Flue gas purification device for ethylene production

Abstract

The invention relates to the technical field of flue gas, in particular to a flue gas purification device for ethylene production, which comprises a gas transition box, a gas inlet pipe and a spraying frame, the two sides of the gas transition box are provided with through preformed holes, the middle positions of the upper and lower ends of an outer cover are provided with notches, the inner side of an inner cylinder is uniformly provided with a plurality of screen plates, and the screen plates are arranged in the gas transition box. Round holes are formed in the circle centers of the screen plates, and catalyst particles are arranged between every two adjacent screen plates and used for catalyzing flue gas; a plurality of groove holes are distributed in the outer side of the inner cylinder in an annular array mode, and a reagent used for cleaning tar is sprayed out of the spraying frame. Tar attached to the surface of the catalyst is removed through a reagent; meanwhile, after sulfur dioxide in the flue gas is oxidized into sulfur trioxide, the sulfur trioxide is combined with the ammonia gas to generate ammonium sulfate, and the ammonium sulfate is used for treating the ammonia gas at the source for blocking active sites on the surface of the catalyst and damaging a pore structure of the catalyst, so that the problem is solved from the source.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flue gas treatment, and particularly relates to a flue gas purification device for ethylene production. BACKGROUND

[0002] The tar in the tail gas of ethylene production is an inevitable product of high-temperature cracking side reactions, which is composed of polycyclic aromatic hydrocarbons and heavy condensates, and is derived from: over-cracking of hydrocarbons -> aromatization / condensation reaction; physical condensation in the quenching process; residues and secondary reactions in the separation system. When the tail gas generated during ethylene production is treated, the flue gas needs to be treated by a catalyst.

[0003] A flue gas purification system for efficiently treating ethylene cracking furnace tube coking tail gas is disclosed in one prior art document CN111482025A, which comprises a flue gas turbine, a heat exchanger, a water washing device, a gas-water separation device and a sedimentation tank. The present application can make full use of the waste heat in the ethylene cracking furnace tube coking tail gas. A part of the waste heat can be used to work by the flue gas turbine to provide mechanical energy or electric energy for other equipment. Another part of the waste heat is used for heat exchange to change the air into hot air as raw material for coking tail gas. The water washing device and the gas-water separation device are used to separate a large amount of coke, iron powder and other particulate matters, thereby reducing the content of particulate matters in the tail gas. The cooling water in the sedimentation tank can be recycled, thereby saving a large amount of water resources. The tail gas of the gas-water separation device is returned to the furnace for combustion, thereby solving the problem of a small amount of solid particles in the tail gas. The present application is environmentally friendly, energy-saving, safe and can greatly reduce the production cost.

[0004] The above-mentioned prior art can separate a large amount of particulate matters when treating the tail gas, but tar will also appear in the tail gas. The tar will adhere to the surface of the catalyst particles, thereby causing the activity of the catalyst to decrease. SUMMARY

[0005] The present application aims at solving the problems in the prior art and provides a flue gas purification device for ethylene production.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: A flue gas purification device for ethylene production is designed, which comprises a gas transition box, an air inlet pipe and a spraying frame. Through holes are formed in the two sides of the gas transition box, and pipe bodies are rotatably arranged on the inner sides of the two through holes. An inner cylinder is fixed between the two pipe bodies, and one of the pipe bodies is connected with a driving member. An outer cover is fixed to the inner side of the outer cover through a connecting frame, and the inner cylinder is rotatably arranged on the inner side of the outer cover. Notches are formed in the middle positions of the upper and lower ends of the outer cover. A plurality of mesh plates are uniformly arranged on the inner side of the inner cylinder, and circular holes are formed in the centers of the mesh plates. Catalyst particles are arranged between adjacent two mesh plates for catalyzing the flue gas. The outer side of the inner cylinder is provided with a plurality of slots in annular array, and the spraying frame sprays reagents for tar cleaning.

[0007] Preferably, the bottom of the outer cover is fixedly provided with a processing box with an open upper end, the processing box is matched with the gap position of the lower end of the outer cover, one of the pipe bodies is in communication with the inner side of the processing box through a conveying pipe, and air holes are formed in the conveying pipe on the inner side of the processing box.

[0008] Preferably, the inner side of the processing box is fixedly provided with a net rack at the upper end, and the net rack is in arched arrangement, and the lower end of the processing box is provided with a groove in the middle.

[0009] Preferably, the driving member comprises a transmission gear, a driving gear and a first motor. The transmission gear is fixed on the outer side of one of the pipe bodies, the output shaft of the first motor is fixedly provided with a driving gear at the end, and the transmission gear and the driving gear are in meshing engagement.

[0010] Preferably, one side of the gas transition box is fixedly provided with a connecting box, one end of the gas inlet pipe extends to the inner side of the connecting box, a filter cartridge is movably arranged between the end of the pipe body and the end of the gas inlet pipe, baffle plates are fixedly arranged in parallel on both sides of the filter cartridge in the connecting box, a plurality of filter cartridges are arranged in linear array between the two baffle plates and are fixed by a control assembly, and when the filter cartridge is fixed, the ends of the filter cartridge are respectively in close contact with the end of the pipe body and the end of the gas inlet pipe.

[0011] Preferably, the control assembly comprises a second motor, a connecting shaft and a fork. The connecting shaft is connected to the end of the output shaft of the second motor, and a plurality of forks are uniformly fixed at the end of the connecting shaft, and when the filter cartridge is fixed, two forks on the same side clamp the outer side of the filter cartridge.

[0012] Preferably, a guide rail is formed on the opposite side of the baffle plate, a limiting block is fixed on the outer side of the filter cartridge, and one end of the limiting block is slidably arranged in the inner side of the guide rail.

[0013] Preferably, air holes are formed at both ends of the filter cartridge for gas to pass through, and activated carbon particles impregnated with phosphoric acid are filled in the inner side of the filter cartridge.

[0014] Preferably, an air blowing pipe is arranged between a plurality of the circular holes, and the other end of the air blowing pipe is connected with the pump body.

[0015] Preferably, the gas blown out by the air blowing pipe is heated nitrogen.

[0016] The beneficial effect of the ethylene production flue gas purification device lies in that: the ethylene production flue gas purification device, when treating flue gas, needs to use a catalyst, since the flue gas generated in the ethylene production process contains tar, the tar will be attached to the surface of the catalyst, resulting in reduced activity of the catalyst, and the tar attached to the surface of the catalyst is removed through a reagent; Meanwhile, the sulfur dioxide in the flue gas is oxidized into sulfur trioxide, and then combined with ammonia to generate ammonium sulfate, and the ammonium sulfate blocks the active sites on the surface of the catalyst and destroys the pore structure of the catalyst, so that the ammonia is treated at the source and solved at the source. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The structure diagram of the ethylene production flue gas purification device is provided.

[0018] Figure 2 The structure isomeric side view of the ethylene production flue gas purification device is provided.

[0019] Figure 3 The structure diagram of the ethylene production flue gas purification device from another perspective is provided.

[0020] Figure 4 The structure diagram of the ethylene production flue gas purification device from another perspective is provided. Figure 3 The structure diagram of the ethylene production flue gas purification device from another perspective is provided.

[0021] Figure 5 The structure diagram of the ethylene production flue gas purification device from another perspective is provided.

[0022] Figure 6 The structure diagram of the ethylene production flue gas purification device from another perspective is provided.

[0023] Figure 7 The structure diagram of the ethylene production flue gas purification device from another perspective is provided.

[0024] Figure 8 The structure diagram of the ethylene production flue gas purification device from another perspective is provided.

[0025] Figure 9 The structure diagram of the ethylene production flue gas purification device from another perspective is provided.

[0026] In the figure: gas transition box 1, spray frame 2, blowing pipe 3, first motor 4, connecting frame 5, outer cover 6, inner cylinder 7, mesh plate 8, round hole 9, conveying pipe 10, processing box 11, mesh frame 12, groove 13, second motor 14, connecting shaft 15, slot hole 16, transmission tooth 17, driving tooth 18, connecting box 19, yoke 20, baffle 21, limit block 22, guide rail 23, filter cartridge 24, pipe body 25, air inlet pipe 26. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0028] Embodiment 1, refer to Figures 1-6 A flue gas purification device for ethylene production, comprising a gas transition box 1, an air inlet pipe 26 and a spray frame 2, the gas transition box 1 is provided with a through-type reserved hole 27 on both sides, the inner side of the two reserved holes 27 is rotatably provided with a pipe body 25, and an inner cylinder 7 is fixed between the two pipe bodies 25, one of the pipe bodies 25 is connected with a driving member, and the driving member comprises a transmission tooth 17, a driving tooth 18 and a first motor 4; the transmission tooth 17 is fixed to the outer side of one of the pipe bodies 25, the output shaft of the first motor 4 is fixed with the driving tooth 18, and the transmission tooth 17 and the driving tooth 18 are in meshing relationship.

[0029] The inner side of the gas transition box 1 is fixed with the outer cover 6 through the connecting frame 5, and the inner cylinder 7 is rotatably arranged on the inner side of the outer cover 6, the outer cover 6 is provided with a notch at the middle position of the upper and lower ends, the inner side of the inner cylinder 7 is uniformly provided with a plurality of mesh plates 8, a round hole 9 is formed at the center of the mesh plate 8, and catalyst particles are arranged between the adjacent two mesh plates 8 for catalyzing the flue gas.

[0030] The outer side of the inner cylinder 7 is annularly arranged with a plurality of slot holes 16, and the spray frame 2 sprays reagents for cleaning tar.

[0031] The flue gas from which the ammonia is removed passes through the inner side of the inner cylinder 7, is segmented by the plurality of mesh plates 8 on the inner side of the inner cylinder 7, and the catalyst particles are located on the inner side of the adjacent two mesh plates 8 and fully contact the flue gas when the flue gas passes through, but in this process, tar is entrained in the tail gas during ethylene production, and the tar adheres to the surface of the catalyst, causing the activity of the catalyst to decrease.

[0032] To this end, the spray frame 2 is arranged at the upper position of the inner cylinder 7, which sprays the reagent for removing tar, the outer cover 6 is fixed outside the inner cylinder 7, the two ends of the outer cover 6 are fixed on the inner side of the upper part of the gas transition box 1 through the connecting frame 5, a plurality of slot holes 16 are uniformly arranged on the outer side of the inner cylinder 7, and the upper and lower ends of the outer cover 6 are both provided with notches. The sprayed reagent enters the notches and the slot holes 16, enters the inside of the inner cylinder 7 and contacts the catalyst, and after the contact, the reagent overflows from the lower end notch, completing the treatment of the tar adhering to the surface of the catalyst. In order to better make the tar fall off, the pipe body 25 at both ends of the inner cylinder 7 is rotatably arranged in the reserved hole 27, and a limiting piece is arranged in the reserved hole 27 to limit the position of the inner cylinder 7, preventing the inner cylinder 7 from deviating. Through the cooperation between the first motor 4, the transmission teeth 17 and the driving teeth 18, the inner cylinder 7 is driven to rotate, and when the inner cylinder 7 rotates, the catalyst particles in the inner cylinder 7 can tumble, which helps to separate the tar by the friction between the particles. Secondly, the catalyst particles can fully contact the falling reagent during the tumbling process, and the mesh plate 8 can prevent the catalyst particles from gathering in a certain area.

[0033] Example 2, reference Figure 7 The difference between this embodiment and example 1 is that the bottom of the outer cover 6 is fixedly provided with a processing box 11 with an open upper end, the processing box 11 matches the position of the notch at the lower end of the outer cover 6, one of the pipe bodies 25 is in communication with the inner side of the processing box 11 through the conveying pipe 10, the conveying pipe 10 on the inner side of the processing box 11 is provided with air holes, the inner side of the processing box 11 is fixedly provided with a mesh frame 12, and the mesh frame 12 is in an arched shape. The lower end of the processing box 11 is provided with a groove 13.

[0034] Since the sulfur dioxide in the flue gas is oxidized into sulfur trioxide and combined with ammonia to form ammonium sulfate, which blocks the active sites on the surface of the catalyst and destroys the pore structure of the catalyst, it is necessary to treat the ammonia at the source.

[0035] Therefore, the flue gas passes through the fixed filter cylinder 24 from the gas inlet pipe 26, the inside of the filter cylinder 24 is filled with activated carbon particles impregnated with phosphoric acid, and the ammonia in the flue gas is adsorbed by the treated activated carbon particles, and the removal rate can reach 98%.

[0036] And a period of time later, the adsorption sites of activated carbon particles will decrease the adsorption efficiency of ammonia gas. Without opening the box, the slot second motor 14 drives the connecting shaft 15 to rotate the filter cartridge 24 that was previously clamped by the two shift forks 20 on the same side. The filter cartridge 24 above will naturally fall between the end of the pipe body 25 and the air inlet pipe 26. The newly clamped filter cartridge 24 is clamped by the two shift forks 20 after adjusting the position. The guide rail 23 on the baffle 21 on both sides of the filter cartridge 24 cooperates with the limiting block 22 on the side of the filter cartridge 24 to facilitate the stable movement of the filter cartridge 24 to the position between the end of the pipe body 25 and the end of the air inlet pipe 26.

[0037] Embodiment 3, refer to Figures 8-9 The difference between this embodiment and embodiments 1 and 2 is that the connecting box 19 is fixed on one side of the gas transition box 1, and one end of the air inlet pipe 26 extends to the inside of the connecting box 19. The filter cartridge 24 is movably arranged between the end of the pipe body 25 and the end of the air inlet pipe 26. The baffle 21 is parallelly installed in the connecting box 19 on both sides of the filter cartridge 24. A plurality of filter cartridges 24 are linearly arranged between the two baffles 21 and are fixed by the adjusting assembly. When the filter cartridge 24 is fixed, the ends of the filter cartridge 24 are respectively attached to the end of the pipe body 25 and the end of the air inlet pipe 26.

[0038] The adjusting assembly includes the second motor 14, the connecting shaft 15, and the shift fork 20. The connecting shaft 15 is connected to the output shaft of the second motor 14. A plurality of shift forks 20 are uniformly fixed to the end of the connecting shaft 15. When the filter cartridge 24 is fixed, the two shift forks 20 on the same side clamp the outside of the filter cartridge 24. The opposite side of the baffle 21 is provided with the guide rail 23. The limiting block 22 is fixed to the outside of the filter cartridge 24. One end of the limiting block 22 is slidably arranged in the inside of the guide rail 23.

[0039] Gas holes are provided at both ends of the filter cartridge 24. Activated carbon particles impregnated with phosphoric acid are filled in the inside of the filter cartridge 24.

[0040] When the catalyst particles are tumbled, the friction between the catalyst particles will generate powder. The sprayed reagent can also play a role in carrying out the powder generated by friction from the gap at the lower end of the outer cover 6 into the inside of the treatment box 11. The arched net rack 12 is arranged at the upper end of the inside of the treatment box 11. The solid-liquid separation is realized by the net rack 12.

[0041] A conveying pipe 10 is introduced on the pipe body 25 at the tail of the equipment. Part of the treated gas is introduced into the inside of the treatment box 11 by the pump body. The conveyed gas is beneficial to dry and solidify the powder on the upper net rack 12, preventing the problem of powder transfer caused by excessive accumulation. The separated reagent is discharged through the pipeline.

[0042] Embodiment 4, refer toFigure 5 The difference between the embodiment and the embodiments 1, 2 and 3 is that the blowing pipe 3 is arranged between the plurality of round holes 9, the other end of the blowing pipe 3 is connected with the pump body, and the gas blown by the blowing pipe 3 is heated nitrogen.

[0043] The blowing pipe 3 is arranged outside and penetrates the plurality of round holes 9, and the heated nitrogen is blown into the inner side region of the inner cylinder 7 through the blowing pipe 9, which can blow off the physical impurities on the surface of the catalyst, such as the powder generated by friction, and secondly, isolate oxygen and reduce the density of oxygen, so that the catalyst avoids the problems of sintering and the combination of sulfur dioxide and oxygen, and inhibits the generation of ammonium sulfate to a certain extent.

[0044] The working principle of the device is as follows: Since the sulfur dioxide in the flue gas is oxidized into sulfur trioxide and combined with ammonia to generate ammonium sulfate, the ammonium sulfate blocks the active sites on the surface of the catalyst and destroys the pore structure of the catalyst, so it is necessary to treat the ammonia at the source.

[0045] Therefore, the flue gas passes through the fixed filter cartridge 24, the inside of the filter cartridge 24 is filled with activated carbon particles impregnated with phosphoric acid, and the ammonia in the flue gas is adsorbed by the treated activated carbon particles, and the removal rate can reach 98%.

[0046] After a period of time, the adsorption efficiency of the activated carbon particles to ammonia will decrease, and under the premise of not opening the box, the slot second motor 14 drives the connecting shaft 15 to rotate the filter cartridge 24 originally clamped by the two shift forks 20 on the same side, which will naturally fall off, and the filter cartridge 24 adjacent above will be located between the pipe body 25 and the end of the air inlet pipe 26, and the new filter cartridge 24 is clamped by the two shift forks 20 after adjusting the position, and the guide rail 23 on the baffle 21 on both sides of the filter cartridge 24 cooperates with the limiting block 22 on the side of the filter cartridge 24, so that the filter cartridge 24 can be stably moved to the position between the pipe body 25 and the end of the air inlet pipe 26.

[0047] The flue gas after removing ammonia passes through the inside of the inner cylinder 7, and is divided by a plurality of mesh plates 8, and the catalyst particles are located inside the adjacent two mesh plates 8 and fully contact with the flue gas when the flue gas passes through, but in this process, tar is entrained in the tail gas during ethylene production, which adheres to the surface of the catalyst, causing the activity of the catalyst to decrease.

[0048] To this end, the upper position of the inner cylinder 7 is provided with a spray frame 2, which sprays the reagent for removing tar, and the outer cover 6 is fixed outside the inner cylinder 7, the two ends of the outer cover 6 are fixed on the inner side of the upper part of the gas transition box 1 through the connecting frame 5, and a plurality of slot holes 16 are uniformly arranged on the outer side of the inner cylinder 7, and the upper and lower ends of the outer cover 6 are also provided with notches, the sprayed reagent enters the notches and the slot holes 16 into the inner cylinder 7 and contacts the catalyst, after the contact, the reagent overflows from the lower end of the notch, and the treatment of the tar adhered to the surface of the catalyst is completed, in order to better make the tar fall off, the pipe body 25 at both ends of the inner cylinder 7 is rotatably arranged in the reserved hole 27, the reserved hole 27 is provided with a limiting piece corresponding to the position of the inner cylinder 7, which prevents the inner cylinder 7 from deviating, and through the cooperation between the first motor 4, the transmission teeth 17 and the driving teeth 18, the inner cylinder 7 is driven to rotate, when the inner cylinder 7 rotates, the catalyst particles in the inner cylinder 7 can tumble, which helps to separate the tar by the friction between the particles, and secondly, the catalyst particles can fully contact the falling reagent during the tumbling process, and the mesh plate 8 can prevent the catalyst particles from gathering in a certain area.

[0049] When the catalyst particles tumble, the friction between the catalyst particles will generate powder, and the sprayed reagent can also play a role in carrying out the powder generated by friction from the lower end of the notch of the outer cover 6 into the inside of the treatment box 11, and an arched net rack 12 is arranged at the upper end of the treatment box 11, which realizes the separation of solid and liquid.

[0050] A conveying pipe 10 is arranged on the pipe body 25 at the tail of the device, and part of the treated gas is introduced into the inside of the treatment box 11 through the pump body, the conveyed gas is beneficial to dry and solidify the powder on the upper net rack 12, preventing the problem of powder transfer caused by excessive accumulation, and the separated reagent is discharged through the pipeline.

[0051] A blowing pipe 3 is arranged outside and penetrates through a plurality of round holes 9, and heated nitrogen is blown into the inside of the inner cylinder 7 through the blowing pipe 9, which can blow off the physical impurities on the surface of the catalyst, such as the powder generated by friction, secondly, it can isolate oxygen and reduce the density of oxygen, so that the catalyst can avoid the problem of sintering and the problem of combination of sulfur dioxide and oxygen, and can inhibit the generation of ammonium sulfate to a certain extent.

[0052] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A flue gas purification device for ethylene production, comprising a gas transition box (1), an air inlet pipe (26) and a spray rack (2), characterized in that : Both sides of the gas transition box (1) are provided with through-type reserved holes (27), and the inner sides of the two reserved holes (27) are both rotatably provided with tube bodies (25), and an inner cylinder (7) is fixed between the two tube bodies (25), and one of the tube bodies (25) is connected to the driving member. The upper end of the inner side of the gas transition box (1) is fixed with an outer cover (6) through a connecting frame (5), and the inner cylinder (7) is rotatably provided on the inner side of the outer cover (6), and a notch is provided at the middle position of the upper and lower ends of the outer cover (6). A plurality of mesh plates (8) are evenly installed on the inner side of the inner cylinder (7), and a circular hole (9) is provided at the center of the mesh plates (8). Catalyst particles are provided between two adjacent mesh plates (8) for catalyzing the flue gas; The outer side of the inner cylinder (7) is provided with a plurality of slots (16) in a circular array, and the spray rack (2) sprays out a reagent for cleaning tar.

2. The flue gas purification device for ethylene production according to claim 1, characterized in that: A processing box (11) with an opening at the upper end is fixedly mounted on the bottom of the outer cover (6). The processing box (11) matches the position of the notch at the lower end of the outer cover (6). A delivery pipe (10) is connected between one of the tube bodies (25) and the inner side of the processing box (11). An air hole is provided on the delivery pipe (10) located on the inner side of the processing box (11).

3. The flue gas purification device for ethylene production according to claim 2, characterized in that: A grid frame (12) is fixedly mounted on the inner upper end of the processing box (11), and the grid frame (12) is arranged in an arch shape. A groove (13) is provided in the middle of the lower end of the processing box (11).

4. The flue gas purification device for ethylene production according to claim 1, characterized in that: The driving member comprises a transmission tooth (17), a driving tooth (18) and a first motor (4); The transmission teeth (17) are fixed on the outside of one of the tube bodies (25), and a driving tooth (18) is fixed to the end of the output shaft of the first motor (4), and the transmission teeth (17) and the driving teeth (18) are meshed with each other.

5. The flue gas purification device for ethylene production according to claim 1, characterized in that: A connecting box (19) is fixed on one side of the gas transition box (1), and one end of the air inlet pipe (26) extends to the inner side of the connecting box (19). A filter cartridge (24) is movably arranged between the end of the tube body (25) and the end of the air inlet pipe (26). Baffles (21) are installed in parallel in the connecting box (19) on both sides of the filter cartridge (24). A plurality of filter cartridges (24) are distributed in a linear array between the two baffles (21) and are fixed by a regulating assembly. When the filter cartridge (24) is fixed, the ends of the filter cartridge (24) are respectively fitted with the ends of the tube body (25) and the end of the air inlet pipe (26).

6. The flue gas purification device for ethylene production according to claim 5, characterized in that: The regulating assembly includes a second motor (14), a connecting shaft (15), and a shift fork (20); The connecting shaft (15) is connected to the end of the output shaft of the second motor (14), and a plurality of shift forks (20) are evenly fixed at the end positions of the connecting shaft (15). When the filter cartridge (24) is fixed, the two shift forks (20) on the same side clamp the outer side of the filter cartridge (24).

7. The flue gas purification device for ethylene production according to claim 6, characterized in that: A guide rail (23) is provided on the opposite side of the baffle (21), and a limit block (22) is fixed on the outside of the filter cartridge (24), with one end of the limit block (22) being slidably disposed on the inside of the guide rail (23).

8. The flue gas purification device for ethylene production according to claim 7, characterized in that: Both ends of the filter cartridge (24) are provided with air holes for gas to pass through, and activated carbon particles impregnated with phosphoric acid are filled inside the filter cartridge (24).

9. The flue gas purification device for ethylene production according to claim 1, characterized in that: An air blowing pipe (3) is inserted between the plurality of circular holes (9), and the other end of the air blowing pipe (3) is connected to the pump body.

10. The flue gas purification device for ethylene production according to claim 9, characterized in that: The gas blown out of the blowing pipe (3) is heated nitrogen.

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