioning regulator combinations, and rupture when the internal gas pressure in the cylinder increases rapidly due to internal decomposition of the gas, and there are ruptures of the cylinder or other undesired gases. Danger of large releases from cylinders.

The patented gas storage and distribution container of Tom et al. Reduces the pressure for storing the adsorbed gas by reversibly adsorbing it to a carrier sorbent medium, such as zeolite or activated carbon material.

When using the aforementioned gas storage and distribution system by Tom et al., In many applications such as, for example, the manufacture of microelectronic device structures, it is desirable to distribute the storage gas at a high purity value.

In many cases, this desired high-purity characteristic of gas storage and distribution systems is limited by the residual or "natural" contaminants adsorbed on the sorbent material. This can be attributed to the sorption characteristics of these materials, and to some extent is characteristic of all commercially available sorbent materials, where the range or concentration of these foreign sorbent species depends on the specific sorbent composition Materials, their manufacturing methods, and their history of storage, transportation, and environmental exposure.

Therefore, for example, sorbent materials that are manufactured with high purity may be exposed to atmospheric moisture and ambient gases during subsequent storage, or the sorbent materials originally supplied by the manufacturer. The type of gas in the container, which can adsorb on and contaminate the sorbent material.

In this case, when a sorbent material containing a foreign sorbable species is contained in a gas storage and distribution container, and the distribution gas (that is, the gas to be stored and then selectively distributed from the container) is introduced to When the sorbent is absorbed and loaded on it, the sorption capacity of the sorbent material may be adversely affected by the presence of foreign sorbables. In addition, these foreign sorbables can then be desorbed in subsequent dispensing operations, with the result that the distribution gas has a reduced purity due to the foreign sorbables.

For example, when using an activated carbon sorbent material in a gas storage and distribution container, and filling a sorbent-containing container with a hydride gas such as tritium (for example, for subsequent distribution in an ion implantation operation, To produce arsenic-doped semiconductor substrates), distributed. Krypton gas may contain relatively high amounts of carbon monoxide and carbon dioxide impurities derived from the original activated carbon sorbent provided-the amount of carbon monoxide is as high as 20-50 parts per million by volume (ppmv) and the relative amount of carbon dioxide The value may exceed 100 ppmv.

Therefore, if such a gas storage and distribution system can provide a system that can overcome such foreign matter that can adsorb impurities, and can dispense high-purity gas as required, it will be a significant advance in the art.

Therefore, an object of the present invention is to provide a general type of gas storage and distribution system disclosed in Tom et al. Patent 5,518,528, which can eliminate the problem of such foreign sorbables and can selectively distribute high purity gas.

Other objects and advantages of the present invention will become more apparent from the following disclosure and the scope of the accompanying patent applications.

Summary of the invention

The present invention generally relates to a method for manufacturing a gas storage and distribution system. The system includes a distribution container for containing a physical sorbent material having an adsorption affinity for the following substances: (i) to be contained in the distribution container, and subsequent selectivity The sorbent distribution gas discharged from the distribution container, and (ii) foreign sorbable material.

In one aspect, the method of the present invention includes: processing a physical sorbent material having a foreign sorbable substance adsorbed thereon, such that at least a portion of the foreign sorbable material is desorbed from the sorbent material; physically The sorbent material is filled in the container; the sorbable distribution gas is introduced into the distribution container containing the physical sorbent material so that the distribution gas is physically adsorbed on the physical sorbent material; and the distributor gas is sealed to contain The distribution container on the physical sorbent material, so that the distribution container thereafter contains a distribution gas in a form for selective distribution by desorbing the distribution gas from the physical sorbent material and discharging the distribution gas from the container.

In this method, the step of processing the physical sorbent material such that at least a portion of the foreign sorbable material is desorbed from the sorbent material may advantageously include at least one of the following steps: (a) heating the physical sorbent material So that the foreign sorbable material is desorbed from its heat; (b) the non-sorbable gas is brought into flow contact with the physical sorbent material, so that the foreign sorbable material is desorbed from the physical sorbent material to In the non-sucking gas in the flow; and (c) applying a vacuum condition to the physical sorbent material to vacuum desorb the foreign sorbable material from the physical sorbent material.

In another aspect of the present invention, the step of processing the physical sorbent material such that at least part of the foreign sorbable material is desorbed from the sorbent material may include at least the foregoing steps (a)-(c) Two steps.

These steps can be performed in any useful combination or variation as needed or desired in the intended use application of the manufacturing method of a particular gas storage and distribution container.

In a preferred aspect, the method of the present invention begins and ends with the steps of (1) processing the physical sorbent material so that at least part of the foreign sorbable material desorbs from the sorbent material. During the period when (2) sealing the distribution container so that subsequent steps including the distribution of gas in a form available for selective distribution are completed, the physical sorbent material is isolated from the atmosphere, and is in contact with oxygen and water Vapor insulation is best for contact.

In another aspect of the present invention, when an activated carbon material is used as the sorbent material, it is generally desirable to perform a physical sorbent material treatment through the following steps to remove foreign sorbables therefrom: The sorbent is heated to a temperature in excess of 650 ° C so that the sorbent is made during and after this treatment until the distribution container is sealed so that it subsequently contains a distribution gas in a form available for selective distribution. It is better to keep the material in contact with oxygen and water vapor.

In the broad practice of the present invention, the treatment of the physical sorbent material that at least partially desorbs the foreign sorbent from the sorbent material may be performed before and / or after the physical sorbent material is filled in the container. It is performed to include, for example, a step of filling the physical sorbent material before heating in a flowing gas flow of an inert gas, and a step of filling the physical sorbent material after heating in a container under vacuum.

The physical sorbent material used in the manufacturing method of the gas storage and distribution system may be of any suitable type, for example, alumina, silica, crystalline aluminosilicate, macroreticular polymer, diatomaceous earth, carbon, and the like. When the present invention is practiced in a broad sense, a bead activated carbon sorbent material is particularly preferred.

Foreign sorbables can be of various types depending on the specific physical sorbent material used, and its history of manufacture, storage, and environmental exposure. Some illustrative types of gases on the sorbent material that are not expected to be sorbed include, but are not limited to, water vapor, oxygen, hydrogen, carbon oxides, nitrogen, hydrocarbons, halogens, and combinations thereof, and Or a combination of the foregoing types.

In the case of preferred carbon sorbent materials, foreign sorbents that are typically of concern include carbon oxides, such as carbon monoxide and carbon dioxide.

In a preferred aspect, wherein carbon is the sorbent material, for example, in the form of bead activated carbon, and carbon monoxide and carbon dioxide are foreign sorbable substances of concern, when the physical sorbent material is sorbed by physical When the weight of the agent material is 50% by weight, the pressure of 700 Torr and the temperature of 22 ° C is used to load the tritium gas, the method of the present invention can be performed to generate a volume per million parts in tritium. A value of less than 20 parts per million (ppmv) of carbon oxide, more preferably less than 10 ppmv, and even more preferably less than 5 ppmv, and / or when the physical sorbent material is 50% by weight based on the weight of the physical sorbent material When loading tritium gas at a loading amount, a pressure of 700 Torr, and a temperature of 22 ° C, the method of the present invention can be performed to generate a carbon dioxide amount value of less than 50 parts per million (ppmv) in tritium volume in tritium, low It is better at 20 ppmv, and even better at less than 10 ppmv.

In another preferred aspect, the method of the present invention is carried out, wherein the physical sorbent material having the foreign sorbable substance adsorbed thereon is treated so that at least part of the foreign sorbable substance is desorbed from the sorbent material. The attached step includes heating the physical sorbent material to a temperature in a range from about 300 to about 800 ° C. for a sufficient time before filling the physical sorbent material in the container, so as to achieve the Its desorption.

During this heating process, an inert gas, such as helium, can be brought into fluid contact with the physical sorbent material, and after filling in the container, such as by further heating the physical sorbent material, and / or the physical sorbent The step of applying a vacuum to the material further processes the sorbent material.

The sorbable distribution gas introduced into the treated physical sorbent material in the gas storage and distribution container may be any suitable type for which the treated sorbent has a proper sorption affinity, such as, for example, Borane, osmium, phosphine, chlorine, BCl ₃ , BF ₃ , B ₂ D ₆ , Tungsten hexafluoride, (CH ₃ ) ₃ Sb, hydrogen fluoride, hydrogen chloride, GeF ₄ SiF ₄ , Deuterated hydride, hydrogen iodide, hydrogen bromide, germane, ammonia, <img file="TW565467B_D0001.tif" /> , Hydrogen sulfide, hydrogen selenide, hydrogen telluride, NF ₃ , Or a compatible mixture of one or more of the foregoing gas species.

In a specific embodiment, the present invention relates to a method for manufacturing a gas storage and distribution system including a distribution container for containing a bead activated carbon physical sorbent material having sorption affinity for the following substances: (i) to be contained in The sorbent distribution gas in the distribution container, and subsequently selectively discharged from the distribution container, and (ii) foreign sorbables, the method includes: treating physical sorption on which foreign sorbables are adsorbed; Agent material to desorb at least part of the foreign sorbable material from the sorbent material, including heating the physical sorbent material to a temperature within a first range from about 300 ° C to about 800 ° C, and Maintain in the first range from about 1 to 15 hours, and during this heating process, make the inert gas flow into contact with the physical sorbent material; fill the physical sorbent material in the container; The sorbent material is heated to a temperature within a second range from about 100 ° C to about 250 ° C, and the temperature is maintained within the second range from about 1 to 10 hours, and during this heating process, the container Physical sorbent material Add vacuum; cool the physical sorbent material to a temperature lower than the second temperature range; introduce the sorbable distribution gas into the distribution container containing the physical sorbent material, so that the distribution gas is physically absorbed by the physical adsorption And a distribution container that seals the dispenser gas on the physical sorbent material, so that the distribution container thereafter contains a gas that can be desorbed from the physical sorbent material and discharged from the container. Distribution gas in the form of selective distribution.

In this specific example, when the treated physical sorbent material is loaded with tritium gas at a loading of 50 weight percent based on the weight of the physical sorbent material, a pressure of 700 Torr, and a temperature of 22 ° C, The method is performed to produce a carbon dioxide amount value of less than 1 part (ppmv) per million parts volume in rhenium and a carbon dioxide amount value of less than 1 part (ppmv) per million parts volume in rhenium.

Other aspects, features, and specific examples of the present invention will be more fully understood from the subsequent disclosure and the scope of the accompanying patent application.

Schematic illustration

FIG. 1 is a schematic diagram of a storage and release system according to a specific example of the present invention.

FIG. 2 is a schematic diagram of a method system for performing the method of the present invention in a specific example.

Fig. 3 is a schematic flow chart showing specific steps of the method according to the present invention.

Figure 4 is a thermogravimetric analysis (TGA) diagram of an activated carbon sorbent material, which shows the desorption loss of the oxygen-containing group from the sorbent material when heated above 650 ° C.

Detailed description of the invention and its preferred specific examples

The entire disclosures of the following US patents and US patent applications are incorporated herein by reference.

US Patent 5,518,528 issued in the name of Glenn M. Tom et al. On May 21, 1996; US Patent 5,704,967 issued in the name of Glenn M. Tom et al. On January 6, 1998; January 6, 1998 US Patent 5,704,965 issued in the name of Glenn M. Tom et al .; US Patent 5,707,424 issued to Glenn M. Tom et al. On January 13, 1998; and James V. McManus issued on October 14, 1997. U.S. Patent 5,676,735; U.S. Patent Application No. 08 / 859,172 filed on behalf of Glenn M. Tom on May 20, 1997; and U.S. Patent Application on behalf of Glenn M. Tom and others on April 11, 1997 Patent Application No. 08 / 809,019.

The present invention is based on the discovery that sorbent materials containing foreign sorbable materials that contaminate the desorbed gas and reduce the purity of the product gas can be used as described in the aforementioned U.S. Pat. The manufacturing part of the gas storage and distribution combination is processed to efficiently remove these foreign sorbables, and to provide high-purity distribution operations from the gas storage and distribution container during subsequent use of the gas storage and distribution system .

Foreign sorbents can be of a variety of different types, including, for example, sorbent ingredients present on the sorbent material when manufacturing a gas storage and distribution system that utilizes these sorbents. The foreign sorbable material may be atmospheric gases such as air, oxygen, nitrogen, water vapor, hydrogen, carbon oxides such as carbon monoxide and carbon dioxide, and nitrogen oxides such as N _x O _y , And hydrocarbons, halogens, and the types of surroundings that may come in contact with and adsorb onto physical sorbent materials.

In the method of the present invention, the physical sorbent material is treated to desorb the foreign sorbable material so that the sorption site on the sorbent material can be more completely prepared for storage on the sorbent, and For subsequent gas distribution from storage and distribution containers containing sorbents.

The treatment of the physical sorbent material for removing foreign sorbables may include any suitable combination of desorption techniques, including, for example, (i) heating the sorbent material to achieve thermal desorption of the foreign sorbables , (Ii) the non-adsorbable gas, such as an inert gas or other gas component or kind, which makes the sorbent material have substantially zero sorption affinity, and the physical sorbent material is in flow contact, and the desorption is achieved by the concentration difference, (iii) A vacuum is applied to the physical sorbent material to achieve vacuum desorption, or a combination of these desorption steps.

It is typically better to utilize more than one of these steps to ensure that foreign sorbables are removed from the height of the sorbent material. For example, heating can be performed concurrently with contacting a physical sorbent with a flow of non-suckable gas.

Another alternative is to apply vacuum conditions to the physical sorbent medium during heating.

In addition, the desorption of the foreign sorbable material from the sorbent material can be performed in the manufacturing process of the gas storage and distribution system before and / or after filling the sorbent material in the storage and distribution container.

For example, in some cases it may be desirable to heat the physical sorbent material to achieve thermal desorption, while flowing a non-absorbable gas stream into contact with the physical sorbent material, and then after the high temperature values from the previous heating operation When cooled down, the sorbent material is maintained under an inert gas blanket or other non-sorption conditions. After cooling, the sorbent material can be filled in a gas storage and distribution container. Alternatively, these cooling steps can be omitted, and the hot sorbent material can be simply filled into the storage and distribution container, so that the container wall can be used as a heat transfer medium to cool the sorbent material.

In a preferred practice of the present invention, the method of the present invention is performed so that the step of (1) processing the physical sorbent material so that at least a portion of the foreign sorbable material is desorbed from the sorbent material, and Ending in (2) sealing the distribution container so that the subsequent steps including the distribution of gas in a form available for selective distribution are completed, the physical sorbent material is kept in contact with the sorbent gas other than the distribution gas . The sorbent material is preferably isolated from any contact with atmospheric gases, such as oxygen, water vapor, and the like, in all these steps.

When an activated carbon material is used as the sorbent material, it is generally desirable to process the physical sorbent material through the following steps to remove foreign sorbables therefrom: heating the sorbent to a temperature exceeding 650 ° C, In this process and after this process, until the distribution container is finally sealed, so that it contains a distribution gas in a form available for selective distribution, the sorbent material is isolated from contact with oxygen, water vapor, etc. good.

In addition, or another way, the sorbent material can be heated after being filled into the storage and distribution container, and a vacuum condition can be applied to the internal volume of the container to remove foreign sorbables.

Yet another way is to perform such a combination of pre-filling and post-filling steps so that the foreign sorbable material is used as a sorbent material for the storage medium of the gas to be stored and distributed from the container in subsequent use The removal is maximized.

After the sorbent material has been processed and the gas to be stored and distributed is directed to the sorbent material and physically adsorbed thereon, the container can be sealed in a conventional manner, for example, by installing a valve head assembly on the container, or The container can be connected to a fluid manifold or other distribution device, which can then be selectively actuated to provide the gas from the storage and distribution container as needed, including desorption of the adsorbed product gas (hereinafter referred to as "distribution gas").

The distribution gas may be any suitable type to which the physical adsorbent material has a proper sorption affinity, for example, silane, diborane, osmium, phosphine, chlorine, BCl ₃ , BF ₃ , B ₂ D ₆ , Tungsten hexafluoride, (CH ₃ ) ₃ Sb, hydrogen fluoride, hydrogen chloride, GeF ₄ SiF ₄ , Deuterated hydride, hydrogen iodide, hydrogen bromide, germane, ammonia, <img file="TW565467B_D0002.tif" /> , Hydrogen sulfide, hydrogen selenide, hydrogen telluride, NF ₃ A compatible mixture of one or more of the foregoing gas species.

The gas storage and distribution system of the present invention provides a convenient device and method for selectively distributing gas in storage and self-storage and distribution containers, which can be maintained at low pressure, and is therefore more suitable for gas storage and transportation in the semiconductor industry. The standard installation of high-pressure gas cylinders offers significant advances in technology.

The term "low pressure" as used herein refers to a pressure that does not substantially exceed 1 atmosphere, for example, a pressure of 1.25 atmospheres, a pressure of 1.0 atmospheres is more preferable, and the pressure in the range from about 0.15 to about 0.8 atmospheres is the most. good.

It is clear that within the broad practice of the present invention, the storage and distribution system of the present invention can be operated at a higher pressure than the aforementioned low pressure strategy. However, the application of such a low pressure storage and distribution system in a flow system under atmospheric pressure is used For example, it has special utility in ion implantation applications. In such applications, the system of the present invention enables fluids to be stored and distributed under low pressure. With this low pressure operation, the system of the present invention can eliminate the need for many applications for high pressure fluid containers of prior art that have been used to date in such applications. Especially in the case of dangerous gases, the use of high-pressure vessels may cause leakage and damage to personnel and / or relative to the low-pressure system of the present invention where the gas can be stored under near room pressure and distributed in a ready and controlled manner. Increased risk of injury from property.

The gas storage and distribution system of the present invention includes an airtight container, such as a gas cylinder, which contains a fluid to be distributed adsorbed to an adsorbent material, such as a carbonaceous physical adsorbent material, such as thorium, boron trifluoride, Germane and so on. In the case of a distribution gas such as a hydride gas, an activated carbon sorbent or a molecular sieve sorbent can effectively reduce the vapor pressure of the sorbed gas to 1 atmosphere.

The term "carbonaceous" as used herein with reference to the physical sorbent material of the present invention means that the sorbent material contains elemental carbon as its main component in the mass of the sorbent. Preferred forms of carbon sorbent materials include: carbons produced by pyrolysis to synthesize hydrocarbon resins such as polyacrylonitrile, sulfonated polystyrene-divinylbenzene, etc .; cellulose coke; charcoal; and materials from natural sources such as coconut Activated carbon produced by shells, asphalt, wood, petroleum, coal, etc.

The preferred carbon sorbent material is activated carbon-a highly adsorbed form of carbon produced by heating granular charcoal to an appropriate high temperature. The most preferred is activated carbon in the form of so-called bead carbon, where the beads, that is, spherical particles of highly uniform diameter, may have a diameter in a range from about 0.1 to about 1 cm, and from about 0.25 to about 2 mm Better diameter.

Commercially available carbon sorbent materials that are preferred in the broader practice of the invention include BAC-MP, BAC-LP, and BAC-G purchased from Kreha Corporation of America, New York, New York -70R bead carbon material; grade Ambersorb from Rohm &amp; Haas Company, Philadelphia ^ 563, Ambersorb ^ 564, Ambersorb ^ 348F, Ambersorb ^ 575, Ambersorb ^ 572, and Ambersorb ^ 1500 Ambersorb ^ Carbonaceous sorbents; CalgonFiltrasorb 400R and BPL GAC carbon sorbent materials purchased from Calgon Carbon Corporation; and beads purchased from Blucher GmbH, Erkrath, Germany Granular activated carbon sorbent material. The aforementioned Ambersorb material has a substantial pore volume with pores greater than 50 Angstroms, and in general, such materials with large pore sizes are inferior to materials with pores not exceeding about 40 Angstroms.

The sorbent used in the storage and distribution system of the present invention may have any suitable size, shape, and configuration suitable for the application in question and the particular type of sorbent fluid. The sorbent material can be, for example, beads, granules, pellets, pastilles, powders, granules, extrudates, cloth or net-shaped materials, honeycomb precursors, (complexes of carbon sorbent and other components) Form, or a crushed or crushed form of the aforementioned structure.

In summary, the storage and release system of the present invention can be usefully composed of standard gas cylinders, cylinder valves connected to cylinders, or other flow distribution combinations (regulators, monitors, sensors, flow guidance devices, pressure controllers, mass Flow controllers, fittings, valves, instruments, automatic switching devices, etc.), where the cylinder contains the sorbent material, and the cylinder is filled with a distribution gas, such as a hydride gas, to a pressure of, for example, 1 atmosphere.

Fluid flow from the storage and release system of the present invention that is desorbed using a differential pressure can be determined by using the pressure difference between the pressure in the internal volume of the storage and release system and the lower pressure outside the sorbent-containing container Made easy.

For example, a sorbent-containing container may contain a reagent gas used in ion implantation methods at a pressure below atmospheric pressure, such as 600 Torr, such as phosphine, for ion implantation for the implantation of a phosphorus component. The chamber is maintained under vacuum or at a low pressure below the internal volume of the storage and distribution container, for example, below 100 Torr. As a result, when an airflow communication is established between the ion implantation chamber and the storage and distribution container containing the adsorbed mass phosphine gas, the phosphine gas will desorb from the sorbent in the container and flow to the ion implantation chamber. The storage and distribution system thus generates the flow of phosphine gas through the connecting pipes, valves and instruments, and can be easily controlled at the desired flow rate. Using a device such as a mass flow controller, a fixed flow rate can be obtained when the pressure of the sorbent container decreases with continuous dispensing operation.

In addition, or another way, the gas distribution combination of the storage and distribution system of the present invention may include a device for heating the sorbent material to thermally desorb the sorbent fluid from it. Such heating devices may include any suitable heat transfer or heat exchange device, structure, or device that is operatively combined with the sorbent material to achieve its heating and thermally desorb the adsorbate from the sorbent medium. Accordingly, the present invention contemplates the distribution of the sorbent fluid caused by heat and / or pressure from the sorbent stored therein.

In the broad practice of the invention, the specific sorbent materials used to practice the invention, as well as their pore size, pore volume, and surface area characteristics, can vary considerably. Those skilled in the art can easily determine the proper sorbent characteristics for the intended use of the storage and distribution system of the present invention without using surface area and porosity measurements. For example, using mercury porosity technology for too many experiments and attempts Special fluids stored on and dispensed from special candidate sorbent materials for affinity studies.

In the manufacture of the storage and distribution system of the present invention, if necessary, the storage and distribution containers are cleaned to ensure that there are no contaminants or species, including the types of outgassing in the container wall, which are disadvantageous Ground influences subsequent storage and distribution operations using the container. For this reason, it may be desirable to bake the container, degrease the solvent, or subject the container and its inner surface to cleaning, removal, or processing steps to provide a properly cleaned container for subsequent installation of the sorbent material.

The sorbent material is then processed according to the method of the present invention to remove foreign sorbable material therefrom, and then the container containing the pre-treated sorbent material is filled with a distribution gas, so that the sorbent material is loaded for storage in Gases dispensed above and after.

During the filling process, the temperature of the container and the sorbent material can be monitored independently, together with the temperature of the dispensed gas, for program control purposes. Monitor the pressure to determine the end of the filling procedure.

It may be desirable to fill the container with a portioned gas distribution and equilibrate the system so that temperature effects are at least partially dissipated to the surrounding environment or a heat transfer medium for this purpose.

Alternatively, the container may be appropriately filled to a specified pressure, and then the container may be cooled to the final temperature and pressure conditions of the sorbent bed and related containers.

Therefore, dose filling or continuous filling of the distribution gas may be performed to introduce the distribution gas into the container and be absorbed by the sorbent material. After the filling sequence, the containers separated from the filling manifold can be transported, stored, or arranged for subsequent distribution purposes by connecting to the fittings, couplers, and distribution electrical circuits at the distribution site.

The storage and release system device and method of the present invention provide a significantly safer alternative to the storage and distribution of sorbable gas than the currently used high-pressure gas cylinders. The present invention provides the ability to transport, store, and release sorbable gas from a cylinder or other container at zero psig. The distribution gas system is physically adsorbed by the pores, surfaces, and micropores of the sorbent material, so that the gas pressure for storage and distribution purposes can be significantly reduced.

In the dispensing operation, the so-called heat-assisted release can be used to increase the release rate of the desorbed gas only by low-level heating of the sorbent material, so that a flow rate above 500 sccm can be easily reached. However, adiabatic operation can be used, and only the pressure difference between the sorbent container and the decompression of the external distribution location can be used to achieve a high gas release rate (no supplementary input of heat or thermal energy to the suction full of sorbent mass) (E.g., a charge medium), and the external distribution location is, for example, in a semiconductor or other industrial or process equipment, such as an ion implantation chamber, a molecular beam epitaxial unit, or a chemical vapor deposition reactor.

The gas storage and distribution device can be easily provided as a single device, for example, by placing one or more storage and distribution systems of the present invention in a gas tank. In such a gas box configuration containing a plurality of sorbent containers, the containers may be multiplexed together to selectively release the sorbed gas from one or more of these containers. The gas tank may also include a separate thermocouple, or other temperature sensing / monitoring equipment and components to prevent overheating of the container and / or other internal components of the gas tank in use.

Such a gas source box may further include a fusible connection heater element for selectively increasing a container and an adsorbent heated therein; a sprinkler pipe system; an exhaust heat sensor; a toxic gas monitor whose function is to sense Stop the device when toxic gas is detected; scrubber or volumetric suction device; and overpressure and temperature control device. With this storage and release system device, a gas release rate of 500 sccm can easily be achieved at 15 psig.

Referring now to the drawings, FIG. 1 is a schematic diagram of a gas storage and distribution system 10 according to a specific example of the present invention.

The gas storage and distribution system 10 includes a gas storage and distribution container 12, which may be in the form of a conventional gas cylinder having a cylindrical wall 14 that seals the internal volume.

A physical sorbent material 16, such as a molecular sieve material or bead activated carbon material, or any other suitable sorbent medium is provided in the internal volume of the container 12. The sorbent media is typically used in finely divided forms such as pellets, beads, granules, etc. to provide sorption with a high surface area measured using standard porosity measurements (eg, Brunnauer-Emmit-Teller) method Of agent material.

The gas storage and distribution container 12 is shown in an elongated nature as shown, and has a neck 18 in combination with a valve head assembly 20, which in this specific example is shown as including a single block valve body 24, which has In conjunction therewith, a manual wheel 26 for manually opening and closing a valve in the valve body. The valve body 24 has a coupler 26 connected thereto, such as a VCR connector, so that when the manual wheel 26 is turned to open the valve in the valve body 24, the gas desorbed from the sorbent material in the gas storage and distribution container is carried out. distribution.

With this configuration, when the external pressure at the downstream distribution location is lower than the pressure of the internal volume of the container 12, such as in the case of ion implantation applications, where the downstream ionizer is maintained under extremely low pressure conditions, the gas can be Release from gas storage and distribution containers.

Alternatively, the coupling 26 may couple the gas storage and distribution container 12 to a manifold or contain a pump, blower, ejector, launcher, compressor, fan, extremely cold pump, pressure build-up circuit, or other The flow circuit of a powered fluid impeller device with gas lifted from a bed of sorbent material in the container 12.

Yet another alternative is that the container 12 or the sorbent material therein can be directly or indirectly heated to thermally desorb the distributed gas from the sorbent material in the container. For example, the container 12 may be provided in a heating jacket (not shown in the figure), or a heating coil (also not shown in the figure) provided in the entire sorbent bed inside the container may be used for this purpose.

The system 10 shown in FIG. 1 can thus selectively distribute the sorbed gas from the physical sorbent material in the container 12 in any suitable distribution form (differential pressure-induced desorption and / or heat-induced desorption), Instead, the dispensing gas is discharged from the container.

FIG. 2 is a schematic diagram of an adsorbent processing system for processing a physical sorbent material according to the method of the present invention to desorb foreign sorbables from the sorbent.

The system of FIG. 2 includes an inert gas source 50, which may be a container containing an inert gas such as helium, argon, krypton, nitrogen, etc., connected to an inert gas feed line 64 having a flow control valve 66 therein. The inert gas feed line 64 is connected to the container 60 of the sorbent material to be processed in a flowing relationship.

The container 60 may, for example, be filled with a gas and then sealed to provide a gas storage and distribution container for the final gas storage and distribution system, or it may include transferring the processed sorbent from it to the product Another container for a gas storage and distribution container of a gas storage and distribution system.

In the system of FIG. 2, the container 60 is configured and configured to heat the contents of the container 60 and its sorbent material to a predetermined temperature so that the foreign sorbable material is thermally desorbed from the sorbent material. Inside the furnace 62. This furnace can be constructed in a conventional manner for this purpose, and can be set, for example, to selectively heat the container 60 and its contents to a temperature in a range from 100 ° C to about 1500 ° C.

An inert gas outflow line 68 containing a flow control valve 70 is also connected to the container 60 to adjust the flow rate of the inert gas flow, so that the inert gas is discharged from the processing system.

A vacuum line 72 containing a flow control valve 74 and coupled to a vacuum pump 52 is coupled to the inert gas exhaust line 68.

The sorbent processing method of the present invention in an illustrative embodiment will now be described with reference to the sorbent material processing system of FIG. 2 and the flowchart of the method steps of FIG. 3.

The explanation method is performed by providing a dispensing container 60 (step 100 in FIG. 3) and providing a sorbent material (step 102 in FIG. 3) filled in the container (step 105 in FIG. 3).

The sorbent material may be processed before and / or after being filled into the container (steps 103 and 104 of FIG. 3). In the illustrated specific example, the container 60 is installed in the furnace 62, and the furnace is actuated to heat the container. At the same time, the flow control valve 66 is opened, so that the inert gas flows from the source 50 through the container 60 in the line 64, and the valve 70 is in an open state, so that the inert gas is discharged from the container 60 to the line 68 to adjust the inert gas and self-passage. Heat the flow of any entrained foreign sorbent that the sorbent material desorbs. The heating and flow of the inert gas causes the desorption of foreign sorbables and their outflow from the system in the discharge line 68.

During this operation, the valve 74 is closed. When the heating and flow of the inert gas is completed, the valves 66 and 70 are closed, and the furnace is closed or maintained at a lower temperature condition in a subsequent step as necessary.

Next, the valve 74 is opened, and the vacuum pump 52 is actuated to vacuum-desorb the remaining foreign sorbable material on the sorbent material in the container 60, and if necessary, can be improved through the heating furnace 62 as mentioned.

A container of sorbent material with a substantially reduced content of foreign sorbables is thus produced.

The container containing the sorbent material is then filled with the distribution gas (step 106 in FIG. 3), and the distribution gas is absorbed by the sorbent material and retained for subsequent distribution operations.

Finally, the container containing the sorbent material filled with the distribution gas is sealed (step 107 in FIG. 3). Sealing operations may include mechanical steps such as closing a valve, or fluidly isolating a container, or installing a valve head assembly, plug, partition wall, or other sealing assembly to provide a gas storage and distribution system in a form for subsequent use. The sealing operation may be performed under a vacuum or inert gas environment, as appropriate or required in the manufacture of the specific gas storage and distribution system of the present invention.

In carrying out the pretreatment of the sorbent material of the present invention, wherein the foreign sorbable material includes carbon monoxide, the physical sorbent material is processed so that at least part of the foreign sorbent material is desorbed from the sorbent material. The steps can be conveniently performed so that when the physical sorbent material is loaded with tritium gas at a loading amount of 50% by weight based on the weight of the physical sorbent material, a pressure of 700 Torr and a temperature of 22 ° C, The value of carbon dioxide per million parts per million in volume is less than 20 parts per million (ppmv).

In contrast, when the foreign sorbent includes carbon dioxide, the physical sorbent material is conveniently processed to desorb the foreign sorbent, so that when the physical sorbent material is in the physical sorbent material, The weight is based on a loading of 50 weight percent, a pressure of 700 Torr, and a temperature of 22 ° C when the radon gas is loaded, resulting in a carbon dioxide amount of less than 50 parts per million (ppmV) per million by volume in the radon.

The step of processing the physical sorbent material so as to desorb the foreign sorbent may suitably include heating the physical sorbent material to a temperature of from about 300 to about 300 before filling the physical sorbent material in the container. A temperature in the range of 800 ° C for a sufficient time to allow the desorbable foreign matter to desorb from it. In this heating process of the physical sorbent material, if necessary, an inert gas such as helium is physically adsorbed with The agent material comes in contact with the flow.

Figure 4 is a thermogravimetric analysis (TGA) diagram of an activated carbon sorbent material, which shows the desorption loss of the oxygen-containing group from the sorbent material when heated above 650 ° C. The illustrated TGA spectrum was obtained for a bead activated carbon material in argon gas. As shown by the weightlessness curve, the material loses weight at a temperature up to about 100 ° C through a gradual desorption of water vapor. Then, when the temperature is increased, the weight of the sorbent material is maintained at a constant value until a temperature of about 650 ° C. At temperatures above 650 ° C, oxygen-containing groups such as CO and CO ₂ The self-adsorbent material is desorbed and repelled, so the weight loss increases significantly.

Therefore, when the remaining foreign sorbables remain on the sorbent material at this point, it is extremely important to ensure that the temperature of the heating operation significantly increases beyond the point where the change in weightlessness becomes zero, in order to achieve high purity in the distribution gas. Therefore, although the initial weight loss (at temperatures up to 100 ° C) and subsequent changes in temperature (up to 600 ° C) can be used to predict that the sorbent has eliminated all foreign sorbables, it is continuously heated to a high level. At a sufficient time and sufficient degree at about 650 ° C, the remaining foreign sorbables can be driven out of the sorbent material, and the purity of the distributed gas can be significantly improved.

In this way, the surrounding environment of the sorbent material is kept free from the possibility of depositing on the sorbent material and contaminating the sorbent material (and distribution gas) during subsequent operations of storage and distribution containers. Sucking ingredients is paramount.

Included in the present invention is a container for accommodating (i) a sorbable distribution gas to be accommodated in a distribution container, and subsequently selectively discharged from the distribution container, and (ii) a foreign sorbable material having sorption affinity In a particularly specific example of a method for manufacturing a gas storage and distribution system for a bead activated carbon physical sorbent material distribution container, the manufacturing method includes the following steps: processing a physical sorption on which a foreign absorbing substance is adsorbed Agent material to desorb at least part of the foreign sorbable material from the sorbent material, including heating the physical sorbent material to a temperature within a first range from about 300 ° C to about 800 ° C, and Maintain in the first range for about 1 to 15 hours, and during this heating process, bring the inert gas into physical contact with the physical sorbent material; fill the physical sorbent material in a container; The physical sorbent material is heated to a temperature within a second range from about 100 ° C to about 250 ° C, and the temperature is maintained within the second range from about 1 to 10 hours, and during this heating, the Physical sorbent material application in container Add vacuum; cool the physical sorbent material to a temperature lower than the second temperature range; introduce the sorbable distribution gas into the distribution container containing the physical sorbent material, so that the distribution gas is physically absorbed by the physical adsorption And a distribution container that seals the dispenser gas on the physical sorbent material, so that the distribution container thereafter contains a gas that can be desorbed from the physical sorbent material and discharged from the container. Distribution gas in the form of selective distribution.

When the foreign sorbable material includes carbon monoxide, such a manufacturing method may be performed so that when the physical sorbent material has a loading amount of 50% by weight based on the weight of the physical sorbent material, a pressure of 700 Torr, and When tritium gas is loaded at a temperature of 22 ° C, the sorbent material has a carbon oxide value of less than 20 parts per million (ppmv) per million by volume in tritium after treatment, and when carbon dioxide is an external sorbable, When the physical sorbent material is loaded with radon gas at a loading of 50 weight percent based on the weight of the physical sorbent material, a pressure of 700 Torr, and a temperature of 22 ° C, the amount of carbon dioxide in the radon is lower than 50 parts per million (ppmv).

For example, when the foreign sorbable material includes carbon monoxide and carbon dioxide, the physical sorbent material can be efficiently processed according to the present invention, so that the foreign sorbable material is desorbed to produce a physical sorbent material. When the radon gas is loaded at 50% by weight based on the weight of the physical sorbent material, a pressure of 700 Torr, and a temperature of 22 ° C, the amount of carbon monoxide in the radon is less than 1 part per million by volume (ppmv), and the amount of carbon dioxide in the plutonium is less than 10 parts per million (ppmv) of the treated sorbent material.

The features and advantages of the present invention are more fully demonstrated by the following non-limiting examples.

Example I

A certain amount of Kureha BAC activated carbon sorbent (Kreha Corporation, New York, NY) was placed in a stainless steel sample cylinder and placed in an oven configured into the method system shown schematically in FIG. 2. The furnace in the method system was directly connected to a glove box for post-furnace treatment.

After the adsorbent is pretreated at 300 to 800 ° C under a helium stream for 12 hours, the adsorbent is filled into a storage and distribution container (gas cylinder) in an inert gas, and then degassed in a vacuum at 150 ° C 5 hours. The container was then filled with tritium gas to 700 Torr pressure at 22 ° C.

The loading amount of rhenium based on the original weight of the sorbent material is 50% by weight, which is the same load as the relative batch of sorbent material that is simultaneously applied in a separate container for control without any pretreatment. Into the amount.

Krypton gas is then dispensed from two containers and independently flows through a gas chromatograph equipped with a discharge ionization detector (DID). CO and CO in radon gas from containers containing pretreated sorbent materials ₂ The magnitude is significantly lower than the radon gas from the control container containing the untreated sorbent material, as shown in Table A below.

<tables><img file="TW565467B_D0003.tif" /></tables>

In the foregoing analysis, the detection limit of GC-DID for CO was 0.05 ppmV, and for CO ₂ It was 0.02 ppmv.

In the relevant test for transferring the pretreated sorbent from the furnace to the glove box physically separated from the furnace, the ambient air contact between the furnace and the glove box caused the sorbent material to absorb substantial CO ₂ So that CO was measured under other relevant processing and processing conditions for the pretreated sorbent samples in Table A ₂ The concentration was 4.9 ppmv. Therefore, this air-exposed material exhibits a lower CO than the pretreated sorbent of Table A ₂ Concentrations (isolated from ambient air exposure) more than 37 times higher CO ₂ concentration.

Although the present invention has been shown and described with reference to various illustrative aspects, characteristics, and specific examples, it should be understood that the application of the present invention is not limited by this, but extends and covers many that can be easily understood by those skilled in the art Other changes, modifications and specific examples. Therefore, the invention disclosed herein should be considered and interpreted broadly as including all such alternative changes, modifications, and other specific examples within the spirit and scope of the scope of patent applications described later.

Explanation of main component symbols

10. . .Gas storage and distribution system

12. . .container

14. . .Cylindrical wall

16. . .Physical sorbent material

18. . .neck

20. . .Valve head combination

twenty four. . .Single block body

26. . .Manual wheel

26a. . .Coupler

50. . .Inert gas source

52. . .Vacuum pump

60. . .container

62. . .furnace

64. . .Inert gas feed line

66. . .Flow control valve

68. . .Inert gas exhaust line

70. . .valve

72. . .Vacuum line

74. . .valve