System and method for concentrating a gas

Abstract

Systems and methods are provided that achieve the same or better performance levels by using lower operating flow rates, pressures, and / or optimized flow distribution within the system. This extends the life of the system components and reduces energy consumption. In one embodiment, a gas separation (or sieve) bed is provided to separate gas components that has lower flow and pressure requirements compared to conventional beds. The sieve bed includes, for example, a diffuser that has a low solid area in cross section and a maximum open area for flow while providing sufficient mechanical properties to contain the sieve material and support the filter media. In another embodiment, systems and methods are provided that have an indicator when a component has been serviced or repaired. This provides an indication of whether the component has been tampered with in any way. This allows the manufacturer to determine whether the component has been serviced, repaired, or tampered with outside the manufacturer's domain.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 052,694, entitled "System and Method for Concentrating Gas" (Attorney's File No. 12873-07004), filed July 16, 2020, and U.S. Provisional Patent Application Serial No. 63 / 212,920 (Attorney's File No. 12873-07156), filed June 21, 2021.

[0003] This application incorporates by reference the following patent applications: U.S. Provisional Patent Application Serial No. 63 / 052,694, entitled "System and Method for Concentrating Gas" (Attorney's File No. 12873-07004); U.S. Provisional Patent Application Serial No. 63 / 052,700, entitled "System and Method for Concentrating Gas" (Attorney's File No. 12873-07033); U.S. Provisional Patent Application Serial No. 63 / 052,869, entitled "System and Method for Concentrating Gas" (Attorney's File No. 12873-07041); U.S. Provisional Patent Application Serial No. 63 / 052,533, entitled "System and Method for Concentrating Gas" (Attorney's File No. 12873-07043); and U.S. Provisional Patent Application Serial No. 63 / 052,533, entitled "System and Method for Concentrating Gas" (Attorney's File No. 12873-07043); and U.S. Provisional Patent Application Serial No. 63 / 052,533, entitled "System and Method for Managing a Medical Device". U.S. Provisional Patent Application Serial No. 63 / 052,647, entitled “System and Method for Concentrating Gas” (Attorney’s File No. 12873-07044), filed on July 16, 2020; and U.S. Provisional Patent Application Serial No. 63 / 212,920, entitled “System and Method for Concentrating Gas” (Attorney’s File No. 12873-07156), filed on June 21, 2020. Background Technology

[0004] There are various applications for the separation of gas mixtures. For example, separating nitrogen from atmospheric air can provide a highly concentrated source of oxygen. These various applications include providing high concentrations of oxygen to medical patients and flight personnel. Therefore, systems are desired to provide systems for separating gas mixtures to provide concentrated product gases, such as breathing gases with a certain concentration of oxygen.

[0005] For example, several existing product gas or oxygen concentration systems and methods are disclosed in U.S. Patent Nos. 4,449,990, 5,906,672, 5,917,135, 5,988,165, 7,294,170, 7,455,717, 7,722,700, 7,875,105, 8,062,003, 8,070,853, 8,668,767, 9,132,377, 9,266,053, and 10,010,696, which are collectively assigned to Invacare Corporation (Elyria, Ohio) and are incorporated herein by reference in their entirety.

[0006] Such systems are known to be fixed, transportable, or portable. Fixed systems are designed to be held in one location, such as, for example, a user's bedroom or living room. Transportable systems are designed to be moved from one location to another and typically include wheels or other mechanisms to facilitate movement. Portable systems are designed to be carried by the user, for example, via shoulder straps or similar accessories.

[0007] As part of a separation and concentration process, gas concentration systems typically generate dynamic flow rates and pressures within their working components. While these flow rates and pressures are necessary, they also affect the mechanical wear and lifespan of system components. Generally, the higher the necessary flow rates and pressures within the system, the greater their impact on the mechanical wear and lifespan of system components. Furthermore, higher necessary flow rates and pressures within the system also require a greater amount of energy to achieve the desired flow rates and pressures. A system that addresses these and other aspects of gas separation or concentration systems is desired.

[0008] On another front, gas concentration systems require maintenance during their lifespan. Various gas separation components need to be replaced, repaired, or serviced. Manufacturers need to know when such components have been serviced outside of their domain. A system that also addresses this aspect of gas separation or concentration systems is desired. Summary of the Invention

[0009] Gas concentration systems and methods are provided. In one embodiment, a system and method are provided to achieve the same or better performance levels by using lower operating flow rates and pressures within the system. This extends the lifespan of system components and reduces energy consumption. In one embodiment, a gas separation (or sieve) bed is provided for separating gas components, which has lower flow rate and pressure requirements compared to conventional beds. The sieve bed includes, for example, a diffuser having a low solid area in its cross-section and a maximum open area for flow, while providing sufficient mechanical properties to accommodate sieve material and support the filter media. This allows for efficient flow of gas into and out of the sieve bed, which reduces pressure loss and energy consumption, lowers the dynamic and static pressures on the sieve bed material, and improves the lifespan of the sieve bed material and reduces the rate of mechanical failure of the sieve bed material. Other embodiments are also disclosed.

[0010] In another embodiment, a system and method are provided that have an indicator when a component has been repaired or tampered with. This provides an indication of whether the component has been tampered with in any way. This allows manufacturers to determine whether a component has been repaired, tampered with, or tampered with outside the manufacturer's territory. Unauthorized repairs or tampering can lead to premature component wear and failure.

[0011] In another embodiment, a system and method are disclosed that provides a more uniform or optimized flow distribution and / or lower velocity of gas entering the screen material. The screen cap and / or gas inlet are provided with flow modification structures, baffles, or protrusions within the flow chamber to distribute the flow more uniformly and reduce the velocity of the gas flow entering the screen material. These structures, baffles, and / or protrusions guide the introduced gas flow into the adjacent space within the inner chamber of the cap / inlet to provide a more uniform flow distribution of the gas entering the screen material. By introducing gas more uniformly into the screen material, thus limiting or eliminating cavities in the screen material that the gas might otherwise not reach when it is unevenly distributed upon entry, the more uniform flow distribution increases screen efficiency. Furthermore, the reduced gas flow velocity decreases mechanical wear and tear on the screen material, which leads to pulverization and fluidization of the material.

[0012] One objective is to provide more efficient gas separation systems and methods.

[0013] Another objective is to provide gas separation systems and methods with lower flow rates and pressures.

[0014] Another objective is to provide a gas separation system and method with a diffuser component having a low solid area in cross-section, thereby providing a large open area for flow.

[0015] Another objective is to provide a gas separation system and method with a diffuser component having a low solid area in cross-section, thereby providing a large open area for flow while also providing sufficient mechanical properties to accommodate the sieve material and support the filter medium.

[0016] Another objective is to provide a gas separation system and method having one or more components for providing at least one tampering indication.

[0017] Another objective is to provide a gas separation system and method having at least one sieve bed with a tamper indicator.

[0018] Another objective is to provide a gas separation system and method having at least one tamper-proof component.

[0019] Another objective is to provide a gas separation system and method having at least one tamper-proof sieve bed.

[0020] Another objective is to provide gas separation systems and methods that distribute the flow into a desired profile to achieve a more uniform distribution of the gas entering the sieve bed.

[0021] Another objective is to provide a gas separation system and method with an input device (e.g., a cap or insert) for deflecting and / or modulating the flow of gas to a desired profile as it enters the sieve bed.

[0022] Another objective is to provide gas separation systems and methods that reduce the flow rate of gas entering the screen bed material in order to reduce wear and tear (e.g., pulverization, fluidization, etc.) of the screen material.

[0023] These and other objects, features, and advantages will become apparent after reading the following description, drawings, and claims. Attached Figure Description

[0024] Embodiments of the invention are illustrated in the accompanying drawings, which are incorporated in and constitute a part of this specification. These embodiments, together with the general description of the invention given above and the detailed description given below, serve to illustrate the principles of the invention.

[0025] Figure 1 An embodiment of a gas concentration system is shown.

[0026] Figure 2 This is an embodiment of a pneumatic block diagram of a gas concentration system.

[0027] Figure 3 This is a block diagram of one embodiment of a gas separation or sieve bed.

[0028] Figures 4A and 4B illustrate prior art filter discs used with gas separation beds.

[0029] Figures 5A to 5B An exploded perspective view of one embodiment of a gas separation bed is shown.

[0030] Figures 6A to 6B yes Figures 5A to 5B Various cross-sectional views of the gas separation bed embodiment.

[0031] Figures 7A to 7F Various views of multiple embodiments of a diffuser with a honeycomb structure are illustrated.

[0032] Figure 8 The illustration shows a top view of a second embodiment of a diffuser having a cylindrical or straw-like structure.

[0033] Figures 9 to 12 Side elevation views of various embodiments of diffusers with different cross-sectional geometries and profiles are illustrated.

[0034] Figure 13 The illustration shows a partial cross-sectional view illustrating one embodiment of the tamper-proof feature.

[0035] Figures 14A to 14B The illustration shows a perspective view and an elevation view of one embodiment of a screen cap including tamper-proof features.

[0036] Figures 15A to 15B Another embodiment of a screen cap with tamper-proof features is illustrated.

[0037] Figures 16A to 16D Another embodiment of a screen cap with tamper-proof features is illustrated.

[0038] Figures 17A to 17I An embodiment of a screen cap for producing a desired flow profile is illustrated.

[0039] Figures 18A to 18C The diagram shows Figures 17A to 17I Various flow trajectories and distributions in the embodiments of the screen bed cap.

[0040] Figures 18D to 18E The diagram shows Figures 17A to 17I Various flow trajectories and distributions are shown in the embodiment of the screen cap, but without any flow modification structure.

[0041] Figures 19A to 19B Another embodiment of a screen cap for producing a desired flow profile is illustrated.

[0042] Figures 20A to 20C The diagram shows Figures 19A to 1 Various flow trajectories and distributions in the 9C screen cap embodiment.

[0043] Figures 21A to 21DVarious views of another embodiment of a screen cap for producing a desired flow profile are illustrated.

[0044] Figures 22A to 22D Various views of another embodiment of a screen cap for producing a desired flow profile are illustrated.

[0045] Figures 23A to 23D Various views of another embodiment of a screen cap for producing a desired flow profile are illustrated.

[0046] Figures 24A to 24D Various views of another embodiment of a screen cap for producing a desired flow profile are illustrated.

[0047] Figures 25A to 25D Various views of another embodiment of a screen cap for producing a desired flow profile are illustrated.

[0048] Figures 26A to 26D Various views of another embodiment of a screen cap for producing a desired flow profile are illustrated.

[0049] Figures 26E to 26F The diagram shows Figures 26A to 26D Various flow trajectories and distributions in the embodiments of the screen bed cap.

[0050] Figures 27A to 27B Various views of another embodiment of a screen cap for producing a desired flow profile are illustrated.

[0051] Unless otherwise indicated, each mechanical drawing is presented relative to scale. That is, the size, position, and location of the parts illustrated in each drawing are shown to scale relative to each other, which may also include enlarged scale representations. Detailed Implementation

[0052] As described herein, when one or more components are described or shown as connected, linked, attached, joined, or otherwise interconnected, such interconnection may be a direct interconnection between components or may be indirect, such as by using one or more intermediate components. Furthermore, as described herein, references to a member, component, or part should not be limited to a single structural member, component, element, or part, but may include assemblies of members, components, elements, or parts.

[0053] Embodiments of the present invention provide, for example, gas separation systems and methods that feature efficient flow of working gases entering and leaving a screen bed, reduced pressure loss and energy consumption, lower dynamic and static pressures on the screen bed material, and extended screen material life achieved by reducing the rate of mechanical and / or structural failure of the screen material. The efficient flow of the working gas also reduces noise generated by the gas flow within the system. In one embodiment, the gas separation system includes at least one screen bed with a diffuser arranged to subdivide the flow in its cross-section into smaller flow channels, thereby reducing turbulence and energy loss. The gas flow is substantially straightened by the diffuser, and more energy is transferred to the intended direction of the gas flow. The diffuser also has a low solid area (e.g., low solidity) in its cross-section and a high and / or maximum open area for flow, while providing sufficient mechanical properties to accommodate the screen material within the screen bed and support the filter media.

[0054] Figure 1 The diagram illustrates one embodiment of a gas separation system 100, which may be an oxygen concentration system. The system may be stationary, such as for use in a hospital or patient's home. The system may also be non-stationary or portable, such as for use by the patient when they are not at home. The system may be configured to allow the patient to carry it, such as by a shoulder strap or by an arrangement including a handle and wheels. Other mobility configurations are also included.

[0055] The oxygen system 100 includes a housing 102, which may be in the form of one or more segments. The housing 102 includes multiple openings for the intake and exhaust of various gases, such as, for example, the intake of room air and the exhaust of nitrogen and other gases. The oxygen system 100 generally draws in room air, which consists primarily of oxygen and nitrogen, and separates the nitrogen from the oxygen. Oxygen is stored in one or more internal or external storage tanks or product tanks, and nitrogen is exhausted back into the room air. For example, oxygen can be exhausted to a patient via tubing and a nasal cannula through port 104. Alternatively, oxygen can be exhausted via a replenishment port to an oxygen cylinder filling device, such as one manufactured by Invacare Corp. (Elyria, Ohio, USA). And one example of it is described in U.S. Patent No. 5,988,165, which is incorporated herein by reference.

[0056] Figure 2An exemplary pneumatic block diagram of a gas concentration system using pressure swing adsorption (PSA) is illustrated in one embodiment. The system may include multiple gas separation sieve beds 206a and 206b, multiple valves 204a, 204b, 204c and 204d, one or more product tanks 208a, 208b, and a throttling valve / device 218. In this embodiment, product tanks 208a and 208b are shown connected, thus acting as one product tank, but they could also be arranged to act as two product tanks. The system also includes a compressor / pump 203 and one or more filters 201 and a silencer 202.

[0057] Sieve beds 206a and 206b are filled with a physical separation medium or material. The separation material selectively adsorbs one or more adsorbable components and one or more non-adsorbable components of a gas mixture. Generally, the physical separation material is a molecular sieve with pores of uniform size and substantially the same molecular dimensions. These pores selectively adsorb molecules based on molecular shape, polarity, saturation, etc. In one embodiment, the physical separation medium is an aluminosilicate composition with 4 to 5 Å (angstroms) of pore size. More specifically, the molecular sieve is a sodium or calcium form of aluminosilicate, such as type 5A zeolite. Alternatively, the aluminosilicate may have a higher silica-to-alumina ratio, larger pore size, and affinity for polar molecules (e.g., type 13x zeolite). Zeolite adsorbs nitrogen, carbon monoxide, carbon dioxide, water vapor, and other significant amounts of components in the air. Other types of separation media may also be used to adsorb nitrogen from ambient or indoor air. Additionally, more than two sieve beds may be used. In other embodiments, sieve beds 206a and 206b may be structurally integrated with one or more product tanks 208a and 208b, as described in U.S. Patent No. 8,668,767, which is incorporated herein by reference in its entirety with respect to that feature and other features.

[0058] In operation, such as by Figure 2 As shown by the solid lines, during an exemplary filling cycle of the separator bed 206a, the pump / compressor 203 draws room air through filter 201 and to valve 204d and separator bed 206a (which produces oxygen at its output), and through valve 210a into product tanks 208a and 208b. The pump / compressor 203 supplies air to the screen bed at up to approximately 32 psi during the filling phase. Other operating pressure ranges include approximately 15–32 psi. Valves 210a and 210b may be check valves or any other similarly functional valves that allow unidirectional flow.

[0059] While separation bed 206a is undergoing a filling cycle, separation bed 206b may be undergoing a purge cycle to remove any nitrogen from the previous filling cycle. During the purge cycle, the previously pressurized separation bed 206b discharges nitrogen through valve 204a and through silencer 202 to the atmosphere. Separation bed 206a is pressurized from its filling cycle. During the purge cycle, a certain amount of oxygen from separation bed 206a or product tanks 208a, 208b may be fed into separation bed 206b to preload or pre-extract the oxygen from separation bed 206b, as per [other process]. Figure 2 It is controlled by the optional relief valve 212 and the fixed orifice 214, as shown by the dashed line.

[0060] As by Figure 2 As shown by the dotted lines, once separation bed 206a has been filled and / or separation bed 206b has been purified, control system 220 switches valves 204a, 204b, 204c, and 204d, causing separation bed 206b to enter a filling cycle while separation bed 206a enters a purification cycle. In this state, pump 203 directs indoor air into separation bed 206b (which generates oxygen at its output) and through valve 210b into product tanks 208a, 208b. During the purification cycle, a certain amount of oxygen from separation bed 206b or product tanks 208a, 208b can be fed into separation bed 206a to preload or pre-extract oxygen from bed 206a, now flowing in the opposite direction compared to the previous cycle. The illustrated system also includes an exemplary pressure equalization valve 216, which equalizes the pressure in the two separation beds before the purification / filling cycle changes. It is worth noting that not all embodiments of the PSA system require a pressure equalization valve.

[0061] Pressure equalization valve 216 allows for more efficient oxygen production by equalizing the pressure between the outputs of a separation bed (e.g., 206a) near the end of its fill cycle and a separation bed (e.g., 206b) near the end of its purge cycle. For example, pressure equalization valve 216 can be activated to equalize the pressure between the outputs of separation beds 206a and 206b near the end of each purge / fill cycle. The operation of the pressure equalization valve is further described in U.S. Patent Nos. 4,449,990 and 5,906,672, which are incorporated herein by reference in their entirety. In this manner, each separation bed 206a, 206b cyclically undergoes alternating fill and purge cycles, as controlled by control system 220, to produce oxygen.

[0062] like Figure 2As shown, an optional throttling valve / device 218 can be used to control the delivery of product gas to user 222. The throttling valve 218 can switch between providing concentrated product gas from product tanks 208a, 208b or venting it to room air. For example, the throttling valve 218 can be used to selectively provide various continuous or pulsed flows of oxygen-concentrated product gas in a quantity and time determined by the control system 220. This timing is typically based on sensing the user's inhalation, which is typically determined by sensing a pressure drop or (flow rate increase) near the user's nose or mouth.

[0063] In this embodiment, the control system 220 can utilize various control schemes, such as optimizing the production and delivery of concentrated product gas by controlling the activation, leveling, and relative timing of pressure source 203 and valves 204a, 204b, 204c, 204d, 216, and 212. This is achieved by using one or more pressure sensors 224 and / or (one or more) oxygen concentration sensors 226. In one embodiment, pressure sensor 224 and oxygen sensor 226 monitor the pressure and oxygen concentration entering (one or more) product tanks 208A and 208(b). In other embodiments, timed cycling can be employed, where the cycle time is determined or optimized using a diagnostic process at plant settings or upon system startup. In other embodiments, the cycle time can be determined based on flow settings and / or sensed patient flow requirements.

[0064] Although Figure 2 The illustration depicts a pressure swing adsorption (PSA) cycle, but other gas concentration cycles, including vacuum rotary adsorption (VSA), vacuum-pressure swing adsorption (VPSA), or other similar modes, may also be used. The specific gas concentration mode is not critical to the embodiments of the invention described herein, as long as they can produce a concentrated gas such as oxygen for the user. Examples of the above-described operating modes are disclosed, for example, in U.S. Patent Nos. 9,266,053 and 9,120,050, which are incorporated herein by reference in their entirety.

[0065] Now for reference Figure 3An embodiment of a sieve bed arrangement 300 is shown. The sieve bed 300 includes, for example, a first gas inlet / outlet 302 for receiving air and discharging adsorbed nitrogen. An optional top space 304 may be provided. The sieve bed 300 also includes a spring 306, a perforated disc or diffuser 308, and one or more filter media 310. The spring 306 biases the perforated disc or diffuser 308 against the sieve material 312 (e.g., particulate matter or zeolite material as previously described) to keep the sieve material 312 packed together and to prevent mechanical movement of the sieve material 312 during the dynamic pressure used to fill and purify the sieve bed 300 during the gas separation process. The other end of the sieve material 312 is biased against one or more filter media 314 and a second perforated disc or diffuser 316. A second top space 318 allows unadsorbed gases (e.g., oxygen) to enter and exit the sieve bed via an inlet / outlet port 320. While this embodiment has been specifically described, one or more components may be omitted, or several components may be integrated. For example, one or more headspaces 304 and 318 can be significantly reduced or eliminated. Furthermore, more than one diffuser 308 can be used. For example, two or more diffusers 308 can be used back-to-back, or two or more diffusers 308 can be used with one or more filter media 310 between them.

[0066] Figures 5A to 5B Another embodiment of the sieve bed 500 is illustrated. The sieve bed 500 includes, for example, regarding... Figure 3 The sieve bed 300 describes many of the same functional components. The sieve bed 500 includes a retaining ring or clamp 502 for holding the input / output gas cap 504. A spring 506, a retainer 508, a diffuser 510, and filter media 512 and 514 are also provided. The spring 506 biases the retainer 508, diffuser 510, and filter media 512 and 514 against the granular sieve material 516 to hold the sieve material 516 together within the sieve bed container wall, preventing or minimizing mechanical movement of the sieve bed material during the dynamic pressures used in the filling and purification cycles of the separation process. The retaining ring 518 and a second diffuser 524, along with one or more filter media 520 and 522, are located at the other end of the sieve material 516. (See also: Regarding...) Figure 3 As described herein, more than one diffuser 510 may be used in any of the embodiments described herein. Figures 6A to 6B The illustration shows various cross-sectional perspective views of the screen bed 500 with its components assembled within the screen bed container wall 600.

[0067] As mentioned above Figure 2The system draws ambient air through a compressor and moves it through a volume of material in one or more sieve beds that tends to retain nitrogen, leaving residual oxygen in the system output. The sieve material used to adsorb nitrogen is typically in granular form and must be held within the sieve bed, allowing air inflow and oxygen outflow, and periodically flushing the sieve bed to remove adsorbed nitrogen. As gas flows in and out of the sieve bed, the granular sieve material must be held and maintained to minimize relative motion. For example, introducing pressurized air into the sieve bed creates a hammering effect on the sieve material, which can damage the particles and reduce them to dust, and the escape of dust from the system must be minimized. Excessive loss of sieve material is itself a failure mode, and with more material lost, the remaining material moves more freely within the sieve bed, accelerating relative motion and degrading into dust.

[0068] Semi-permeable membranes or filter-type media (e.g., 512, 514, 520, and 522) can be used to hold the sieved material in place while allowing gas to flow through it. These membranes or filters may have a flexible construction, and in this case, mechanical support is required to hold the pressurized particulate media in place to prevent movement and to retain it within a confined volume. To adequately support the filter media, some areas of the filtration zone must impede flow through a support mechanism such as the prior art discs shown in Figures 4A and 4B. Typically, such a structure has pores to allow gas flow while also providing mechanical support through solid portions of the structure. However, the solid portions do not allow gas flow.

[0069] Regarding diffuser structure, there are limitations on the open area of ​​individual orifices and the total open area summed from the areas of all orifices. The area of ​​individual orifices is limited by the mechanical properties of the filter medium; if the orifice geometry (diameter in a circular orifice) varies too much, it may cause the filter medium to sag. The total open area is also limited by the stress and mechanical properties of the screen material and the ability of the screen bed container wall to withstand static and cyclic loads. The geometry and type of individual orifices also significantly contribute to system energy loss and noise by inducing pressure losses in the flowing gas. As will be further discussed here, appropriate diffuser geometry can reduce energy loss if the orifice size, orifice length in the flow direction, orifice and solid region type, appropriate orifice orientation characteristics, and other orifice characteristics affecting flow are provided. This can include using the methods described above regarding... Figure 3The description refers to multiple diffusers. In the case of multiple diffusers, each diffuser may have the same or different geometry to obtain desired flow and structural characteristics. Furthermore, in the sense of non-uniform flow entering or leaving the screen bed during exhaust circulation, other losses exist, which can be corrected or improved by the influence of one or more diffusers and / or screen caps / interfaces with flow-modifying structures at the face of the screen bed, on the flow-changing characteristics or geometry.

[0070] Figures 7A to 7F Various views of several embodiments of a diffuser 510 for a screen bed are illustrated. The diffuser 510 has low solidity, thus providing a significantly large open area for flow. The diffuser 510 also has structural strength to support the filter media and transmit the forces or biases of the springs to maintain the buildup of the screen material and prevent mechanical movement within the screen bed container walls. The diffuser 510 includes a body 700 having a honeycomb wall structure in one embodiment. The body 700 can have any suitable size and shape, including, for example, a disc shape as shown in the figures. In one example, the disc has a diameter of 2.44 inches and a height D2 of 0.5 inches. Other sizes and shapes are also possible for the open area, including, for example, triangles, squares, rectangles, other polygons, and circles (e.g., see the circular wall 802 having a defined circular open area 704). Figure 8 The body in the middle is 800), elliptical, etc.

[0071] like Figure 7B As shown in the enlarged view, wall 706 has a honeycomb (or hexagonal) arrangement of closed open spaces 704. The solidity (the ratio of solid area to open area) of diffuser 510 can be greater than or less than 0.10% to 50%. For example, in Figures 7A to 7D In one embodiment shown, a solidity of 2.46% is achieved when the cell size D1 is 0.125 inches, the wall 706 thickness is 0.001 inches, and the diffuser body diameter is 2.44 inches. Figure 7E In another embodiment shown, a solidity of 0.41% is achieved when the cell size D1 is 0.5 inches, the wall 706 thickness is 0.001 inches, and the diffuser body diameter is 2.44 inches. Figure 7F In another embodiment shown, a solidity of 0.17% is achieved when the cell size D1 is 1.0 inch, the wall 706 thickness is 0.001 inch, and the diffuser body diameter is 2.44 inches. Ideally, while maximizing the open area of ​​the diffuser is highly desirable, improving / increasing the arrangement of the open area compared to the prior art is also desirable and provides efficiency. That is, maximizing the open area is not necessary to achieve efficiency.

[0072] By altering the size of the subdivided channels and / or independently changing the channel length in the flow direction, the characteristics of the diffuser flow stream can be modified to offer benefits such as lower energy loss, a more uniform flow into the screen bed, lower peak velocities at or near the surface of the screened material, lower overall flow velocities in any part of the screen bed, lower flow acceleration into the screen bed, lower flow acceleration leaving the screen bed during the exhaust cycle, lower forces on the screened material, and a smaller impact of lower peak-to-peak acceleration from dynamic pressure or bidirectional flow on the screened material. A uniform flow rate or pressure entering the screen bed will reduce or eliminate flow within the screen bed that is not parallel to the overall direction of flow through the screen bed. This increases the distance air must travel to pass through the screened material, reducing the screen's time efficiency and oxygen production efficiency. Similarly, non-uniform restriction of the outlet pressure at exit will cause the flow to converge or diverge and is not parallel to the overall direction of flow leaving the screen bed, thus prolonging the duration of the exhaust / purification cycle and reducing the efficiency of the exhaust / purification cycle and the entire bidirectional (fill / purify) cycle.

[0073] Figures 9 to 12 Various embodiments of the diffuser 510 cross-sectional body profile are illustrated. For example, Figure 9 The figure shows a body 900 having a first concave surface profile 902. Figure 10 The figure shows a body 1000 having a first concave surface profile 1002 and a second concave surface profile 1004. Figure 11 The figure shows a body 1100 having a first convex surface profile 1102. Figure 12 The illustration shows a body 1200 having a first convex surface profile 1202 and a second convex surface profile 1204. Due to the relatively high height of the diffuser walls and those portions, Figure 11 and Figure 12 The embodiments of these designs offer the particular advantage of additional structural strength in their central sections. This resists bending and other undesirable mechanical deformation. Other cross-sectional body profiles are also possible, including, for example, wavy or corrugated profiles, triangular, serrated, etc. The diffuser body can be made of any suitable material. This includes, for example, metals and plastics. Suitable metals include aluminum and stainless steel. The diffuser body can also be formed via 3D printing technology, which allows for simple and complex spatial and wall arrangements, including those disclosed herein.

[0074] The height of the diffuser body (e.g., Figure 7C D2 in the middle) or Figures 9 to 12The various heights of the body cross-sectional profiles shown reduce flow inefficiencies by straightening the flow entering and / or leaving the screen bed. They also reduce turbulence in the flow through diffuser wall geometry (e.g., honeycomb, circular, etc.) and through multiple walls or channels. They also orient the inward and outward flow in the overall direction of the screen bed to reduce tangential or off-axis flow, which would guide air molecules to travel greater distances to enter and / or exit the screen bed. The height D2, or the height of the cross-sectional profile, can be any height determined to improve flow efficiency, including those related to… Figures 9 to 12 The various heights shown and described.

[0075] As mentioned earlier, the height of the diffuser body (e.g., Figure 7C D2 in the middle) or Figures 9 to 12 The various heights of the body cross-sectional profile shown also provide structural or retaining components. That is, spring 506 applies a bias or force against the screen material to keep it fixed and prevent movement through the diffuser (see, for example, [reference needed]). Figures 6A to 6B Ideally, the diffuser body is made of a material with sufficient shear, tensile, and cyclic fatigue properties to provide the necessary mechanical support (e.g., to prevent sagging under load). Therefore, it is possible to optimize the diffuser body by increasing or maximizing the open cross-sectional area for the flow while still providing sufficient mechanical strength to hold the filter media and filter material, taking into account the properties of the diffuser body material and minimizing the gap volume of the diffuser body material.

[0076] In one embodiment, increasing or maximizing the open area of ​​the diffuser body can be linked to the mechanical properties required for the hold-up function of the diffuser body. The hold-up function of the diffuser body involves the ability of the diffuser body to adequately support the packed screen material and filter media. In addition to potentially stronger body materials with higher shear, tensile, and cyclic fatigue properties, diffusers with a very high percentage of open area for flow relative to the total available area and therefore a low solidity ratio can be formed by using optimal orifice sizes based on the mechanical requirements of the filter media (e.g., avoiding sagging under mechanical loads) and by packing the maximum number of orifices by minimizing the interstitial volume of the material by increasing the moment of inertia of the mechanical design in the flow direction.

[0077] Figures 7A to 7DThe use of the diffuser 510 shown has demonstrated that by reducing the peak velocity of the gas entering the screen bed (i.e., at or near the surface of the screen material), the separation process can become more efficient while still achieving conventional gas separation results. The conventional peak velocity of up to 168.6 inches per second is reduced to 70.1 inches per second, a reduction of approximately 60%. This reduction in the peak velocity of the gas entering the screen bed translates to several practical advantages. For example, less energy is required to operate the gas separation process due to the lower peak flow rate. A lower peak flow rate also means that the compressor does not have to work as hard, thus reducing component wear and extending compressor life. Furthermore, the reduced peak velocity decreases the pressure or mechanical forces within the screen material, and therefore reduces pulverization and mechanical failure of the screen material by reducing relative movement of the screen bed material. It also reduces the dynamic forces on the surface of the screen bed, on (one or more) the screen filters, and / or on the screen material, thereby reducing mechanical degradation of the screen bed material. Additionally, the reduced peak velocity reduces noise caused by airflow within the system.

[0078] By having a height / length (e.g., that straightens the rheology of the material entering and leaving the sieve) Figure 7C The diffuser space / channel in D2 also achieves efficiency. Rheometry also reduces inefficiencies by reducing turbulence within the diffuser and / or turbulence caused by the diffuser at the surface of the screen material. Rheometry also directs the flow inward and outward in the overall direction of the bed to reduce tangential or off-axis flow, which would guide air molecules to travel greater distances to enter or exit the screen bed. The disclosed diffuser arrangement also provides mechanical support for any holding mechanism of the screen material that must be in the flow path. The overall result is a gas separation system with lower energy consumption, greater oxygen output or specific output (oxygen produced per unit energy input), higher reliability limited by the screen bed's anti-pulverization life, and lower noise. While all these benefits and advantages are available, any one or more are sufficient to provide an improved gas separation process.

[0079] In another embodiment, a system and method are provided that have an indicator when a component has been repaired or tampered with. In one embodiment, the indicator provides a visual indication if the component has been tampered with in any way. This allows the manufacturer to determine whether the component has been repaired, tampered with, or tampered with outside the manufacturer's territory. Unauthorized repairs or tampering can lead to premature component wear and failure.

[0080] Figure 13 The diagram illustrates an example of a system with tamper-proof features or arrangements. Figure 13 It shows Figures 6A to 6BAn enlarged partial cross-sectional view of the top portion of the sieve bed. The sieve bed includes tamper-proof features or arrangements that provide a visual indication of whether the sieve bed has been opened, for example, to replace the sieve material. The sieve material 516 is a component that needs to be replaced over time. This is because the sieve material 516 degrades over time due to factors such as pulverization or mechanical degradation, moisture, saturation wear, etc. Typically, the sieve material 516 needs to be replaced approximately every 18 months. Unauthorized replacement of the sieve material 516 with unauthorized materials can lead to pulverization and premature failure of other gas separation components. Figure 13 The arrangement shown provides a visual indication of whether the screen bed is open.

[0081] Although Figure 13 The illustration shows an example of one tamper-evident cap 504 associated with a single screen container 600, but in other embodiments, a common tamper-evident cap 504 (functioning similarly to a manifold) can be used in a screen container assembly having more than one screen container. In other embodiments, the screen container 600 may use more than one tamper-evident cap 504.

[0082] Still referencing Figure 13 The tamper-evident cap 504 for the screen bed includes a body 1300. The body 1300 includes one or more ribs 1302A-D (see also...). Figure 14A The ribs include recesses or spaces 1304A-D. These recesses, together with edges 1308, are arranged to receive and secure a retaining ring or clip 502 designed to hold a cap 504 to the screen container wall 600. The screen container wall 600 also includes an annular recess 1310 for receiving and securing a portion of the retaining ring 502. Ribs 1302A-D also include an outer surface or wall having portions 1316A-D arranged to contact or nearly contact the container wall 600. In this way, the retaining ring 502 cannot be removed unless one or more rib portions 1316A-D are tampered with (e.g., cut, damaged, destroyed, or otherwise modified) to allow the retaining clip 502 to be removed. Tampering with rib portions 1316A-D provides a visual indication that the screen may have been opened through visible damage. Furthermore, tampering with the ribs 1316A-D could also result in visible damage to the screen container wall 600 at those locations. Additionally, damage to the ribs 1316A-D and / or the screen container wall 600, and to those locations, could lead to irreparable damage to the cap 504 and / or the screen bed container wall 600. The ultimate goal is to prevent tampering with or unauthorized repairs to the screen bed, as it could be irreparably damaged.

[0083] Figures 14A to 14B The diagram shows Figure 13The figures show a perspective view and a side elevation view of an embodiment of the cap 504. As described above, the cap body 1300 includes four ribs 1302A-D, and each rib includes a recess or space (e.g., 1304A-D) for receiving and securing a portion of the retaining ring 502. Each rib 1302A-D also includes one or more wall portions or surfaces (e.g., 1316A-D) arranged to contact or nearly contact a portion of the screen container wall 600 in those locations. Contact with the screen container wall 600 in those locations is unnecessary as long as any gaps formed are small enough to limit the removal of the retaining ring 502. The body 1300 also includes spaced edges 516 and 1314 (together with edge 1308) for securing washers or O-rings and forming an interference fit that secures the cap body 1300 to the screen container wall 600. Edges 1308, 1312, and 1314 are not essential parts of the anti-tampering feature, but they can be modified to include them.

[0084] It should be noted that in other embodiments, the cap body 1300 may include fewer than four ribs 1302A-D, and each rib does not need to have walls and recesses for securing the retaining ring 502. At least one rib containing these features is sufficient. Furthermore, the geometry of the ribs, walls, and recesses may be modified from the shapes shown in the embodiments herein, as long as they are partially disposed within the cap body 1300 to secure the retaining ring 502 and prevent easy removal (e.g., removal without creating visual indicators such as, for example, physical damage or modification to the cap body 1300 and / or the screen bed container wall 600). For example, the cap body 1300 may include a protruding member or tab 1306 adjacent to the recess 1304B. The protruding tab 1306 may be a component of the rib 1302B or a separate component thereon. While one protruding tab 1306 is shown, more than one tab may be provided as a component of the ribs 1302A-D. In some other embodiments, ribs 1302A-D may be eliminated and replaced by multiple protruding tabs, such as tab 1306, used in the same or more locations as ribs 1302A-D to achieve the same result. In some other embodiments, multiple tabs, such as tab 1306, may be used in conjunction with one or more ribs. The number, geometry, and shape are not critical, as long as the protruding members (e.g., ribs, tabs, and combinations thereof) at least partially close the retaining ring in the manner described herein to prevent tampering and / or provide a tampering indicator.

[0085] Figures 15A to 15B Other embodiments of the screen cap with tamper-proof features are illustrated. This includes a ribless screen cap design. In one embodiment, the screen cap body may include a dome of revolution with various configurations. Figure 15AAn embodiment of a ribless screen cap body 1300 is illustrated. The body includes a cylindrical surface 1500 that rotates horizontally (e.g., relative to having individual vertically arranged ribs), protrudes or extends from the body 1300, and in a manner similar to... Figures 13 to 14B The wall portions 1316A-D are arranged to have edge portions 1504 that contact or are very close to the wall of the contact screen container 600 to secure the retaining ring or clip 502. Figure 15B It shows the relationship with Figure 15A This embodiment is compared to another embodiment of the ribless screen cap body 1300, which has fewer or smaller cylindrical surfaces 1502. The cylindrical surfaces 1502 are also arranged to have edge regions 1504, so as to resemble... Figures 13 to 14B The wall portion 1316A-D contacts or approaches the screen container wall 600 to secure the retaining ring or clamp 502. The remaining features of the screen cap body are similar. Figures 13 to 14B The features already described. Therefore, the ribless walls / surfaces 1500 and 1502 are secured to the retaining ring / clamp 502 in the same manner as the wall portions 1316A-D, but with a larger perimeter than by using separate ribs 1302A-D. Attempting to... Figure 15A and Figure 15B Removing the retaining ring or clip 502 in an embodiment would result in damage to the edge or peripheral portion 1504 that holds the retaining ring or clip 502 in place, thereby providing a tamper indication. Therefore, the screen cap body disclosed herein is not limited to ribbed tamper-proof features, but includes both ribbed and / or unribbed arrangements.

[0086] Figures 16A to 16D Another embodiment of a screen cap 504 with tamper-proof features is illustrated. In this embodiment, the cap 504 includes one or more structural portions that break or fracture upon attempt to remove the retaining ring or clip 502, rendering the cap 504 unusable. This is achieved by forming one or more weakened portions in the body 1300.

[0087] In the illustrated embodiment, the body 1300 includes a dome portion 1600 arranged to partially or completely break upon attempt to remove the retaining ring or clamp 502. Partial or complete breakage or fracture, among other things, impairs the ability of the internal space 1604 to function properly under the required operating screen pressure, effectively disabling the gas separation system. Reference Figure 16C and Figure 16D The body 1300 includes recesses or spaces 1304A-D for at least partially securing the retaining ring or clip 502. The recesses or spaces 1304A-D are defined on one side by a peripheral wall 1602 of the body 1300. Figure 16CAs shown, wall 1602 has a first wall thickness, at which wall 1602 defines a recess or space 1304A-D. As... Figure 16D As shown, where the peripheral wall 1602 does not define the recess or space 1304A-D, the wall 1602 has a smaller than Figure 16C The second thickness is shown as the first thickness. The difference in thickness can be any difference that makes the wall 1602 more prone to breakage or fracture when attempting to remove the retaining ring or clamp 502. In one embodiment, the thickness difference can be greater than or less than 25% to 90%. The exact thickness difference is not important as long as one or more portions of the screen cap break or fracture when attempting to remove the retaining ring or clamp 502.

[0088] In another embodiment, the lower dome peripheral wall 1606 adjacent to wall 1602 may have a portion of different thickness in the same manner as described for wall 1602, to achieve the same cracking or fracture result. That is, Figure 16C The portion of wall 1606 shown may have a size greater than Figure 16D The first thickness of a portion of wall 1606 shown. In this way, Figure 16D The smaller thickness of the portion of wall 1606 shown is arranged to break or fracture when an attempt is made to remove the retaining ring or clamp 502. Other arrangements of cap 504 with portions arranged to break, fracture, or fracture can also be used to prevent unauthorized access to the screen bed and / or reuse of tampered screen beds and caps.

[0089] In one embodiment, the cap 504 may be made of polycarbonate or other plastics and / or thermoplastics. The material composition may be any composition that allows structural portions to break or fracture upon attempted removal of the retaining ring or clip 502, rendering the cap 504 unusable. This may also include metals, alloys, ceramics, and other moldable, printable, and / or machinable materials.

[0090] Another factor that can contribute to screen bed wear and tear (including pulverization and fluidization of the screen bed material) is the uneven flow distribution and velocity of the gas (e.g., air) entering the screen bed. Air is typically introduced into the screen bed via a cap or other inlet interface. The internal geometry of the cap / interface can lead to uneven flow distribution of the gas entering the screen bed material and / or concentrated areas of high flow velocity. These undesirable effects can be addressed by using flow modification structures, baffles, and / or protrusions to achieve a more uniform and / or optimized flow distribution and velocity of the gas entering the screen bed material. Figures 17A to 27B Various embodiments of screen caps / interfaces for modifying the flow distribution and / or flow velocity of gas entering the screen material are shown.

[0091] Now for reference Figure 14A , Figure 14B and Figures 17A to 17B An embodiment of a screen cap / interface 504 with a flow modification structure, baffles, and / or protrusions is shown. Reference is now made to... Figure 17A The bottom view shows that the body 1300 includes an inner chamber geometry having hemispherical or dome-shaped walls or surfaces 1700 and first flow modification structures 1702 and 1704, second flow modification structures 1706 and 1708, and a third flow modification structure 1710. A first gap 1712 is located between the first flow modification structures 1702 and 1704. A second gap 1714 is located between the second flow modification structures 1706 and 1708. In this embodiment, the flow modification structures are generally arranged in three rows spaced apart from a gas port 1716, which feeds gas into the chamber. The first flow modification structures 1702 and 1704 are juxtaposed near the gas port 1716 at a first distance D1, which may be approximately 0.45 inches. Figure 17A (Shown scaled up). The second flow modification structures 1706 and 1708 are spaced apart from the first flow modification structures 1702 and 1704 by a distance D2, which may be approximately 0.42 inches. The third flow modification structure 1710 is spaced apart from the second flow modification structures 1706 and 1708 by a distance D3, which may be approximately 0.33 inches. In other embodiments, these distances may be varied without substantially altering the flow modification result.

[0092] In one embodiment, the flow modification structures 1702-1710 are baffles or ribs that deflect gas introduced from port 1716. Figure 17A As shown, the first flow modification structures 1702 and 1704 and the third flow modification structure 1710 have substantially flat bodies with rounded or curved end faces. The second flow modification structures 1706 and 1708 have curved bodies with curved end faces. In this embodiment, the curved bodies of structures 1706 and 1708 are shown as curved in a generally direction toward the gas port 1716. In other embodiments, the flatness and curvature of any of these structures may differ from those shown without significantly affecting the flow modification results.

[0093] Now for reference Figure 17B , Figure 17AThe cross-sectional views are shown to scale. Each of the bodies of flow modification structures 1702-1710 extends downward from wall 1700 and into a chamber. The inner chamber has a height H3 as shown, which may be approximately 1.2 inches. The first flow modification structures 1702 and 1704 extend downward to a height H1 as shown, which may be approximately 0.91 inches. The second flow modification structures 1706, 1708 and the third flow modification structure 1710 extend downward to a height H2 as shown, which may be approximately 0.71 inches. In other embodiments, these dimensions may be varied without significantly affecting the flow modification results. Figure 17C This is a bottom perspective view, further illustrating the size, position, and shape of the flow modification structures 1702-1710 and the gaps 1712 and 1714. Figure 17D It is a cross-sectional perspective view of the screen bed cap, and Figure 17E This shows the first flow modification structures 1702 and 1704 and the gap 1712. Figure 17D The associated cross-sectional view. Figure 17F It is another cross-sectional perspective view, and Figure 17G This shows the second flow modification structures 1706 and 1708 and the gap 1714. Figure 17F The associated cross-sectional view. And, Figure 17H It is another cross-sectional perspective view, and Figure 17I This illustrates the third flow modification structure 1710. Figure 17H The associated cross-sectional view.

[0094] Now refer to it again Figure 17AGas is fed into the chamber from port 1716 and encounters first flow modification structures 1702 and 1704 and gap 1712. This provides a first flow modification to the gas, with a portion passing through gap 1712 and entering space 1718, and other portions being deflected to spaces 1720 and 1722, where they encounter dome surface 1700. The gas flow then encounters second flow modification structures 1706 and 1708 and gap 1714, with a smaller portion of the gas passing through gap 1714, and other portions being directed to spaces 1720 and 1722 and encountering dome surface 1700. In the illustrated embodiment, gap 1714 is smaller than gap 1712, thus allowing less gas to pass through it compared to gap 1712. In other embodiments, gap 1714 may be about 0.1 to 1.0 times the size of gap 1712. In other embodiments, gap 1712 may be correspondingly smaller than gap 1714. The second flow modification structures 1706 and 1708, by virtue of their shape, deflect a portion of the gas inward toward gap 1714 and a portion outward toward spaces 1720 and 1722. This provides an additional, or second, flow modification for the gas flow. The gas flow then encounters the third flow modification structure 1710. This causes the gas to deflect into spaces 1726 and 1728, where it encounters the dome surface 1700. (Discussed below...) Figure 18B These flow patterns were illustrated using computational fluid dynamics simulations.

[0095] Therefore, the gas flow can be incrementally modified with each row of structures or baffles to achieve the desired flow distribution and / or velocity of the gas entering the screen material. This provides optimization for the flow to achieve a more uniform distribution and flow velocity of the gas as it enters the screen material, thereby reducing wear and tear on the screen material (e.g., pulverization, fluidization, etc.).

[0096] Figures 18A to 18C The diagram illustrates the process of... Figures 17A to 17I The flow distribution and velocity generated by the structure of the cap / interface, baffles and / or protrusions, as modeled using Ansys, Inc.'s computational fluid dynamics software. Figure 18A It shows something similar to Figure 17B A cross-sectional view showing the calculated flow 1800 guided within the cap / interface and their velocities along the x-axis and y-axis directions. Figure 18B It shows something similar to Figure 17A The bottom view shows the calculated flow 1800 and their velocities along the x-axis and z-axis. Figure 18A and Figure 18B In the context of flow 1800, the speed is indicated as high to low as the shadow changes from bright to dark.

[0097] Figure 18C The illustration shows that Figure 18A The calculated flow rate and / or velocity distribution is obtained at the plane location indicated in the diagram, which is close to the surface of the screen bed material and / or diffuser (e.g., 510). Therefore, Figure 18C This represents the calculated flow distribution and velocity at or near the surface of the sieve bed material. As shown, the flow distribution includes a relatively large, substantially uniform distribution in a flow region 1802 extending outward from the center. A second, smaller region 1804 with an arcuate shape also exists, which has a substantially uniform flow distribution. Similar to... Figure 18A and Figure 18B As the shadow changes from bright to dark, the velocity is indicated as decreasing from high to low. Two exceptions are small areas 1806 and 1808, where these dark areas represent flow velocities above the average. Apart from the very small areas 1806 and 1808, an optimized and substantially uniform gas flow distribution is achieved, representing approximately 70-80% (or more) of the area near the screen bed material. This uniformity, by introducing gas more evenly into the screen bed material, limits or eliminates cavities in the screen bed material that the gas might otherwise not reach when it is unevenly distributed upon entry, thus making the screen bed more efficient.

[0098] For reference only. Figure 18D and Figure 18E The diagram shows Figures 17A to 17I The flow distribution and velocity of the cap / interface are controlled, but without any flow modification to the structure, baffles, and / or protrusions. For example... Figure 18D As observed, the flow is unevenly distributed within the inner chamber of the cap. Furthermore, as... Figure 18E As seen, the resulting flow distribution is concentrated along a narrow arc 1810 along the inner chamber boundary wall opposite the gas port 1716. This non-uniform flow distribution produces undesirable higher flow velocities and / or required pressures, which contribute to screen bed wear and tear, including pulverization and fluidization of the screen material, wear of the filter media, compressor wear (over time), etc.

[0099] Figure 19A and Figure 19B Another embodiment of the screen cap / interface 504 with a flow modification structure is illustrated. Figure 19A and Figure 19B The embodiments are similar to Figures 17A to 17I The embodiment differs in that the second flow modification structures 1900 and 1902 are not curved (as opposed to those shown as curved). Figures 17A to 17I The second flow modification structures 1706 and 1708). As shown in the figure, the second flow modification structures 1900 and 1902 have a substantially flat body with rounded or curved end faces. Apart from this difference, Figures 17A to 17I and Figures 19A to 19B The implementations are similar (including flow patterns; see Figure 20B ), and the corresponding description is incorporated here by reference.

[0100] Figures 20A to 20C The diagram illustrates the process of... Figures 19A to 19B The flow distribution and velocity generated by the structure of the cap / interface, baffles, and / or protrusions, as modeled using Ansys, Inc.'s computational fluid dynamics software. Therefore, for Figures 19A to 19B Implementation of the example and Figures 18A to 18C The same analysis is shown and described. Figure 20A It shows something similar to Figure 19B A cross-sectional view, in which the resulting calculated flow 2000 guided within the cap / interface and their velocities are shown along the x-axis and y-axis directions. Figure 20B It shows something similar to Figure 19A The bottom view shows the calculated flow 1800 and their velocities along the x-axis and z-axis. Figure 20A and Figure 20B In the context of flow 2000, the speed is indicated as high to low as the shadow changes from bright to dark.

[0101] Figure 20C The illustration shows that Figure 20A The calculated flow rate and / or velocity distribution is obtained at the plane location indicated in the diagram, which is close to the surface of the screen bed material and / or diffuser (e.g., 510). Therefore, Figure 20C This represents the calculated flow distribution and velocity near the surface of the screen bed material. As shown, the flow distribution includes a relatively large, substantially uniform distribution in a flow region 2002 extending outward from the center. There is also a second, smaller region 2004 with a slightly interrupted, arcuate shape, which also has a substantially uniform flow distribution. Similar to... Figure 20A and Figure 20B As the shadow changes from bright to dark, the velocity is indicated as higher to lower. Two exceptions are small areas 2006 and 2008, where these dark areas represent flow velocities above the average. Apart from the very small areas 2006 and 2008, an optimized and substantially uniform gas flow distribution was achieved, representing approximately 70-80% (or more) of the area near the screen bed material. As previously mentioned, this uniformity, by introducing gas more evenly into the screen bed material, limits or eliminates cavities in the screen bed material that the gas might otherwise not reach when it is unevenly distributed upon entry, thus making the screen bed more efficient.

[0102] In addition to a more uniform distribution (which contributes to screen bed efficiency), the flow rates according to these embodiments are generally lower than those provided in other ways. Lower flow rates reduce pulverization, fluidization, and other abrasion and tearing on the screen bed and screen bed material. This extends the life of the screen bed, and therefore the life of the gas concentration system.

[0103] Figures 21A to 21D Another embodiment of the screen cap / interface 504 with a flow modification structure is illustrated. This embodiment includes two rows of flow modification structures. The first row is... Figures 17A to 17I The embodiments are identical and include first flow modification structures 1702 and 1704 and gap 1712. Second flow modification structures are different. These include flow modification structures 2100 and 2102 and gap 2104, which form a V-shape with curved legs (e.g., 2100 and 2102) and a small gap (e.g., 2104) at the apex of the V-shape. As previously described, flow modification structures 1702 and 1704 and gap 1712 provide first gas flow modification. Gas through gap 1712 enters space 2106 and encounters second flow modification structures 2100 and 2102 and gap 2104. A portion of the gas passes through gap 2104, and another portion is deflected by structures 2100 and 2102 into spaces 2108 and 2110, where they encounter dome surface 1700. Gas through gap 2104 enters space 2112, where it encounters dome surface 1700. In the illustrated embodiment, gap 2104 is smaller than gap 1712, thereby allowing less gas to pass through it compared to gap 1712. In other embodiments, gap 2104 may be about 0.1 to 1.0 times the size of gap 1712. In other embodiments, gap 1712 may be correspondingly smaller than gap 2104. Therefore, the second flow modification structures 2100 and 2102 and gap 2104 provide a second flow modification.

[0104] Figures 22A to 22DAnother embodiment of a screen cap / interface 504 with a flow modification structure is illustrated. This embodiment includes a flow modification structure 2200 having a V-shaped portion with stepped or wavy legs 2204 and 2206. Gas entering the inner chamber encounters the V-shaped portion and is separated and deflected into spaces 2208 and 2210. However, because the legs 2204 and 2206 of the V-shaped portion have stepped or wavy surfaces as shown, a small portion of the gas flow is deflected back against the oncoming flow. The end result is that a portion of the gas flow is not deflected into spaces 2208 and 2210, which helps to distribute the flow more evenly, since not all the flow is deflected into the side spaces 2208 and 2210. The portion of the flow deflected into spaces 2208 and 2210 also flows into space 2212 via the dome surface 1700 and the cylindrical portion 2202 of the flow modification structure 2200.

[0105] Figures 23A to 23D Another embodiment of a screen cap / interface 504 with a flow modification structure is illustrated. This embodiment includes a flow modification structure 2300, which is essentially cylindrical and includes a cylindrical first portion 2302 and a tapered or conical second portion 2304. The first portion 2302 provides a first gas flow modification by deflecting gas around the structure 2300 into a space near the dome surface 1700. With its tapered or conical geometry, the second portion 2304 provides a second flow modification by deflecting the gas flow downwards into the screen material. In other embodiments, the second portion 2304 may be more tapered or less tapered, or more conical or less conical than the portion shown.

[0106] Figures 24A to 24D Another embodiment of a screen cap / interface 504 with a flow modification structure is illustrated. This embodiment includes a flow modification structure 2400, which is essentially cylindrical and includes a generally cylindrical first portion 2402 and an inclined second portion 2404, which may be curved (including concave and / or convex shapes as shown). The first portion 2402 provides a first gas flow modification by deflecting gas around the structure 2400 into a space near the dome surface 1700. Due to its inclination, the second portion 2404 provides a second flow modification by deflecting the gas flow downwards into the screen material near the gas inlet port 1716. In other embodiments, the second portion 2404 may be more or less inclined than the portion shown.

[0107] Figures 25A to 25DAnother embodiment of a screen cap / interface 504 with a flow modification structure is illustrated. This embodiment includes a flow modification structure 2500 located very close to the gas inlet port 1716. The reason for such proximity to the gas inlet port 1716 is to deflect the introduced gas flow into at least two smaller gas flow streams, thereby allowing a more uniform flow distribution on the dome surface 1700 compared to when only a single gas flow encounters the dome surface 1700. The flow modification structure 2500 includes a substantially flat surface 2504 with curved end surfaces 2502 and 2506 on its sides, respectively. The curved end surfaces 2502 and 2506 provide less turbulence and less noise deflection of the gas flow towards the dome surface 1700. In other embodiments, the end surfaces 2502 and 2506 need not be curved, but may be substantially flat and angled relative to surface 2504. Figure 25D As shown, the flow modification structure 2500 can extend significantly downward into the inner chamber of the screen cap / interface. In other embodiments, it can extend to a length less than shown, including, for example, reaching only or just beyond the periphery of the gas inlet port 1716.

[0108] Figures 26A to 26D Another embodiment of the screen cap / interface 504 is illustrated, which has a cylindrical wall 2600 instead of, for example, a dome surface 1700. In this embodiment, the side and top portions of the cylindrical wall 2600 act as flow modification structures, distributing the flow into two regions. The gas flow entering from port 1716 encounters a sidewall portion 2602, which splits the flow into an upper flow and a lower flow. The upper flow is then deflected downwards by the top surface 2604 and the side surface portion 2606, forming a second lower flow. Splitting the main gas flow entering from the gas inlet port 1716 into two or more flow flows provides a more uniform flow distribution of the gas entering the screen material. Surfaces 2608, 2610, 2612, and 2614 optionally extend the lower portion of the body 1300 in a stepwise manner to provide an attachment base to the screen container wall 600 (see Figure 6).

[0109] Figures 26E to 26F The diagram illustrates the process of... Figures 26A to 26D The flow distribution and velocity generated by the cap / interface are modeled, for example, using computational fluid dynamics software from Ansys, Inc. Therefore, for Figures 26A to 26D Implementation of the example and Figures 18A to 18C The same analysis is shown and described. Figure 26D It shows something similar to Figure 19B A cross-sectional view, showing the calculated flow 2614 guided within the cap / interface and their velocities along the x-axis and y-axis directions. Figure 26DIn the context of flow 2000, the speed is indicated as high to low as the shadow changes from bright to dark.

[0110] Figure 26F The illustration shows that Figure 26E The calculated flow rate and / or velocity distribution is obtained at the plane location indicated in the diagram, which is close to the surface of the screen bed material and / or diffuser (e.g., 510). Therefore, Figure 26E This represents the flow distribution and velocity calculated at the surface of the screen bed material. As shown in the figure, the flow distribution includes a substantially uniform distribution in flow region 2616. A second region 2618 also exists with a uniform flow distribution. Similar to... Figure 26E As the shadow changes from bright to dark, the velocity is indicated as higher to lower. Two exceptions are small areas 2622 and 2624, where these dark areas represent flow velocities above the average. Apart from the very small areas 2622 and 2624, an optimized and substantially uniform gas flow distribution was achieved, representing approximately 70-80% (or more) of the area near the screen bed material. As previously mentioned, this uniformity, by introducing gas more evenly into the screen bed material, limits or eliminates cavities in the screen bed material that the gas might otherwise not reach when it is unevenly distributed upon entry, thus making the screen bed more efficient.

[0111] Figure 27A and Figure 27B Another embodiment of a screen cap / interface 504 is illustrated, which has a continuous flow modification structure 2700 rather than, for example, a discrete row or column structure. Structure 2700 includes several portions, including curved side portions 2712 and 2714 and a central portion 2706. The curved side portions 2712 and 2714 and the central portion 2706 extend from the dome surface 1700 and enter the inner chamber of the cap via curved surfaces 2702, 2704, and 2708 and surface 2710. Surface 2710 may be linear or curved (as shown by 2716) (including having multiple curves), and performs a first flow modification by splitting the gas flow introduced from port 1716 into at least two flow flows. The curved side portions 2712 and 2714 provide a second flow modification similar to the curved flow modification structures 1706 and 1708 (e.g., ...). Figure 17AThis second flow modification works by redirecting a portion of the gas flow back toward spaces 2718 and 2720, where the gas flow encounters the dome surface 1700 and is directed downward toward the screen material. This redirection provides a greater distribution of the flow entering the screen bed from this region (e.g., spaces 2718 and 2720) compared to what was originally provided, resulting in a more uniform overall flow distribution of the gas entering the screen material. While this embodiment shows a single central portion 2706 extending into the inner chamber of the cap, in other embodiments, the central portion 2706 may be divided into sections mimicking, for example... Figures 17A to 21D Several parts of the low-modification structure, wherein these structures can be extended from the dome surface 1700 by curved surfaces and connected to each other by curved surfaces, while still maintaining the same overall construction as shown in these embodiments.

[0112] The end result of the foregoing embodiments is a more uniform flow distribution and lower flow velocity compared to a screen cap 504 without any associated flow modification structures. Furthermore, the flow modification structures of the various embodiments shown and described herein can be further combined to form additional combinations of flow modification structures. Additionally, the embodiments of the screen cap / interface shown and described can be used with or without a flow diffuser such as the diffuser 510 disclosed herein. Moreover, while the flow modification structures have been shown by example as part of the screen cap / interface, these same structures can also be implemented as separate components, inserts, and / or adapters to be placed within an existing screen cap / interface or mounted separately within a screen assembly for operation in conjunction with the screen cap or interface. Furthermore, the screen cap / interface may include both tamper-proof features and flow modification structures as disclosed herein.

[0113] While the invention has been described through its embodiments, and while the embodiments have been described in considerable detail, the description is not intended to limit the scope of this disclosure or in any way restrict it to such details. Additional advantages and modifications will readily become apparent to those skilled in the art. For example, the relative size, dimensions, and shape of components may be altered without significantly affecting their function. Therefore, the invention is not limited in its broader aspects to the specific details, representative devices, and illustrative examples shown and described. Thus, deviations from such details may be made without departing from the spirit or scope of the overall inventive concept.

Claims

1. An input interface for a sieve bed, comprising: a body having: at least one gas feed port; a chamber that receives gas from the port; and at least one flow modification structure extending from a chamber wall into the chamber, the flow modification structure positioned in juxtaposition with the gas feed port, wherein the at least one flow modification structure is configured to variably extend from the chamber wall into the chamber and is configured to provide more than one modification of gas flow by deflecting gas around the flow modification structure to a space proximate the chamber wall in order to more evenly distribute gas flow and reduce gas flow velocity. The at least one flow modification structure comprises a baffle.

2. The input interface of claim 1, wherein, The at least one flow modification structure comprises a rib.

3. The input interface of claim 1, wherein, The at least one flow modification structure comprises a gap.

4. The input interface of claim 1, wherein, The at least one flow modification structure comprises a first baffle and a second baffle and a gap between the first and second baffles.

5. The input interface of claim 1, wherein, The at least one flow modification structure comprises a first row and a second row of baffles.

6. The input interface of claim 1, wherein, The at least one flow modification structure comprises a first row, a second row, and a third row of baffles.

7. The input interface of claim 1, wherein, The at least one flow modification structure comprises a first row and a second row of baffles and a gap between the baffles of each row.

8. The input interface of claim 1, wherein, The at least one flow modification structure comprises a first baffle and a second baffle, and wherein the second baffle has a curved body.

9. The input interface of claim 1, wherein, The at least one flow modification structure comprises a first baffle and a second baffle, and wherein the first and second baffles have substantially planar bodies.

10. The input interface of claim 1, wherein, 11. A sieve bed, comprising: a vessel for containing separation media and having a vessel wall; a cap having a body comprising: at least one gas feed port; a chamber that receives gas from the port; and at least one flow modification structure extending from a chamber wall into the chamber, the flow modification structure positioned in juxtaposition with the gas feed port, wherein the at least one flow modification structure is configured to variably extend from the chamber wall into the chamber and is configured to provide more than one modification of gas flow by deflecting gas around the flow modification structure to a space proximate the chamber wall in order to more evenly distribute gas flow and reduce gas flow velocity. The at least one flow modification structure comprises a baffle.

12. The sieve bed according to claim 11, wherein, The at least one flow modification structure comprises a rib.

13. The sieve bed of claim 11, wherein, The at least one flow modification structure comprises a gap.

14. The sieve bed of claim 11, wherein, The at least one flow modification structure comprises a first baffle and a second baffle and a gap between the first and second baffles.

15. The sieve bed of claim 11, wherein, The at least one flow modification structure comprises a first row and a second row of baffles.

16. The sieve bed of claim 11, wherein, The at least one flow modification structure comprises a first row, a second row, and a third row of baffles.

17. The sieve bed of claim 11, wherein, The at least one flow modification structure comprises a first row and a second row of baffles and a gap between the baffles of each row.

18. The sieve bed of claim 11, wherein, The at least one flow modification structure comprises a first baffle and a second baffle, and wherein the second baffle has a curved body.

19. The sieve bed of claim 11, wherein, 20. An oxygen concentrator, comprising: a pressure source; at least one sieve bed having: a vessel for containing separation media and having a vessel wall; a cap having a body comprising: ​ at least one gas feed port; a chamber that receives gas from the port; and at least one flow modification structure that extends from a chamber wall into the chamber, the flow modification structure positioned in juxtaposition with the gas feed port, wherein the at least one flow modification structure is configured to variably extend from the chamber wall into the chamber and is configured to provide more than one modification of gas flow by deflecting gas around the flow modification structure into a space close to the chamber wall in order to more evenly distribute gas flow and reduce gas flow velocity; a plurality of valves; and a patient output.

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