Air separation device with double expansion machines

Abstract

The utility model relates to the technical field of air separation, and discloses a double-expansion-machine air separation device which comprises a rectifying tower, a support is fixedly installed on the right side of the rectifying tower, a nitrogen collecting bottle and an oxygen collecting bottle are fixedly installed on the top of the support, and the nitrogen collecting bottle communicates with the upper end of the rectifying tower; the oxygen collecting bottle is communicated with the lower end of the rectifying tower. Through the design of the pre-cooling box, after the expansion machine expands air, expanded cold air circulates in the pre-cooling pipe, the temperature of the air in the pre-cooling box is further reduced, meanwhile, when the air circulates to the second communicating pipe, the air is discharged into the rectifying tower through the second communicating pipe, and compared with a traditional device, the energy consumption is reduced, and the energy consumption is reduced. Through the design of the precooling pipe in the precooling box, air is precooled in advance, the equipment load of a follow-up expansion machine is relieved, and the performance and the service life of the expansion machine are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air separation, more particularly, the present application relates to a double-expander air separation device. BACKGROUND

[0002] A double-expander is a device for gas separation and liquefaction, which is usually composed of two expanders, which convert high-pressure gas into low-temperature and low-pressure gas through the expansion process, thereby realizing the cooling and liquefaction of the gas. When the double-expander is applied to an air separation device, it realizes the separation and liquefaction of oxygen, nitrogen and other gases by compressing, cooling and expanding the air. The device usually includes an air compressor, a double-expander, a rectification tower and other parts, and can efficiently produce high-purity gas, which is widely used in industrial gas supply, medical treatment, chemical industry and other fields.

[0003] However, in actual use, the gas entering the device is usually at ambient temperature, and direct cooling to extremely low temperature requires a large amount of energy consumption, and the refrigeration effect of the expander is related to the temperature of its inlet. When the temperature of the gas entering the expander is high, the refrigeration effect of the expander is not obvious, which affects the subsequent separation operation, and therefore needs to be improved and optimized. CONTENT OF THE UTILITY MODEL

[0004] In order to overcome the shortcomings of the prior art, the present application provides a double-expander air separation device, which has the advantages of good precooling effect.

[0005] To achieve the above purpose, the present application provides the following technical scheme: a double-expander air separation device, comprising a rectification tower, a bracket is fixedly installed on the right side of the rectification tower, a nitrogen collection bottle and an oxygen collection bottle are fixedly installed on the top of the bracket, the upper end of the nitrogen collection bottle is communicated with the rectification tower, the lower end of the oxygen collection bottle is communicated with the rectification tower, a heat exchanger is fixedly installed on the outer wall of the rectification tower, and the heat exchanger and the rectification tower are communicated with each other;

[0006] An air compressor is arranged on the left side of the rectification tower, a precooling box is arranged on the right side of the air compressor, the air compressor and the precooling box are communicated through an air inlet pipe, a first communication pipe is fixedly installed on the top of the air compressor, the other end of the first communication pipe is communicated with the top of the rectification tower, expanders are arranged on the front and rear sides of the precooling box, the air compressor and the expanders are communicated through an air outlet pipe, a precooling pipe is fixedly installed in the precooling box, air pipes are fixedly installed on the top of the two groups of expanders, the other ends of the two groups of air pipes penetrate into the interior of the precooling box and are communicated with the precooling pipe, a second communication pipe is fixedly installed on the top of the precooling box, one end of the second communication pipe is communicated with the precooling pipe, and the other end is communicated with the bottom of the rectification tower.

[0007] The inside of the pre-cooling box is fixedly provided with a fixed frame, and the inside of the fixed frame is movably provided with a pre-treatment plate.

[0008] As a preferred technical solution of the present application, the fixed frame and the pre-treatment plate are both two groups, wherein the lower pre-treatment plate is a filter plate for adsorbing impurities in the gas, and the upper pre-treatment plate is a water absorption plate for adsorbing moisture in the gas.

[0009] As a preferred technical solution of the present application, one side of the pre-treatment plate is provided with a mounting hole, the outer wall of the pre-cooling box is fixedly provided with a fixed cylinder, the inside of the fixed cylinder is movably provided with a mounting rod, one end of the mounting rod penetrates into the inside of the pre-cooling box and abuts against the mounting hole, the other end of the mounting rod and the fixed cylinder are elastically connected through a second spring, the left side of the mounting rod is fixedly provided with a pull rod, and one end of the pull rod penetrates to the outside of the fixed cylinder.

[0010] As a preferred technical solution of the present application, the rear wall of the pre-cooling box is fixedly provided with a fixed shell, and the inside of the fixed shell is movably provided with a push plate, one end of the push plate and the fixed shell are elastically connected through a first spring, and the other end of the push plate penetrates the pre-cooling box and the fixed frame and abuts against the pre-treatment plate.

[0011] Compared with the prior art, the present application has the following advantages:

[0012] 1. The pre-cooling box is designed to make the expanded cold air circulate in the inside of the pre-cooling pipe after the air is expanded by the expander, thereby further reducing the temperature of the air in the pre-cooling box, and when the air circulates to the second communication pipe, it is discharged into the inside of the rectifying tower through the second communication pipe. Compared with the traditional device, the device pre-cools the air in advance through the design of the pre-cooling pipe in the pre-cooling box, thereby relieving the equipment load of the subsequent expander, ensuring the performance and service life of the expander, and making the device run more efficiently through pre-cooling to reduce the inlet temperature of the expander.

[0013] 2. The design of the two groups of pre-treatment plates makes the air entering the inside of the pre-cooling box first remove impurities and moisture, thereby avoiding the problem of equipment blockage caused by freezing of moisture and impurities in a low-temperature state, and the design of the mounting rod and the mounting hole makes the pre-treatment plate easy to disassemble and replace after long-term use. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0015] Figure 1 The structure schematic diagram of the present application;

[0016] Figure 2 The structure schematic diagram of the air compressor of the present application;

[0017] Figure 3 The structure schematic diagram of the air inlet pipe of the present application;

[0018] Figure 4 The structure schematic diagram of the pre-cooling pipe of the present application;

[0019] Figure 5 The structure schematic diagram of the push plate of the present application;

[0020] Figure 6 The structure schematic diagram of the mounting rod of the present application;

[0021] Figure 7 The structure schematic diagram of the mounting hole of the present application.

[0022] In the drawings: 1, rectifying tower; 2, nitrogen collection bottle; 3, oxygen collection bottle; 4, support; 5, heat exchanger; 6, air compressor; 7, first communication pipe; 8, expander; 9, exhaust pipe; 10, pre-cooling box; 11, air pipe; 12, air inlet pipe; 13, pre-cooling pipe; 14, second communication pipe; 15, pre-treatment plate; 16, fixed frame; 17, fixed shell; 18, push plate; 19, first spring; 20, fixed cylinder; 21, mounting rod; 22, second spring; 23, pull rod; 24, mounting hole. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor also belong to the protection scope of the present application.

[0024] As Figures 1 to 7As shown, the present application provides a double expander air separation device, including rectifying tower 1, the right side of rectifying tower 1 is fixedly installed with support 4, the top of support 4 is fixedly installed with nitrogen collection bottle 2 and oxygen collection bottle 3, nitrogen collection bottle 2 and the upper end of rectifying tower 1 are communicated, oxygen collection bottle 3 and the lower end of rectifying tower 1 are communicated, the outer wall of rectifying tower 1 is fixedly installed with heat exchanger 5, heat exchanger 5 and rectifying tower 1 are communicated with each other;

[0025] The left side of rectifying tower 1 is provided with air compressor 6, the right side of air compressor 6 is provided with precooling box 10, air compressor 6 and precooling box 10 are communicated through air inlet pipe 12, the top of air compressor 6 is fixedly installed with first communication pipe 7, the other end of first communication pipe 7 is communicated with the top of rectifying tower 1, the front and back sides of precooling box 10 are both provided with expander 8, air compressor 6 and expander 8 are communicated through exhaust pipe 9, precooling box 10 is fixedly installed with precooling pipe 13 in the inside, the top of two groups of expanders 8 is fixedly installed with air pipe 11, the other end of two groups of air pipes 11 penetrates to the inside of precooling box 10 and is communicated with precooling pipe 13, the top of precooling box 10 is fixedly installed with second communication pipe 14, one end of second communication pipe 14 is communicated with precooling pipe 13, the other end is communicated with the bottom of rectifying tower 1.

[0026] When the device is put into use, air compressor 6 starts to work, the work of air compressor 6 will suck the outside air from the bottom of precooling box 10 into the inside of precooling box 10, further air will enter into air compressor 6 through air inlet pipe 12 after precooling of precooling box 10, with the compression of air compressor 6, air is compressed to high pressure state, then part of high pressure gas enters into the inside of rectifying tower 1 through first communication pipe 7, and the other part of high pressure gas enters into the inside of two groups of expanders 8 through two exhaust pipes 9 respectively, two groups of expanders 8 are adopted to improve work efficiency, the work of expander 8 will make air expand, the pressure of expanded air is reduced, the temperature is significantly reduced, then low temperature gas will enter into the inside of precooling pipe 13 through air pipe 11, at this time, the low temperature gas circulating in the inside of precooling pipe 13 will precool the inside of precooling box 10, so that the temperature of subsequent outside air is reduced after entering into precooling box 10 under the work of air compressor 6 and then entering into air compressor 6 through air inlet pipe 12, further reducing the high heat generated when air compressor 6 compresses air, also reducing the load of expander 8, finally, the low temperature gas in precooling pipe 13 enters into the inside of rectifying tower 1 through second communication pipe 14, finally, the difference of boiling points of oxygen and nitrogen is used in rectifying tower 1, combined with heat exchanger 5, separation is realized through multiple gas-liquid contact, oxygen is discharged from the tower low to oxygen collection bottle 3, and nitrogen is discharged from the top of the tower to nitrogen collection bottle 2.

[0027] Through the design of the two sets of expanders 8 and the pre-cooling box 10, the expanded cold air enters the pre-cooling box 10 from two different directions after the air is expanded by the two sets of expanders 8 and circulates inside the pre-cooling pipe 13, further reducing the temperature of the air inside the pre-cooling box 10, and when the air circulates to the second communication pipe 14, it is discharged into the inside of the rectifying tower 1 through the second communication pipe 14. Compared with the traditional device, the device pre-cools the air in advance through the design of the pre-cooling pipe 13 inside the pre-cooling box 10, and the pre-cooled air also relieves the equipment load of the subsequent expander 8, ensuring the performance and service life of the expander 8. At the same time, by pre-cooling the expander inlet temperature, the device can run more efficiently.

[0028] The pre-cooling box 10 is internally fixedly provided with a fixed frame 16, and the fixed frame 16 is movably provided with a pre-treatment plate 15, and the pre-treatment plate 15 is located below the air inlet pipe 12.

[0029] When the air is compressed, the water and impurities in the air will freeze into solids, further blocking the pipeline, valve, heat exchanger and expander and other key equipment, causing the system to run inefficiently or even shut down, and in the rectifying tower, the water and impurities in the air will also change the gas-liquid balance, affecting the separation effect, so after the air enters the inside of the pre-cooling box 10, not only is the air pre-cooled by the pre-cooling pipe 13, but also the air is purified by the design of the pre-treatment plate 15, at this time the air is isolated from dust and impurities by the pre-treatment plate 15 and then enters the air compressor 6 through the air inlet pipe 12. Through the design of the pre-treatment plate 15, the air entering the inside of the pre-cooling box 10 is first removed of impurities to avoid the problem of equipment blockage caused by water and impurities freezing at low temperature.

[0030] The fixed frame 16 and the pre-treatment plate 15 are both two sets, wherein the lower pre-treatment plate 15 is a filter plate for adsorbing impurities in the gas, and the upper pre-treatment plate 15 is a water absorption plate for adsorbing water in the gas.

[0031] The impurities in the air are first isolated by the lower filter plate, and then the water in the air is removed by the upper water absorption plate to avoid the problem of equipment blockage.

[0032] The pre-treatment plate 15 is provided with a mounting hole 24 on one side, the pre-cooling box 10 is fixedly provided with a fixed cylinder 20 on the outer wall, the fixed cylinder 20 is movably provided with a mounting rod 21 inside, one end of the mounting rod 21 penetrates into the inside of the pre-cooling box 10 and abuts with the mounting hole 24, the other end of the mounting rod 21 and the fixed cylinder 20 are elastically connected through the second spring 22, and the left side of the mounting rod 21 is fixedly provided with a pull rod 23, one end of the pull rod 23 penetrates to the outside of the fixed cylinder 20.

[0033] After a long time of use, the effect of the pre-treatment plate 15 will decrease, at this time the worker pulls the pull rod 23, the mounting rod 21 is displaced to the left along the fixed cylinder 20, further, the mounting rod 21 is separated from the inside of the mounting hole 24, the pre-treatment plate 15 loses the fixed effect, the worker takes out the pre-treatment plate 15 from the pre-cooling box 10 to replace, after replacement, the worker resets the pre-treatment plate 15, finally, the pull rod 23 is loosened, the mounting rod 21 is inserted into the inside of the mounting hole 24 through the elastic potential energy of the second spring 22, and the fixing is completed. Through the design of the mounting rod 21 and the mounting hole 24, the pre-treatment plate 15 is convenient to disassemble and replace after a long time of use.

[0034] The rear side wall of the pre-cooling box 10 is fixedly provided with a fixed shell 17, the inside of the fixed shell 17 is movably provided with a push plate 18, one end of the push plate 18 is elastically connected with the fixed shell 17 through a first spring 19, and the other end of the push plate 18 penetrates through the pre-cooling box 10 and the fixed frame 16 and abuts against the pre-treatment plate 15.

[0035] When the worker pulls the pull rod 23 to make the pre-treatment plate 15 lose the fixing, at this time, the first spring 19 is in a compressed state, the push plate 18 is popped out forward through the elastic potential energy of the first spring 19, further, the push plate 18 pushes the pre-treatment plate 15 forward, and the pre-treatment plate 15 is actively separated.

[0036] The working principle and use process of the present application are as follows:

[0037] When the device is put into use, the air compressor 6 starts to work, the working of the air compressor 6 can suck the outside air into the inside of the pre-cooling box 10, further, the air is pre-cooled through the pre-cooling box 10 and then enters into the air compressor 6 through the air inlet pipe 12, along with the compression of the air compressor 6, the air is compressed to a high pressure state, then part of the high pressure gas enters into the inside of the rectifying tower 1 through the first communication pipe 7, and the other part of the high pressure gas enters into the inside of the two sets of expanders 8 through the two air outlet pipes 9, the working of the expander 8 can make the air expand, the pressure of the expanded air is reduced, and the temperature is significantly reduced, then the low temperature gas enters into the inside of the pre-cooling pipe 13 through the air pipe 11, at this time, the low temperature gas flowing in the inside of the pre-cooling pipe 13 can pre-cool the inside of the pre-cooling box 10, so that the temperature of the subsequent outside air is reduced after entering into the pre-cooling box 10 under the working of the air compressor 6 and then entering into the air compressor 6 through the air inlet pipe 12, further, the high heat generated when the air compressor 6 compresses the air is reduced, and the load of the expander 8 is also reduced, finally, the low temperature gas in the pre-cooling pipe 13 enters into the inside of the rectifying tower 1 through the second communication pipe 14, finally, the rectifying tower 1 is used to separate the oxygen and the nitrogen through multiple gas-liquid contactings according to the boiling point difference between the oxygen and the nitrogen, the oxygen is discharged from the tower bottom to the oxygen collecting bottle 3, and the nitrogen is discharged from the tower top to the nitrogen collecting bottle 2.

[0038] When the air is compressed, the moisture and impurities in the air will freeze into solid, further blocking the pipeline, valve, heat exchanger and expander and other key equipment, resulting in system operation efficiency decline or even shutdown, and in the rectifying column, the moisture and impurities in the air will also change the gas-liquid equilibrium, affect the separation effect, therefore, after the air enters the inside of the pre-cooling box 10, not only the air is pre-cooled through the pre-cooling pipe 13, but also the air is purified through the design of the two groups of pretreatment plates 15, at this time, the air will first be isolated from the dust impurities through the setting of the lower filter plate, and then the moisture in the air will be removed through the upper water absorption plate. After a long time of use, the effect of the pretreatment plate 15 will decrease, at this time, the worker pulls the pull rod 23, so that the installation rod 21 displaces leftward along the fixed cylinder 20, further, the installation rod 21 is separated from the inside of the installation hole 24, so that the pretreatment plate 15 loses fixation, at this time, since the pretreatment plate 15 loses fixation, the push plate 18 will pop out forward through the elastic potential of the first spring 19, further, the push plate 18 pushes the pretreatment plate 15 forward, so that the pretreatment plate 15 actively separates, which is convenient for the worker to replace. After the replacement is completed, the worker resets the pretreatment plate 15, and finally loosens the pull rod 23, so that the installation rod 21 is re-inserted into the inside of the installation hole 24 through the elastic potential of the second spring 22, and the fixation is completed.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions described in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A double expander air separation plant comprising a rectification column (1), characterized in that: The right side of the rectifying tower (1) is fixedly installed with a support (4), the top of the support (4) is fixedly installed with a nitrogen collection bottle (2) and an oxygen collection bottle (3), the nitrogen collection bottle (2) is communicated with the upper end of the rectifying tower (1), the oxygen collection bottle (3) is communicated with the lower end of the rectifying tower (1), the outer wall of the rectifying tower (1) is fixedly installed with a heat exchanger (5), and the heat exchanger (5) and the rectifying tower (1) are communicated with each other; The left side of the rectifying tower (1) is provided with an air compressor (6), the right side of the air compressor (6) is provided with a pre-cooling box (10), the air compressor (6) and the pre-cooling box (10) are communicated with each other through an air inlet pipe (12), the top of the air compressor (6) is fixedly installed with a first communicating pipe (7), the other end of the first communicating pipe (7) is communicated with the top of the rectifying tower (1), the front and rear sides of the pre-cooling box (10) are both provided with an expander (8), the air compressor (6) and the expander (8) are communicated through an exhaust pipe (9), the inside of the pre-cooling box (10) is fixedly installed with a pre-cooling pipe (13), the tops of the two groups of expanders (8) are fixedly installed with air pipes (11), the other ends of the two groups of air pipes (11) penetrate into the inside of the pre-cooling box (10) and are communicated with the pre-cooling pipe (13), the top of the pre-cooling box (10) is fixedly installed with a second communicating pipe (14), one end of the second communicating pipe (14) is communicated with the pre-cooling pipe (13), and the other end is communicated with the bottom of the rectifying tower (1).

2. The dual-expander air separation apparatus of claim 1, wherein: The inside of the pre-cooling box (10) is fixedly installed with a fixed frame (16), the inside of the fixed frame (16) is movably installed with a pretreatment plate (15), and the pretreatment plate (15) is located below the air inlet pipe (12).

3. The dual-expander air separation apparatus of claim 2, characterized by: The fixed frame (16) and the pretreatment plate (15) are both two groups, wherein the lower pretreatment plate (15) is a filter plate and is used for adsorbing impurities in the gas, and the upper pretreatment plate (15) is a water absorption plate and is used for adsorbing water in the gas.

4. A double-expander air separation apparatus according to claim 2 or 3, characterized by: One side of the pretreatment plate (15) is provided with a mounting hole (24), the outer wall of the pre-cooling box (10) is fixedly installed with a fixed cylinder (20), the inside of the fixed cylinder (20) is movably installed with a mounting rod (21), one end of the mounting rod (21) penetrates into the inside of the pre-cooling box (10) and abuts against the mounting hole (24), the other end of the mounting rod (21) and the fixed cylinder (20) are elastically connected through a second spring (22), the left side of the mounting rod (21) is fixedly installed with a pull rod (23), and one end of the pull rod (23) penetrates to the outside of the fixed cylinder (20).

5. The dual-expander air separation apparatus of claim 4, wherein: The rear wall of the pre-cooling box (10) is fixedly installed with a fixed shell (17), the inside of the fixed shell (17) is movably installed with a push plate (18), one end of the push plate (18) and the fixed shell (17) are elastically connected through a first spring (19), the other end of the push plate (18) penetrates the pre-cooling box (10) and the fixed frame (16) and abuts against the pretreatment plate (15).

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