Gas Processing System and Method

Abstract

A gas processing system including a media vessel and a preheater used to process a gas by flowing the gas into contact with a media contained in the media vessel, such as a catalyst or adsorbent material, and associated methods are described.

Description

[Technical field]

[0001] Claiming priority This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 318,894, filed March 11, 2022, the entire contents of which are incorporated herein by reference in their entirety.

[0002] The present disclosure relates to a gas processing system including a media vessel and a preheater, and associated methods, used to process gas by flowing the gas into contact with a media (e.g., a catalyst or adsorbent material) contained in the media vessel. [Background technology]

[0003] Industrial gases are used as raw materials or process materials (called "reagent gases") for a variety of commercial and industrial purposes, including the manufacture of semiconductors and microelectronic devices.

[0004] To prepare a reagent gas for use in a process, the gas can be handled or treated to produce any of a variety of effects on the gas. Reagent gases can be heated, cooled, purified, filtered, catalytically treated, etc.

[0005] The gas purification system is adapted to supply a consistent flow of purified reagent gas to manufacturing equipment, such as semiconductor or microelectronic processing tools. Examples of reagent gases include purified forms of nitrogen, argon, helium, hydrogen, carbon dioxide, clean dry air ("CDA"), and oxygen.

[0006] Techniques for purifying a gas stream may involve contacting the gas with a media material capable of removing (i.e., reducing) the amount of impurities contained in the gas. In some techniques, impurities are removed from the gas stream by trapping the impurities, such as by adsorbing them onto the surface of an adsorbent (i.e., an "adsorption media"). In other techniques, the impurities may be contacted with a solid catalytic material that chemically converts (e.g., oxidizes) the impurities into derivative compounds that are considered more desirable (or less undesirable) compared to the original impurities.

[0007] Manufacturers have designed highly specialized equipment to perform the gas purification process. Systems for purifying gas include a container that holds a type of media (e.g., purification media), such as an adsorbent, filter, or catalyst, and associated flow control equipment that directs a flow of reagent gas through the vessel to contact the media. Controls are included to control the conditions of the process, such as temperature, pressure, and flow rate.

[0008] Many gas processing systems include a gas preheater. Gas preheaters are used to preheat the gas before it flows through a vessel containing a medium. For example, to improve the efficiency of a catalytic purification process, the gas can be preheated before contacting the catalyst. Equipment for these types of catalytic processes includes a vessel containing the catalyst, a flow control that causes the gas to flow through the catalyst, and a preheater that heats the gas to a high temperature before it contacts the catalyst.

[0009] Gas preheaters may also be useful in adsorption-based gas purification systems, either in the adsorption (for filtration or purification) step or in the regeneration step. In these systems, purification by adsorption is performed by flowing the gas in contact with an adsorption medium. As the gas flows through the adsorption medium, impurities in the gas are adsorbed onto the adsorption medium while the gas passes through the medium unadsorbed.

[0010] Over the period of use to adsorb impurities, impurities accumulate on the adsorption media. The accumulated impurities can be removed from the adsorbent by a regeneration process, which exposes the media to a stream of clean ("regeneration") gas at elevated temperature, causing the impurities to desorb and be removed from the adsorbent. The regeneration process can be carried out while leaving the adsorption media in the same vessel that contained the media during the purification step, by passing a heated gas ("regeneration gas") through the adsorption media in its original vessel. The regeneration gas contacts the surface of the adsorption media, and the adsorbed impurities that have accumulated on the surface of the media desorb from the surface and are carried away from the adsorption media by the regeneration gas. For efficient regeneration, the regeneration gas is usually preheated before contacting the adsorption media.

[0011] For example, for any type of process step, media, and reagent gas (including regeneration gas) in a catalytic process, adsorption process, filtration process, purification process, or regeneration process, etc., the process may include passing a bed of heated media, with a uniform temperature distribution throughout, and heated gas passing through the media. Preferably, the vessel containing the media is controlled at the desired process temperature with the gas flowing through the media, and the entire vessel, as well as all locations of the vessel, gas, and media, are ideally kept at a single desired process temperature. Equipment and processes are designed to reduce or eliminate temperature gradients within the media vessel.

[0012] To control the temperature of the gas and avoid thermal gradients, the treatment system can include a preheater that heats the gas before it contacts the medium contained in the media vessel. In one embodiment, the gas can be heated before entering the media vessel by using a separate stand-alone preheater device that is a separate structure from the media vessel. The gas first flows through the stand-alone preheater device, where the gas is heated, and then the heated gas flows from the preheater device to a separate media vessel. The separate preheater device requires separate flow control, separate temperature and pressure control and sensors, separate heating and insulation equipment, and a completely separate physical housing structure.

[0013] An alternative preheating technique involves heating the gas at a location "upstream" of the media as it passes through a space contained in a vessel ("media vessel") that contains the media. The preheater is a portion of the interior space of the media vessel that also contains the media, and the preheater portion contains a heating element or another type of heating mechanism that adds thermal energy to the gas stream as it passes from the inlet of the vessel through the preheater space and then contacts the media. The preheater space is physically located "in-line" with the media contained in the media vessel, upstream of the media, and is typically located vertically above or below the media, within a shared structure. Summary of the Invention

[0014] For a variety of reasons, commercial processes may include steps of contacting a gas with a medium and allowing the medium to interact with the gas to perform an action on the gas or to perform an action on the medium. Exemplary processes include processes for filtering or purifying a gas or for regenerating a medium.

[0015] These types of processes require, or can be improved by, operating the process at elevated temperatures by heating the gas, the medium, or both. For example, processes that purify reagent gases by catalytic techniques are typically carried out at elevated temperatures. Similarly, processes that regenerate beds of solid adsorption media used in adsorptive purification or filtration processes are typically carried out at elevated temperatures. In these methods, the relevant gas (reagent gas or regeneration gas) is typically preheated before the gas contacts the relevant media (catalyst or adsorption media).

[0016] The following describes a gas treatment device that includes a combination of a media vessel and an annular preheater that surrounds the media vessel. The new and inventive device design includes a media vessel that contains a media, such as an adsorbent, catalyst, etc., and an annular preheater that surrounds the media vessel and is preferably in thermal contact with the media vessel. In use, a gas stream enters the annular preheater through an inlet, then flows through the annular preheater that surrounds the media vessel, and then flows through a preheater outlet that leads to the media vessel and the media. As the gas passes through the preheater, the preheater adds thermal energy to the gas, and the gas that flows from the preheater into the media vessel has been heated to a high temperature by the preheater.

[0017] The novel design allows the preheater device to share common structures and controls with the media vessel. In a preferred example, the preheater may be in thermal contact with the media vessel to share thermal energy with the media vessel through adjacent or common structures of the preheater and media vessel, e.g., side walls of the structures, in addition to the heat exchanged by the preheated gas flowing from the preheater to the media vessel. The overall effect is that the amount of energy required to heat the gas and media is reduced. This effect can be enhanced by using flow control structures within the preheater volume, such as baffles, to control the flow of gas between the inlet and outlet of the preheater.

[0018] Another preferred feature of the apparatus may be that the exterior of the preheater and media vessel gas treatment apparatus combination may be insulated, but may not require, and preferably may be omitted, a heating element as part of an insulation device (e.g., blanket) on the exterior of the apparatus.

[0019] In one aspect, the present disclosure relates to a gas treatment apparatus. The apparatus includes a media vessel and a preheater. The media vessel includes a media vessel inlet end with a media vessel inlet, a media vessel outlet end with a media vessel outlet, a media vessel sidewall extending between the media vessel inlet and the media vessel outlet, and a media vessel interior defined by the media vessel sidewall. The preheater includes a preheater sidewall located outside the media vessel sidewall and external to the media vessel sidewall, the preheater sidewall spaced apart from the media vessel sidewall to define a preheater space between an outer surface of the media vessel sidewall and an inner surface of the preheater sidewall, a preheater inlet, and a preheater outlet in fluid communication with the media vessel inlet.

[0020] In another aspect, the disclosure relates to a method of using the gas treatment device herein, the method including flowing a gas through a preheater to preheat the gas, and passing the preheated gas through a media vessel interior and contacting the media contained within the media vessel. [Brief description of the drawings]

[0021] [Figure 1A] FIG. 2 is a side perspective view of the exterior of the illustrated apparatus including a media vessel and a preheater. [Figure 1B] FIG. 2 is a top view of the exterior of the illustrated apparatus, including a media vessel and a preheater. [Figure 1C] FIG. 2 is a side cross-sectional view of the illustrated apparatus including a media vessel and a preheater. [Figure 1D] FIG. 2 is a side cross-sectional view of the illustrated apparatus including a media vessel and a preheater. [Figure 1E] FIG. 2 is a detailed cross-sectional view of the described apparatus including a media vessel and a preheater. [Figure 2A] FIG. 1 shows an example of an apparatus having the baffles described. [Figure 2B] FIG. 1 shows an example of an apparatus having the baffles described. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] All figures are schematic, illustrative, and not necessarily to scale.

[0023] The following is a description of a gas processing apparatus useful for processing a gas stream and including a preheater. Methods of using the apparatus for processing a gas by heating the gas ("preheating") prior to a subsequent processing operation performed by contacting the gas stream with a medium are also described.

[0024] The gas treatment device includes a media vessel containing some type of treatment medium (e.g., adsorbent, catalyst) and an annular preheater that surrounds the exterior of the media vessel and preheats the gas stream before the gas enters the media vessel and contacts the medium. The preheated gas contacts the medium in the media vessel, which may be a solid catalyst or adsorption medium. The preheater is integrated into the physical structure of the media vessel to allow the preheater to share space and structure with the media vessel, share thermal energy with the media vessel by conductive heat transfer, or both. A preferred design allows thermal energy to pass from the preheater to the media vessel by thermal conduction through the structure of the preheater and media vessel, particularly the sidewall structure of the preheater and media vessel.

[0025] An exemplary gas treatment device includes a media vessel including an inlet at one end, an outlet at a second end, and a length and volume extending between the two ends. A preheater is located along at least a portion of the length of the media vessel outside of the media vessel. The preheater is in thermal contact with the media vessel along the length of the media vessel and can pass thermal energy by thermal conduction between the preheater and the media vessel. In an exemplary design, a surface of the preheater along the length of the preheater is in contact with or shared with a surface of the media vessel along the length of the media vessel. When the two surfaces are shared or in thermal contact, the combined structure may be designed with an overall reduction in physical components compared to other media vessel and preheater designs. As an example, the described device may include a blanket that is external, i.e., surrounds the preheater, to insulate the device and retain heat within the preheater. However, the exemplary device does not require, and may specifically exclude, a heating element (any thermal energy source) that applies heat to the preheater from a location external to the preheater.

[0026] Reducing the amount of physical components of the combined media vessel-preheater structure can enable cost savings, can reduce the overall size (especially the length) and space requirements of the media vessel and preheater device, or can both.

[0027] Various different types of gas processing operations involve contacting a gas, referred to herein as a "reagent gas" or "process gas," with a solid material, referred to generally herein as a "media," and performing a process operation on the gas (such as filtration or purification) or on the media (e.g., regeneration of an adsorption media). The media may be any of a variety of materials, and examples are solid materials (i.e., as opposed to liquid or gaseous materials) that may be in a variety of forms (e.g., particles, granules, etc. of solid (non-liquid, non-gaseous) pieces of various sizes having porous morphology) that may function as a catalyst, adsorbent, or for another purpose when in contact with a gas.

[0028] For use in gas purification processes, a reagent gas containing impurities can be flowed in contact with a medium that can reduce the amount of impurities in the gas during contact between the medium and the gas. Purification processes include processes of filtration, adsorption of impurities from the gas, and catalytic conversion of impurities from the gas.

[0029] Some gas purification techniques remove impurities from a process gas stream by trapping the impurities, such as by adsorbing them onto the surface of an adsorbent material. The gas is passed through and contacted with a solid adsorbent material, and impurities present in the gas are attracted to and adsorbed onto the surface of the adsorbent, substantially removing non-adsorbed impurities from the gas. A variety of adsorbent materials are known. The adsorbents can be any of a variety of sizes and shapes, such as small particulates, granules, pellets, shells, cubes, monoliths, etc., having a desired amount of surface area per volume.

[0030] The composition of the adsorbent material may also vary and may be selected based on the type of gas being treated, the type of impurity, the desired removal efficiency, or other factors. Examples of adsorbents known to be useful for adsorbing impurities from gas streams include, among others, activated carbon, zeolite materials, "metal organic framework" (MOF) adsorbents, getters such as zinc-vanadium and zinc-aluminum getters, etc.

[0031] Types of reagent gases that contain impurities and can be treated to reduce the levels of impurities using adsorbents include nitrogen, argon, helium, hydrogen, ammonia, carbon dioxide, clean dry air ("CDA"), and oxygen, among others.

[0032] During use of an adsorption-based gas purification system, a certain amount of impurities accumulates on the adsorbent. The accumulated impurities can be removed from the adsorbent by a "regeneration" step, and the regenerated adsorbent can be used again to purify a gas stream by contact with the adsorbent. In the regeneration step, a relatively clean gas ("regeneration gas") stream is passed through and contacted with the adsorbent at an elevated temperature. The regeneration gas may be heated to an elevated temperature by use of a preheater, as described herein.

[0033] The regeneration gas may be any gas that is effective in the regeneration step to remove accumulated impurities from the adsorption media. The composition of the regeneration gas for removing impurities from a particular type of adsorption media will depend on factors including the type of reagent gas processed using the adsorption media, the type of impurity, the type of adsorbent, etc. In accordance with certain exemplary systems, regeneration gases useful for removing accumulated impurities from adsorption media used to remove impurities from a particular type of reagent gas (identified in parentheses) include nitrogen / hydrogen mixture (nitrogen), argon / hydrogen mixture (argon), helium / hydrogen mixture (helium), hydrogen (hydrogen), nitrogen / hydrogen mixture (ammonia), nitrogen / hydrogen mixture (carbon dioxide), clean dry air (clean dry air), and oxygen (oxygen).

[0034] Other gas purification techniques allow the gas purification step to use a catalyst to reduce or remove a certain amount of impurities from the gas stream. These techniques allow impurities contained in the gas to be contacted with a solid catalyst and the impurity compounds to be chemically converted (e.g., chemically reduced or chemically oxidized) into derivative chemical compounds that are more desirable (or less undesirable) compared to the original impurities.

[0035] The catalyst can be selected to react with a particular impurity present in the reagent gas. Examples of catalysts are nitrogen oxides (NO x These techniques may be effective in chemically reducing impurities, oxidizing carbon monoxide, or oxidizing hydrocarbons such as methane to form water and carbon dioxide. With these techniques, a stream of reagent gas is directed into contact with a medium that is a catalyst, and impurities (e.g., nitrogen oxides, carbon monoxide, or hydrocarbons such as methane) are chemically converted (e.g., chemically reduced or chemically oxidized) to a favorable chemical compound compared to the original impurity. In the specific example of oxidizing a hydrocarbon such as methane, the hydrocarbon is catalytically oxidized to form water and carbon dioxide.

[0036] The composition of the catalyst for the gas purification process may also vary and may be selected based on the type of gas being treated, the type of impurities contained in the gas being treated, the desired efficiency of removal of the impurities, as well as other factors. Examples of catalysts known to be useful for converting impurities contained in gas streams include rhodium, platinum, palladium, among others.

[0037] In accordance with an exemplary gas treatment apparatus, a useful apparatus includes a media vessel having a media vessel inlet, a media vessel outlet, a length extending between the inlet and the outlet, and a sidewall extending along the length and defining an interior volume of the media vessel. The sidewall may be made of a rigid, thermally conductive material, such as metal.

[0038] A "media vessel inlet" can be considered an open portion of the media vessel that is connected (in fluid communication) to the interior of the media vessel and is part of a flow path into the interior of the media vessel such that process gas flowing through the media vessel inlet enters the media vessel interior containing the media. The media vessel inlet also communicates directly or indirectly with the preheater outlet. The media vessel inlet may be directly connected to the preheater outlet or may be connected to the preheater outlet through a closed flow path between the preheater outlet and the media vessel inlet, such as a path extending from the preheater outlet through an inlet headspace and then to the media vessel inlet.

[0039] Also, according to the described apparatus, an annular preheater is located adjacent to the exterior surface of the media vessel along at least a portion of the length of the media vessel and around the entire exterior surface, i.e., the circumference (perimeter), of the media vessel. A useful or preferred preheater can include a sidewall surface in thermal contact with the exterior surface of the media vessel. The term "perimeter" herein refers to the closed geometric shape of a vessel, sidewall, preheater, or space of the gas processing apparatus herein when viewed in cross section along a length generally along a horizontal cross section of the vessel, sidewall, or space (e.g., when viewed vertically or "at height" as shown in FIG. 1).

[0040] A preheater that is "in thermal contact" with the media vessel refers to a preheater that includes structure, such as a sidewall, that is common to the structure of the media vessel, or that is located in sufficient proximity to a surface (such as a sidewall) of the media vessel that allows a useful amount of thermal energy to pass from the preheater interior to the media vessel interior. A useful amount of thermal energy may be more than the negligible amount that passes from the preheater to the media vessel during use of the preheater to supply preheated gas to the media vessel.

[0041] To provide a useful amount of thermal contact between the preheater and the media vessel, the exemplary gas treatment apparatus may be configured such that a thermally conductive surface of the preheater sidewall is in direct contact with a thermally conductive surface of the media vessel sidewall. The preheater sidewall structure may be identifiable as a separate physical structure that is not a necessary component of the media vessel, with the two distinct sidewall structures being in direct physical contact with each other to enable efficient transfer of thermal energy by thermal conduction from the surface of the preheater sidewall to the surface of the media vessel sidewall.

[0042] Alternatively, the described gas treatment apparatus may be configured such that the sidewall of the media vessel and the sidewall of the preheater are fabricated from a single physical structure that defines an interior of the media vessel on one side of the sidewall (the "inside" of the single sidewall) and an interior of the preheater on the opposite side of the sidewall (the "outside" of the single sidewall).

[0043] In contrast, the sidewall structures of the media vessel and the preheater are considered not in thermal contact with one another if they are positioned such that they do not allow for a useful amount of thermal energy transfer from the sidewall of the preheater through the sidewall of the media vessel during the gas processing steps described herein. Various designs of conventional gas processing systems include a preheater and a media vessel, where the two are positioned such that they do not allow for heat transfer between the sidewall structures, i.e., the preheater is not in thermal contact with the media vessel. For example, a particular preheater design involves preheating the process gas as the gas passes through a space in the media vessel that is "upstream" of the media in the same vessel, where the preheater space includes a heating element that transfers heat to the gas passing through the preheater space. The preheater space and heating element are contained in a single vessel with the media, and the process gas flows through the vessel by first contacting the heating element and then contacting the media. In-line preheaters are often located either above the media or below the media. The sidewalls of the preheater structure are not considered to be in thermal contact with the sidewall structure of the media vessel.

[0044] In accordance with the novel gas treatment apparatus herein, the preheater includes a preheater interior volume that extends along the length of the media vessel exterior to the media vessel. More specifically, the preheater includes an interior volume that is annular ("annular volume") and through which gas flows during use, extending along the exterior surface of the media vessel for at least a portion of the length of the media vessel between the media vessel inlet and the media vessel outlet.

[0045] The preheater includes an annular volume defined by an inner sidewall and an outer sidewall, the outer sidewall being spaced apart from the inner sidewall to create the interior space of the preheater. The inner sidewall may be of the same construction as, connected to, or in thermal contact with the outer wall (sidewall) of the media vessel. The volume (interior space) between the inner sidewall of the preheater and the outer sidewall of the preheater is nominally referred to as "annular" and is preferably cylindrical with a circular cross section (when viewed along its length) for high efficiency of the design of the apparatus. However, the "annular" cross section may be of a non-circular shape, such as, for example, an elliptical, rectangular shape, etc., as desired.

[0046] An exemplary preheater includes a preheater inlet at a lower portion of the preheater, passing through an outer sidewall of the preheater, and a preheater outlet at an upper portion of the preheater, passing through or across an inner sidewall of the preheater. If desired, the described apparatus may be configured to operate with different flows of gas through the preheater and the media vessel. For example, the preheater inlet may be in an upper region of the apparatus, and gas may enter the inlet and then flow vertically downward through the preheater, followed by gas flowing vertically upward through the media vessel.

[0047] According to certain exemplary devices, the preheater inlet includes an opening or aperture that passes through the outer sidewall of the preheater on one side of the preheater and does not extend beyond a short portion of the circumference of the preheater. This means, for example, that the inlet does not extend from the front to the back of the preheater as the preheater outlet does, but can extend only a short length of the circumference of the preheater, such as a portion of the circumference that is less than 3025 degrees or 20 degrees of 360 degrees around the circumference. The inlet has an area that is defined by the size (area) of the opening through the outer sidewall of the preheater, for example, the area of ​​a circular opening.

[0048] The inlet can be any form of opening through the exterior sidewall of the preheater that allows gas to flow from an exterior location through an inlet opening in the exterior sidewall of the preheater into the preheater interior. The inlet can be round or include a tubular flow conduit, such as a circular pipe or tube, that enters through the opening to allow gas to flow from an exterior location into the preheater interior.

[0049] The preheater outlet is located at the end of the device opposite the location of the preheater inlet and also extends around most of the perimeter of the annular preheater between the front of the device and the rear of the device. The outlet extends along at least a portion of the front of the preheater (front 180 degrees from 90 degrees to 270 degrees, including 0 degrees front, see FIG. 1B) and also extends along at least a portion of the rear of the preheater (rear 180 degrees from 90 degrees to 270 degrees, including 180 degrees rear, see FIG. 1B). The location of the outlet around most of the perimeter of the annular preheater allows gas to enter the media vessel from most or all parts of the annular preheater. The location along the perimeter allows preheated gas to enter the media vessel from all or substantial directions around the circumference of the media vessel (e.g., from about the entire 360 ​​degrees of the annular preheater).

[0050] The outlet extends along the length of the inner sidewall of the media vessel as a horizontal opening that may be referred to as a horizontal flow gap, horizontal space, horizontal slot, having a length along the perimeter or inner sidewall of the preheater, along the sidewall of the media vessel, or both. The outlet opening may be continuous along its length (i.e., extending uninterrupted around the entire 360 ​​degree circumference), segmented (e.g., including multiple regular interruptions), or otherwise interrupted, such as to reduce the amount of flow at a location using a baffle that blocks flow through the outlet. Unlike the preheater inlet, the outlet opening includes openings that allow gas to flow out of the preheater over a substantial range of locations along the 360 ​​degree circumference of the preheater, optionally including at or near the front, the rear, and locations between the front and rear.

[0051] The outlet also has an area equal to the size of the opening between the preheater interior and the media vessel interior. The opening may be an area equal to the size of the flow gap, which means the length of the flow gap around the perimeter of the media vessel sidewall (excluding any interruptions or baffles) multiplied by the "height" of the flow gas, which is the dimension of the flow gap along the "length" of the media vessel.

[0052] According to a preferred example, the apparatus can have a desired ratio of the area of ​​the preheater inlet to the media vessel outlet (shown as 30 and 40, respectively, in FIG. 1). An exemplary ratio of the area of ​​the preheater inlet to the media vessel outlet can be 2:1 to 1:2, e.g., 1.5:1 to 1:1.5 (area of ​​the preheater inlet: area of ​​the media vessel outlet). In an exemplary system, the area of ​​the media vessel outlet can be slightly larger than the area of ​​the preheater inlet, e.g., the media vessel outlet can have an area equal to the area of ​​the preheater inlet, or an area between 100% and 150% of the size of the preheater inlet, or between 110% and 130% of the size of the preheater inlet.

[0053] The preheater includes a heat source, referred to as a "heating element," that operates at an elevated temperature relative to the process gas that enters the preheater through the preheater inlet during use. The heating element transfers thermal energy to the gas flowing through the preheater interior to raise the temperature of the gas before it leaves the preheater at the preheater outlet and enters the media vessel. The temperature of the heating element can be controlled to be elevated, for example, by any useful source or method, such as electrical resistance heating, or by a fluid circulating through the heating element, such as hot water, steam, or a different fluid that can transfer thermal energy to the fluid passing through the preheater. The heating element can be of any useful design, including heating elements that are sometimes referred to as heating rods, electrical resistance heaters, heating bars, strip heaters, and the like.

[0054] The heating elements may be distributed uniformly within the preheater around the circumference of the annular preheater interior, or may be distributed non-uniformly within the preheater around the circumference of the preheater. One example of a heating element is a heating rod that may be mounted within the annular interior space of the preheater. In certain exemplary arrangements, the heating rod may be distributed non-uniformly around the circumference of the annular preheater interior.

[0055] As a result of the preheater inlet being located along a limited portion of the preheater periphery (e.g., only at the front of the preheater), as compared to a preheater outlet being located around a wider area of ​​the preheater periphery, gas entering the annular preheater passes from inlet to outlet over a range of flow paths within the annular preheater. The various flow paths extend various distances around the length of the preheater periphery to allow gas to exit the front, sides, and rear of the preheater outlet and enter the media vessel from all portions of the circumference of the media vessel.

[0056] The various flow paths between the reduced length (relative to the periphery) inlet at the front of the preheater and the range of outlet locations around the front, back, and sides of the preheater periphery have different flow path lengths and therefore different residence times within the preheater.

[0057] For example, the flow of gas through the inlet into the annular preheater interior at the front of the preheater can also flow out the preheater outlet (into the media vessel) to the front. The gas traveling this flow path through the preheater interior travels the shortest possible distance between the inlet and the outlet. This gas flow path through the preheater also has the shortest possible residence time inside the preheater.

[0058] In contrast, the gas flow entering the inlet at the front inside the annular preheater and exiting the outlet at the rear of the preheater (and media vessel) travels 180 degrees around the circumference of the preheater relative to the inlet, as far away from the inlet as possible, to reach the outlet at the rear of the preheater. Gas traveling this path travels as great a distance as possible between the inlet and the outlet. This gas flow has the longest possible residence time within the annular space of the preheater.

[0059] Gas traveling along a longer flow path has a higher residence time inside the preheater, and gas traveling along a shorter flow path has a lower residence time inside the preheater. In a preheater that includes heating elements evenly distributed within the preheater around the circumference of the preheater, differences in residence time can cause imbalances or non-uniformities in the temperature of gas exiting the preheater at various locations along the circumference of the preheater outlet. Because the heating elements are evenly distributed around the circumference of the preheater, gas that has a longer residence time within the preheater experiences a higher amount of heat transfer from the heating elements as the gas flows through the preheater from the inlet to the outlet, and absorbs a higher amount of heat from the heating elements compared to gas that has a shorter residence time within the preheater.

[0060] In accordance with the exemplary methods and apparatus herein, the heating elements within the preheater can be designed and distributed to transfer different amounts of heat to gases flowing through the preheater along different flow paths and experiencing different residence times within the preheater. The preheater allows for higher heat transfer rates to gases flowing along shorter flow paths and lower heat transfer rates to gases flowing along longer flow paths.

[0061] As an example, the heating elements may be distributed non-uniformly within the preheater, e.g., non-uniformly around the circumference of the preheater (such as by varying the spacing between heating elements), desirably such that gas streams along different flow paths through the preheater and having different residence times within the preheater are exposed to different amounts of heating.

[0062] In an alternative embodiment, instead of or in addition to distributing the heating elements non-uniformly within the preheater, the heating elements may be designed or controlled to cause varying and non-uniform amounts of heat transfer to gas flowing along different flow paths and experiencing different residence times within the preheater. According to another example, the heating elements within the preheater may have different sizes (diameter, length) or be set at different temperatures to cause different amounts of heat transfer to gas traveling along longer or shorter flow paths through the preheater.

[0063] In these and other embodiments, the preheater can optionally include a flow control or restrictor (e.g., a baffle) that impedes the flow of gas through the preheater to reduce the velocity or volume of fluid through a flow path and increase residence time for the gas along that flow path. The flow control can be, for example, a baffle located at the preheater outlet at the front of the preheater to reduce the flow rate of gas flowing through the front of the preheater (e.g., flow path p1, see below) and increase the residence time of gas flowing through the front of the preheater.

[0064] Heat transfer of different amounts (e.g., rates) to gas streams traveling through longer and shorter flow paths and having longer and shorter residence times can be designed to reduce the temperature difference of gas leaving various locations around the perimeter of the preheater outlet and entering the media vessel at various locations around the perimeter of the media vessel inlet. Desirably, the gas streams traveling along the various flow paths can be exposed to similar (preferably substantially equal) amounts of heat transfer along their respective different flow paths. The gas streams traveling along the various flow paths can be exposed to similar amounts of heat transfer from the non-uniformly distributed heating elements to cause the various gas streams to absorb approximately the same amount of thermal energy in the preheater and exit the preheater through the preheater outlet at similar temperatures. To cause the same amount of thermal energy transfer over the longer and shorter flow paths, the heat transfer rate can be higher along the shorter flow paths and lower along the longer flow paths.

[0065] An exemplary apparatus is shown in FIG. 1A (side perspective view), FIG. 1B (top view), and FIG. 1C (cross-section view), FIG. 1D (detailed cross-section view), and FIG. 1E (side cross-section view). FIGS. 1A-1D show an exemplary apparatus including an annular preheater space external to a media vessel. The preheater includes an inlet only at the front and an outlet into the media vessel that extends around the periphery of the media vessel including portions thereof at both the front and rear. The preheater interior includes heating elements arranged asymmetrically around the periphery of the preheater with more heating rods at the front of the apparatus and fewer heating rods at the rear of the apparatus. A partial baffle reduces flow through the preheater outlet through the front of the outlet.

[0066] Referring to FIG. 1A, the exterior of a gas treatment apparatus 10 is shown. The apparatus 10 includes a media vessel 20 therein adapted to contain a media (not shown). A preheater 18 is a structure surrounding the media vessel 20 along its length (vertical length, as shown) from a lower portion 22 to an upper portion 24. The preheater 18 includes an outer preheater sidewall 12, an inner preheater sidewall 14 (not shown in FIG. 1A) spaced apart from the outer preheater sidewall 12, and an annular preheater interior 16 formed between an inner surface of the outer sidewall 12 and an outer surface of the inner sidewall 14. The inner sidewall 14 of the perheater 18 can also function as a sidewall (outer sidewall) of the media vessel 20.

[0067] Heating elements (e.g., heating rods) 42 extend vertically from the top of the annular preheater interior 16 into the interior 16. As shown, all of the heating elements may be of the same size, construction, and heat transfer properties. In alternative embodiments, the heating elements may vary in size (length or diameter).

[0068] Apparatus 10 has a perimeter (P) and a perimeter measured around the exterior of apparatus 10. Inlet 30 is a round opening through outer sidewall 12 that comprises a closed conduit (e.g., a pipe or tube) that connects the exterior of apparatus 10 to the annular interior 16 of annular preheater 18, and may be considered to be located at the "front" of apparatus 10.

[0069] In use, gas enters inlet 30, passes through annular interior 16 of preheater 18, then through outlet 44 of preheater 30 (not contacted in FIG. 1A ) into media vessel 20. Gas flows through media vessel 20 (media contained within media vessel 20) and then passes from media vessel 20 through preheater outlet 44, which extends around the periphery of preheater 18 at an upper portion or end of preheater 18.

[0070] Gas flows through the annular interior 16 of the preheater 18 along a number of flow paths of various lengths (e.g., p1, p2, p3, p4 shown in FIG. 1A ). Flow path p1 extends vertically directly up from the inlet 30 (as shown) and passes through the preheater outlet 44 at the top of the preheater interior 16. This flow path p1 is the minimum length flow path between the inlet 30 and the preheater outlet 44. Gas flowing along flow path p1 has the minimum residence time within the preheater interior 18.

[0071] Flow path p4 is shown extending from inlet 30 along a curved path within the annular preheater interior to the front of the apparatus 10 and to the rear, 180 degrees opposite inlet 30. Curved flow path p4 extends from inlet 30 in a curved vertical direction along a length along the annular interior of preheater 18 that extends along 180 degrees of the annular interior circumference. Flow path p4 terminates at the preheater outlet at the rear of the apparatus 10 and is the maximum flow path length between inlet 30 and the preheater outlet. Gas flowing along flow path p4 has the maximum residence time within the preheater 18.

[0072] Flow paths p2 and p3 are intermediate curved lengths between the inlet 30 and the preheater outlet and exit the preheater interior 16 through an outlet 44 at a side between the front and back of the preheater 18. Gas flowing along flow paths p2 and p3 experiences an intermediate residence time compared to the maximum and minimum residence times of gas flowing through flow paths p4 and p1.

[0073] 1B shows a top view of the apparatus 10. This view shows that the heating elements 42 are distributed non-uniformly within the annular preheater interior 16 about the length of the perimeter P. Along the length of the front half of the preheater 18, between 90 degrees and 270 degrees, including a front position of 0 degrees along the perimeter, the heating elements 42 are distributed at a first concentration with relatively little separation between adjacent heating elements. In the rear half of the preheater 18, between 90 degrees and 270 degrees, including a rear position of 180 degrees, the concentration of heating elements 42 is reduced and there is greater spacing between the heating elements 42.

[0074] All heating elements 42 are of the same construction, dimensions (diameter, length) and operate at the same temperature, allowing each of them to have identical heat transfer properties for the gas flowing in contact with the heating element. When the gas flows through the preheater interior 16 through a longer flow path toward the rear of the device 10, for example when taking flow paths p3 or p4, the gas has a longer residence time in the preheater. The gas contacts the heating elements 42 in the front half where there is a higher concentration of heating elements, and also in the rear half or preheater 18 where there is a lower concentration of heating elements. In the rear half of the preheater 18, the lower concentration of heating elements results in a lower amount of heat energy being transferred to the gas compared to the amount of heat energy being transferred to the gas in the front half of the preheater 18.

[0075] In the illustrated design, and more generally in devices that include heating rods as heating elements, the number of heating rods included within the preheater interior can be any useful number. An exemplary device can include 10 to 60 individual heating rods evenly or unevenly distributed around the circumference of the preheater interior, such as 40 to 50 heating rods evenly or unevenly distributed around the circumference of the preheater interior.

[0076] 1C (cross-sectional perspective view), FIG. 1D (cross-sectional side view), and FIG. 1E (cross-sectional detailed view), the interior of the apparatus 10 is shown, as well as details of the annular preheater interior 16 between the inner preheater sidewall 14 (which is also the sidewall of the media vessel 20) and the outer preheater sidewall 12.

[0077] As shown in FIG. 1D, gas enters the preheater interior 16 at the front of the apparatus 10 through inlet 30. The gas flows through the preheater interior and contacts heating elements 42 that are unevenly distributed around the circumference of the interior 16. Upon reaching the top of the preheater interior 16, the gas passes through a horizontal preheater outlet (flow gap) 44 and then enters headspace 46 from outlet 44 and a range of locations around the circumference of the media vessel 20. The gas flows through the interior volume of the media vessel 20, contacts the media (not shown) contained therein, and exits the media vessel 20 through outlet 40.

[0078] The amount of heat transfer to the gas along the various flow paths varies due to the different spacing of the heating elements 42 in the front half of the preheater interior 16 relative to the back half of the preheater interior 16. Additionally or alternatively, the amount of heat transfer to the gas along the various flow paths may also be influenced by one or more structures that affect the residence time of the gas through the various flow paths, for example, by retarding, impeding, or slowing the flow rate of the gas along shorter flow paths compared to the flow rate along longer flow paths. As shown in FIG. 1C, a baffle 50 is placed in the preheater outlet 44 to prevent flow through a front segment of the length of the preheater outlet 44 at the front of the apparatus 10.

[0079] As shown, the apparatus 10 does not include a thermal insulation blanket external to the preheater 18. Optionally, a thermal insulation blanket may be included external to the preheater 18 to retain heat within the preheater 18. Optionally, the heating blanket may include a heating element to apply heat to the preheater 18, however, the apparatus 10 does not require and may exclude a heating element as part of the heating blanket or external to the preheater 18 to apply heat to the preheater 18.

[0080] Also, as shown, the apparatus 10 does not include any form of heating element present within the media container 20, i.e., at the location of the media, for directly heating a type of media (catalyst, adsorption media, etc.), or present within the headspace 46. According to useful or preferred examples, the apparatus 10 does not require, and can specifically exclude, any form of heating element present within the media container 20, e.g., at the location of the media, for directly heating the media, or present within the headspace 46.

[0081] 2A, the gas treatment apparatus 110 is shown in a side cross-sectional view without showing the outer preheater sidewall on the side of the apparatus 110. The apparatus 110 includes a media vessel (not shown) adapted to contain a media, and a preheater 118 therein. The preheater 118 surrounds the media vessel along its length (vertical length, as shown) from a lower portion 122 to an upper portion 124. The preheater 118 includes an outer preheater sidewall 112 (partially not shown), an inner preheater sidewall 114 spaced apart from the outer preheater sidewall 112, and an annular preheater interior 116 formed between an inner surface of the outer sidewall 112 and an outer surface of the inner sidewall 114. The inner sidewall 114 of the preheater 118 can also function as a sidewall (outer sidewall) of the media vessel surrounded by the preheater 118.

[0082] Heating elements (e.g., heating rods) 142 extend vertically from the top of the annular preheater interior 116 into the interior 116. As shown, all of the heating elements may be of the same size, construction, heat transfer properties, and are uniformly spaced around the circumference of the interior 116. In alternative embodiments, the heating elements may vary in size (length or diameter), temperature, heat transfer properties, and may be non-uniformly distributed around the circumference of the interior 116.

[0083] Apparatus 110 is an example of an apparatus that includes baffles as a method of controlling gas flow through the preheater interior between the preheater inlet 130 and the preheater outlet, which is located at the top of the preheater interior 116 and leads to the interior of a media vessel (not shown), not specifically shown in Figures 2A or 2B.

[0084] Baffle 120 is a partial circular insert that can fit into interior 116 between inner sidewall 114 and outer sidewall 116 at locations around a portion of the circumference of interior 116. When contained within interior 116, baffle 120 contacts gas flowing through interior 116 and diverts or otherwise controls or influences the flow of gas along a flow path through interior 1160 between a preheater inlet and a preheater outlet.

[0085] As shown, the apparatus 110 includes a plurality (five) of baffles 120 each positioned at a different vertical level within the interior 116. Along the partially circular length of each baffle, the baffle has a width that fits between the gap space between the inner surface of the outer sidewall 112 and the outer surface of the inner sidewall 114 of the preheater 118. When positioned within the preheater interior 116, each baffle 120 blocks vertical gas flow along its partially circular length. The baffles force gas to flow laterally in a direction around the periphery of the preheater 118 and prevent vertical movement of gas at the location of the baffle.

[0086] Each baffle 120 defines a gap 122 between the ends of the baffle. When the baffle is positioned within the interior 116, gas that is prevented from flowing vertically by the baffle 120 can flow vertically through the gap 122 between the ends of the baffle. Each baffle 120 also includes a series of openings 124 through which a heating rod 142 can be positioned when the baffle and heating rod are installed within the interior 116.

[0087] As shown in FIG. 2A, gas entering through the preheater inlet 130 at the front of the apparatus 110 is directed by the first baffle 120a to flow from the front of the preheater interior 116 to the rear of the preheater interior 116 (see the lowest arrow). At the rear of the interior 116, the lowest baffle 120a defines a gap between the ends of the baffle 120a that allows the gas to flow vertically. The second baffle 120b again blocks the vertical flow of gas at a higher vertical level, forcing the gas to flow back toward the front of the interior 116. The gap between the ends of the second baffle 120b at the front of the interior 116 allows the gas to flow to a higher vertical position. Three additional baffles 120c, 120d, and 120e are positioned with gaps staggered between front and rear positions within the interior 116. This arrangement creates a front-to-back-to-front-to-back, etc. flow of gas through the interior 116 as the gas flows vertically from an inlet 130 in the lower portion 122 of the preheater 118 to a preheater outlet (not shown) in the upper portion 124 of the preheater 118.

[0088] 2B illustrates a cross-sectional rear view of the apparatus 110, showing the baffles 120a, 120b, 120c, 120d, and 120e installed in the interior 116, as well as the heating rod 142. With reference to FIG. 2B, the baffles 120a, 120b, 120c, 120d, and 120e are shown in a vertically ordered position, with gaps 122a, 122c, and 122e located at the rear of the interior 116. Gas flows from the lower portion of the interior 116 in the direction of the arrows, with vertical flow restricted along the way by each baffle, and allowing vertical flow at the rear of the interior 116 through gaps 122a, 122c, and 122e. The baffles cause a flow of gas through the interior 116 that is substantially equal on both sides of the interior 116 (left and right as shown).

[0089] example Example 1. A gas processing apparatus comprising: a media container having a media container inlet end with a media container inlet, a media container outlet end with a media container outlet, a media container sidewall extending between the media container inlet and the media container outlet, and a media container interior defined by the media container sidewall; and a preheater exterior to the media container sidewall, the preheater comprising a preheater sidewall spaced apart from the media container sidewall to define a preheater space between an exterior surface of the media container sidewall and an interior surface of the preheater sidewall, a preheater inlet, and a preheater outlet in fluid communication with the media container inlet.

[0090] Example 2. The apparatus of example 1, further comprising a heating element within the preheater space.

[0091] Example 3. The apparatus of example 2, wherein the heating elements are heating rods, the heating rods extending vertically within the preheater space, and the heating rods being distributed along a periphery of the preheater space.

[0092] Example 4. The apparatus of claim 3, wherein the heating rods are distributed along the circumference with non-uniform spacing between the heating rods.

[0093] Example 5. The apparatus of example 3 or 4, wherein the perimeter of the preheater space has a perimeter including a first half perimeter and a second half perimeter, the preheater inlet is located at a center of the first half perimeter, a first half group of heating rods are distributed along the first half perimeter and a second half group of heating rods are distributed along the second half perimeter, and the first half group has a greater number of heating rods than the second half group.

[0094] Example 6. The apparatus of any one of Examples 1-5, further comprising at least one horizontally extending baffle positioned within the preheater space.

[0095] Example 7. The apparatus of example 6, wherein the baffle has a partially circular shape and defines a gap between two ends of the baffle.

[0096] Example 8. The apparatus of example 6 or 7, further comprising heating rods, the heating rods extending vertically within the preheater space, the heating rods extending through openings in the baffle, and the heating rods being distributed along a perimeter of the preheater space.

[0097] Example 9. The apparatus of example 8, wherein the heating rods are distributed along the circumference with uniform spacing between the heating rods.

[0098] Example 10. The apparatus of any one of Examples 1-9, wherein the preheater comprises a preheater inlet end adjacent to the media vessel outlet end and a preheater outlet end adjacent to the media vessel inlet end, the preheater inlet being located at the preheater inlet end and the preheater outlet being located at the preheater outlet end.

[0099] Example 11. The apparatus of any one of Examples 1-10, wherein the preheater outlet connects the preheater interior with the media vessel interior and comprises an opening extending along a perimeter of the preheater including a front surface of the preheater and a back surface of the preheater.

[0100] Example 12. The apparatus of any one of Examples 1-11, wherein the preheater inlet is an opening in a front face of the preheater and extends less than 30 degrees of the perimeter of the preheater.

[0101] Example 13. The apparatus of any one of Examples 1 to 12, wherein the ratio of the area of ​​the preheater inlet to the area of ​​the media vessel outlet is 2:1 to 1:2.

[0102] Example 14. The apparatus of any one of Examples 1 to 13, wherein the preheater space has a cylindrical annular cross section.

[0103] Example 15. The media vessel containing an adsorption media or a media comprising a catalyst, the apparatus of any one of Examples 1 to 14.

[0104] Example 16. The apparatus of any one of Examples 1 to 15, further comprising an inlet end headspace connecting the media vessel inlet and the preheater outlet, and comprising a flow path from the preheater outlet through the inlet end headspace to the media vessel inlet.

[0105] Example 17. The apparatus of any one of Examples 1-16, wherein the preheater space includes flow paths of various lengths between the preheater inlet and the preheater outlet, and the preheater enables a higher rate of heat transfer to gas flowing along shorter flow paths compared to a lower rate of heat transfer to gas flowing along longer flow paths.

[0106] Example 18. A method of using the gas treatment device of any one of Examples 1-17, comprising flowing a gas through the preheater to preheat the gas, and passing the preheated gas through the media vessel and contacting the media contained within the media vessel.

[0107] Example 19. The method of example 18, wherein the gas is selected from nitrogen, argon, hydrogen, ammonia, carbon dioxide, clean dry air, and oxygen.

[0108] Example 20. The method of example 19, wherein the medium comprises a catalyst and the gas is a reagent gas selected from nitrogen, argon, hydrogen, carbon dioxide, clean dry air, and oxygen.

[0109] Example 21. The method of example 19 or 20, wherein the impurity is nitrogen oxides, carbon monoxide, or hydrocarbons.

[0110] Example 22. The method of example 19 or 20, wherein the impurity is methane.

[0111] Example 23. The method of any one of Examples 19-22, wherein the apparatus does not include a heating element within the media vessel and the apparatus does not include a heating element external to the preheater.

Claims

1. 1. A medium container comprising: a media container inlet end having a media container inlet; a media container outlet end having a media container outlet; a media container sidewall extending between the media container inlet and the media container outlet; and a media container interior defined by said media container sidewalls A medium container comprising: a preheater on the exterior sidewall of the media vessel, a preheater sidewall exterior to the media vessel sidewall, the preheater sidewall being spaced apart from the media vessel sidewall to define a preheater space between an exterior surface of the media vessel sidewall and an interior surface of the preheater sidewall; Preheater inlet, and a preheater outlet in fluid communication with the media vessel inlet; A preheater comprising: A gas treatment device comprising:

2. The apparatus of claim 1 further comprising a heating element within the preheater space.

3. the heating element is a heating rod; The heating rod extends vertically within the preheater space; The heating rods are distributed along the periphery of the preheater space.

3. The apparatus of claim 2.

4. The apparatus of claim 3 , wherein the heating rods are distributed along the circumference with non-uniform spacing between the heating rods.

5. The periphery of the preheater space has a periphery including a first half periphery and a second half periphery, The preheater inlet is located at the center of the periphery of the first half, the front half group of heating rods is distributed along the periphery of said front half; the rear half group of heating rods are distributed along the periphery of said rear half, The first half group has a greater number of heating rods than the second half group.

5. Apparatus according to claim 3 or 4.

6. The apparatus of claim 1 , further comprising at least one horizontally extending baffle positioned within the preheater space.

7. The apparatus of claim 6 , wherein the baffle has a partially circular shape and defines a gap between two ends of the baffle.

8. Further comprising a heating rod; The heating rod extends vertically within the preheater space; the heating rod extends through an opening in the baffle; The heating rods are distributed along the periphery of the preheater space.

8. Apparatus according to claim 6 or 7.

9. The apparatus of claim 8 , wherein the heating rods are distributed along the circumference with uniform spacing between the heating rods.

10. The preheater is a preheater inlet end adjacent the media vessel outlet end; a preheater outlet end adjacent the media vessel inlet end; Equipped with the preheater inlet is located at the preheater inlet end, The preheater outlet is located at the preheater outlet end.

10. Apparatus according to any one of claims 1 to 9.

11. 11. The apparatus of claim 1, wherein the preheater outlet comprises an opening connecting a preheater interior with a media vessel interior and extending along a perimeter of the preheater including a front surface of the preheater and a back surface of the preheater.

12. 12. The apparatus of claim 1, wherein the preheater inlet is an opening in a front face of the preheater and extends less than 30 degrees of the circumference of the preheater.

13. 13. The apparatus of claim 1, wherein a ratio of an area of ​​the preheater inlet to an area of ​​the media vessel outlet is between 2:1 and 1:

2.

14. 14. Apparatus according to any one of claims 1 to 13, wherein the preheater space has a cylindrical annular cross section.

15. 15. The apparatus of claim 1 , wherein the media vessel contains an adsorption media or a media comprising a catalyst.

16. 16. The apparatus of claim 1, further comprising an inlet end headspace connecting the media vessel inlet and the preheater outlet, the inlet end headspace providing a flow path from the preheater outlet through the inlet end headspace to the media vessel inlet.

17. the preheater space includes flow paths of various lengths between the preheater inlet and the preheater outlet; the preheater allows for a higher rate of heat transfer to gas flowing along a shorter path compared to a lower rate of heat transfer to gas flowing along a longer path; 17. Apparatus according to any one of claims 1 to 16.

18. A method of using a gas treatment device according to any one of claims 1 to 17, comprising the steps of: flowing a gas through the preheater to preheat the gas; passing a preheated gas through the media container and contacting the media contained therein; A method comprising:

19. 20. The method of claim 18, wherein the gas is selected from nitrogen, argon, hydrogen, ammonia, carbon dioxide, clean dry air, and oxygen.

20. 20. The method of claim 19, wherein the medium comprises a catalyst and the gas is a reagent gas selected from nitrogen, argon, hydrogen, carbon dioxide, clean dry air, and oxygen.

21. 21. The method of claim 19 or 20, wherein the impurities are nitrogen oxides, carbon monoxide, or hydrocarbons.

22. 21. The method of claim 19 or 20, wherein the impurity is methane.

23. 23. The method of any one of claims 19 to 22, wherein the apparatus does not include a heating element within the media vessel and the apparatus does not include a heating element external to the preheater.

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