Low-pressure pressure swing adsorption oxygen equipment

Abstract

The invention belongs to the technical field of oxygen production, and particularly relates to low-pressure variable-pressure oxygen adsorption equipment which comprises an air compressor, a filter, a buffer tank, an oxygen storage tank and two groups of adsorption towers, and each group of adsorption towers is composed of an initial-end adsorption tower and a tail-end adsorption tower which are connected in series. The device further comprises a first valve assembly, a second valve assembly, a third valve assembly, a fourth valve assembly, a fifth valve assembly, a sixth valve assembly, a seventh valve assembly, an eighth valve assembly and a ninth valve assembly. The first valve assembly switches the two initial-end adsorption towers to be communicated with the buffer tank by collecting the same-end pressure difference of the same-end adsorption towers in the two sets of adsorption towers. The two groups of adsorption towers are automatically switched by using the pressure difference of the same ends of the two adsorption towers at the same end in the two groups of adsorption towers, so that the related structure for realizing the automatic switching is simple, and the cost is relatively low.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oxygen production, and particularly relates to a low-pressure pressure swing adsorption oxygen equipment. BACKGROUND

[0002] The low-pressure pressure swing adsorption (PSA) oxygen equipment is a technical equipment for realizing air separation and oxygen production under a low working pressure based on the selective adsorption characteristics of an adsorbent to a gas. Compared with the traditional high-pressure PSA oxygen production, the core feature of the low-pressure PSA oxygen equipment is that the system runs at a low pressure, and through optimization of the adsorbent performance and process control, oxygen can still be efficiently enriched under a low pressure condition, and the low-pressure PSA oxygen equipment has low energy consumption, high safety and flexible applicability, and is widely applied to small and medium-sized oxygen demand scenarios.

[0003] The essence of the low-pressure PSA oxygen production is to realize air separation under a low pressure condition by using the selective adsorption of zeolite molecular sieve to nitrogen, and the core process includes four steps: 1, an adsorption stage; and 2, a desorption regeneration stage.

[0004] Most of the existing low-pressure PSA oxygen equipment is of a double-adsorption-tower structure, and the adsorption efficiency and oxygen production purity of the double-adsorption-tower structure are low, and the oxygen outlet pressure of the adsorption tower will be sharply reduced with the outside of the molecular sieve in the adsorption tower tending to be saturated, and the molecular sieve in the middle of the adsorption tower cannot fully enter the oxygen storage tank due to the low utilization rate of the molecular sieve in the middle of the adsorption tower.

[0005] In addition, the desorption of the existing low-pressure PSA oxygen equipment is to release the nitrogen and other impurities captured by the molecular sieve by reducing the system pressure, so as to restore the adsorption capacity of the adsorbent and ensure the continuous and efficient operation of the cycle. The structure and operation involved in reducing the system pressure are relatively complex, resulting in high cost.

[0006] The switching of the two adsorption towers in the existing low-pressure PSA oxygen equipment is mostly manual switching rather than automatic switching, and the degree of automation is low.

[0007] The application designs a low-pressure pressure swing adsorption oxygen equipment to solve the above problems. SUMMARY

[0008] Based on this, it is necessary to provide a low-pressure pressure swing adsorption oxygen equipment for the problems existing in the current low-pressure pressure swing adsorption oxygen equipment, the two groups of adsorption towers in the application utilize the pressure difference of the same end of the two same-end adsorption towers in the two groups of adsorption towers for automatic switching, the related structure for realizing automatic switching is simple, and the cost is low. The ninth valve assembly in the application utilizes the raw material gas from the air compressor to pressurize the oxygen generated by one group of adsorption towers in an adsorption working state and input the oxygen storage tank, and the ninth valve assembly controls the amount of raw material gas for driving pressurization by collecting the pressure difference between the initial end of the initial end adsorption tower and the end of the end adsorption tower in one group of adsorption towers in an adsorption working state. The pressure difference between the initial end of the initial end adsorption tower and the end of the end adsorption tower in one group of adsorption towers in an adsorption working state increases as the initial end adsorption tower gradually tends to be adsorbed. The amount of raw material gas entering the ninth valve assembly increases as the pressure difference between the initial end of the initial end adsorption tower and the end of the end adsorption tower in one group of adsorption towers in an adsorption working state increases, so that the oxygen generated by one group of adsorption towers in an adsorption working state has sufficient pressure to input the oxygen storage tank, and at the same time, a certain negative pressure is generated at the end of the end adsorption state, which is beneficial to improve the utilization rate of molecular sieve and the adsorption oxygen efficiency of the two groups of adsorption towers.

[0009] The above object is realized by the following technical scheme: A low-pressure pressure swing adsorption oxygen equipment, comprising an air compressor, a filter, a buffer tank, an oxygen storage tank, two groups of adsorption towers, each group of adsorption towers being composed of an initial end adsorption tower and an end adsorption tower connected in series, further comprising a first valve assembly, a second valve assembly, a third valve assembly, a fourth valve assembly, a fifth valve assembly, a sixth valve assembly, a seventh valve assembly, an eighth valve assembly and a ninth valve assembly, the first valve assembly switches the communication between the two initial end adsorption towers and the buffer tank by collecting the pressure difference of the same end of the same-end adsorption towers in the two groups of adsorption towers, the second valve assembly automatically switches the initial end desorption waste gas discharge of the two initial end adsorption towers by collecting the pressure difference of the same end of the same-end adsorption towers in the two groups of adsorption towers, the fourth valve assembly automatically switches the initial end desorption waste gas discharge of the two end adsorption towers by collecting the pressure difference of the same end of the same-end adsorption towers in the two groups of adsorption towers, the seventh valve assembly completes the series switching of the two groups of adsorption towers by collecting the pressure difference of the same end of the same-end adsorption towers in the two groups of adsorption towers, the eighth valve assembly makes the end adsorption tower about to produce oxygen utilize part of the oxygen production to complete the reverse desorption of the adsorption group by collecting the pressure difference between the initial end of the initial end adsorption tower and the end of the end adsorption tower in one group of adsorption towers in an adsorption working state, the fifth valve assembly switches the oxygen output of the two groups of adsorption towers to the oxygen storage tank by collecting the pressure difference of the same end of the same-end adsorption towers in the two groups of adsorption towers, the ninth valve assembly controls the raw material gas to pressurize and input the oxygen storage tank by collecting the pressure difference of the two ends of one group of adsorption towers in an adsorption state, and the third valve assembly and the sixth valve assembly are used to switch the pressure difference collection of the ninth valve assembly to the two groups of adsorption towers.

[0010] In one of the embodiments, the first valve assembly comprises a first valve shell, a first air port, a second air port and a third air port are arranged on the outer wall of the first valve shell and communicate with the first column cavity, the first air port is coaxial with the first column cavity, the second air port and the third air port are 90 degrees apart from each other in the circumference of the first column cavity, a third air pipe, a first air pipe and a second air pipe are arranged at the first air port, the second air port and the third air port respectively, a first guide sleeve and a second guide sleeve coaxial with each other are arranged on the outer side of the first valve shell, the first guide sleeve and the second guide sleeve communicate with the first air pipe and the second air pipe through a fifth pressure taking pipe and a sixth pressure taking pipe respectively, a first sliding plug and a second sliding plug are slidably arranged in the first guide sleeve and the second guide sleeve respectively, a first connecting rod and a second connecting rod are arranged on the first sliding plug and the second sliding plug respectively, the first connecting rod is connected with the second connecting rod through a first rack, a first limiting block and a second limiting block are arranged in the first guide sleeve and the second guide sleeve respectively to limit the movement amplitude of the first rack, the first rack is engaged with a second gear arranged on the outer side of the first valve shell, a second rotating sleeve is rotatably arranged on the surface of the second gear through a fixing pin, a first rotating sleeve is rotatably arranged on the outer side of the first valve shell through a fixing pin, the first rotating sleeve is connected with the second rotating sleeve through a first spring, a first plug is rotatably arranged in the first column cavity, a first air channel is arranged on the first plug to communicate the first air port with the second air port or the first air port with the third air port, a first end shaft is arranged on the end of the first plug, a first gear engaged with the second gear is arranged on the first end shaft, the axis of the first gear is in the same plane with the axes of the first rotating sleeve and the second gear.

[0011] In one of the embodiments, the second valve assembly, the third valve assembly, the fourth valve assembly, the fifth valve assembly and the sixth valve assembly have the same structure as the first valve assembly.

[0012] In one of the embodiments, the third air pipe of the first valve assembly communicates with the buffer tank through a clean air main pipe, the first air pipe and the second air pipe of the first valve assembly communicate with the initial space of the two initial end adsorption towers of the two groups of adsorption towers through a second branch pipe respectively, the third air pipe of the second valve assembly communicates with the outside, the first air pipe and the second air pipe of the second valve assembly communicate with the initial space of the two initial end adsorption towers of the two groups of adsorption towers through a first exhaust pipe respectively, the third air pipe of the fourth valve assembly communicates with the outside, the first air pipe and the second air pipe of the fourth valve assembly communicate with the initial space of the two terminal end adsorption towers of the two groups of adsorption towers through a second exhaust pipe respectively.

[0013] In one of the embodiments, the seventh valve assembly comprises a second valve housing, fourth, fifth, sixth and seventh gas ports are arranged on the outer wall of the second valve housing and communicate with the second column cavity, the fourth and fifth gas ports are coaxial and opposite to each other at 180 degrees around the second column cavity, the sixth and seventh gas ports are coaxial and opposite to each other at 180 degrees around the second column cavity, the axis of the fourth gas port is perpendicular to the axis of the sixth gas port and is spaced along the axis of the second column cavity, the fourth, fifth, sixth and seventh gas ports are respectively provided with fourth, fifth, sixth and seventh gas tubes, the second valve housing is provided with coaxial third and fourth guide sleeves, the third and fourth guide sleeves are respectively communicated with the fifth and seventh gas tubes through seventh and eighth pressure taking tubes, the third and fourth guide sleeves are respectively slidably provided with third and fourth sliding plugs, the third and fourth sliding plugs are respectively provided with third and fourth connecting rods, the third connecting rod is connected with the fourth connecting rod through a second rack, the third and fourth guide sleeves are respectively provided with third and fourth limit blocks for limiting the movement amplitude of the second rack, the second rack is engaged with a third gear provided on the outer side of the second valve housing, the wheel surface of the third gear is rotatably provided with a fourth rotating sleeve through a fixing pin, the outer side of the second valve housing is rotatably provided with a third rotating sleeve through a fixing pin, the third rotating sleeve is connected with the fourth rotating sleeve through a second spring, the second column cavity is sealingly and rotatably provided with a second plug, the second plug is provided with a second gas channel matched with the fourth and fifth gas ports and a third gas channel matched with the sixth and seventh gas ports, the end of the second plug is provided with a second end shaft, the second end shaft is provided with a fourth gear engaged with the third gear, the axis of the fourth gear is in the same plane with the axes of the third rotating sleeve and the third gear.

[0014] In one of the embodiments, the fourth and sixth gas tubes of the seventh valve assembly are respectively communicated with the initial end space of the initial end adsorption tower and the terminal space of the terminal adsorption tower of the two groups of adsorption towers through first communication tubes, the fifth and seventh gas tubes of the seventh valve assembly are respectively communicated with the terminal end space of the initial end adsorption tower and the initial end space of the terminal adsorption tower of the two groups of adsorption towers through second communication tubes, the fourth and fifth gas tubes are used for connecting the initial end adsorption tower and the terminal adsorption tower of one group of adsorption towers, and the sixth and seventh gas tubes are used for connecting the initial end adsorption tower and the terminal adsorption tower of the other group of adsorption towers.

[0015] In one embodiment, the eighth valve assembly includes an eighth air pipe, a second annular groove formed in the middle of the eighth air pipe, a first annular groove formed in the middle of the second annular groove, an eighth air port and a tenth air port formed on one end wall of the first annular groove at 180-degree intervals around the circumference of the first annular groove and coaxially opposite each other, and a ninth air port and an eleventh air port formed on the other end wall of the first annular groove at 180-degree intervals around the circumference of the first annular groove and coaxially opposite each other. A ninth, tenth, eleventh, and twelfth air pipe are respectively provided at the air inlet. A fifth sliding plug is slidably disposed in the first annular groove. A Y-shaped fourth air passage is opened on the eighth air inlet side end face of the fifth sliding plug, which communicates with the cylindrical surface of the fifth sliding plug and cooperates with the eighth and tenth air inlets. A Y-shaped fifth air passage is opened on the ninth air inlet side end face of the fifth sliding plug, which communicates with the cylindrical surface of the fifth sliding plug and cooperates with the ninth and eleventh air inlets. The two ends of the fifth sliding plug are respectively connected to the corresponding side ends of the second annular groove through a third spring.

[0016] In one embodiment, the eighth port side end of the eighth gas pipe and the tenth gas pipe are respectively connected to the end space of the end adsorption tower of a set of adsorption towers through the fourth oxygen supply pipe and the fifth oxygen supply pipe. The twelfth gas pipe is connected to the end space of the beginning adsorption tower of the set of adsorption towers corresponding to the eighth port side end of the eighth gas pipe through the sixth oxygen supply pipe. The ninth port side end of the eighth gas pipe and the ninth gas pipe are respectively connected to the end space of the end adsorption tower of another set of adsorption towers through the fourth oxygen supply pipe and the fifth oxygen supply pipe. The eleventh gas pipe is connected to the end space of the beginning adsorption tower of the set of adsorption towers corresponding to the ninth port side end of the eighth gas pipe through the sixth oxygen supply pipe.

[0017] In one embodiment, the ninth valve assembly includes a thirteenth air pipe and a third valve housing. A fourth annular groove is formed in the middle of the thirteenth air pipe, and a third annular groove is formed at one end of the fourth annular groove. A fourteenth air pipe and a fifteenth air pipe are provided on the pipe wall of the thirteenth air pipe, communicating with the middle of the third annular groove. A sixth sliding plug is slidably disposed in the third annular groove. A sixth air passage is formed on the cylindrical surface of the sixth sliding plug, which cooperates with the fourteenth and fifteenth air pipes. The sixth sliding plug is connected to the end side of the fourth annular groove by a fourth spring. A cylindrical drive chamber and a cylindrical booster chamber are formed in the third valve housing. The center of the cylindrical surface and one end face of the drive chamber are respectively connected to the fifteenth air pipe and the third exhaust pipe. The center of the cylindrical surface and one end face of the booster chamber are respectively connected to the sixteenth air pipe and the seventeenth air pipe. A first turbine and a second turbine are respectively disposed in the drive chamber and the booster chamber, and the first turbine and the second turbine are respectively disposed at both ends of the same rotating shaft.

[0018] In one of the embodiments, a third annular groove side end of the thirteenth gas pipe is communicated with a third gas pipe of the second valve assembly through a second pressure taking pipe, a fourth annular groove side end of the thirteenth gas pipe is communicated with a third gas pipe of the sixth valve assembly through a fourth pressure taking pipe, the fourteenth gas pipe is communicated with a raw gas main pipe for communicating the air compressor and the filter through a first branch pipe, the seventeenth gas pipe is communicated with the third gas pipe of the fifth valve assembly through a second oxygen supply pipe, and the sixteenth gas pipe is communicated with the oxygen storage tank through a third oxygen supply pipe.

[0019] The beneficial effects of the present application are: 1. The first valve assembly in the present application automatically switches the clean gas from the buffer tank to a group of adsorption towers in a desorption state when the group of adsorption towers in an adsorption state tends to be adsorption saturated by collecting the initial end pressure difference of two initial end adsorption towers in the two groups of adsorption towers.

[0020] The second valve assembly automatically desorbs the waste gas of the group of adsorption towers tending to be adsorption saturated and closes the waste gas of the group of adsorption towers completing desorption when the group of adsorption towers in an adsorption state tends to be adsorption saturated by collecting the initial end pressure difference of two initial end adsorption towers in the two groups of adsorption towers.

[0021] The third valve assembly and the sixth valve assembly respectively collect the initial end pressure difference of two initial end adsorption towers and the end pressure difference of two end adsorption towers in the two groups of adsorption towers to automatically switch the ninth valve assembly to collect the pressure difference of the two ends of the group of adsorption towers tending to be adsorption saturated to the two ends of the group of adsorption towers completing desorption when the group of adsorption towers in an adsorption state tends to be adsorption saturated.

[0022] The fourth valve assembly automatically desorbs the waste gas of the end adsorption tower in the group of adsorption towers tending to be adsorption saturated and closes the waste gas of the end adsorption tower in the group of adsorption towers completing desorption by collecting the initial end pressure difference of two end adsorption towers in the two groups of adsorption towers when the group of adsorption towers in an adsorption state tends to be adsorption saturated. The fifth valve assembly automatically closes the oxygen supply of the end adsorption tower in the group of adsorption towers tending to be adsorption saturated to the ninth valve assembly and opens the oxygen supply of the end adsorption tower in the group of adsorption towers completing desorption to the ninth valve assembly by collecting the end pressure difference of two end adsorption towers in the two groups of adsorption towers when the group of adsorption towers in an adsorption state tends to be adsorption saturated. The seventh valve assembly automatically blocks the series connection of the two adsorption towers tending to be adsorption saturated and connects the two adsorption towers completing desorption in series by collecting the initial end pressure difference of two end adsorption towers in the two groups of adsorption towers when the group of adsorption towers in an adsorption state tends to be adsorption saturated. The eighth valve assembly automatically blocks the end of the end adsorption tower tending to adsorption saturation from desorbing oxygen to the end of the initial end adsorption tower completing desorption and automatically connects the end of the end adsorption tower tending to adsorption saturation and the end of the end adsorption tower completing desorption when the end adsorption tower tending to adsorption saturation is close to adsorption saturation, so that the two groups of adsorption towers are automatically operated by pressure difference.

[0023] 2、The ninth valve assembly in the application uses the raw material gas from the air compressor to pressurize the oxygen generated by the group of adsorption towers in adsorption working state and input the oxygen storage tank, and the ninth valve assembly controls the amount of raw material gas for driving pressurization by collecting the pressure difference between the initial end of the initial end adsorption tower and the end of the end adsorption tower in the group of adsorption towers in adsorption working state. The pressure difference between the initial end of the initial end adsorption tower and the end of the end adsorption tower in the group of adsorption towers in adsorption working state increases as the initial end adsorption tower gradually tends to adsorption saturation, and the amount of raw material gas entering the ninth valve assembly increases as the pressure difference between the initial end of the initial end adsorption tower and the end of the end adsorption tower in the group of adsorption towers in adsorption working state increases, ensuring that the oxygen generated by the group of adsorption towers in adsorption working state has sufficient pressure to input the oxygen storage tank, while generating a certain negative pressure at the end of the end adsorption state, which is beneficial to improve the utilization rate of molecular sieve and the adsorption oxygen efficiency of the two adsorption towers.

[0024] 3、The group of adsorption towers in desorption state in the application uses the oxygen generated by the group of adsorption towers in adsorption oxygen state for desorption, which has simple structure, convenient operation and low cost of related structure. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the overall schematic diagram of the application; Figure 2 is the overall sectional view of the application; Figure 3 is the schematic diagram of the first valve assembly; Figure 4 is the first sectional view of the first valve assembly; Figure 5 is the second sectional view of the first valve assembly; Figure 6 is the third sectional view of the first valve assembly; Figure 7 is the first valve shell and its sectional view in the first valve assembly; Figure 8 is the first plug and its sectional view in the first valve assembly; Figure 9 is the schematic diagram of the seventh valve assembly; Figure 10 is a first sectional view of a seventh valve assembly; Figure 11 is a second sectional view of the seventh valve assembly; Figure 12 is a third sectional view of the seventh valve assembly; Figure 13 is a fourth sectional view of the seventh valve assembly; Figure 14 is a second valve housing and sectional view thereof in the seventh valve assembly; Figure 15 is a second plug and sectional view thereof in the seventh valve assembly; Figure 16 is an eighth valve assembly and sectional view thereof; Figure 17 is a schematic view of a ninth valve assembly; Figure 18 is a sectional view of the ninth valve assembly; Figure Number Name 101, air compressor; 102, filter; 103, buffer tank; 104, adsorption tower; 105, molecular sieve; 106, oxygen storage tank; 107, raw gas main pipe; 108, first branch pipe; 109, clean gas main pipe; 110, second branch pipe; 111, first exhaust pipe; 112, first pressure taking pipe; 113, second pressure taking pipe; 114, first communication pipe; 115, second communication pipe; 116, second exhaust pipe; 117, first oxygen delivery pipe; 118, second oxygen delivery pipe; 119, third pressure taking pipe; 120, fourth pressure taking pipe; 121, third oxygen delivery pipe; 122, fourth oxygen delivery pipe; 123, fifth oxygen delivery pipe; 124, sixth oxygen delivery pipe; 200, first valve assembly; 201, first valve housing; 202, first column cavity; 203, first gas port; 204, second gas port; 205, third gas port; 206, first gas pipe; 207, fifth pressure taking pipe; 208, first guide sleeve; 209, first limit block; 210, first sliding plug; 211, first connecting rod; 212, second gas pipe; 213, sixth pressure taking pipe; 214, second guide sleeve; 215, second limit block; 216, second sliding plug; 217, second connecting rod; 218, first rack; 219, third gas pipe; 220, first plug; 221, first gas channel; 222, first end shaft; 223, first gear; 224, second gear; 225, first rotating sleeve; 226, first spring; 227, second rotating sleeve; 300, second valve assembly; 400, third valve assembly; 500, fourth valve assembly; 600, fifth valve assembly; 700, sixth valve assembly; 800, seventh valve assembly; 801, second valve shell; 802, second column cavity; 803, fourth gas port; 804, fifth gas port; 805, sixth gas port; 806, seventh gas port; 807, fourth gas tube; 808, fifth gas tube; 809, seventh pressure taking tube; 810, third guide sleeve; 811, third limit block; 812, third sliding plug; 813, third connecting rod; 814, sixth gas tube; 815, seventh gas tube; 816, eighth pressure taking tube; 817, fourth guide sleeve; 818, fourth limit block; 819, fourth sliding plug; 820, fourth connecting rod; 821, second rack; 822, second plug; 823, second air passage; 824, third air passage; 825, second end shaft; 826, third gear; 827, fourth gear; 828, third rotating sleeve; 829, second spring; 830, fourth rotating sleeve; 900, eighth valve assembly; 901, eighth gas tube; 902, first annular groove; 903, second annular groove; 904, eighth gas port; 905, ninth gas port; 906, tenth gas port; 907, eleventh gas port; 908, ninth gas tube; 909, tenth gas tube; 910, eleventh gas tube; 911, twelfth gas tube; 912, fifth sliding plug; 913, fourth air passage; 914, fifth air passage; 915, third spring; 1000, ninth valve assembly; 1001, thirteenth gas tube; 1002, third annular groove; 1003, fourth annular groove; 1004, fourteenth gas tube; 1005, fifteenth gas tube; 1006, sixth sliding plug; 1007, sixth air passage; 1008, fourth spring; 1009, third valve shell; 1010, driving cavity; 1011, pressurizing cavity; 1012, third exhaust tube; 1013, sixteenth gas tube; 1014, seventeenth gas tube; 1015, first turbine; 1016, second turbine. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present application clearer, the following further describes the present application in detail through embodiments and in conjunction with the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0027] The serial numbers of components in this document, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any sequence or technical meaning. The "connection" and "coupling" in the present application include direct and indirect connection (coupling) unless otherwise specified. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0028] In the present application, unless otherwise explicitly specified and limited, the "on" or "under" of the first feature to the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the "over", "above" and "on" of the first feature to the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "under", "below" and "under" of the first feature to the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0029] As Figures 1-18As shown, a low-pressure pressure swing adsorption oxygen equipment includes an air compressor 101, a filter 102, a buffer tank 103, an oxygen storage tank 106, two groups of adsorption towers 104, each group of adsorption towers 104 being composed of a primary end adsorption tower 104 and a terminal end adsorption tower 104 connected in series, and further including a first valve assembly 200, a second valve assembly 300, a third valve assembly 400, a fourth valve assembly 500, a fifth valve assembly 600, a sixth valve assembly 700, a seventh valve assembly 800, an eighth valve assembly 900, and a ninth valve assembly 1000. The first valve assembly 200 switches the communication of two primary end adsorption towers 104 with the buffer tank 103 by collecting the pressure difference of the same end of the same end adsorption towers 104 in the two groups of adsorption towers 104. The second valve assembly 300 automatically switches the primary end desorption exhaust of the two primary end adsorption towers 104 by collecting the pressure difference of the same end of the same end adsorption towers 104 in the two groups of adsorption towers 104. The fourth valve assembly 500 automatically switches the primary end desorption exhaust of the two terminal end adsorption towers 104 by collecting the pressure difference of the same end of the same end adsorption towers 104 in the two groups of adsorption towers 104. The seventh valve assembly 800 completes the series switching of the two groups of adsorption towers 104 by collecting the pressure difference of the same end of the same end adsorption towers 104 in the two groups of adsorption towers 104. The eighth valve assembly 900 makes the terminal end adsorption tower 104 about to produce oxygen perform reverse desorption on the group of adsorption towers 104 completed with adsorption by using part of the oxygen production by collecting the pressure difference of the same end of the same end adsorption towers 104 in the two groups of adsorption towers 104. The fifth valve assembly 600 switches the oxygen output of the two groups of adsorption towers 104 to the oxygen storage tank 106 by collecting the pressure difference of the same end of the same end adsorption towers 104 in the two groups of adsorption towers 104. The ninth valve assembly 1000 controls the pressurized input of raw material gas into the oxygen storage tank 106 by collecting the pressure difference of the two ends of the group of adsorption towers 104 in the adsorption state. The third valve assembly 400 and the sixth valve assembly 700 are used to switch the pressure difference collection of the two groups of adsorption towers 104 by the ninth valve assembly 1000.

[0030] In further embodiments, as Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8As shown, the first valve assembly 200 comprises a first valve shell 201, an outer wall of the first valve shell 201 is provided with a first air port 203, a second air port 204 and a third air port 205 in communication with a first column cavity 202 in the first valve shell 201, the first air port 203 is coaxial with the first column cavity 202, the second air port 204 and the third air port 205 are circumferentially apart by 90 degrees around the first column cavity 202, the first air port 203, the second air port 204 and the third air port 205 are respectively provided with a third air pipe 219, a first air pipe 206 and a second air pipe 212, the first valve shell 201 is provided with coaxial first guide sleeve 208 and second guide sleeve 214, the first guide sleeve 208 and the second guide sleeve 214 are respectively in communication with the first air pipe 206 and the second air pipe 212 through the fifth pressure taking pipe 207 and the sixth pressure taking pipe 213, the first guide sleeve 208 and the second guide sleeve 214 are respectively provided with a first sliding plug 210 and a second sliding plug 216, the first sliding plug 210 and the second sliding plug 216 are respectively provided with a first connecting rod 211 and a second connecting rod 217, the first connecting rod 211 is connected with the second connecting rod 217 through a first rack 218, the first guide sleeve 208 and the second guide sleeve 214 are respectively provided with a first limiting block 209 and a second limiting block 215 to limit the movement amplitude of the first rack 218, the first rack 218 is engaged with a second gear 224 arranged outside the first valve shell 201, the second gear 224 is rotatably arranged with a second rotating sleeve 227 through a fixed pin on the surface of the second gear 224, the first valve shell 201 is rotatably arranged with a first rotating sleeve 225 through a fixed pin, the first rotating sleeve 225 is connected with the second rotating sleeve 227 through a first spring 226, the first column cavity 202 is rotatably sealed with a first plug 220, the first plug 220 is provided with a first air channel 221 to communicate the first air port 203 with the second air port 204 or to communicate the first air port 203 with the third air port 205, an end of the first plug 220 is provided with a first end shaft 222, the first end shaft 222 is provided with a first gear 223 engaged with the second gear 224, the axis of the first gear 223 is coplanar with the axes of the first rotating sleeve 225 and the second gear 224.

[0031] In further embodiments, as shown in Figure 1 、 Figure 2 The structures of the second valve assembly 300, the third valve assembly 400, the fourth valve assembly 500, the fifth valve assembly 600 and the sixth valve assembly 700 are the same as that of the first valve assembly 200.

[0032] In further embodiments, as shown in Figure 1 、 Figure 2As shown, the third gas pipe 219 of the first valve assembly 200 is communicated with the buffer tank 103 through the clean gas main pipe 109, and the first gas pipe 206 and the second gas pipe 212 of the first valve assembly 200 are respectively communicated with the initial end space of the two initial end adsorption towers 104 of the two groups of adsorption towers 104 through the second branch pipe 110; the third gas pipe 219 of the second valve assembly 300 is communicated with the outside, and the first gas pipe 206 and the second gas pipe 212 of the second valve assembly 300 are respectively communicated with the initial end space of the two initial end adsorption towers 104 of the two groups of adsorption towers 104 through the first exhaust pipe 111; the third gas pipe 219 of the fourth valve assembly 500 is communicated with the outside, and the first gas pipe 206 and the second gas pipe 212 of the fourth valve assembly 500 are respectively communicated with the initial end space of the two terminal adsorption towers 104 of the two groups of adsorption towers 104 through the second exhaust pipe 116.

[0033] In further embodiments, as Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 、 Figure 15As shown, the seventh valve assembly 800 comprises a second valve shell 801, an outer wall of the second valve shell 801 is provided with a fourth gas port 803, a fifth gas port 804, a sixth gas port 805 and a seventh gas port 806 in communication with a second column cavity 802 in the second valve shell 801, the fourth gas port 803 and the fifth gas port 804 are coaxial and opposite to each other at a circumferential distance of 180 degrees around the second column cavity 802, the sixth gas port 805 and the seventh gas port 806 are coaxial and opposite to each other at a circumferential distance of 180 degrees around the second column cavity 802, the axis of the fourth gas port 803 and the axis of the sixth gas port 805 are perpendicular to each other and are spaced along the axis of the second column cavity 802, the fourth gas port 803, the fifth gas port 804, the sixth gas port 805 and the seventh gas port 806 are respectively provided with a fourth gas pipe 807, a fifth gas pipe 808, a sixth gas pipe 814 and a seventh gas pipe 815, the outer side of the second valve shell 801 is provided with a third guide sleeve 810 and a fourth guide sleeve 817 coaxial, the third guide sleeve 810 and the fourth guide sleeve 817 are respectively in communication with the fifth gas pipe 808 and the seventh gas pipe 815 through a seventh pressure taking pipe 809 and an eighth pressure taking pipe 816, the third guide sleeve 810 and the fourth guide sleeve 817 are respectively slidably provided with a third sliding plug 812 and a fourth sliding plug 819, the third sliding plug 812 and the fourth sliding plug 819 are respectively provided with a third connecting rod 813 and a fourth connecting rod 820, the third connecting rod 813 is connected with the fourth connecting rod 820 through a second rack 821, the third guide sleeve 810 and the fourth guide sleeve 817 are respectively provided with a third limit block 811 and a fourth limit block 818 limiting the movement amplitude of the second rack 821, the second rack 821 is engaged with a third gear 826 provided on the outer side of the second valve shell 801, the wheel surface of the third gear 826 is rotatably provided with a fourth rotating sleeve 830 through a fixed pin, the outer side of the second valve shell 801 is rotatably provided with a third rotating sleeve 828 through a fixed pin, the third rotating sleeve 828 is connected with the fourth rotating sleeve 830 through a second spring 829, the second column cavity 802 is sealingly rotatable provided with a second plug 822, the second plug 822 is provided with a second gas channel 823 matched with the fourth gas port 803 and the fifth gas port 804 and a third gas channel 824 matched with the sixth gas port 805 and the seventh gas port 806, the end of the second plug 822 is provided with a second end shaft 825, the second end shaft 825 is provided with a fourth gear 827 engaged with the third gear 826, the axis of the fourth gear 827 is coplanar with the axis of the third rotating sleeve 828 and the axis of the third gear 826.

[0034] In further embodiments, as Figure 1 、 Figure 2As shown, the fourth gas pipe 807 and the sixth gas pipe 814 of the seventh valve assembly 800 are connected to the end spaces of the initial adsorption tower 104 of the two sets of adsorption towers 104 respectively through the first connecting pipe 114. The fifth gas pipe 808 and the seventh gas pipe 815 of the seventh valve assembly 800 are connected to the initial space of the end adsorption tower 104 of the two sets of adsorption towers 104 respectively through the second connecting pipe 115. The fourth gas pipe 807 and the fifth gas pipe 808 are used to connect the initial adsorption tower 104 and the end adsorption tower 104 of one set of adsorption towers 104. The sixth gas pipe 814 and the seventh gas pipe 815 are used to connect the initial adsorption tower 104 and the end adsorption tower 104 of the other set of adsorption towers 104.

[0035] In a further embodiment, such as Figure 16 As shown, the eighth valve assembly 900 includes an eighth air pipe 901. A second annular groove 903 is formed in the middle of the eighth air pipe 901. A first annular groove 902 is formed in the middle of the second annular groove 903. An eighth air port 904 and a tenth air port 906 are formed on one end wall of the first annular groove 902, which are distributed at 180-degree intervals around the first annular groove 902 and are coaxially opposite. A ninth air port 905 and an eleventh air port 907 are formed on the other end wall of the first annular groove 902, which are distributed at 180-degree intervals around the first annular groove 902 and are coaxially opposite. The eighth air port 904, the ninth air port 905, the tenth air port 906, and the eleventh air port 907 are respectively provided with It has a ninth trachea 908, a tenth trachea 909, an eleventh trachea 910, and a twelfth trachea 911. A fifth slide plug 912 is slidably disposed in the first annular groove 902. A Y-shaped fourth air passage 913 is opened on the eighth air port 904 side end face of the fifth slide plug 912, which communicates with the cylindrical surface of the fifth slide plug 912 and cooperates with the eighth air port 904 and the tenth air port 906. A Y-shaped fifth air passage 914 is opened on the ninth air port 905 side end face of the fifth slide plug 912, which communicates with the cylindrical surface of the fifth slide plug 912 and cooperates with the ninth air port 905 and the eleventh air port 907. The two ends of the fifth slide plug 912 are respectively connected to the corresponding side ends of the second annular groove 903 through a third spring 915.

[0036] In a further embodiment, such as Figure 1 , Figure 2As shown, the end of the eighth gas port 904 of the eighth gas pipe 901 and the tenth gas pipe 909 are respectively communicated with the end space of the end adsorption tower 104 of a group of adsorption towers 104 through the fourth oxygen supply pipe 122 and the fifth oxygen supply pipe 123, the twelfth gas pipe 911 is communicated with the end space of the end adsorption tower 104 of the initial end adsorption tower 104 of a group of adsorption towers 104 corresponding to the end of the eighth gas port 904 of the eighth gas pipe 901 through the sixth oxygen supply pipe 124, the end of the ninth gas port 905 of the eighth gas pipe 901 and the ninth gas pipe 908 are respectively communicated with the end space of the end adsorption tower 104 of a group of adsorption towers 104 through the fourth oxygen supply pipe 122 and the fifth oxygen supply pipe 123, and the eleventh gas pipe 910 is communicated with the end space of the end adsorption tower 104 of the initial end adsorption tower 104 of a group of adsorption towers 104 corresponding to the end of the ninth gas port 905 of the eighth gas pipe 901 through the sixth oxygen supply pipe 124.

[0037] In further embodiments, as shown in Figure 17 、 Figure 18 As shown, the ninth valve assembly 1000 includes a thirteenth gas pipe 1001 and a third valve shell 1009, a fourth annular groove 1003 is formed in the middle of the thirteenth gas pipe 1001, one end of the fourth annular groove 1003 is provided with a third annular groove 1002, the thirteenth gas pipe 1001 is provided with a fourteenth gas pipe 1004 and a fifteenth gas pipe 1005 which are in communication with the middle of the third annular groove 1002, a sixth sliding plug 1006 is slidably arranged in the third annular groove 1002, a sixth gas channel 1007 is formed in the cylindrical surface of the sixth sliding plug 1006 and matched with the fourteenth gas pipe 1004 and the fifteenth gas pipe 1005, the sixth sliding plug 1006 is connected with the end side of the fourth annular groove 1003 through a fourth spring 1008, a cylindrical driving cavity 1010 and a cylindrical pressurizing cavity 1011 are formed in the third valve shell 1009, the cylindrical surface and one end surface of the driving cavity 1010 are respectively communicated with the fifteenth gas pipe 1005 and a third exhaust pipe 1012, the cylindrical surface and one end surface of the pressurizing cavity 1011 are respectively communicated with a sixteenth gas pipe 1013 and a seventeenth gas pipe 1014, a first turbine 1015 and a second turbine 1016 are respectively arranged in the driving cavity 1010 and the pressurizing cavity 1011, and the first turbine 1015 and the second turbine 1016 are arranged at the two ends of the same rotating shaft.

[0038] In further embodiments, as shown in Figure 1 、 Figure 2As shown, the third ring groove 1002 side end of the thirteenth gas pipe 1001 is communicated with the third gas pipe 219 of the third valve assembly 400 through the second pressure taking pipe 113, the fourth ring groove 1003 side end of the thirteenth gas pipe 1001 is communicated with the third gas pipe 219 of the sixth valve assembly 700 through the fourth pressure taking pipe 120, the fourteenth gas pipe 1004 is communicated with the raw material gas main pipe 107 for communicating the air compressor 101 and the filter 102 through the first branch pipe 108, the seventeenth gas pipe 1014 is communicated with the third gas pipe 219 of the fifth valve assembly 600 through the second oxygen conveying pipe 118, and the sixteenth gas pipe 1013 is communicated with the oxygen storage tank 106 through the third oxygen conveying pipe 121.

[0039] In the present application, the two groups of adsorption towers 104 utilize the pressure difference of the same end of the two same-end adsorption towers 104 in the two groups of adsorption towers 104 for automatic switching, and the related structure for realizing automatic switching is simple and has low cost. In the present application, the ninth valve assembly 1000 utilizes the raw material gas from the air compressor 101 to pressurize the oxygen generated by the group of adsorption towers 104 in the adsorption working state and input the oxygen storage tank 106, and the ninth valve assembly 1000 controls the amount of raw material gas for driving pressurization by collecting the pressure difference between the initial end of the initial-end adsorption tower 104 and the end of the end-end adsorption tower 104 in the group of adsorption towers 104 in the adsorption working state. The pressure difference between the initial end of the initial-end adsorption tower 104 and the end of the end-end adsorption tower 104 in the group of adsorption towers 104 in the adsorption working state increases as the initial-end adsorption tower 104 gradually tends to be adsorption saturated, and the amount of raw material gas entering the ninth valve assembly 1000 increases as the pressure difference between the initial end of the initial-end adsorption tower 104 and the end of the end-end adsorption tower 104 in the group of adsorption towers 104 in the adsorption working state increases, so as to ensure that the oxygen generated by the group of adsorption towers 104 in the adsorption working state has sufficient pressure to input the oxygen storage tank 106, and at the same time, a certain negative pressure is generated at the end of the end-end adsorption state, which is beneficial to improve the utilization rate of the molecular sieve 105 and the adsorption oxygen efficiency of the two adsorption towers 104. In the present application, the group of adsorption towers 104 in the desorption state utilizes the oxygen generated by the group of adsorption towers 104 in the adsorption oxygen state for desorption, which has simple structure, convenient operation and low cost of related structure.

[0040] The operation flow of the present application is as follows: In the initial state, the first air passage 221 of the first valve assembly 200 is communicated with the third air port 205, and the group of adsorption towers 104 corresponding to the second air passage 212 of the first valve assembly 200 is in the adsorption working state. The first air passage 221 of the second valve assembly 300 is communicated with the second air port 204, and the second air passage 212 of the second valve assembly 300 is communicated with the group of adsorption towers 104 in the adsorption working state. The first air passage 221 of the third valve assembly 400 is communicated with the third air port 205, and the second air passage 212 of the third valve assembly 400 is communicated with the group of adsorption towers 104 in the adsorption working state. The first air passage 221 of the fourth valve assembly 500 is communicated with the second air port 204, and the second air passage 212 of the fourth valve assembly 500 is communicated with the group of adsorption towers 104 in the adsorption working state. The first air passage 221 of the fifth valve assembly 600 is communicated with the third air port 205, and the second air passage 212 of the fifth valve assembly 600 is communicated with the group of adsorption towers 104 in the adsorption working state. The first air passage 221 of the sixth valve assembly 700 is communicated with the third air port 205, and the second air passage 212 of the sixth valve assembly 700 is communicated with the group of adsorption towers 104 in the adsorption working state. The sixth air passage 814 and the seventh air passage 815 of the seventh valve assembly 800 are communicated with the group of adsorption towers 104 in the adsorption working state, and the third air passage 824 is communicated with the sixth air port 805 and the seventh air port 806. The tenth air passage 909 and the twelfth air passage 911 of the eighth valve assembly 900 are communicated with the group of adsorption towers 104 in the desorption state, the tenth air passage 909 and the twelfth air passage 911 are communicated with the fifth air passage 914, the compression amount of the third spring 915 on the side of the fourth air passage 913 is greater than the compression amount of the third spring 915 on the side of the fifth air passage 914, and the end adsorption tower 104 in the adsorption working state will make part of the oxygen prepared to be desorbed by being respectively input into the end space of the end adsorption tower 104 and the initial end adsorption tower 104 in the desorption state through the fifth air passage 914, the tenth air passage 909 and the twelfth air passage 911. The sixth sliding plug 1006 of the ninth valve assembly 1000 closes the fourteenth air passage 1004 and the fifteenth air passage 1005, and the first turbine 1015 and the second turbine 1016 do not rotate. The group of adsorption towers 104 in the adsorption working state is in the high-efficiency adsorption oxygen production state, the gas pressure of the initial end space of the initial end adsorption tower 104 is greater than the gas pressure of the end space of the end adsorption tower 104, and the gas pressure difference between the two is small and cannot overcome the fourth spring 1008 in the ninth valve assembly 1000 to communicate the fourteenth air passage 1004 and the fifteenth air passage 1005. Because the group of adsorption towers 104 in the adsorption working state is in the high-efficiency adsorption oxygen production state at this time, the gas pressure difference between the initial end spaces of the adsorption towers 104 in the two groups of adsorption towers 104 is small and cannot drive the first valve assembly 200, the second valve assembly 300, the third valve assembly 400, the fourth valve assembly 500, the fifth valve assembly 600, the sixth valve assembly 700 and the seventh valve assembly 800 to perform the switching action.The oxygen produced by the group of adsorption towers 104 in the adsorption working state is transported to the oxygen storage tank 106 through the seventeenth gas pipe 1014, the pressurizing cavity 1011 and the sixteenth gas pipe 1013.

[0041] With the continuous adsorption of the group of adsorption towers 104 in the adsorption working state, the molecular sieve 105 in the two adsorption towers 104 gradually tends to be saturated in adsorption, the oxygen production decreases, the gas pressure in the initial space of the initial adsorption tower 104 significantly increases, the gas pressure in the terminal space of the terminal adsorption tower 104 significantly decreases, the pressure difference between the initial space of the initial adsorption tower 104 and the terminal space of the terminal adsorption tower 104 significantly increases and overcomes the fourth spring 1008 in the ninth valve assembly 1000 to push the sixth valve plug to move a certain amplitude, so that the sixth gas passage 1007 on the sixth valve plug starts to communicate the fourteenth gas pipe 1004 and the fifteenth gas pipe 1005, the raw material gas from the air compressor 101 enters the driving cavity 1010 through the fourteenth gas pipe 1004, the sixth gas passage 1007 and the fifteenth gas pipe 1005 to push the first turbine 1015 and the second turbine 1016 to rotate synchronously, the second turbine 1016 turbocharges the “thin” oxygen gas entering the pressurizing cavity 1011 from the seventeenth gas pipe 1014, so that the sixteenth gas pipe 1013 continues to effectively transport the pressurized oxygen to the oxygen storage tank 106. At the same time, the pressurization of the oxygen by the ninth valve assembly 1000 also increases the vacuum degree in the terminal space of the terminal adsorption tower 104 in the adsorption working state, so that the two adsorption towers 104 in the adsorption working state which tend to be saturated in adsorption can still work at a high adsorption efficiency and oxygen production in a short time, so that the internal molecular sieve 105 in the adsorption tower 104 fully participates in the adsorption of oxygen production, effectively improving the utilization rate of the molecular sieve 105 in the adsorption tower 104.

[0042] The working process of the group of adsorption towers 104 in the desorption state is that the seventh valve assembly 800 blocks the series connection between the two adsorption towers 104 in the desorption state, the terminal adsorption tower 104 in the adsorption working state transports the oxygen produced to the terminal space of the two adsorption towers 104 in the desorption state through the fifth gas passage 914, the tenth gas pipe 909 and the twelfth gas pipe 911 of the eighth valve assembly 900 respectively for reverse desorption, and the two adsorption towers 104 in the desorption state are respectively discharged to the outside through the second valve assembly 300 and the fourth valve assembly 500.

[0043] When the molecular sieve 105 in the two adsorption towers 104 in the adsorption working state reaches the adsorption saturation state, and the pressure of the two end spaces of the initial end adsorption tower 104 and the two end spaces of the terminal end adsorption tower 104 in the adsorption working state increases significantly, the first valve assembly 200, the second valve assembly 300, the third valve assembly 400, the fourth valve assembly 500, the fifth valve assembly 600, the sixth valve assembly 700 and the seventh valve assembly 800 are switched on to make the group of adsorption towers 104 reaching the saturation adsorption state in the desorption state and the group of adsorption towers 104 completing the desorption in the adsorption working state.

[0044] During the switching of the two groups of adsorption towers 104, the working processes of the first valve assembly 200, the second valve assembly 300, the third valve assembly 400, the fourth valve assembly 500, the fifth valve assembly 600, the sixth valve assembly 700 and the seventh valve assembly 800 are as follows: The first rack 218 in the first valve assembly 200 or the second valve assembly 300 or the third valve assembly 400 or the fourth valve assembly 500 or the fifth valve assembly 600 or the sixth valve assembly 700 is driven to rotate by the second gear 224 under the pressure difference between the first gas pipe 206 and the second gas pipe 212, overcoming the elastic force of the first spring 226. The first spring 226 drives the first rack 218 to move to the limit and forms a new limit for the rack after the second rotating sleeve 227 passes the center line of the first rotating sleeve 225 and the second gear 224. The second gear 224 drives the first plug 220 by 90 degrees through the first gear 223 and the end shaft, so that the first valve assembly 200 switches the raw material gas to the initial end adsorption tower 104 completing the desorption. The second valve assembly 300 and the fourth valve assembly 500 close the desorption waste gas discharge of the two adsorption towers 104 completing the desorption and open the desorption waste gas discharge of the two adsorption towers 104 completing the adsorption. The third valve assembly 400, the fifth valve assembly 600 and the sixth valve assembly 700 complete the switching from the communication of the ninth valve assembly 1000 with the group of adsorption towers 104 completing the adsorption to the communication of the ninth valve assembly 1000 with the group of adsorption towers 104 completing the desorption. The seventh valve assembly 800 blocks the series connection between the two adsorption towers 104 in the adsorption saturation state and connects the two adsorption towers 104 completing the desorption in series. The eighth valve assembly 900 completes the switching from the communication of the terminal end space of the terminal end adsorption tower 104 completing the adsorption with the terminal end space of the two adsorption towers 104 completing the desorption to the communication of the terminal end space of the terminal end adsorption tower 104 completing the desorption with the terminal end space of the two adsorption towers 104 completing the adsorption. The fourth ring groove 1003 side end of the thirteenth gas pipe 1001 and the sixth sliding plug 1006 side end of the thirteenth gas pipe 1001 in the ninth valve assembly 1000 respectively complete the communication with the terminal end space of the terminal end adsorption tower 104 completing the desorption and the initial end space of the initial end adsorption tower 104.

[0045] Each group of adsorption tower 104 from the buffer tank 103 clean gas in turn for double adsorption, effectively improve the purity of oxygen.

Claims

1. A low-pressure swing adsorption (PSA) oxygen device, comprising an air compressor, a filter, a buffer tank, an oxygen storage tank, and two sets of adsorption towers, each set of adsorption towers consisting of a primary adsorption tower and a secondary adsorption tower connected in series, characterized in that, It also includes a first valve assembly, a second valve assembly, a third valve assembly, a fourth valve assembly, a fifth valve assembly, a sixth valve assembly, a seventh valve assembly, an eighth valve assembly, and a ninth valve assembly. The first valve assembly switches the connection between the two initial adsorption towers and the buffer tank by collecting the pressure difference at the same end of the two adsorption towers. The second valve assembly automatically switches the initial desorption gas emission of the two initial adsorption towers by collecting the pressure difference at the same end of the two adsorption towers. The fourth valve assembly automatically switches the initial desorption gas emission of the two final adsorption towers by collecting the pressure difference at the same end of the two adsorption towers. The seventh valve assembly switches the initial desorption gas emission of the two final adsorption towers by collecting the pressure difference at the same end of the two adsorption towers. The pressure difference at the same end of the adsorption towers in the adsorption tower group enables the series switching of the two adsorption tower groups. The eighth valve assembly, by collecting the pressure difference at the same end of the adsorption towers in the two adsorption tower groups, enables the terminal adsorption tower that is about to produce oxygen to use part of the produced oxygen to reverse desorb the adsorption of the adsorption tower group that has completed adsorption. The fifth valve assembly, by collecting the pressure difference at the same end of the adsorption towers in the two adsorption tower groups, switches the two adsorption tower groups to supply oxygen to the oxygen storage tank. The ninth valve assembly, by collecting the gas pressure difference at both ends of the adsorption tower group that is in the adsorption state, controls the raw material gas to pressurize and input the produced oxygen into the oxygen storage tank. The third valve assembly and the sixth valve assembly are used to switch the pressure difference collection of the two adsorption tower groups by the ninth valve assembly.

2. The low-pressure swing adsorption oxygen device according to claim 1, characterized in that, The first valve assembly includes a first valve housing. A first air port, a second air port, and a third air port are formed on the outer wall of the first valve housing, communicating with a first cylindrical cavity inside. The first air port is coaxial with the first cylindrical cavity. The second and third air ports are 90 degrees apart circumferentially around the first cylindrical cavity. A third air pipe, a first air pipe, and a second air pipe are respectively provided at the first, second, and third air ports. A first guide sleeve and a second guide sleeve, coaxial, are provided on the outer side of the first valve housing. The first and second guide sleeves are respectively connected to the first and second air pipes via a fifth pressure tapping pipe and a sixth pressure tapping pipe. A first sliding plug and a second sliding plug are slidably disposed in the first and second guide sleeves, respectively. A first connecting rod and a second connecting rod are respectively provided on the first and second sliding plugs. The first connecting rod is connected to a first rack and pinion... The second connecting rod is connected. The first guide sleeve and the second guide sleeve are respectively provided with a first limiting block and a second limiting block to limit the movement range of the first rack. The first rack meshes with a second gear provided on the outside of the first valve body. A second rotating sleeve is rotatably provided on the wheel surface of the second gear through a fixing pin. A first rotating sleeve is rotatably provided on the outside of the first valve body through a fixing pin. The first rotating sleeve is connected to the second rotating sleeve through a first spring. A first plug is rotatably sealed in the first column cavity. A first air passage is opened on the first plug to connect the first air port with the second air port or to connect the first air port with the third air port. A first end shaft is provided at the end of the first plug. A first gear that meshes with the second gear is provided on the first end shaft. The axis of the first gear is coplanar with the axis of the first rotating sleeve and the axis of the second gear.

3. The low-pressure swing adsorption oxygen device according to claim 2, characterized in that, The second, third, fourth, fifth, and sixth valve assemblies have the same structure as the first valve assembly.

4. A low-pressure swing adsorption oxygen device according to claim 3, characterized in that, The third gas pipe of the first valve assembly is connected to the buffer tank through the clean gas main pipe. The first gas pipe and the second gas pipe of the first valve assembly are respectively connected to the initial end space of the two initial adsorption towers of the two sets of adsorption towers through the second branch pipe. The third gas pipe of the second valve assembly is connected to the outside. The first gas pipe and the second gas pipe of the second valve assembly are respectively connected to the initial end space of the two initial adsorption towers of the two sets of adsorption towers through the first exhaust pipe. The third gas pipe of the fourth valve assembly is connected to the outside. The first gas pipe and the second gas pipe of the fourth valve assembly are respectively connected to the initial end space of the two final adsorption towers of the two sets of adsorption towers through the second exhaust pipe.

5. A low-pressure swing adsorption oxygen device according to claim 1, characterized in that, The seventh valve assembly includes a second valve housing. The outer wall of the second valve housing has a fourth, fifth, sixth, and seventh air port communicating with the second cylindrical cavity inside. The fourth and fifth air ports are 180 degrees apart circumferentially around the second cylindrical cavity and are coaxially opposite each other. The sixth and seventh air ports are also 180 degrees apart circumferentially around the second cylindrical cavity and are coaxially opposite each other. The axes of the fourth and sixth air ports are perpendicular to each other and are spaced apart along the axis of the second cylindrical cavity. A fourth, fifth, sixth, and seventh air pipe are respectively installed at the fourth, fifth, sixth, and seventh air ports. A third and fourth guide sleeve, coaxially aligned, are installed on the outer side of the second valve housing. The third and fourth guide sleeves are connected to the fifth and seventh air pipes respectively via a seventh and an eighth pressure tapping pipe. A third and fourth sliding plug are slidably installed in the third and fourth guide sleeves respectively. The fourth slide plug is provided with a third connecting rod and a fourth connecting rod. The third connecting rod is connected to the fourth connecting rod through a second rack. The third guide sleeve and the fourth guide sleeve are respectively provided with a third limiting block and a fourth limiting block to limit the movement range of the second rack. The second rack meshes with a third gear located on the outside of the second valve body. A fourth rotating sleeve is rotatably mounted on the surface of the third gear through a fixing pin. A third rotating sleeve is rotatably mounted on the outside of the second valve body through a fixing pin. The third rotating sleeve is connected to the fourth rotating sleeve through a second spring. A second plug is rotatably sealed inside the second cylindrical cavity. The second plug has a second air passage that mates with the fourth and fifth air ports and a third air passage that mates with the sixth and seventh air ports. A second end shaft is provided at the end of the second plug. A fourth gear that meshes with the third gear is mounted on the second end shaft. The axis of the fourth gear is coplanar with the axis of the third rotating sleeve and the axis of the third gear.

6. A low-pressure swing adsorption oxygen device according to claim 5, characterized in that, The fourth and sixth gas pipes of the seventh valve assembly are connected to the end spaces of the initial adsorption towers of the two sets of adsorption towers respectively through the first connecting pipe. The fifth and seventh gas pipes of the seventh valve assembly are connected to the beginning spaces of the end adsorption towers of the two sets of adsorption towers respectively through the second connecting pipe. The fourth and fifth gas pipes are used to connect the initial adsorption tower and the end adsorption tower of one set of adsorption towers. The sixth and seventh gas pipes are used to connect the initial adsorption tower and the end adsorption tower of another set of adsorption towers.

7. A low-pressure swing adsorption oxygen device according to claim 1, characterized in that, The eighth valve assembly includes an eighth air pipe. A second annular groove is formed in the middle of the eighth air pipe. A first annular groove is formed in the middle of the second annular groove. An eighth air port and a tenth air port are formed on one end wall of the first annular groove, spaced 180 degrees apart and coaxially opposite each other. A ninth air port and an eleventh air port are formed on the other end wall of the first annular groove, spaced 180 degrees apart and coaxially opposite each other. The eighth, ninth, tenth, and eleventh air ports are... The device is provided with a ninth, tenth, eleventh, and twelfth air tube. A fifth sliding plug is slidably disposed in the first annular groove. A Y-shaped fourth air passage is opened on the eighth air port side end face of the fifth sliding plug, which communicates with the cylindrical surface of the fifth sliding plug and cooperates with the eighth and tenth air ports. A Y-shaped fifth air passage is opened on the ninth air port side end face of the fifth sliding plug, which communicates with the cylindrical surface of the fifth sliding plug and cooperates with the ninth and eleventh air ports. The two ends of the fifth sliding plug are respectively connected to the corresponding side ends of the second annular groove through a third spring.

8. A low-pressure swing adsorption oxygen device according to claim 7, characterized in that, The eighth port side end of the eighth gas pipe and the tenth gas pipe are respectively connected to the end space of the end adsorption tower of a group of adsorption towers through the fourth oxygen supply pipe and the fifth oxygen supply pipe. The twelfth gas pipe is connected to the end space of the initial adsorption tower of the group of adsorption towers corresponding to the eighth port side end of the eighth gas pipe through the sixth oxygen supply pipe. The ninth port side end of the eighth gas pipe and the ninth gas pipe are respectively connected to the end space of the end adsorption tower of another group of adsorption towers through the fourth oxygen supply pipe and the fifth oxygen supply pipe. The eleventh gas pipe is connected to the end space of the initial adsorption tower of the group of adsorption towers corresponding to the ninth port side end of the eighth gas pipe through the sixth oxygen supply pipe.

9. A low-pressure swing adsorption oxygen device according to claim 1, characterized in that, The ninth valve assembly includes a thirteenth air pipe and a third valve housing. A fourth annular groove is formed in the middle of the thirteenth air pipe, and a third annular groove is formed at one end of the fourth annular groove. A fourteenth air pipe and a fifteenth air pipe are provided on the pipe wall of the thirteenth air pipe, communicating with the middle of the third annular groove. A sixth sliding plug is slidably arranged in the third annular groove. A sixth air passage is formed on the cylindrical surface of the sixth sliding plug, which cooperates with the fourteenth and fifteenth air pipes. The sixth sliding plug is connected to the end side of the fourth annular groove by a fourth spring. A cylindrical drive chamber and a cylindrical booster chamber are formed in the third valve housing. The center of the cylindrical surface and one end face of the drive chamber are respectively connected to the fifteenth air pipe and the third exhaust pipe. The center of the cylindrical surface and one end face of the booster chamber are respectively connected to the sixteenth air pipe and the seventeenth air pipe. A first turbine and a second turbine are respectively arranged in the drive chamber and the booster chamber. The first turbine and the second turbine are respectively arranged at both ends of the same rotating shaft.

10. A low-pressure swing adsorption oxygen device according to claim 3 or 9, characterized in that, The third annular groove end of the thirteenth gas pipe is connected to the third gas pipe of the third valve assembly via the second pressure tapping pipe. The fourth annular groove end of the thirteenth gas pipe is connected to the third gas pipe of the sixth valve assembly via the fourth pressure tapping pipe. The fourteenth gas pipe is connected to the main raw material gas pipe for connecting the air compressor and the filter via the first branch pipe. The seventeenth gas pipe is connected to the third gas pipe of the fifth valve assembly via the second oxygen supply pipe. The sixteenth gas pipe is connected to the oxygen storage tank via the third oxygen supply pipe.

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