Sulfur recovery device for treating low-concentration acid gas

Abstract

The utility model relates to the technical field of sulfur recovery and flue gas purification, in particular to a sulfur recovery device for treating low-concentration acid gas. Comprising an absorption regeneration unit, a sulfur filtering unit and an absorption liquid adding unit, the absorption regeneration unit is communicated with the sulfur filtering unit, the absorption liquid adding unit is communicated with the absorption regeneration unit, the absorption regeneration unit comprises a tank body, the lower portion of the tank body is conical, an inner cylinder with an upper opening and a lower opening is fixed in the tank body, and a filter screen is fixed at the lower end of the inner cylinder. An inner gas distributor is arranged in the inner cylinder, an outer gas distributor is arranged between the inner cylinder and the tank body, the inner gas distributor is communicated with the inlet pipe, and the outer gas distributor is communicated with a first air compressor; an inner ring is fixed on the outer side of the inner cylinder below the outer gas distributor; and an outer ring is fixed on the inner wall of the tank body below the inner ring. When air is introduced into the absorption liquid through the upper ring pipe, the impact force on the absorption liquid at the lower part of the tank body can be reduced, and sulfur particles can be effectively precipitated in the conical part of the tank body.

Description

Technical Field

[0001] This utility model relates to the field of sulfur recovery and flue gas purification technology, specifically to a device for recovering sulfur from low-concentration acid gas. Background Technology

[0002] The removal of hydrogen sulfide from natural gas using the amine method requires further treatment of the hydrogen sulfide-containing acid gas released during regeneration. Common treatment methods include venting combustion, Claus sulfur recovery, and dual-tower wet oxidation-reduction processes. Venting combustion converts hydrogen sulfide into sulfur dioxide for high-point venting, causing environmental pollution and making it difficult to meet environmental protection requirements. The Claus sulfur recovery process converts hydrogen sulfide in the acid gas into elemental sulfur. However, this process is highly sensitive to the concentration of hydrogen sulfide in the acid gas, and its adaptability is poor when the concentration is too low or fluctuates greatly, resulting in unsatisfactory exhaust emissions. Due to strict limitations, this process is complex, requires numerous devices and supporting facilities, involves high investment, complicated operation, large footprint, and long construction period. Conventional wet oxidation-reduction processes involve absorption and regeneration in two separate reactors, the absorption tower and the regeneration tower, resulting in numerous devices, complex processes, and large pressure drops caused by sulfur particles. Therefore, it is necessary to develop a sulfur recovery process that is simple, efficient, compact, requires less investment, and is flexible, suitable for acid gas treatment in the desulfurization and regeneration of alcohol amines. This is of great significance for the desulfurization of sulfur-containing natural gas.

[0003] Patent document CN102794086B discloses an integrated acid gas and sulfur recovery and treatment device. Regenerated acid gas enters the intermediate gas distributor of an integrated reactor. A cross-shaped gas distributor evenly distributes the regenerated acid gas, forming microbubbles that react with the lean liquid inside the gas distributor from bottom to top. The lean liquid absorbs hydrogen sulfide from the acid gas. After removing the hydrogen sulfide, the acid gas meets venting standards and is directly discharged into the atmosphere through the vent at the top of the absorption and regeneration tank of the integrated regeneration reactor. The lean liquid in the gas distributor, after absorbing hydrogen sulfide, becomes a rich liquid. Under the action of air flotation, the rich liquid enters the absorption and regeneration tank of the integrated reactor from the top of the gas distributor. An air compressor evenly distributes air through a ring-shaped gas distributor inside the absorption and regeneration tank, oxidizing the rich liquid and regenerating it into lean liquid. Under the influence of air flotation and density difference, a convection circulation is formed. The lean liquid enters the gas distribution absorber, where sulfur particles are generated simultaneously. The sulfur particles sink and collect at the bottom of the absorption and regeneration tank cone of the integrated reactor. The purging air compressor blows air through nozzles to purge the sulfur particles at regular intervals. The sulfur slurry formed by the sulfur particles and desulfurization liquid flows into the sulfur filter skid through pipelines. The sulfur slurry first enters the vacuum drum filter. Under the suction of the vacuum pump, the desulfurization liquid in the sulfur slurry enters the gas-liquid separator. The sulfur particles gather on the surface of the vacuum drum filter to form sulfur paste. The sulfur paste can be loaded and transported off-site. The desulfurization liquid in the gas-liquid separator is pumped back to the integrated reactor through the filtrate pump. The absorbent stored in the absorbent tank is replenished to the integrated reactor through the dosing pump for circulation treatment, ultimately removing almost all the sulfur from the regenerated acid gas. In the process of recovering sulfur from acid gas, the air compressor distributes air evenly through the annular air distributor in the absorption and regeneration tank, oxidizing the rich liquid and turning it into a lean liquid for regeneration. Under the action of air flotation and specific gravity difference, a convection circulation is formed. The lean liquid enters the air distributor absorber, and sulfur particles are formed at the same time as the lean liquid is generated. The sulfur particles settle and collect at the bottom of the cone of the absorption and regeneration tank of the integrated reactor. It is also necessary to purge the sulfur particles at regular intervals. However, the convection circulation of rich and lean liquid between the absorption and regeneration tank and the liquid distributor absorber can easily cause the sulfur particles to not settle effectively, so the efficiency of sulfur particle discharge is low. Utility Model Content

[0004] The technical problem to be solved by this utility model is a sulfur recovery device for treating low-concentration acid gas that can ensure the efficiency of sulfur particle discharge.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] A device for recovering sulfur from low-concentration acid gas includes an absorption and regeneration unit, a sulfur filtration unit, and an absorbent addition unit. The absorption and regeneration unit is connected to the sulfur filtration unit, and the absorbent addition unit is also connected to the absorption and regeneration unit. The absorption and regeneration unit includes a tank body with a drain pipe fixedly connected to its upper end. The lower part of the tank body is conical, and an inner cylinder with openings at the top and bottom is fixed inside the tank body. A filter screen is fixed to the lower end of the inner cylinder, and an inner gas distributor is installed inside the inner cylinder. An outer gas distributor is installed between the inner cylinder and the tank body. The inner gas distributor is connected to an inlet pipe, and the outer gas distributor is connected to a first air compressor. An inner ring is fixed to the outer side of the inner cylinder below the outer gas distributor, and the tank body is located below the inner ring. An outer ring is fixed to the inner wall of the tank; a purging unit is fixed inside the conical part of the tank; the outer air distributor includes an upper ring pipe, which is located in the annular cavity between the inner cylinder and the tank, and multiple side holes are opened on both the inner and outer sides of the upper ring pipe, which is connected to the first air compressor; the inner air distributor includes an inner shell, which is fixed inside the inner cylinder and is connected to the inlet pipe, and multiple outlet holes are opened at both the upper and lower ends of the inner shell, with the outlet holes at the upper and lower ends of the inner shell corresponding one to one, and an inner plate is provided inside the inner shell, with sealing posts corresponding to the outlet holes fixed on the inner plate, the sealing posts penetrating the inner plate, and the inner plate is connected to the inner shell through a drive unit, and the inner plate can move in the vertical direction inside the inner shell.

[0007] Specifically, the purging unit includes a lower ring pipe fixed inside the conical part of the tank body. The lower ring pipe is connected to the second air compressor. A slit is opened on the lower ring pipe, and the outlet end of the slit faces the inner wall of the conical part of the tank body.

[0008] Specifically, the sulfur filtration unit includes a filter, the inlet of which is connected to the lower end of the tank, the outlet of which is connected to the inlet of a gas-liquid separator, the liquid outlet of which is connected to the inlet of a filtrate pump, the outlet of which is connected to the inner cylinder via a return pipe, and the gas outlet of which is connected to a vacuum pump.

[0009] Specifically, the absorbent unit includes a storage tank containing absorbent, and the storage tank is connected to the tank body via a transfer pump.

[0010] Specifically, the air outlet direction of the side hole is perpendicular to the axial direction of the tank.

[0011] Specifically, both the outer side of the inner ring and the inner side of the outer ring are inclined downwards.

[0012] Specifically, the drive unit includes multiple vertical telescopic rods, one end of which is fixedly connected to the inner shell, and the other end of which is fixedly connected to the inner plate.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] 1. Because the upper ring pipe has side holes on the inner and outer sides, and the air outlet direction of the side holes is perpendicular to the axial direction of the tank, when air is introduced into the absorbent liquid through the upper ring pipe, the impact force on the absorbent liquid at the bottom of the tank can be reduced, which can make the sulfur particles effectively precipitate in the conical part of the tank.

[0015] 2. By setting outer and inner rings, the impact force on the absorbent liquid in the lower part of the tank can be further reduced, allowing sulfur particles to effectively settle in the conical part of the tank.

[0016] 3. A slit is provided on the lower ring pipe, and the outlet end of the slit faces the inner wall of the conical part of the tank. Therefore, the compressed air discharged from the slit can thoroughly purge the sulfur particles on the inner wall of the conical part of the tank, thereby improving the discharge efficiency of sulfur particles.

[0017] 4. A filter screen is installed at the lower end of the inner cylinder. When the absorbent liquid circulates in the inner cylinder and between the inner cylinder and the tank, it can prevent sulfur particles from circulating along with it, thereby improving the sedimentation efficiency of sulfur particles.

[0018] 5. The inner plate can move up and down inside the inner shell. When the sealing column blocks the outlet at the upper end of the inner shell, the acid gas can be discharged through the outlet at the lower end of the inner shell, which can blow away the sulfur particles clogging the filter screen.

[0019] 6. The absorption and regeneration unit integrates acid gas absorption and solution regeneration, reducing the number of devices and improving operating efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of the tank's structure.

[0022] Figure 3 This is a schematic diagram of the internal air distributor.

[0023] The components in the attached diagram are named as follows: 1. Tank body, 2. Filter, 3. Gas-liquid separator, 4. Filtrate pump, 5. Vacuum pump, 6. Storage tank, 7. Transfer pump, 8. Inlet pipe, 9. Exhaust pipe, 10. Return pipe, 11. Upper ring pipe, 12. Inner ring, 13. Outer ring, 14. Lower ring pipe, 15. Slit, 16. Inner cylinder, 17. Side hole, 18. Filter screen, 19. Inner shell, 20. Outlet hole, 21. Inner plate, 22. Sealing column, 23. Telescopic rod, 24. External air distributor, 25. Internal air distributor, 26. First air compressor, 27. Second air compressor. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0025] Example 1: Refer to Figures 1-3 As shown, a sulfur recovery device for treating low-concentration acid gas includes an absorption and regeneration unit, a sulfur filtration unit, and an absorbent addition unit. The absorption and regeneration unit is connected to the sulfur filtration unit, and the absorbent addition unit is connected to the absorption and regeneration unit.

[0026] The absorption and regeneration unit includes a tank 1, with a drain pipe 9 fixedly connected to the upper end of the tank 1, and the lower part of the tank 1 is conical. An inner cylinder 16 with openings at the top and bottom is fixed inside the tank 1, and a filter screen 18 is fixed to the lower end of the inner cylinder 16.

[0027] An inner air distributor 25 is installed inside the inner cylinder 16, and an outer air distributor 24 is installed between the inner cylinder 16 and the tank body 1. The inner air distributor 25 is connected to the inlet pipe 8, and the outer air distributor 24 is connected to the first air compressor 26.

[0028] An inner ring 12 is fixed to the outer side of the inner cylinder 16 below the outer air distributor 24, and an outer ring 13 is fixed to the inner wall of the tank 1 below the inner ring 12. By setting the outer ring 13 and the inner ring 12, when the outer air distributor 24 introduces air into the absorbent liquid, it can reduce the impact force on the absorbent liquid in the lower part of the tank 1, and enable the sulfur particles to effectively settle in the cone part of the tank 1.

[0029] The external air distributor 24 includes an upper ring pipe 11, which is located in the annular cavity between the inner cylinder 16 and the tank body 1. Multiple side holes 17 are provided on both the inner and outer sides of the upper ring pipe 11. The air outlet direction of the side holes 17 is perpendicular to the axial direction of the tank body 1. The upper ring pipe 11 is connected to the first air compressor 26.

[0030] When air is introduced into the absorbent through the upper ring pipe 11, the impact force on the absorbent in the lower part of the tank 1 can be reduced, which can effectively allow sulfur particles to settle in the cone part of the tank 1.

[0031] The internal air distributor 25 includes an inner shell 19, which is fixed inside the inner cylinder 16. The inner shell 19 is connected to the inlet pipe 8, and multiple outlet holes 20 are provided at both the upper and lower ends of the inner shell 19.

[0032] A purging unit is fixed inside the conical part of the tank body 1. The purging unit includes a lower ring pipe 14 fixed inside the conical part of the tank body 1. The lower ring pipe 14 is connected to the second air compressor 27. A slit 15 is opened on the lower ring pipe 14, and the outlet end of the slit 15 faces the inner wall of the conical part of the tank body 1.

[0033] The sulfur filtration unit includes a filter 2, the inlet of which is connected to the lower end of the tank 1, the outlet of which is connected to the inlet of the gas-liquid separator 3, the liquid outlet of which is connected to the inlet of the filtrate pump 4, the outlet of which is connected to the inner cylinder 16 through the return pipe 10, and the gas outlet of which is connected to the vacuum pump 5.

[0034] The absorbent unit includes a storage tank 6, which stores absorbent liquid. The storage tank 6 is connected to the tank body 1 via a transfer pump 7.

[0035] When the absorbent does not absorb hydrogen sulfide from the acid gas, it is a lean solution. The acid gas enters the inner shell 19 through the inlet pipe 8 and is discharged through the outlet 20. The acid gas discharged from the outlet 20 forms tiny bubbles that come into contact with the lean solution in the inner cylinder 16 from bottom to top. The lean solution absorbs the hydrogen sulfide from the acid gas. After the hydrogen sulfide is removed, the acid gas meets the venting standard and is discharged into the atmosphere through the vent pipe 9.

[0036] After absorbing hydrogen sulfide, the lean liquid in the inner cylinder 16 becomes rich liquid. Under the action of air flotation, the rich liquid enters from the upper part of the inner cylinder 16 between the inner cylinder 16 and the tank body 1.

[0037] The first air compressor 26 distributes air evenly into the rich liquid through the side holes 17 of the upper ring pipe 11, oxidizing the rich liquid and turning it into a regenerated lean liquid. Since the upper ring pipe 11 has side holes 17 on its inner and outer sides, and the air outlet direction of the side holes 17 is perpendicular to the axial direction of the tank 1, when air is introduced into the absorbent through the upper ring pipe 11, the impact force on the absorbent in the lower part of the tank 1 can be reduced, which can effectively allow sulfur particles to settle in the conical part of the tank 1.

[0038] By setting the outer ring 13 and the inner ring 12, the impact force on the absorbent liquid in the lower part of the tank 1 can be further reduced, and the sulfur particles can be effectively precipitated in the cone part of the tank 1.

[0039] Under the influence of air flotation and specific gravity difference, the rich liquor and the regenerated lean liquor form a convective circulation, and the regenerated lean liquor enters the inner cylinder 16.

[0040] Sulfur particles are formed during the production of regenerated lean liquid, and these particles settle and collect at the bottom of tank 1. A filter screen 18 is installed at the lower end of the inner cylinder 16. When the absorbent liquid circulates within the inner cylinder 16 and between the inner cylinder 16 and tank 1, the sulfur particles are prevented from circulating along with it, thus improving the sedimentation efficiency of the sulfur particles.

[0041] The second air compressor 27 causes air to be discharged through the slit 15 of the lower ring pipe 14 to purge sulfur particles at regular intervals. The compressed air discharged from the slit 15 can thoroughly purge the sulfur particles on the inner wall of the cone of the tank body 1, thereby improving the discharge efficiency of sulfur particles.

[0042] The sulfur slurry formed by sulfur particles and absorbent flows into filter 2. Under the suction of vacuum pump 5, the absorbent in the sulfur slurry enters gas-liquid separator 3. Sulfur particles gather on the surface of filter 2 to form sulfur paste. The absorbent in gas-liquid separator 3 is pumped back into tank 1 through filtrate pump 4 and return pipe 10. The gas in gas-liquid separator 3 is output through vacuum pump 5.

[0043] After the volume of absorbent liquid in the tank decreases, the absorbent liquid in the storage tank 6 is replenished into the tank 1 by the transfer pump 7.

[0044] Example 2: Based on Example 1, referring to... Figure 2 As shown, the outer side of the inner ring 12 and the inner side of the outer ring 13 are both inclined downwards. This prevents sulfur particles from accumulating on the inner ring 12 and the outer ring 13.

[0045] Example 3: Based on Example 1, referring to... Figure 3 As shown, the outlet holes 20 at the upper and lower ends of the inner shell 19 correspond one-to-one. An inner plate 21 is provided inside the inner shell 19, and a sealing post 22 corresponding to the outlet hole 20 is fixed on the inner plate 21, with the sealing post 22 penetrating through the inner plate 21. The inner plate 21 is connected to the inner shell 19 through a driving unit, and the inner plate 21 can move vertically within the inner shell 19. Specifically, the driving unit includes multiple vertical telescopic rods 23, one end of which is fixedly connected to the inner shell 19, and the other end of which is fixedly connected to the inner plate 21.

[0046] The inner plate 21 can move up and down inside the inner shell 19. When the sealing column 22 blocks the outlet 20 at the upper end of the inner shell 19, the acid gas can be discharged only through the outlet 20 at the lower end of the inner shell 19. The acid gas discharged from the outlet 20 at the lower end of the inner shell 19 can blow away the sulfur particles that are clogging the filter screen 18.

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for treating low-concentration acid gas and recovering sulfur, comprising an absorption and regeneration unit, a sulfur filtration unit, and an absorbent addition unit, wherein the absorption and regeneration unit is connected to the sulfur filtration unit, and the absorbent addition unit is connected to the absorption and regeneration unit, characterized in that, The absorption and regeneration unit includes a tank (1), with an empty pipe (9) fixedly connected to the upper end of the tank (1). The lower part of the tank (1) is conical. An inner cylinder (16) with openings at the top and bottom is fixed inside the tank (1). A filter screen (18) is fixed at the lower end of the inner cylinder (16). An inner air distributor (25) is installed inside the inner cylinder (16). An outer air distributor (24) is installed between the inner cylinder (16) and the tank (1). The inner air distributor (25) is connected to the inlet pipe (8), and the outer air distributor (24) is connected to the first air compressor (26). An inner ring (12) is fixed to the outer side of the inner cylinder (16) below the outer air distributor (24). An outer ring (13) is fixed to the inner wall of the tank (1) below the inner ring (12). A purging unit is fixed inside the conical part of the tank (1). The outer air distributor (24) includes an upper ring pipe (11). The upper ring pipe (11) is located inside the inner cylinder (16). In the annular cavity between the cylinder (16) and the tank (1), multiple side holes (17) are provided on the inner and outer sides of the upper annular pipe (11). The upper annular pipe (11) is connected to the first air compressor (26). The inner air distributor (25) includes an inner shell (19). The inner shell (19) is fixed inside the inner cylinder (16). The inner shell (19) is connected to the inlet pipe (8). Multiple outlet holes (20) are provided at both the upper and lower ends of the inner shell (19). The outlet holes (20) at the upper and lower ends of the inner shell (19) correspond one-to-one. An inner plate (21) is provided inside the inner shell (19). A sealing column (22) corresponding to the outlet hole (20) is fixed on the inner plate (21). The sealing column (22) penetrates the inner plate (21). The inner plate (21) is connected to the inner shell (19) through a drive unit. The inner plate (21) can move in the vertical direction inside the inner shell (19).

2. The sulfur recovery device for treating low-concentration acid gas according to claim 1, characterized in that, The purging unit includes a lower ring pipe (14) fixed inside the conical part of the tank body (1). The lower ring pipe (14) is connected to the second air compressor (27). A slit (15) is opened on the lower ring pipe (14), and the outlet end of the slit (15) faces the inner wall of the conical part of the tank body (1).

3. The sulfur recovery device for treating low-concentration acid gas according to claim 1, characterized in that, The sulfur filtration unit includes a filter (2), the inlet of which is connected to the lower end of the tank (1), the outlet of which is connected to the inlet of the gas-liquid separator (3), the liquid outlet of which is connected to the inlet of the filtrate pump (4), the outlet of which is connected to the inner cylinder (16) through the return pipe (10), and the gas outlet of which is connected to the vacuum pump (5).

4. The sulfur recovery device for treating low-concentration acid gas according to claim 1, characterized in that, The absorbent unit includes a storage tank (6) containing absorbent, and the storage tank (6) is connected to the tank body (1) via a transfer pump (7).

5. The sulfur recovery device for treating low-concentration acid gas according to claim 1, characterized in that, The air outlet direction of the side hole (17) is perpendicular to the axial direction of the tank body (1).

6. The sulfur recovery device for treating low-concentration acid gas according to claim 1, characterized in that, The outer side of the inner ring (12) and the inner side of the outer ring (13) are both inclined downwards.

7. The sulfur recovery device for treating low-concentration acid gas according to claim 1, characterized in that, The drive unit includes multiple vertical telescopic rods (23), one end of which is fixedly connected to the inner shell (19), and the other end of which is fixedly connected to the inner plate (21).

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