A device for extracting nitrogen gas using space-divided exhaust gas

Abstract

The application discloses a device for extracting nitrogen gas by using space-divided waste gas, which comprises a main air inlet pipe, a confluence valve, a flow guide pipe one, a flow guide pipe two, an electric control valve one and a rectifying oxygen removal tower, and further comprises an electric control three-way valve, a dust removal and filtration equipment and a pre-purifier, wherein the electric control three-way valve comprises an electric control three-way valve one and an electric control three-way valve two, the main air inlet pipe is connected with an air inlet end of the electric control three-way valve one, an air outlet end of the electric control three-way valve one is connected with an air inlet end of the dust removal and filtration equipment, an air outlet end of the dust removal and filtration equipment is connected with the pre-purifier through the flow guide pipe one, the pre-purifier is connected with the rectifying oxygen removal tower through the flow guide pipe two, and the electric control valve one is arranged on the flow guide pipe two; the device can complete the filtration and purification of crude nitrogen gas and the removal and purification of carbon hydrocompounds at normal temperature, the manual participation in the purification process is less, the purification efficiency of the crude nitrogen gas can be effectively improved, the energy consumption is low, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of air separation equipment technology, specifically to a device for extracting nitrogen from air separation waste gas. Background Technology

[0002] Currently, the three main nitrogen production processes capable of large-scale nitrogen production are cryogenic nitrogen production, PSA (Pressure Swing Adsorption) nitrogen production, and membrane separation nitrogen production. Cryogenic nitrogen production, based on the principle of low-temperature distillation, has relatively simple equipment operation and produces nitrogen products with a purity ≥99.999% and high reliability, thus enjoying widespread application. The main equipment for cryogenic nitrogen production includes: an air compressor, a precooling unit, a molecular sieve adsorber, an electric heater, a cold box, a turbine expander, a main heat exchanger, a distillation column, and a condenser-evaporator.

[0003] Oxygen or rare gases such as neon generate crude nitrogen waste gas during air separation. Directly discharging this crude nitrogen would waste resources. Current technologies often use this crude nitrogen waste gas as a raw material to produce high-purity nitrogen. Crude nitrogen contains trace amounts of dust particles, which need to be removed to ensure the smooth progress of the crude nitrogen purification process and the safe operation of downstream equipment. Before being fed into the air compressor, the raw crude nitrogen gas must first pass through a mechanical filter for filtration and purification to remove dust and other impurities. After filtration, the dust content should not exceed 1 mg / m³. Current technologies mostly use multi-layer filter cloths to filter the crude nitrogen. During filtration, dust adheres to the filter surface, so the filter needs to be cleaned and replaced regularly. To improve the filtration efficiency of crude nitrogen, current technologies typically use two sets of filtration equipment operating in parallel. When filter cleaning and maintenance are required, one filtration unit can be shut down. However, cleaning the filter requires manual operation, wasting manpower, and the installation of the filter is also relatively cumbersome.

[0004] The filtered and purified crude nitrogen gas is compressed to approximately 5 bara by an oil-injected screw air compressor, and then fed into a downstream pre-purifier. The pre-purifier, filled with molecular sieves of various sizes and activated alumina, further removes trace amounts of moisture, hydrocarbons, carbon dioxide, and other impurities from the compressed air, achieving the process safety goal of purifying the crude nitrogen gas and ensuring the safe operation of downstream equipment. The pre-purifier utilizes the temperature-switching adsorption principle of the molecular sieves: low-temperature adsorption and high-temperature desorption. However, existing purifiers suffer from slow filtration efficiency due to the small contact area between the gas and the sieve. To improve filtration efficiency, current technologies often use single-layer adsorption sieves, resulting in poor adsorption effects. The pre-purified crude nitrogen gas is then separated and deoxygenated by distillation to obtain high-purity nitrogen gas. Summary of the Invention

[0005] This invention provides a device for extracting nitrogen from air separation waste gas. Compared with the cryogenic separation technology in the prior art, this device can complete the filtration and purification of crude nitrogen and the purification of hydrocarbons at room temperature. Moreover, the purification process requires less manual intervention, which can effectively improve the purification efficiency of crude nitrogen. At the same time, it has low energy consumption and reduces production costs, which can effectively solve the problems in the background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an apparatus for extracting nitrogen from air separation waste gas, comprising a main inlet pipe, a confluence valve, a first guide pipe, a second guide pipe, an electrically controlled valve, and a distillation deoxygenation tower, and further comprising an electrically controlled three-way valve, a dust removal and filtration device, and a pre-purifier, wherein the electrically controlled three-way valve comprises an electrically controlled three-way valve and an electrically controlled three-way valve.

[0007] The main air inlet pipe is connected to the air inlet end of the electrically controlled three-way valve one, the air outlet end of the electrically controlled three-way valve one is connected to the air inlet end of the dust removal and filtration equipment, the air outlet end of the dust removal and filtration equipment is connected to the pre-purifier through the guide pipe one, and the air outlet end of the pre-purifier is connected to the distillation deoxygenation tower through the guide pipe two, and the electrically controlled valve one is installed on the guide pipe two.

[0008] The dust removal and filtration equipment includes two sealed outer covers, which are symmetrically arranged front and back. A guide pipe is provided between the two sealed outer covers. An air blowing pipe is connected to the sealed outer cover through a diversion pipe on its outer side. An air inlet and an air outlet are respectively provided at the left and right ends of the sealed outer cover. Multiple hollow cylindrical shells are arranged side by side inside the sealed outer cover. The multiple hollow cylindrical shells are connected through a guide channel. A stepper motor is provided at the lower end of the outer side of the sealed outer cover near the hollow cylindrical shell. A diversion hood is provided inside the hollow cylindrical shell. A filter screen protection cover is provided inside the diversion hood. Multiple air inlets are provided on the outer side of the filter screen protection cover. A strip filter screen is snapped into the air inlet. An air blowing pipe is provided inside the filter screen protection cover. The lower end of the filter screen protection cover is connected to the output shaft of the stepper motor.

[0009] The lower end of the air blowing pipe is closed, and an air guiding channel is provided at the lower end of the outer side of the air blowing pipe. An air guiding groove is provided inside the air blowing pipe. An air blowing hole is provided at the lower end of the outer side of the air blowing pipe near the air guiding channel. The air blowing hole communicates with the air guiding groove, but the air guiding channel does not communicate with the air guiding groove. A sealing cover is provided at the upper end of the outer side of the air blowing pipe. The sealing cover is rotatably connected to the filter screen protective cover.

[0010] The pre-purifier includes a protective cover, inside which are two filter conveyor belts arranged symmetrically front and back. Inside the protective cover is a stepper motor three, which drives the filter conveyor belts to rotate through a transmission mechanism.

[0011] The filter-type conveyor belt includes a flexible conveyor belt with several mounting holes evenly distributed on its outer surface. A rectangular frame plate is installed on the mounting holes, and an adsorption net is provided on the inner surface of the rectangular frame plate.

[0012] One end of the protective cover is provided with a flow guide pipe four, which is connected to two flexible connector inlets one through an electrically controlled three-way valve two. The upper left side of the outer side of the filter conveyor belt is provided with an adsorption mechanism, the lower left side of the outer side of the filter conveyor belt is provided with a cooling mechanism, and the lower right side of the outer side of the filter conveyor belt is provided with a heating separation mechanism.

[0013] The adsorption mechanism includes overflow cover 2 and overflow cover 1. Both overflow cover 2 and overflow cover 1 are connected to the inside of the protective cover through the first lifting device. A flexible connector inlet 1 is connected to overflow cover 1, and a flexible connector inlet 2 is connected to overflow cover 2.

[0014] The cooling mechanism includes overflow cover five and overflow cover six. Both overflow cover five and overflow cover six are connected to the inside of the protective cover through the second lifting device. Both overflow cover five and overflow cover six are provided with liquid guiding chambers, which are connected to refrigerant output pipes and refrigerant input pipes.

[0015] The heating separation mechanism includes overflow cover three and overflow cover four. Both overflow cover three and overflow cover four are connected to the inside of the protective cover through a third lifting device. The inside of overflow cover three is equipped with a motor heating wire, and overflow cover four is connected to a vacuum tube.

[0016] The cross-sectional size and shape of the overflow shields 2, 1, 3, 4, 5 and 6 are consistent with the rectangular frame plate, and a horizontal plate is provided in the middle of the inner side of the protective shield.

[0017] Preferably, a confluence valve is provided on the guide pipe.

[0018] Preferably, the electrically controlled three-way valve consists of a stepper motor, a spherical shell, an air outlet connector, a sealing ball, and an air inlet connector. There are two air outlet connectors. The upper end of the sealing ball is connected to the output shaft of the stepper motor, and the sealing ball is in sealed rotatable contact with the spherical shell.

[0019] Preferably, the sealing ball is composed of a three-way guide cavity and a sealing ball body, wherein the two air outlets of the three-way guide cavity are respectively connected to two air outlet connectors, and the air inlet of the three-way guide cavity is connected to an air inlet connector.

[0020] Preferably, a dustproof filter bag is connected to the flow guide pipe.

[0021] Preferably, the diversion hood includes a hollow cylindrical tube, and four air inlets are provided on the outer side of the hollow cylindrical tube. An isolation plate is provided between the air inlets. The four air inlets are respectively located in the left, right, front and rear directions of the hollow cylindrical tube. The air inlet located at the left end is connected to the air inlet. The air inlet located at the rear end is connected to the diversion pipe. A one-way valve is provided on the diversion pipe. The air inlet located at the front end is connected to the guide pipe. A one-way valve is provided on the guide pipe. The air inlet located at the right end is connected to the adjacent hollow cylindrical outer shell or to the air outlet.

[0022] Preferably, the eight air inlets are evenly distributed in a ring on the outer side of the filter screen protective cover, and a wear-resistant plate is provided between adjacent air inlets, with a silicone sealing layer provided on the outer side of the wear-resistant plate.

[0023] Preferably, the output shaft of the second stepper motor is provided with a locking block, and the lower end face of the filter screen protective cover is provided with a locking groove corresponding to the locking block.

[0024] Preferably, the outer sides of the rectangular frame plate are covered with sealing strips at both the top and bottom.

[0025] Preferably, the flexible conveyor belt has gear grooves at both the front and rear ends of its inner side, and the output shaft of the stepper motor is connected to a drive shaft via a coupling. A drive gear is installed on the drive shaft, and the drive gear meshes with the gear groove.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. Compared with the existing cryogenic separation technology, this device can complete the filtration and purification of crude nitrogen and the purification of hydrocarbons at room temperature. Moreover, the purification process requires less manual intervention, which can effectively improve the purification efficiency of crude nitrogen. At the same time, the energy consumption ratio is low, reducing production costs.

[0028] 2. The guide pipe is equipped with an anti-backflow valve. The gas blown out by the air blowing pipe is used to clean the filter screen. The air inlet is connected to the main air inlet pipe, and the air outlet is connected to the air inlet of the pre-purifier. The stepper motor is used to drive the equipment filter screen to rotate, so as to facilitate the segmented cleaning of the filter screen. The air blowing pipe is equipped with an anti-backflow valve. The air inlet of the air blowing pipe is connected to the air outlet through a high-pressure air pump. The strip filter screen is used for dust adsorption and filtration.

[0029] 3. The nitrogen gas that needs to be purified enters the interior of the electrically controlled three-way valve 1 through the main inlet pipe. The electrically controlled three-way valve 1 controls the airflow to enter the interior of the sealed outer cover through the inlet end 1. First, the dust-laden gas enters the strip filter screen on the left end through the left end air guide port 1. The strip filter screen filters the dust in the gas and leaves it in the mesh. After the gas is filtered and dust-removed, it passes through the air guide channel and another strip filter screen on the right end, and then enters the next filtration device through the right end air guide port 1. The nitrogen gas after three-stage filtration is discharged through the outlet end 1 and enters the downstream treatment device. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention;

[0031] Figure 2 This is a cross-sectional view of an electrically controlled three-way valve.

[0032] Figure 3 This is a cross-sectional view of the sealed sphere;

[0033] Figure 4 This is a top view of the dust removal and filtration equipment;

[0034] Figure 5 This is the front view of the dust removal and filtration equipment;

[0035] Figure 6 This is a schematic diagram of the flow divider structure;

[0036] Figure 7 Front view after the air blowing pipe is installed on the diversion hood;

[0037] Figure 8 A schematic diagram of the structure after installing the air blowing pipe on the diversion hood;

[0038] Figure 9 This is a schematic diagram of the structure of a strip filter screen;

[0039] Figure 10 This is a schematic diagram of the air blowing pipe;

[0040] Figure 11 This is a front cross-sectional view of the pre-purifier;

[0041] Figure 12 Top view of the pre-purifier;

[0042] Figure 13 This is a schematic diagram of a filter conveyor belt.

[0043] In the diagram: 1 Main intake pipe, 2 Electrically controlled three-way valve 1, 21 Stepper motor 1, 22 Spherical shell, 23 Exhaust connector, 24 Sealing ball, 241 Three-way guide chamber, 242 Sealing ball, 25 Intake connector, 3 Dust removal and filtration equipment, 31 Dust filter bag, 32 Intake end 1, 33 Sealed end cap, 34 Handle, 35 Air blowing pipe 1, 36 Diverter pipe, 37 Exhaust end 1, 38 Sealed outer cover, 39 Guide tube. 3. Pipe 3, 310 Diverter shroud, 3101 Hollow cylindrical tube, 3102 Air inlet 1, 3103 Isolation plate, 311 Stepper motor 2, 312 Hollow cylindrical outer shell, 313 Slot, 314 Sealing cover, 315 Air blowing pipe, 3151 Air guide pipe groove, 3152 Air blowing hole, 3153 Air guide channel, 316 Air inlet 2, 317 Wear-resistant plate, 318 Strip filter screen, 4 Confluence valve, 5 Guide pipe 1 6. Pre-purifier; 61. Flexible connector inlet 1; 62. Electrically controlled telescopic rod 1; 63. Overflow cover 1; 64. Electrically controlled telescopic rod 2; 65. Overflow cover 2; 66. Filter-type conveyor belt; 661. Adsorption screen; 662. Rectangular frame plate; 663. Mounting hole; 664. Flexible conveyor belt; 665. Drive shaft; 666. Drive gear; 667. Gear groove; 67. Flexible connector inlet 2; 68. Electrically controlled telescopic rod 3; 69. Protective cover; 610. Protective shield. Overflow Cover III, 611 Overflow Cover IV, 612 Electrically Controlled Telescopic Rod IV, 613 Vacuum Tube, 614 Horizontal Plate, 615 Overflow Cover V, 616 Refrigerant Output Pipe, 617 Electrically Controlled Telescopic Rod V, 618 Refrigerant Input Pipe, 619 Overflow Cover VI, 620 Electrically Controlled Telescopic Rod VI, 621 Guide Pipe IV, 622 Stepper Motor III, 623 Electrically Controlled Three-Way Valve II, 7 Guide Pipe II, 8 Electrically Controlled Valve I, 9 Distillation Deoxygenation Tower. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, if directional descriptions are involved, such as "up," "down," "front," "back," "left," "right," etc., indicating directional or positional relationships, they are based on the appendix. Figure 1 The orientations or positional relationships shown are for the convenience of describing the invention and simplifying the description only, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. When a feature is referred to as "set", "fixed", or "connected" to another feature, it can be set, fixed, or connected to the other feature directly, or it can be set, fixed, or connected to the other feature indirectly.

[0046] This invention provides a technical solution:

[0047] Please see Figure 1 A device for extracting nitrogen from air separation waste gas includes a main inlet pipe 1, a confluence valve 4, a guide pipe 1 5, a guide pipe 2 7, an electrically controlled valve 1 8, and a distillation deoxygenation tower 9. It also includes an electrically controlled three-way valve, a dust removal and filtration device 3, and a pre-purifier 6. The electrically controlled three-way valve includes an electrically controlled three-way valve 1 2 and an electrically controlled three-way valve 2 623.

[0048] Specifically, the dust removal and filtration equipment 3 is used to remove dust and impurities from the crude nitrogen gas. After filtration, the dust content in the crude nitrogen gas does not exceed 1 mg / m3. The pre-purifier 6 allows the crude nitrogen gas to pass through the pre-purifier. The pre-purifier is filled with molecular sieves of various specifications, activated alumina and other adsorbents, which will further remove small amounts of moisture, hydrocarbons, carbon dioxide and other impurities from the compressed air, so as to achieve the process safety purpose of purifying the crude nitrogen gas and ensuring the safe operation of downstream equipment.

[0049] Furthermore, the main air inlet pipe 1 is connected to the air inlet end of the electrically controlled three-way valve 2, the air outlet end of the electrically controlled three-way valve 2 is connected to the air inlet end of the dust removal and filtration equipment 3, the air outlet end of the dust removal and filtration equipment 3 is connected to the pre-purifier 6 through the guide pipe 5, and the air outlet end of the pre-purifier 6 is connected to the distillation deoxygenation tower 9 through the guide pipe 7. The guide pipe 7 is equipped with an electrically controlled valve 8.

[0050] Specifically, the distillation deoxygenation tower 9 is used to separate oxygen from crude nitrogen. The electrically controlled three-way valve 2 supplies gas to the two dust removal and filtration devices 3, so that the filtration of crude nitrogen is not affected by cleaning the filter screen, effectively improving the filtration efficiency of crude nitrogen.

[0051] Please see Figure 4-10 The dust removal and filtration device 3 includes two sealed outer covers 38, arranged symmetrically front to back. A guide pipe 39 is provided between the two sealed outer covers 38. Each sealed outer cover 38 is connected to an air blowing pipe 35 via a diversion pipe 36 on its outer side. Each sealed outer cover 38 has an air inlet 32 ​​and an air outlet 37 at its left and right ends, respectively. Inside each sealed outer cover 38 are three hollow cylindrical outer shells 312 arranged side-by-side. The three hollow cylindrical outer shells 312 are connected by... The flow channels are connected. A stepper motor 311 is provided at the lower end of the outer side of the sealed outer cover 38 near the hollow cylindrical outer shell 312. A flow divider 310 is provided inside the hollow cylindrical outer shell 312. A filter screen protection cover is provided inside the flow divider 310. Eight air guide ports 316 are provided on the outer side of the filter screen protection cover. A strip filter screen 318 is snapped into the inside of the air guide ports 316. An air blowing pipe 315 is provided inside the filter screen protection cover. The lower end face of the filter screen protection cover is connected to the output shaft of the stepper motor 311.

[0052] Specifically, the guide pipe 39 is equipped with an anti-backflow valve, the gas blown out by the air blowing pipe 35 is used to purge the filter screen, the air inlet 32 ​​is connected to the main air inlet pipe 1, the air outlet 37 is connected to the air inlet of the pre-purifier 6, and the stepper motor 311 is used to drive the equipment filter screen to rotate, so as to facilitate the segmented purging and cleaning of the filter screen.

[0053] More specifically, the air blowing pipe 35 is equipped with an anti-backflow valve, and the air inlet end of the air blowing pipe 35 is connected to the air outlet end 37 through a high-pressure air pump. The strip filter screen 318 is used for dust adsorption and filtration.

[0054] The lower end face of the air blowing pipe 315 is closed. The lower end of the outer side of the air blowing pipe 315 is provided with an air guiding channel 3153. The interior of the air blowing pipe 315 is provided with an air guiding groove 3151. The lower end of the outer side of the air blowing pipe 315 is provided with an air blowing hole 3152 near the air guiding channel 3153. The air blowing hole 3152 communicates with the air guiding groove 3151. The air guiding channel 3153 does not communicate with the air guiding groove 3151. The upper end of the outer side of the air blowing pipe 315 is provided with a sealing cover 314. The sealing cover 314 is rotatably connected to the filter screen protection cover.

[0055] Specifically, the air guide channel 3153 is used to guide the flow of nitrogen on the filter screen, the air guide tube groove 3151 is used to guide the flow of nitrogen for purging, and the nitrogen blown out by the air blowing hole 3152 carries the dust clogged on the filter screen into the dust bag.

[0056] Please see Figure 11-13 The pre-purifier 6 includes a protective cover 69, inside which are two filter conveyor belts 66 arranged symmetrically front and back, and inside which is a stepper motor 622, which drives the filter conveyor belts 66 to rotate through a transmission mechanism.

[0057] Specifically, the stepper motor 622 drives the filter conveyor belt 66 to rotate through the transmission mechanism, realizing the recycling of the adsorption equipment.

[0058] The filter conveyor belt 66 includes a flexible conveyor belt 664. The outer side of the flexible conveyor belt 664 is evenly distributed with a plurality of mounting holes 663. A rectangular frame plate 662 is installed on the mounting holes 663. An adsorption net 661 is provided on the inner side of the rectangular frame plate 662.

[0059] Specifically, the rectangular frame plate 662 is connected to the flexible conveyor belt 664 by bolts. When the adsorption net 661 needs to be replaced, simply unscrew the bolts, remove the old adsorption net 661, and then install the new one.

[0060] One end of the protective cover 69 is provided with a guide pipe 621. The guide pipe 621 is connected to two flexible connectors 61 through an electrically controlled three-way valve 623. The upper left side of the outer side of the filter conveyor belt 66 is provided with an adsorption mechanism. The lower left side of the outer side of the filter conveyor belt 66 is provided with a cooling mechanism. The lower right side of the outer side of the filter conveyor belt 66 is provided with a heating separation mechanism.

[0061] Specifically, the adsorption mechanism is used for nitrogen purification, the cooling mechanism is used to cool the adsorption net 661 so that it can adsorb more impurity gases, and the heating separation mechanism is used to heat the adsorption net 661 so that the impurity gases adsorbed on the adsorption net 661 are released.

[0062] The adsorption mechanism includes overflow cover 2 65 and overflow cover 1 63. Both overflow cover 2 65 and overflow cover 1 63 are connected to the inside of the protective cover 69 through the first lifting device. A flexible connector inlet 1 61 is connected to overflow cover 1 63, and a flexible connector inlet 2 67 is connected to overflow cover 2 65.

[0063] Specifically, overflow cover 2 65 is connected to the inner side of protective cover 69 via electrically controlled telescopic rod 2 64, and overflow cover 1 63 is connected to the inner side of protective cover 69 via electrically controlled telescopic rod 1 62.

[0064] The cooling mechanism includes overflow cover five 615 and overflow cover six 619. Both overflow cover five 615 and overflow cover six 619 are connected to the inside of the protective cover 69 through the second lifting device. Both overflow cover five 615 and overflow cover six 619 are provided with liquid guiding chambers, which are connected to refrigerant output pipe 616 and refrigerant input pipe 618.

[0065] Specifically, the overflow cover 615 is connected to the inner side of the protective cover 69 via the electrically controlled telescopic rod 620, and the overflow cover 619 is connected to the inner side of the protective cover 69 via the electrically controlled telescopic rod 617.

[0066] The heating separation mechanism includes overflow cover 3 610 and overflow cover 4 611. Both overflow cover 3 610 and overflow cover 4 611 are connected to the inside of the protective cover 69 through a third lifting device. The inside of overflow cover 3 610 is equipped with a motor heating wire, and the overflow cover 4 611 is connected to a vacuum tube 613.

[0067] Specifically, overflow shield 3 610 and overflow shield 4 611 are connected to the inner side of protective shield 69 via electrically controlled telescopic rod 3 68 and electrically controlled telescopic rod 4 612, respectively.

[0068] The cross-sectional size and shape of the overflow cover 65, overflow cover 63, overflow cover 610, overflow cover 611, overflow cover 615 and overflow cover 619 are consistent with the rectangular frame plate 662, and a horizontal plate 614 is provided in the middle of the inner side of the protective cover 69.

[0069] Specifically, overflow shields 2 (65), 1 (63), 3 (610), 4 (611), 5 (615), and 6 (619) can achieve a good sealing effect after being placed on the rectangular frame plate 662.

[0070] Furthermore, a confluence valve 4 is provided on the flow guide pipe 5.

[0071] Specifically, the confluence valve 4 is used to collect the nitrogen produced by the two dust removal and filtration devices 3, and both dust removal and filtration devices 3 are equipped with anti-backflow valves.

[0072] Furthermore, the electrically controlled three-way valve is composed of a stepper motor 21, a spherical shell 22, an air outlet connector 23, a sealing ball 24, and an air inlet connector 25. There are two air outlet connectors 23. The upper end of the sealing ball 24 is connected to the output shaft of the stepper motor 21, and the sealing ball 24 is in sealed rotatable contact with the spherical shell 22.

[0073] Specifically, the stepper motor 21 can switch the flow channel by rotating the sealing ball 24.

[0074] More specifically, the sealing ball 24 is composed of a three-way guide cavity 241 and a sealing ball 242, wherein the two air outlets of the three-way guide cavity 241 are respectively connected to two air outlet connectors 23, and the air inlet of the three-way guide cavity 241 is connected to an air inlet connector 25.

[0075] Furthermore, a dust filter bag 31 is connected to the flow guide tube 39.

[0076] Specifically, dust can be filtered and collected through the dust filter bag 31.

[0077] Furthermore, the diversion hood 310 includes a hollow cylindrical tube 3101. The outer side of the hollow cylindrical tube 3101 is provided with four air inlets 3102. An isolation plate 3103 is provided between the air inlets 3102. The four air inlets 3102 are respectively located in the left, right, front and rear directions of the hollow cylindrical tube 3101. The air inlet 3102 located at the left end is connected to the air inlet 32. The air inlet 3102 located at the rear end is connected to the diversion pipe 36. A one-way valve is provided on the diversion pipe 36. The air inlet 3102 located at the front end is connected to the guide pipe 39. A one-way valve is provided on the guide pipe 39. The air inlet 3102 located at the right end communicates with the adjacent hollow cylindrical outer shell 312 or with the air outlet 37.

[0078] Specifically, the air inlets 3102 on the front and rear sides are used to purge the filter screen, and the air inlets 3102 on the left and right sides are used to guide the filtered nitrogen.

[0079] Furthermore, the eight air inlets 316 are evenly distributed in a ring on the outer side of the filter screen protective cover, and a wear-resistant plate 317 is provided between adjacent air inlets 316. The outer side of the wear-resistant plate 317 is provided with a silicone sealing layer.

[0080] Specifically, the combination of the 317 wear-resistant plate and the silicone sealing layer can effectively prevent nitrogen leakage during the filtration process.

[0081] Furthermore, the output shaft of the stepper motor 311 is provided with a locking block, and the lower end face of the filter screen protective cover is provided with a locking groove 313 corresponding to the locking block.

[0082] Specifically, the combination of the slot 313 and the card block facilitates the quick snap-fit ​​installation of the filter screen protective cover.

[0083] Furthermore, the upper and lower ends of the outer side of the rectangular frame plate 662 are covered with sealing strips.

[0084] Specifically, the sealing strip design effectively prevents air leakage after the spill cover is properly sealed.

[0085] Furthermore, the flexible conveyor belt 664 has gear grooves 667 at both the front and rear ends of its inner side. The output shaft of the stepper motor 622 is connected to a drive shaft 665 via a coupling. A drive gear 666 is installed on the drive shaft 665, and the drive gear 666 meshes with the gear groove 667.

[0086] Specifically, the arrangement of the transmission gear 666 and the gear groove 667 can effectively prevent the flexible conveyor belt 664 from slipping during rotation.

[0087] In use: The nitrogen gas that needs to be purified enters the interior of the electrically controlled three-way valve 2 through the main air inlet pipe 1. The electrically controlled three-way valve 2 controls the airflow to enter the interior of the sealed outer cover 38 through the air inlet end 32. First, the dust-laden gas is introduced into the strip filter screen 318 on the left end through the left end air guide port 3102. The strip filter screen 318 filters the dust in the gas and leaves it in the mesh. After the gas is filtered and dust-removed, it passes through the air guide channel 3153 and another strip filter screen 318 on the right end, and then enters the next filtration device through the right end air guide port 3102. The nitrogen gas after three-stage filtration is discharged through the air outlet end 37 and enters the downstream treatment device.

[0088] When the strip filter screen 318 needs cleaning, the stepper motor 311 drives the filter screen protective cover to rotate at a set angle, so that the strip filter screen 318 that needs to be blown rotates to the front of the air blowing hole 3152. At this time, a small amount of nitrogen gas after dust removal is accelerated by the high-pressure pump and sprayed out from the air blowing hole 3152, spraying onto the strip filter screen 318. The dust on the strip filter screen 318 enters the dustproof filter bag 31 through the guide pipe 39 with the airflow, and the dustproof filter bag 31 filters and collects the dust.

[0089] When the strip filter screen 318 needs to be replaced, the stepper motor 21 drives the sealing ball 24 to rotate 30 degrees. At this time, one of the air outlets of the electric three-way valve 2 is closed. The sealing end cover 33 is opened by rotating the handle 34. Then the sealing cover 314 is removed, the filter screen protection cover is pulled out, and the strip filter screen 318 is removed and replaced. After that, the filter screen protection cover is reinstalled.

[0090] After dust removal, the nitrogen gas enters the overflow cover 63 through the flexible connector inlet 61. The impurity gas is adsorbed by the adsorption net 661. The purified gas is discharged to the next process through the flexible connector inlet 67. After the adsorption net 661 is saturated, the electronically controlled three-way valve 623 controls the corresponding air inlet to close. At this time, the electronically controlled telescopic rod retracts to lift the overflow cover. The external vacuum pump connected to the protective cover 69 starts to evacuate the inside of the protective cover 69. Then, the stepper motor 622 starts to drive the filter conveyor belt 66 to rotate and move the next adjacent adsorption net 661 to the corresponding adsorption station. The electronically controlled telescopic rod extends to press the overflow cover tightly onto the rectangular frame plate 662. At this time, the gas supply can be quickly turned on. The two symmetrical passivation and impurity removal mechanisms alternately perform the above steps.

[0091] When the adsorption net 661 moves to the overflow cover 610, the overflow cover 610 heats the adsorption net 661. After heating, the impurity gas adsorbed on the adsorption net 661 is extracted through the vacuum tube 613. When the adsorption net 661 moves to the overflow cover 615, the overflow cover 615 and the overflow cover 619 cool the upper and lower surfaces of the adsorption net 661 to increase the adsorption capacity of the adsorption net 661. The pre-purified crude nitrogen gas can be separated and deoxygenated by distillation to obtain high-purity nitrogen gas.

[0092] It is worth noting that the filter screen protective cover is sealed to the inner side of the hollow cylindrical tube 3101.

[0093] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for extracting nitrogen gas by using space separation exhaust gas, comprising a main air inlet pipe (1), a merging valve (4), a flow guide pipe I (5), a flow guide pipe II (7), an electric control valve I (8) and a rectifying oxygen removal tower (9), characterized in that: Also include electrically controlled three-way valve, dust removal filter equipment (3) and pre-purifier (6), wherein the electrically controlled three-way valve includes electrically controlled three-way valve one (2) and electrically controlled three-way valve two (623); The main air inlet pipe (1) is connected with the air inlet end of the electrically controlled three-way valve one (2), the air outlet end of the electrically controlled three-way valve one (2) is connected with the air inlet end of the dust removal filter equipment (3), the air outlet end of the dust removal filter equipment (3) is connected with the pre-purifier (6) through the flow guide pipe one (5), and the air outlet end of the pre-purifier (6) is connected with the rectifying oxygen removal tower (9) through the flow guide pipe two (7), and the flow guide pipe two (7) is provided with the electrically controlled valve one (8); The dust removal filter equipment (3) includes two sealing covers (38), the two sealing covers (38) are symmetrically arranged front and back, a flow guide pipe three (39) is arranged between the two sealing covers (38), the sealing cover (38) is connected with the air blowing pipe one (35) through the shunt pipe (36) arranged on the outer side surface thereof, the left and right ends of the sealing cover (38) are respectively provided with the air inlet end one (32) and the air outlet end one (37), and the inside of the sealing cover (38) is provided with a plurality of hollow cylindrical outer shell bodies (312) arranged side by side and uniformly distributed, the plurality of hollow cylindrical outer shell bodies (312) are connected through flow guide channels, the lower end of the outer side surface of the sealing cover (38) is provided with the step motor two (311) close to the hollow cylindrical outer shell body (312), the inside of the hollow cylindrical outer shell body (312) is provided with a shunt cover (310), the inside of the shunt cover (310) is provided with a filter screen protection cover, the outer side surface of the filter screen protection cover is provided with a plurality of air guide holes two (316), the air guide holes two (316) are clamped with strip-shaped filter screen sieves (318) inside, the inside of the filter screen protection cover is provided with the air blowing pipe (315), and the lower end surface of the filter screen protection cover is connected with the output shaft of the step motor two (311); The lower end surface of the air blowing pipe (315) is closed, the lower end of the outer side surface of the air blowing pipe (315) is provided with an air guide channel (3153), the inside of the air blowing pipe (315) is provided with an air guide pipe groove (3151), the lower end of the outer side surface of the air blowing pipe (315) is provided with an air blowing hole (3152) close to the air guide channel (3153), the air blowing hole (3152) is communicated with the air guide pipe groove (3151), the air guide channel (3153) is not communicated with the air guide pipe groove (3151), and the outer side surface of the air blowing pipe (315) is provided with a sealing cover (314) at the upper end thereof; The pre-purifier (6) includes a protective cover (69), the inside of the protective cover (69) is provided with two filter type conveying belts (66) symmetrically arranged front and back, the inside of the protective cover (69) is provided with a step motor three (622), and the step motor three (622) drives the filter type conveying belt (66) to rotate through a transmission mechanism; The filter type conveying belt (66) includes a flexible conveying belt (664), a plurality of mounting holes (663) are uniformly distributed on the outer side surface of the flexible conveying belt (664), rectangular frame plates (662) are mounted on the mounting holes (663), and adsorption nets (661) are arranged on the inner side surface of the rectangular frame plates (662); One end of the protective cover (69) is provided with a flow guide pipe four (621), the flow guide pipe four (621) is connected with two soft connection head one (61) through the electric control three-way valve two (623), the outer side of the left end of the filter type conveying belt (66) is provided with an adsorption mechanism, the outer side of the left end of the filter type conveying belt (66) is provided with a cooling mechanism, the outer side of the right end of the filter type conveying belt (66) is provided with a heating separation mechanism; The adsorption mechanism includes anti-overflow cover two (65) and anti-overflow cover one (63), both of which are connected with the inside of the protective cover (69) through the first lifting device; the anti-overflow cover one (63) is connected with the soft connection head one (61), and the anti-overflow cover two (65) is connected with the soft connection head two (67); The cooling mechanism includes anti-overflow cover five (615) and anti-overflow cover six (619), both of which are connected with the inside of the protective cover (69) through the second lifting device; the inside of the anti-overflow cover five (615) and the anti-overflow cover six (619) is provided with a liquid guide cavity, which is connected with a refrigerant output pipe (616) and a refrigerant input pipe (618); The heating separation mechanism includes anti-overflow cover three (610) and anti-overflow cover four (611), both of which are connected with the inside of the protective cover (69) through the third lifting device; the inside of the anti-overflow cover three (610) is provided with a motor heating wire, and the anti-overflow cover four (611) is connected with a vacuum extraction pipe (613); The cross-sectional size and shape of the anti-overflow cover two (65), the anti-overflow cover one (63), the anti-overflow cover three (610), the anti-overflow cover four (611), the anti-overflow cover five (615) and the anti-overflow cover six (619) are consistent with the rectangular frame plate (662), and the inner side of the protective cover (69) is provided with a horizontal plate (614).

2. The apparatus for extracting nitrogen gas using space division exhaust according to claim 1, wherein: The flow guide pipe one (5) is provided with a confluence valve (4).

3. The apparatus for extracting nitrogen gas using space division of exhaust gas according to claim 1, wherein: The electric control three-way valve is composed of a stepping motor one (21), a spherical shell (22), a gas outlet connector (23), a sealing ball (24) and a gas inlet connector (25), the number of the gas outlet connector (23) is two, the upper end of the sealing ball (24) is connected with the output shaft of the stepping motor one (21), and the sealing ball (24) is in sealing rotation with the spherical shell (22).

4. The apparatus for extracting nitrogen gas using space division of exhaust gas according to claim 3, wherein: The sealing ball (24) is composed of a three-way flow guide cavity (241) and a sealing ball body (242), wherein the two gas outlet ends of the three-way flow guide cavity (241) are communicated with the two gas outlet connectors (23) respectively, and the gas inlet end of the three-way flow guide cavity (241) is communicated with the gas inlet connector (25).

5. The apparatus for extracting nitrogen gas using space division of exhaust gas according to claim 1, wherein: The flow guide pipe three (39) is connected with a dustproof filter bag (31).

6. The apparatus for extracting nitrogen from air using waste gas according to claim 1, wherein: The shunt cover (310) comprises a hollow cylindrical barrel (3101), the outer side of the hollow cylindrical barrel (3101) is provided with four air guide openings (3102), the air guide openings (3102) are provided with a partition plate (3103) therebetween, the four air guide openings (3102) are arranged in left, right, front and rear directions of the hollow cylindrical barrel (3101) respectively, the air guide opening (3102) arranged at the left end is connected with the air inlet end (32), the air guide opening (3102) arranged at the rear end is connected with the shunt pipe (36), the shunt pipe (36) is provided with a one-way valve (3102), the air guide opening (3102) arranged at the front end is connected with the flow guide pipe (39), the flow guide pipe (39) is provided with a one-way valve (3102), the air guide opening (3102) arranged at the right end is communicated with the adjacent hollow cylindrical outer shell (312) or communicated with the air outlet end (37).

7. The apparatus for extracting nitrogen from air using waste gas according to claim 1, wherein: Eight air guide openings (316) are annularly and evenly arranged on the outer side of the filter screen protection cover, the adjacent air guide openings (316) are provided with wear-resistant plates (317), and the outer side of the wear-resistant plate (317) is provided with a silica gel sealing layer.

8. The apparatus for extracting nitrogen from air using waste gas according to claim 1, wherein: The output shaft of the stepper motor (311) is provided with a clamping block, and the lower end surface of the filter screen protection cover is provided with a clamping groove (313) corresponding to the clamping block.

9. The apparatus for extracting nitrogen from air using waste gas according to claim 1, wherein: The outer side of the rectangular frame plate (662) is covered with a sealing rubber strip at the upper and lower ends.

10. The apparatus for extracting nitrogen from air using waste gas according to claim 1, wherein: The inner side of the flexible conveying belt (664) is provided with gear grooves (667) at the front and rear ends, the output shaft of the stepper motor (622) is connected with a transmission shaft (665) through a shaft coupling, the transmission shaft (665) is provided with a transmission gear (666), and the transmission gear (666) is engaged with the gear groove (667).

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