Gas treatment systems and methods

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] Claims of Priority This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 318,894, filed on Mar. 11, 2022, the entire content of which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to a gas treatment system including a media vessel and a preheater, and related methods. The gas treatment system is used to treat a gas by flowing the gas into contact with a media (e.g., a catalyst or an adsorbent material) contained in the media vessel.

Background Art

[0003] Industrial gases are used as raw materials or processing materials (referred to as "reagent gases") for a variety of commercial and industrial purposes. Commercial and industrial purposes include the manufacture of semiconductor and microelectronic devices.

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

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

[0006] Techniques for purifying gas flows may involve contacting the gas with a medium material capable of removing (i.e., reducing) the amount of impurities contained in the gas. In some techniques, impurities are removed from the gas flow by capturing them, such as by adsorbing them onto the surface of an adsorbent (i.e., an "adsorption medium"). In other techniques, impurities may be contacted with a solid catalyst material that chemically converts (e.g., oxidizes) the impurities into derivative compounds. The impurities converted into derivative compounds are considered more desirable (or not undesirable) than the original impurities.

[0007] The manufacturer designed highly specialized equipment for carrying out the gas purification process. The gas purification system includes a container (vessel) for holding a medium of a type such as an adsorbent, filter, or catalyst (e.g., a purification medium), and accompanying flow control equipment that guides the flow of the reagent gas through the container into contact with the medium. A control unit is included for controlling process conditions such as temperature, pressure, and flow rate.

[0008] Many gas processing systems include a gas preheater. A gas preheater is used to preheat a gas before it flows through a container containing a medium. For example, to improve the efficiency of a catalytic purification process, the gas may be preheated before contact with the catalyst. Equipment for these types of catalytic processes includes a container containing the catalyst, a flow control unit that produces a flow of gas through the catalyst, and a preheater that heats the gas to a high temperature before it comes into contact with the catalyst.

[0009] Gas preheaters can also be useful in adsorption-type gas purification systems in either an adsorption (for filtration or purification) step or a regeneration step. In these systems, purification by adsorption is carried out by flowing the gas through an adsorption medium. As the gas flows through the adsorption medium, impurities in the gas are adsorbed onto the medium while the gas passes through the medium without being adsorbed.

[0010] Over the course of its use, impurities accumulate on the adsorbent medium. These accumulated impurities can be removed from the adsorbent by a regeneration process. The regeneration process involves exposing the medium to a stream of clean ("regeneration") gas at high temperatures to desorb and remove impurities from the adsorbent. The regeneration process can be carried out while the adsorbent medium remains in the same container containing the medium during the purification step, by passing a heated gas ("regeneration gas") through the adsorbent medium in the original container. The regeneration gas comes into contact with the surface of the adsorbent medium, and adsorbed impurities accumulated on the surface of the medium are desorbed from the surface and carried away by the regeneration gas. For efficient regeneration, the regeneration gas is usually preheated before contact with the adsorbent medium.

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

[0012] To control the temperature of the gas and avoid thermal gradients, the processing system may include a preheater that heats the gas before it comes into contact with the medium contained in the medium container. In one embodiment, the gas may be heated before it enters the medium container by using a separate, standalone preheater device, which is a separate structure from the medium container. The gas first flows through the standalone preheater device, where it is heated, and then the heated gas flows from the preheater device to the other medium container. The separate preheater device requires a separate flow control unit, a separate temperature and pressure control unit and sensors, separate heating and insulation equipment, and an entirely separate physical housing structure.

[0013] Alternative preheating techniques involve heating the gas at an "upstream" position of the medium as it passes through a space containing the medium ("medium container"). A preheater is similarly part of the internal space of the medium container, and the preheater portion includes a heating element or another type of heating mechanism, thereby adding thermal energy to the gas flow as it passes from the container inlet through the preheater space and then comes into contact with the medium. The preheater space is located upstream of the medium, physically "inline" with the medium contained in the medium container, and within a shared structure, typically located vertically above or below the medium. [Overview of the project]

[0014] For various reasons, commercial processes may include steps that bring a gas into contact with a medium, causing the medium to interact with the gas to perform an action on the gas or on the medium. Illustrative processes include filtering or purifying a gas, or regenerating a medium.

[0015] These types of processes require, or can be improved by, operating at high temperatures by heating the gas, the medium, or both. For example, the process of purifying reagent gases by catalytic techniques is typically carried out at high temperatures. Similarly, the process of regenerating the bed of solid adsorption media used in adsorption purification or filtration processes is typically carried out at high temperatures. In these methods, the relevant gas (reagent gas or regeneration gas) is typically preheated before the gas comes into contact with the relevant medium (catalyst or adsorption medium).

[0016] The following describes a gas processing apparatus including a combination of a medium container and an annular preheater surrounding the medium container. The novel apparatus design of the present invention includes a medium container containing a medium such as an adsorbent or catalyst, and an annular preheater surrounding the medium container, preferably in thermal contact with the medium container. During use, the gas flow enters the annular preheater through the inlet, then flows through the annular preheater surrounding the medium container, and then flows through the preheater outlet leading to the medium container and the medium. As the gas passes through the preheater, the preheater adds thermal energy to the gas, and the gas flowing from the preheater into the medium container is heated to a high temperature by the preheater.

[0017] Novel designs allow the preheater device to share common structures and control units with the medium container. In a preferred example, the preheater may be in thermal contact with the medium container to share thermal energy with the medium container through adjacent or common structures of the preheater and medium container, such as the side walls of the structure, in addition to the heat exchanged by the preheated gas flowing from the preheater to the medium container. The overall effect is a reduction in the amount of energy required to heat the gas and medium. This effect can be enhanced by using flow control structures within the volume of the preheater, such as baffles, to control the gas flow between the inlet and outlet of the preheater.

[0018] Another preferred feature of the apparatus is that the exterior of the combination of the preheater and the medium container gas processing apparatus can be insulated, but heating elements as part of an external insulating device (e.g., a blanket) may not be required and may be preferably excluded.

[0019] In one aspect, the present disclosure relates to a gas treatment apparatus. The apparatus includes a media container and a preheater. The media container includes a media container inlet end portion having a media container inlet, a media container outlet end portion having a media container outlet, a media container side wall extending between the media container inlet and the media container outlet, and a media container interior defined by the media container side wall. The preheater is located outside the media container side wall and includes a preheater side wall that is outside the media container side wall, spaced apart from the media container side wall, and defines a preheater space between an outer surface of the media container side wall and an inner surface of the preheater side wall, a preheater inlet, and a preheater outlet in fluid communication with the media container inlet.

[0020] In another aspect, the present disclosure relates to a method of using the gas treatment apparatus of this specification. The method includes flowing gas through a preheater to preheat the gas and passing the preheated gas into the media container interior to contact a media contained within the media container interior.

Brief Description of the Drawings

[0021] [Figure 1A] It is an external side perspective view of the described apparatus including a media container and a preheater. [Figure 1B] It is an external top view of the described apparatus including a media container and a preheater. [Figure 1C] It is a side cross-sectional view of the described apparatus including a media container and a preheater. [Figure 1D] It is a side cross-sectional view of the described apparatus including a media container and a preheater. [Figure 1E] It is a detailed cross-sectional view of the described apparatus including a media container and a preheater. [Figure 2A] It is a diagram showing an example of an apparatus having the described baffle. [Figure 2B] It is a diagram showing an example of an apparatus having the described baffle.

Modes for Carrying Out the Invention

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

[0023] The following is an explanation of gas treatment equipment that includes a preheater and is useful for processing a gas flow. A method of using equipment for treating a gas by heating ( "preheating") the gas prior to subsequent processing operations that are carried out by contacting the gas flow with a medium is also described.

[0024] The gas treatment apparatus includes a medium container that contains a certain type of treatment medium (e.g., adsorbent, catalyst), and an annular preheater that surrounds the outside of the medium container and preheats the gas flow before the gas flows into the medium container and contacts the medium. The preheated gas contacts the medium within the medium container, which can be a solid catalyst or an adsorption medium, etc. The preheater is incorporated into the physical structure of the medium container such that the preheater shares space and structure with the medium container, shares thermal energy with the medium container by conductive heat transfer, or both. A preferred design enables thermal energy to pass from the preheater to the medium container by conduction through the structures of the preheater and the medium container, particularly the sidewall structures of the preheater and the medium container.

[0025] An exemplary gas treatment apparatus includes a medium container that has an inlet at one end, an outlet at a second end, and a length and volume that extend between the two ends. The preheater is located outside the medium container and along at least a portion of the length of the medium container. The preheater is in thermal contact with the medium container along the length of the medium container and can pass thermal energy by conduction between the preheater and the medium container. In an exemplary design, the surface of the preheater along its length contacts or is shared with the surface of the medium container along the length of the medium container. 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 medium container and preheater designs. As an example, the apparatus described can include a blanket that is external to the apparatus to insulate the apparatus and retain heat within the preheater, i.e., surround the preheater. However, the exemplary apparatus does not require, and can specifically exclude, a heating element (any source of thermal energy) that adds heat to the preheater from an external location.

[0026] Reducing the number of physical components in the combination of media container and preheater structures can enable cost reductions, and can reduce the overall size (especially length) and spatial requirements of the media container and preheater device, or both.

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

[0028] For use in gas purification processes, a reagent gas containing impurities can be passed through a medium and brought into contact with it, and the medium can reduce the amount of impurities in the gas during the contact between the medium and the gas. The purification process includes processes of filtration, adsorption of impurities from the gas, and catalytic conversion of impurities from the gas.

[0029] Several gas purification techniques remove impurities from the process gas flow by capturing them, such as by adsorbing them onto the surface of an adsorbent material. In one technique, a gas is passed through a solid adsorbent material, and impurities present in the gas are attracted to and adsorbed onto the surface of the adsorbent, effectively removing impurities that are not substantially adsorbed from the gas. Various adsorbent materials are known. The adsorbent can be any of various sizes and shapes, such as small particles, granules, pellets, shells, cubes, or monoliths, having a desired surface area per unit 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 flows include, among others, activated carbon, zeolite materials, "metal-organic frame" (MOF) adsorbents, and getters such as zinc-vanadium and zinc-aluminum getters.

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

[0032] During the use of an adsorption-type gas purification system, a certain amount of impurities accumulate on the adsorbent. The accumulated impurities can be removed from the adsorbent by a “regeneration” step, and the regenerated adsorbent can be reused to purify the gas flow by contact with the adsorbent. In the regeneration step, a flow of relatively clean gas (“regenerated gas”) is passed through and brought into contact with the adsorbent at a high temperature. The regenerated gas may be heated to a high temperature by the use of a preheater, as described herein.

[0033] The regeneration gas can be any gas effective in the regeneration step of removing impurities accumulated from the adsorption medium. The composition of a regeneration gas for removing impurities from a particular type of adsorption medium depends on factors including the type of reagent gas treated using the adsorption medium, the type of impurity, and the type of adsorbent. According to a particular exemplary system, regeneration gases useful for removing impurities accumulated from an adsorption medium 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 involve contacting the impurities in the gas with a solid catalyst, which chemically converts (e.g., chemically reduces or chemically oxidizes) the impurity compounds into more desirable (or not undesirable) derivative chemical compounds compared to the original impurities.

[0035] Catalysts can be selected to react with specific impurities present in the reagent gas. An example of a catalyst is nitrogen oxides (NOx). x These techniques can be effective in chemically reducing ) or oxidizing carbon monoxide, or oxidizing hydrocarbons such as methane to form water and carbon dioxide. Through these techniques, a stream of reagent gas is guided to come into contact with a catalyst medium, and impurities (e.g., nitrogen oxides, carbon monoxide, or hydrocarbons such as methane) are chemically converted (e.g., chemically reduced or chemically oxidized) into preferred chemical compounds compared to the original impurities. In the specific example of oxidizing hydrocarbons such as methane, the hydrocarbon is catalytically oxidized to form water and carbon dioxide.

[0036] The catalyst composition of 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 removal efficiency of the impurities, and other factors. Examples of catalysts known to be useful for transforming impurities in a gas stream include, among others, rhodium, platinum, and palladium.

[0037] According to an exemplary gas processing apparatus, a useful apparatus includes a medium container having a medium container inlet, a medium container outlet, a length extending between the inlet and outlet, and side walls extending along the length and defining the internal volume of the medium container. The side walls can be made of a rigid, thermally conductive material such as metal.

[0038] The "medium container inlet" can be considered an open portion of the medium container that is part of the flow path into the medium container, connected (fluidally) to the inside of the medium container, allowing process gases flowing through the medium container inlet to enter the medium container containing the medium. The medium container inlet also communicates directly or indirectly with the preheater outlet. The medium container inlet may be connected directly to the preheater outlet, or it may be connected to the preheater outlet through a closed flow path between the preheater outlet and the medium container inlet, such as a path extending from the preheater outlet through the inlet headspace and then to the medium container inlet.

[0039] Furthermore, according to the apparatus described, the annular preheater is located adjacent to the outer surface of the medium container along at least a portion of the length of the medium container and around the entire outer surface of the medium container, i.e., the circumference (periphery). Useful or preferred preheaters may include sidewall surfaces that are in thermal contact with the outer surface of the medium container. The term “periphery” as used herein refers to the closed geometric shape of the container, sidewall, preheater, or space when viewed in cross-section along a length generally along the horizontal cross-section of the container, sidewall, or space of the gas processing apparatus described herein (for example, when viewed vertically or “height” as shown in Figure 1).

[0040] A preheater "in thermal contact" with a medium container refers to a preheater that includes structures such as side walls that are common to the structure of the medium container, or a preheater that is located close enough to the surface (such as a side wall) of the medium container to allow a useful amount of thermal energy to pass from inside the preheater to inside the medium container. A useful amount of thermal energy may be more than a negligible amount of thermal energy that passes from the preheater to the medium container during use to supply preheated gas to the medium container.

[0041] To provide a useful amount of thermal contact between the preheater and the medium container, the exemplary gas processing apparatus may be configured such that the thermally conductive surface of the preheater sidewall is in direct contact with the thermally conductive surface of the medium container sidewall. The preheater sidewall structure may be identifiable as a separate physical structure that is not a required component of the medium container, and the two different sidewall structures are in direct physical contact with each other to allow for efficient transfer of thermal energy by heat conduction from the surface of the preheater sidewall to the surface of the medium container sidewall.

[0042] Alternatively, the gas processing apparatus described may be configured such that the side walls of the medium container and the side walls of the preheater are made from a single physical structure. The single side wall structure defines the interior of the medium container on one side of the side wall (the "inside" of the single side wall) and the interior of the preheater on the opposite side of the side wall (the "outside" of the single side wall).

[0043] In contrast, the sidewall structures of the medium container and the preheater are considered not to be in thermal contact with each other if they are positioned so as not to allow a useful amount of heat energy transfer from the sidewall of the preheater through the sidewall of the medium container during the gas processing steps described herein. Various designs of conventional gas processing systems include a preheater and a medium container, and these two are positioned so as not to allow heat transfer between the sidewall structures, i.e., the preheater does not have thermal contact with the medium container. For example, certain preheater designs involve preheating a process gas as the gas passes through a space in the medium container that is "upstream" of the medium in the same container, and 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 container together with the medium, and the process gas flows through the container by first coming into contact with the heating element and then with the medium. In-line preheaters are often located either above or below the medium. The sidewalls of the preheater structure are not considered to be in thermal contact with the sidewall structure of the medium container.

[0044] According to the novel gas processing apparatus described herein, the preheater includes a preheater internal volume extending along the length of the medium container outside the medium container. More specifically, the preheater is annular ("annular volume") and includes an internal volume through which the gas flows during use, extending along the outer surface of the medium container over at least a portion of the length of the medium container between the medium container inlet and the medium container outlet.

[0045] The preheater comprises an annular volume defined by an inner side wall and an outer side wall, the outer side wall being separated from the inner side wall to create the internal space of the preheater. The inner side wall may have the same structure as the outer wall (side wall) of the medium container, or may be connected to it, or may be in thermal contact with it. The volume (internal space) between the inner side wall and the outer side wall of the preheater is nominally called "annular" and is preferably cylindrical with a circular cross-section (when viewed along its length) for high efficiency in the design of the apparatus. However, the "annular" cross-section may be non-circular, such as elliptical or rectangular, as desired.

[0046] An exemplary preheater includes a preheater inlet located in the lower part of the preheater and passing through the outer side wall of the preheater, and a preheater outlet located in the upper part of the preheater and passing through or across the inner side wall of the preheater. Optionally, the described apparatus may be configured to operate with different flows of gas through the preheater and the medium container. For example, the preheater inlet may be in the upper region of the apparatus, and the gas may flow into the inlet and then vertically downward through the preheater, and then vertically upward through the medium container.

[0047] According to a particular exemplary apparatus, the preheater inlet includes an opening or opening that passes through the outer side wall of the preheater on one side of the preheater and does not extend beyond a short portion of the length of the circumference of the preheater. This means, for example, that the inlet does not extend from the front to the rear of the preheater as the preheater outlet does, but can extend only over 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 defined by the size (area) of the opening that passes through the outer side wall of the preheater, for example, the area of ​​a circular opening.

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

[0049] The preheater outlet is located at the end of the apparatus opposite the preheater inlet and extends around most of the circumference of the annular preheater between the front and rear of the apparatus. The outlet extends along at least a portion of the front of the preheater (including the 0-degree front, 90 degrees to 270 degrees front 180 degrees, see Figure 1B) and also along at least a portion of the rear of the preheater (including the 180-degree rear, 90 degrees to 270 degrees rear 180 degrees, see Figure 1B). The location of the outlet around most of the circumference of the annular preheater allows the gas to flow into the medium container from most or all of the annular preheater. The location along the circumference allows the preheated gas to enter the medium container from all or substantial directions around the circumference of the medium container (e.g., from approximately 360 degrees of the annular preheater).

[0050] The outlet extends along the length of the inner sidewall of the medium vessel as a horizontal opening, which may be called a horizontal flow gap, horizontal space, or horizontal slot, having a length along the perimeter or the inner sidewall of the preheater, along the sidewall of the medium vessel, or both. The outlet opening may be continuous along its length (i.e., extending uninterrupted around the entire 360 ​​degrees), segmented (e.g., including multiple regular interruptions), or otherwise interrupted, such as to reduce the amount of flow at locations where baffles are used to block the flow through the outlet. Unlike the preheater inlet, the outlet opening includes an opening that allows the gas to flow out of the preheater over a substantial range of locations along the 360 ​​degrees perimeter of the preheater, which optionally include locations at or near the front, at the rear, and between the front and the rear.

[0051] The outlet also has an area equal to the size of the opening between the inside of the preheater and the inside of the medium container. The opening may also have an area equal to the size of the flow gap, which means the length of the flow gap around the side wall of the medium container (excluding the shutoff or baffle) multiplied by the "height" of the flow gas (the dimension of the flow gap along the "length" of the medium container).

[0052] In a preferred example, the apparatus may have a desired ratio of the area of ​​the preheater inlet to the area of ​​the medium container outlet (shown as 30 and 40, respectively, in Figure 1). Exemplary ratios of the area of ​​the preheater inlet to the area of ​​the medium container outlet may be 2:1 to 1:2, for example, 1.5:1 to 1:1.5 (area of ​​preheater inlet: area of ​​medium container outlet). In the exemplary system, the area of ​​the medium container outlet may be slightly larger than the area of ​​the preheater inlet; for example, the medium container outlet may have an area equal to the area of ​​the preheater inlet, or an area of ​​100% to 150% of the size of the preheater inlet, or 110% to 130% of the size of the preheater inlet.

[0053] A preheater includes a heat source called a "heating element" that operates at a high temperature for the process gas entering the preheater through the preheater inlet during use. The heating element transfers thermal energy to the gas flowing through the inside of the preheater in order to raise the temperature of the gas before it leaves the preheater at the preheater outlet and enters the medium container. The temperature of the heating element can be controlled to rise, for example, by any useful source or method such as electric 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 may include any useful design, including a heating element sometimes called a heating rod, electric resistance heater, heating bar, or strip heater.

[0054] The heating elements may be uniformly distributed within the preheater around the periphery of the annular preheater, or they may be non-uniformly distributed within the preheater around its circumference. An example of a heating element is a heating rod that can be placed within the annular internal space of the preheater. In certain exemplary devices, the heating rod may be non-uniformly distributed around the periphery of the annular preheater.

[0055] As a result of the preheater inlet being located along a limited portion of the preheater's perimeter (for example, only at the front of the preheater), the gas flowing into the annular preheater passes from inlet to outlet across a range of flow paths within the annular preheater, compared to the preheater outlet being located around a wider area of ​​the preheater's perimeter. Various flow paths extend at varying distances around the length of the preheater's perimeter to allow the gas to exit the front, side, and rear of the preheater outlet and to enter the medium container from all parts of the medium container's perimeter.

[0056] The various flow paths between the shortened inlet (relative to the perimeter) at the front of the preheater and the range of outlet positions around the front, rear, and sides of the preheater have various flow path lengths and therefore various residence times within the preheater.

[0057] For example, the gas flow that passes through the inlet and enters the annular preheater at the front of the preheater can also flow out from the preheater outlet (into the medium container) and into the front. The gas moving through this path inside the preheater travels the shortest possible distance between the inlet and outlet. This gas path through the preheater also has the shortest possible residence time inside the preheater.

[0058] In contrast, a gas flow entering the inlet at the front of the annular preheater and exiting the outlet at the rear of the preheater (and medium container) travels as far as possible from the inlet around the circumference of the preheater, at a 180-degree angle relative to the inlet, before reaching the outlet at the rear of the preheater. The gas traveling along this path travels the largest possible distance between the inlet and outlet. This gas flow has the longest possible residence time within the annular space of the preheater.

[0059] Gases traveling along longer flow paths have longer residence times within the preheater, while gases traveling along shorter flow paths have shorter residence times. In a preheater containing heating elements evenly distributed within the preheater around its perimeter, the difference in residence times can lead to temperature imbalances or inconsistencies in the gases exiting the preheater at various positions along the perimeter of the preheater outlet. Because the heating elements are evenly distributed around the circumference of the preheater, gases with longer residence times within the preheater receive a greater amount of heat transfer from the heating elements as they flow through the preheater from inlet to outlet, absorbing a greater amount of heat from the heating elements compared to gases with shorter residence times within the preheater.

[0060] According to the exemplary methods and apparatus of this specification, heating elements within a preheater can be designed and distributed to transfer varying amounts of heat to gases flowing through the preheater along various paths and experiencing varying residence times within the preheater. The preheater allows for a higher heat transfer rate to gases flowing along shorter paths and a lower heat transfer rate to gases flowing along longer paths.

[0061] For example, the heating elements may be distributed non-uniformly within the preheater, for example, around the circumference of the preheater (by varying the spacing between the heating elements). Preferably, the non-uniform distribution of the heating elements exposes gas flows with varying residence times within the preheater to varying amounts of heating along various flow paths through the preheater.

[0062] In alternative embodiments, instead of distributing heating elements unevenly within the preheater, or in addition to that, the heating elements may be designed or controlled to cause a varied, uneven amount of heat transfer to the gas flowing along various channels and experiencing varying residence times within the preheater. In other examples, the heating elements within the preheater may have varying sizes (diameter, length) or be set to varying temperatures to cause varying amounts of heat transfer to the gas moving along longer or shorter channels through the preheater.

[0063] In these and other embodiments, the preheater may optionally include a flow control unit or flow limiter (e.g., a baffle) that obstructs the flow of gas through the preheater, thereby reducing the velocity or volume of fluid through the flow path and increasing the residence time of the gas along the flow path. The flow control unit may be, for example, a baffle located at the preheater outlet on 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 the gas flowing through the front of the preheater.

[0064] The heat transfer of varying amounts (e.g., rates) to gas flows traveling through longer and shorter channels, with longer and shorter residence times, can be designed to reduce the temperature difference between the gas exiting the preheater outlet and entering the medium container at various positions around the medium container inlet. Preferably, the gas flows traveling along the various channels may be exposed to similar (preferably substantially equal) amounts of heat transfer along each different channel. The gas flows traveling along the various channels may be exposed to similar amounts of heat transfer from non-uniformly distributed heating elements so that the different gas flows 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 across longer and shorter channels, the heat transfer rate can be higher along the shorter channel and lower along the longer channel.

[0065] Exemplary apparatuses are shown in Figures 1A (side perspective view), 1B (top view), 1C (section view), 1D (detailed section view), and 1E (side section view). Figures 1A–1D show an exemplary apparatus that includes an annular preheater space outside the medium vessel. The preheater includes an outlet into the medium vessel, extending around the perimeter of the medium vessel, with an inlet only at the front and a portion of its portion at both the front and rear. The interior of the preheater includes heating elements asymmetrically arranged around the perimeter of the preheater, with more heating rods at the front of the apparatus and fewer heating rods at the rear of the apparatus. Partial baffles reduce the flow through the preheater outlet via the front of the outlet.

[0066] Referring to Figure 1A, the exterior of the gas processing apparatus 10 is shown. The apparatus 10 contains a medium container 20 adapted to contain a medium (not shown). The preheater 18 is a structure that surrounds the medium container 20 along its length (as shown, the vertical length) from the lower portion 22 to the upper portion 24. The preheater 18 includes an outer preheater sidewall 12, an inner preheater sidewall 14 (not shown in Figure 1A) separated from the outer preheater sidewall 12, and an annular preheater interior 16 formed between the inner surface of the outer sidewall 12 and the 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 medium container 20.

[0067] The heating element (e.g., a heating rod) 42 extends vertically into the interior 16 from the top of the annular preheater interior 16. As shown in the figure, all heating elements may be of the same size, structure, and heat transfer properties. In alternative embodiments, the heating elements may differ in size (length or diameter).

[0068] The apparatus 10 has a circumference (P) and a perimeter length measured around the outside of the apparatus 10. The inlet 30 is a round opening through the outer side wall 12 that includes a closed conduit (e.g., a pipe or tube) connecting the outside of the apparatus 10 to the annular interior 16 of the annular preheater 18, and can be considered to be located at the "front" of the apparatus 10.

[0069] During use, the gas enters the inlet 30, passes through the annular interior 16 of the preheater 18, and then enters the medium container 20 through the outlet 44 of the preheater 30 (not in contact in Figure 1A). The gas flows through the medium container 20 (the medium contained within the medium container 20) and then passes from the medium container 20 through the preheater outlet 44, which extends around the perimeter of the preheater 18 at the upper part or upper end of the preheater 18.

[0070] The gas flows through the annular interior 16 of the preheater 18 along multiple channels of varying lengths (for example, p1, p2, p3, p4 shown in Figure 1A). Channel p1 extends directly upward vertically from the inlet 30 (as shown) and passes through the preheater outlet 44 at the upper end of the preheater interior 16. This channel p1 is the shortest channel length between the inlet 30 and the preheater outlet 44. The gas flowing along channel p1 has the shortest residence time within the preheater interior 18.

[0071] The flow path p4 is shown to extend from the inlet 30 along a curved path within the annular preheater to the front and rear of the apparatus 10, which is 180 degrees opposite the inlet 30. The curved flow path p4 extends from the inlet 30 in a curved vertical direction along its length along the annular interior of the preheater 18, which extends along 180 degrees around the annular interior. The flow path p4 terminates at the preheater outlet at the rear of the apparatus 10, which is the maximum flow path length between the inlet 30 and the preheater outlet. The gas flowing along the flow path p4 has the maximum residence time within the preheater 18.

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

[0073] Figure 1B shows a top view of the apparatus 10. This figure shows that the heating elements 42 are unevenly distributed within the annular preheater interior 16 around the length of the circumference P. Along the length of the front half of the preheater 18, between 90° and 270°, including the front position at 0° along the circumference, the heating elements 42 are distributed with a first degree of concentration, with relatively small separation between adjacent heating elements. In the rear half of the preheater 18, between 90° and 270°, including the rear position at 180°, the concentration of the heating elements 42 is reduced, and the spacing between the heating elements 42 becomes larger.

[0074] Since all heating elements 42 have the same structure, dimensions (diameter, length), and operate at the same temperature, each of them allows for the same heat transfer properties to the gas flowing in contact with the heating element. When the gas flows through the inside of the preheater 16 through a longer flow path toward the rear of the apparatus 10, for example, when taking flow path p3 or p4, the gas has a longer residence time in the preheater. The gas comes into contact with the heating elements 42 in the front half where the concentration of heating elements is higher, and also in the rear half or preheater 18 where the concentration of heating elements is lower. In the rear half of the preheater 18, the lower the concentration of heating elements, the less thermal energy is transferred to the gas compared to the amount of thermal energy transferred to the gas in the front half of the preheater 18.

[0075] In the illustrated design, and more generally in a device that includes heating rods as heating elements, the number of heating rods contained within the preheater can be any useful number. An exemplary device may include 10 to 60 individual heating rods evenly or unevenly distributed around the periphery inside the preheater, for example, 40 to 50 heating rods evenly or unevenly distributed around the periphery inside the preheater.

[0076] Referring to Figures 1C (sectional perspective view), 1D (sectional side view), and 1E (sectional detail view), the interior of the apparatus 10 and the details of the annular preheater interior 16 between the inner preheater side wall 14 (which is also the side wall of the medium container 20) and the outer preheater side wall 12 are shown.

[0077] As shown in Figure 1D, the gas flows through the inlet 30 into the preheater interior 16 at the front of the apparatus 10. The gas flows through the preheater interior and comes into contact with heating elements 42 that are unevenly distributed around the perimeter of the interior 16. Upon reaching the top of the preheater interior 16, the gas passes through the horizontal preheater outlet (flow gap) 44 and then enters the headspace 46 from a range of positions around the outlet 44 and the medium container 20. The gas flows through the internal volume of the medium container 20, comes into contact with the medium (not shown) contained in the medium container 20, and exits the medium container 20 through the outlet 40.

[0078] The amount of heat transferred to the gas along various flow paths varies due to the varying spacing of the heating elements 42 in the front half of the preheater interior 16 relative to the rear half of the preheater interior 16. Additionally or alternatively, the amount of heat transferred to the gas along various flow paths may also be affected by one or more structures that influence the residence time of the gas through the various flow paths, for example, by slowing, hindering, or slowing the flow rate of gas along shorter flow paths compared to the flow rate along longer flow paths. As shown in Figure 1C, a baffle 50 is placed inside the preheater outlet 44 to prevent flow through the front segment of the preheater outlet 44 at the front of the device 10.

[0079] As shown in the figure, the apparatus 10 does not include an insulating blanket outside the preheater 18. Optionally, an insulating blanket may be included outside the preheater 18 to retain heat within the preheater 18. Optionally, the heating blanket may include a heating element for adding heat to the preheater 18, but the apparatus 10 may exclude a heating element, either as part of the heating blanket or outside the preheater 18, for adding heat to the preheater 18.

[0080] Furthermore, as shown in the figure, the apparatus 10 does not include any heating element of any kind located within the media container 20, i.e., at the location of the media, for directly heating a certain type of media (such as a catalyst or adsorption medium), or located within the headspace 46. In a useful or preferred example, the apparatus 10 does not require, and may even exclude, any heating element of any kind located within the media container 20, for example, at the location of the media, for directly heating the media, or located within the headspace 46.

[0081] Referring to Figure 2A, the gas processing apparatus 110 is shown in a side section view without showing the outer preheater sidewall on the side of the apparatus 110. The apparatus 110 includes a medium container (not shown) adapted to contain a medium and a preheater 118. The preheater 118 surrounds the medium container along its length (as shown, the vertical length) from the lower portion 122 to the upper portion 124. The preheater 118 includes an outer preheater sidewall 112 (partially not shown), an inner preheater sidewall 114 separated from the outer preheater sidewall 112, and an annular preheater interior 116 formed between the inner surface of the outer sidewall 112 and the outer surface of the inner sidewall 114. The inner sidewall 114 of the preheater 118 can also function as the sidewall (outer sidewall) of the medium container surrounded by the preheater 118.

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

[0083] Apparatus 110 is an example of an apparatus that includes a baffle as a method for controlling the flow of gas through the inside of the preheater between the preheater inlet 130 and the preheater outlet. The preheater outlet is located at the top of the inside of the preheater 116 and leads to the inside of a medium container (not shown), but is not specifically shown in Figure 2A or Figure 2B.

[0084] The baffle 120 is a partially circular insert that can be fitted into the interior 116 between the inner sidewall 114 and the outer sidewall 116, at a position around a portion of the interior 116. When contained within the interior 116, the baffle 120 comes into contact with the gas flowing through the interior 116, and diverts, controls, or influences the gas flow along the passage through the interior 1160 between the preheater inlet and the preheater outlet.

[0085] As shown, the device 110 includes a plurality (five) of baffles 120, each positioned at different vertical levels within the interior 116. Along the partially circular length of each baffle, the baffle has a width that fits into the gap space between the inner surface of the outer side wall 112 and the outer surface of the inner side wall 114 of the preheater 118. When positioned within the preheater interior 116, each baffle 120 blocks the vertical gas flow along the partially circular length. The baffles cause the gas to flow laterally around the periphery of the preheater 118, preventing vertical movement of the gas at the baffle's location.

[0086] Each baffle 120 defines a gap 122 between its ends. 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 its ends. Each baffle 120 also includes a series of openings 124 that allow the heating rod 142 to be positioned when the baffle and heating rod are installed within the interior 116.

[0087] As shown in Figure 2A, the gas entering the preheater inlet 130 at the front of the device 110 is guided by the first baffle 120a to flow from the front to the rear of the preheater interior 116 (see lowest arrow). At the rear of the interior 116, the lowest baffle 120a defines a gap between the ends of the baffle 120a, allowing the gas to flow vertically. The second baffle 120b again blocks the vertical flow of the gas at a higher vertical level, causing the gas to flow back towards 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 that are staggered between their front and rear positions within the interior 116. This arrangement creates a gas flow through the interior 116 in a front-to-rear-to-front-to-rear pattern when the gas flows vertically from the inlet 130 of the lower part 122 of the preheater 118 to the preheater outlet (not shown) of the upper part 124 of the preheater 118.

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

[0089] example Example 1. A gas processing apparatus comprising a medium container having a medium container inlet end with a medium container inlet, a medium container outlet end with a medium container outlet, a medium container side wall extending between the medium container inlet and the medium container outlet, and the interior of the medium container defined by the medium container side wall; and a preheater located outside the medium container side wall, the preheater comprising a preheater side wall located outside the medium container side wall, spaced apart from the medium container side wall and defining a preheater space between the outer surface of the medium container side wall and the inner surface of the preheater side wall, a preheater inlet, and a preheater outlet that is in fluid communication with the medium container inlet.

[0090] Example 2. The apparatus according to Example 1, further comprising a heating element in the preheater space.

[0091] Example 3. The apparatus according to Example 2, wherein the heating element is a heating rod, the heating rod extends vertically within the preheater space, and the heating rod is distributed along the perimeter of the preheater space.

[0092] Example 4. The apparatus according to claim 3, wherein the heating rods are distributed along the periphery at non-uniform intervals between the heating rods.

[0093] Example 5. The apparatus according to Example 3 or 4, wherein the perimeter of the preheater space has a perimeter length including a front half perimeter length and a perimeter length including a back half perimeter length, the preheater inlet is located in the center of the front half perimeter length, the front half group of heating rods is distributed along the front half perimeter length, the rear half group of heating rods is distributed along the back half perimeter length, and the front half group has a greater number of heating rods than the back half group.

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

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

[0096] Example 8. The apparatus according to Example 6 or 7, further comprising heating rods, the heating rods extending vertically within the preheater space, the heating rods extending through an opening in the baffle, and the heating rods distributed along the perimeter of the preheater space.

[0097] Example 9. The apparatus according to Example 8, wherein the heating rods are distributed along the periphery at uniform intervals between the heating rods.

[0098] Example 10. The apparatus according to any one of Examples 1 to 9, wherein the preheater comprises a preheater inlet end adjacent to the outlet end of the medium container and a preheater outlet end adjacent to the inlet end of the medium container, 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 according to any one of Examples 1 to 10, wherein the preheater outlet has an opening that connects the inside of the preheater to the inside of the medium container and extends along the length of the circumference of the preheater, including the front and back of the preheater.

[0100] Example 12. The apparatus according to any one of Examples 1 to 11, wherein the preheater inlet is an opening on the front surface of the preheater and extends at an angle of less than 30 degrees of the length of the circumference of the preheater.

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

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

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

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

[0105] Example 17. The apparatus according to any one of Examples 1 to 16, wherein the preheater space comprises flow channels of varying lengths between the preheater inlet and the preheater outlet, and the preheater allows for a higher heat transfer rate to the gas flowing along a shorter flow channel compared to a lower heat transfer rate to the gas flowing along a longer flow channel.

[0106] Example 18. A method using a gas processing apparatus described in any one of Examples 1 to 17, comprising: passing gas through the preheater to preheat the gas; and passing the preheated gas through the inside of the medium container to bring it into contact with the medium contained inside the medium container.

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

[0108] Example 20. The method according to 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 according to Example 19 or 20, wherein the impurity is a nitrogen oxide, carbon monoxide, or hydrocarbon.

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

[0111] Example 23. The method according to any one of Examples 19 to 22, wherein the apparatus does not include a heating element in the medium container, and the apparatus does not include a heating element outside the preheater.

Claims

1. A medium container, Media container inlet end having a media container inlet, A media container outlet end having a media container outlet, The media container side wall extending between the media container inlet and the media container outlet, The interior of the medium container defined by the side wall of the medium container. A media container equipped with, A preheater located on the outside of the side wall of the media container, A preheater side wall located outside the media container side wall, which is separated from the media container side wall and defines a preheater space between the outer surface of the media container side wall and the inner surface of the preheater side wall. Preheater inlet, and Preheater outlet that is in fluid communication with the media container inlet A preheater equipped with, A heating element and A gas processing apparatus comprising, 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, The heating rods are distributed along the periphery at uneven intervals between them. Gas treatment device.

2. A medium container, Media container inlet end having a media container inlet, A media container outlet end having a media container outlet, The media container side wall extending between the media container inlet and the media container outlet, The interior of the medium container defined by the side wall of the medium container. A media container equipped with, A preheater located on the outside of the side wall of the media container, A preheater side wall located outside the media container side wall, which is separated from the media container side wall and defines a preheater space between the outer surface of the media container side wall and the inner surface of the preheater side wall. Preheater inlet, and Preheater outlet that is in fluid communication with the media container inlet A preheater equipped with, A heating element and A gas processing apparatus comprising, 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, The perimeter of the preheater space has a perimeter that includes the perimeter of the front half and the perimeter of the back half. The preheater inlet is located at the center of the circumference of the front half, The group of the front half of the heating rod is distributed along the circumference of the front half, The group in the latter half of the heating rod is distributed along the circumference of the aforementioned latter half, The first half of the group has more heating rods than the second half of the group. Gas treatment device.

3. The gas apparatus according to claim 1 or 2, further comprising at least one horizontally extending baffle positioned within the preheater space.

4. Equipped with an additional heating rod, The heating rod extends vertically within the preheater space, The heating rod extends through the opening in the baffle, The heating rods are distributed along the periphery of the preheater space. The gas treatment apparatus according to claim 3.

5. The gas apparatus according to claim 1 or 2, further comprising an inlet end headspace connecting the medium container inlet and the preheater outlet, and a flow path from the preheater outlet through the inlet end headspace to the medium container inlet.

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