Degassing tower for preparing nitrile rubber

Abstract

The degassing tower comprises a tower body, the tower kettle of the tower body is communicated with a steam tank, the top of the tower body is communicated with a condenser, the part, close to the top, of the tower body is communicated with an input unit, a column-shaped tower plate unit is arranged in the tower body, the tower plate unit adapts to the inner wall of the tower body, and the tower plate unit is located between the input unit and the steam tank; a gas distributor is arranged in the tower body and located between the steam tank and the tower plate unit, the inner wall of a tower kettle of the tower body is connected with a fan-shaped water collecting box, the water collecting box is arranged far away from the steam tower, and the water collecting box is communicated with the gas distributor through an overflow pipe; and a defoaming unit is arranged at the top in the tower body, so that the problems that the strip-shaped hole of the tower plate of the degassing tower is blocked due to rubber hanging and the tower plate is seriously hardened at the tower kettle in the prior art are solved.

Description

Technical Field

[0001] This invention belongs to the technical field of rubber processing equipment, and relates to a degassing tower for preparing nitrile rubber. Background Technology

[0002] Degassing towers used in the preparation of nitrile rubber typically employ sieve tray towers as a key component. However, as the plant operates for longer periods, a series of problems arise during production. For example, in the degassing tower, the free acrylonitrile content in the degassed latex gradually increases, leading to the tower bottom consuming a large amount of heating steam, causing severe blockage of the sieve holes in the trays, and severe coking on the trays near the bottom.

[0003] Coking on tray sieves is a major challenge in degassing towers. It reduces the actual open area ratio, hindering the flow of liquid and gas phases within the tower and preventing efficient fluid passage through the trays, thus affecting mass transfer efficiency. Furthermore, it exacerbates liquid buildup and dead zones. Due to the reduced open area ratio, the pressure drop in the tower increases, requiring an increased steam supply to the reboiler to maintain normal operation, leading to increased energy consumption. Simultaneously, coking becomes more pronounced near the reboiler, with severe coking occurring on the tray surface.

[0004] In industrial production, the trays of degassing towers need to be cleaned regularly to ensure the normal operation of the equipment. Due to issues such as glue buildup and coking on the screens, cleaning the trays becomes even more tedious and difficult. Typically, cleaning is required monthly. This work usually involves high intensity and harsh working conditions, placing a significant burden on the operators. Summary of the Invention

[0005] The purpose of this invention is to provide a degassing tower for the preparation of nitrile rubber, which solves the problems of easy clogging of the strip holes of the degassing tower trays and severe coking of the trays at the bottom of the tower in the prior art.

[0006] The technical means adopted in this invention is a degassing tower for preparing nitrile rubber, comprising a tower body, a steam tank connected to the bottom of the tower body, a condenser connected to the top of the tower body, an input unit connected near the top of the tower body, a columnar tray unit provided inside the tower body, the tray unit being adapted to the inner wall of the tower body, and the tray unit being located between the input unit and the steam tank; a gas distributor provided inside the tower body, the gas distributor being located between the steam tank and the tray unit; a fan-shaped water collection box connected to the inner wall of the bottom of the tower body, the water collection box being located away from the steam tower, and the water collection box being connected to the gas distributor through an overflow pipe; and a defoaming unit provided at the top of the tower body.

[0007] The invention is further characterized by:

[0008] The input unit includes an undeaerated latex tank, a demineralized water tank, and a defoamer tank.

[0009] The tray unit includes trays located away from the gas distributor. Both ends of the trays are vertically connected to overflow weirs. A second downcomer connects every two adjacent trays, and every two adjacent second downcomers are staggered. The unit also includes laminar flow plates, both ends of which are vertically connected to overflow weirs. The trays and laminar flow plates are arranged alternately. A first downcomer is provided between the laminar flow plates and the trays, and the second downcomers are staggered from the first downcomers.

[0010] There shall be no fewer than three laminar flow plates and no fewer than nine trays.

[0011] The tower plate has non-uniformly distributed strip-shaped holes, and the laminar flow plate has inverted conical holes. The diameter of the conical holes near the water collection box is smaller than the diameter of the conical holes near the defoaming unit.

[0012] The gas distributor includes a circular connecting plate that is adapted to the inner wall of the tower. Several vent holes are evenly opened on the connecting plate. The connecting plate is connected to a distribution pipe through the vent holes. The end of the distribution pipe away from the connecting plate is connected to a circular top cover plate through a connecting rod. The top cover plate is connected to an annular expansion plate. The expansion plate is set at an angle of 90 to 180 degrees with the top cover plate. The top cover plate is set close to the distribution pipe.

[0013] The side wall of the overflow pipe is connected to the connecting plate, and the top cover plate is at least 100mm away from the end of the overflow pipe away from the water collection box.

[0014] The defoaming unit includes two L-shaped foam traps, one end of which is connected to the inner wall of the tower. The foam traps are set at an angle of 40 to 50 degrees to the inner wall of the tower. The other ends of the two foam traps form a rectangular space. The unit also includes a first nozzle and a second nozzle. Both the first nozzle and the second nozzle penetrate the side wall of the tower and are connected to the defoamer tank. The first nozzle is located between the top of the tower and the foam trap, facing the rectangular space. The second nozzle is located between the foam trap and the tower plate unit and faces the tower plate unit.

[0015] The beneficial effects of this invention are as follows: the gas distributor reduces excessive flow and voids, stabilizes flow rate, improves degassing efficiency and quality, and effectively prevents coking of the latex; the laminar flow plate combined with the conical hole structure optimizes the contact between gas and high-viscosity latex, improves mass transfer efficiency and operational stability, effectively distributes the liquid phase, and solves the problem of uneven liquid accumulation; the holes on the tray are irregular strip-shaped holes, ensuring smooth gas flow and the latex falling into the un-holeed area, maintaining smooth operation; the foam breaker is achieved by combining a foam eliminator plate with a first nozzle and a second nozzle. The two foam eliminators form a rectangular area, and the bubbles can be broken after passing through the rectangular area. The defoamer sprayed by the first and second nozzles can effectively control the foam generated by the emulsion polymer. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the degassing tower used in the preparation of nitrile rubber according to the present invention;

[0017] Figure 2 This is a schematic diagram of the input unit in the degassing tower used in the preparation of nitrile rubber according to the present invention;

[0018] Figure 3 This is a schematic diagram of the structure of the tray unit in the degassing tower used in the preparation of nitrile rubber according to the present invention;

[0019] Figure 4 This is a schematic diagram of the structure of the tray in the degassing tower used in the preparation of nitrile rubber according to the present invention;

[0020] Figure 5 This is a schematic diagram of the structure of the laminar flow plate in the degassing tower used in the preparation of nitrile rubber according to the present invention;

[0021] Figure 6 This is a schematic diagram of the gas distributor in the degassing tower used in the preparation of nitrile rubber according to the present invention;

[0022] Figure 7 This is a schematic diagram of the defoaming unit in the degassing tower used in the preparation of nitrile rubber according to the present invention.

[0023] In the diagram, 1. Tower body, 2. Steam tank, 3. Condenser, 4. Input unit, 401. Undegassed latex tank, 402. Demineralized water tank, 403. Defoamer tank, 5. Tray unit, 501. First downcomer, 502. Tray, 503. Overflow weir, 504. Laminar flow plate, 505. Second downcomer, 506. Conical orifice, 507. Strip orifice, 6. Gas distributor, 601. Connecting plate, 602. Vent hole, 603. Distribution pipe, 604. Connecting rod, 605. Top cover plate, 606. Outer expansion plate, 7. Water collection box, 8. Overflow pipe, 9. Defoaming unit, 901. Foam eliminator plate, 902. First nozzle, 903. Second nozzle. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] This invention relates to a degassing tower for preparing nitrile rubber, such as... Figure 1 As shown, the tower includes a tower body 1, a steam tank 2 connected to the bottom of the tower body 1, a condenser 3 connected to the top of the tower body 1, an input unit 4 connected near the top of the tower body 1, a columnar tray unit 5 inside the tower body 1, the tray unit 5 being adapted to the inner wall of the tower body 1, and the tray unit 5 being located between the input unit 4 and the steam tank 2; a gas distributor 6 inside the tower body 1, the gas distributor 6 being located between the steam tank 2 and the tray unit 5, a fan-shaped water collection box 7 connected to the inner wall of the bottom of the tower body 1, the water collection box 7 being located away from the steam tank 2, and the water collection box 7 being connected to the gas distributor 6 through an overflow pipe 8; and a defoaming unit 9 being located at the top of the tower body 1.

[0026] like Figure 2 As shown, input unit 4 includes an undegassed latex tank 401, a demineralized water tank 402, and a defoamer tank 403.

[0027] like Figure 3 As shown, the tray unit 5 includes a tray 502 located away from the gas distributor 6. Both ends of the tray 502 are provided with vertically connected overflow weirs 503. A second downcomer 505 is connected between every two adjacent trays 502, and every two adjacent second downcomers 505 are staggered. It also includes a laminar flow plate 504, both ends of which are vertically connected to the overflow weirs 503. The trays 502 and laminar flow plates 504 are arranged alternately. A first downcomer 501 is provided between the laminar flow plate 504 and the tray 502. The second downcomers 505 are staggered from the first downcomers 501.

[0028] There shall be no fewer than three laminar flow plates (504) and no fewer than nine trays (502).

[0029] The tray 502 has non-uniformly distributed strip-shaped holes 507, such as... Figure 4 As shown; the laminar flow plate 504 has an inverted conical hole 506, the diameter of the conical hole 506 near the water collection box 7 is smaller than the diameter of the conical hole 506 near the defoaming unit 9, as shown. Figure 5 As shown.

[0030] like Figure 6 As shown, the gas distributor 6 includes a circular connecting plate 601, which is adapted to the inner wall of the tower body 1. A plurality of vent holes 602 are evenly opened on the connecting plate 601. The connecting plate 601 is connected to a distribution pipe 603 through the vent holes 602. The end of the distribution pipe 603 away from the connecting plate 601 is connected to a circular top cover plate 605 through a connecting rod 604. The top cover plate 605 is connected to an annular expansion plate 606. The expansion plate 606 and the top cover plate 605 are set at an angle of 90 to 180 degrees. The top cover plate 605 is set close to the distribution pipe 603.

[0031] The side wall of the overflow pipe 8 is connected to the connecting plate 601, and the top cover plate 605 is not less than 100mm away from the end of the overflow pipe 8 away from the water collection box 7.

[0032] like Figure 7As shown, the defoaming unit 9 includes two L-shaped foam traps 901. One end of each foam trap 901 is connected to the inner wall of the tower body 1, and the foam traps 901 are set at an angle of 40 to 50 degrees to the inner wall of the tower body 1. The other ends of the two foam traps 901 form a rectangular space. It also includes a first nozzle 902 and a second nozzle 903. Both the first nozzle 902 and the second nozzle 903 penetrate the side wall of the tower body 1 and are connected to a defoamer tank 403. The first nozzle 902 is located between the top of the tower body 1 and the foam trap 901 and faces the rectangular space. The second nozzle 903 is located between the foam trap 901 and the tower plate unit 5 and faces the tower plate unit 5.

[0033] The laminar flow plate 504 is located at the top, middle, and bottom of the tower body 1. The small-diameter portion of the conical hole 506 on the laminar flow plate 504 is positioned close to the bottom of the tower body 1. The laminar flow plate 504 redistributes the steam from bottom to top, making it evenly distributed and improving the mass and heat transfer effect. The inverted conical hole 506 allows the gas to be evenly sprayed into the surrounding high-viscosity latex, ensuring the uniform distribution of gas on the laminar flow plate. This optimizes the contact effect between the gas and the latex, improves the mass transfer efficiency and operational stability. The irregular strip-shaped holes 507 of the tower plate 502 reduce the amount of latex adhering to the tower plate 502.

[0034] The laminar flow plate 504 is not only a gas diffuser, but it also rationally distributes the liquid phase. During operation, the liquid phase can be effectively distributed through the structure of the laminar flow plate 504, avoiding uneven accumulation and uncontrolled flow of liquid within the tower body 1, thus ensuring the efficiency and quality stability of the degassing process. This gas diffusion structure design of the tower plate 502 and the conical orifice 506 combines advanced gas distribution technology and effective liquid phase management, making it suitable for handling the complex process requirements of high-viscosity latex.

[0035] The 507 slotted perforations ensure smooth gas flow, and the entrained adhesive effectively settles in the unperforated areas of the tray, maintaining flow path unobstructedness and operational stability. This irregular design effectively prevents adhesive from clogging the sieve holes, thereby improving the operating efficiency and degassing effect of the degassing tower. Selecting appropriate materials is crucial for solving the adhesive buildup problem. By increasing the polishing precision of the stainless steel trays, adhesive accumulation on the surface of the 507 slotted perforations can be effectively reduced, thus lowering the incidence of adhesive buildup on tray 502. Optimizing the polishing process not only improves the surface quality of the 507 slotted perforations but also enhances the material's corrosion resistance and cleanability, extending equipment lifespan and reducing maintenance costs.

[0036] The function of the foam trap 901 is to allow the gas phase containing foam to pass through its narrow gaps, thereby compressing and breaking down larger foam particles into smaller ones. Subsequently, the gas phase passes through the area of ​​the first nozzle 902, which is connected to the defoamer canister 403, effectively breaking down and dispersing most of the remaining foam. Finally, the gas phase, after foam breaking treatment, can smoothly exit the top of the degassing tower.

[0037] The foam trap 901 is designed with two pieces, one large and one small, which are arranged at an angle inside the tower body 1. This arrangement not only facilitates the natural flow of the liquid phase back into the tower by gravity, reducing liquid phase loss, but also improves the foam separation effect. The foam trap 901 is equipped with a second nozzle 903 near the tower plate 502. The second nozzle 903 first performs large-area defoaming on all the bubbles that rise to the top of the tower body 1.

[0038] The main function of the gas distributor 6 is to evenly distribute steam from the inlet into the interior of the tower body 1, effectively reducing local excessive flow and void phenomena, and optimizing the gas-liquid contact effect. After entering the tower body 1, the steam flows towards the top of the tower body 1 due to gravity. The gas is discharged after passing through the vent 602 opened in the connecting plate 601. The discharged steam is discharged from the gap between the top cover plate 605 and the distribution pipe 603, ensuring a stable flow rate and uniform distribution of steam, thereby improving the operating efficiency and quality stability of the entire degassing process. The distributor 6 is also equipped with a dedicated overflow pipe 8, which is connected to the water collection box 7 to control the flow of the liquid phase. This effectively prevents the glue from coking in the tower plate and steam contact area near the tower bottom.

[0039] The outer expansion plate 606 and the top cover plate 605 are umbrella-shaped. When steam rises, it emerges from under the outer expansion plate 606. When the undegassed latex falls, it will not enter the distribution pipe 603 due to the obstruction of the outer expansion plate 606. The undegassed latex flows into the overflow pipe 8 and then into the water collection box 7. When the water collection box 7 is full, the liquid flows into the tower bottom along the water collection box 7. The water collection box 7 plays a buffering role.

[0040] The work process is as follows:

[0041] When the input unit 4 and steam tank 2 are opened, steam, undegassed latex, demineralized water, and defoamer simultaneously enter the tower body 1. The steam rises and passes through the gas distributor 6, then through the tray unit 5 and the defoaming unit 9 to the top of the tower body 1. At the same time, the undegassed latex flows from the top of the tray unit 5 to the bottom of the tower body 1, combines with the rising steam, and finally flows into the bottom of the tower body 1 through the water collection box 7.

[0042] Example 1

[0043] A degassing tower for preparing nitrile rubber includes a tower body 1, a steam tank 2 connected to the bottom of the tower body 1, a condenser 3 connected to the top of the tower body 1, an input unit 4 connected near the top of the tower body 1, a columnar tray unit 5 inside the tower body 1 adapted to the inner wall of the tower body 1, and the tray unit 5 located between the input unit 4 and the steam tank 2; a gas distributor 6 inside the tower body 1, located between the steam tank 2 and the tray unit 5; a fan-shaped water collection box 7 connected to the inner wall of the bottom of the tower body 1, the water collection box 7 being located away from the steam tank 2, and the water collection box 7 being connected to the gas distributor 6 through an overflow pipe 8; and a defoaming unit 9 at the top of the tower body 1.

[0044] The tray unit 5 consists of tray 502 and 28 Φ159×4mm distribution pipes 603. Its main function is to distribute steam evenly from the inlet to the surface of tray 502. The height of each distribution pipe 603 is 150mm.

[0045] Example 2

[0046] A degassing tower for preparing nitrile rubber includes a tower body 1, a steam tank 2 connected to the bottom of the tower body 1, a condenser 3 connected to the top of the tower body 1, an input unit 4 connected near the top of the tower body 1, a columnar tray unit 5 inside the tower body 1 adapted to the inner wall of the tower body 1, and the tray unit 5 located between the input unit 4 and the steam tank 2; a gas distributor 6 inside the tower body 1, located between the steam tank 2 and the tray unit 5; a fan-shaped water collection box 7 connected to the inner wall of the bottom of the tower body 1, the water collection box 7 being located away from the steam tank 2, and the water collection box 7 being connected to the gas distributor 6 through an overflow pipe 8; and a defoaming unit 9 at the top of the tower body 1.

[0047] Input unit 4 includes an undeaerated latex tank 401, a demineralized water tank 402, and a defoamer tank 403.

[0048] The tray unit 5 includes a tray 502 located away from the gas distributor 6. Both ends of the tray 502 are vertically connected to overflow weirs 503. A second downcomer 505 connects every two adjacent trays 502, with each pair of adjacent second downcomers 505 staggered. It also includes a laminar flow plate 504, both ends of which are vertically connected to the overflow weirs 503. The trays 502 and laminar flow plates 504 are alternately arranged. A first downcomer 501 connects the laminar flow plate 504 to the tray 502, and the second downcomers 505 are staggered from the first downcomer 501. There are at least three laminar flow plates 504 and at least nine trays 502. The tray 502 has non-uniformly distributed strip-shaped holes 507; the laminar flow plate 504 has inverted conical holes 506, with the diameter of the conical holes 506 near the water collection box 7 being smaller than the diameter of the conical holes 506 near the defoaming unit 9.

[0049] The tray 502 consists of 28 distribution pipes 603 with a diameter of 159×4mm. Its main function is that each distribution pipe 603 is 150mm high, the overflow pipe 8 is 1550mm high, the laminar flow plate 504 is 5mm thick, and the polishing precision requirement is Ra0.04. The conical holes 506 have a hole spacing of 39, with the upper part of the conical hole 14mm and the lower part 9mm. The tray 502 is 5mm thick, and the polishing precision requirement is Ra0.04. The elongated strip-shaped holes 507 have an opening width of 7mm.

[0050] Example 3

[0051] A degassing tower for preparing nitrile rubber includes a tower body 1, a steam tank 2 connected to the bottom of the tower body 1, a condenser 3 connected to the top of the tower body 1, an input unit 4 connected near the top of the tower body 1, a columnar tray unit 5 inside the tower body 1 adapted to the inner wall of the tower body 1, and the tray unit 5 located between the input unit 4 and the steam tank 2; a gas distributor 6 inside the tower body 1, located between the steam tank 2 and the tray unit 5; a fan-shaped water collection box 7 connected to the inner wall of the bottom of the tower body 1, the water collection box 7 being located away from the steam tank 2, and the water collection box 7 being connected to the gas distributor 6 through an overflow pipe 8; and a defoaming unit 9 at the top of the tower body 1.

[0052] Input unit 4 includes an undeaerated latex tank 401, a demineralized water tank 402, and a defoamer tank 403.

[0053] The tray unit 5 includes a tray 502 located away from the gas distributor 6. Both ends of the tray 502 are vertically connected to overflow weirs 503. A second downcomer 505 connects every two adjacent trays 502, with each pair of adjacent second downcomers 505 staggered. It also includes a laminar flow plate 504, both ends of which are vertically connected to the overflow weirs 503. The trays 502 and laminar flow plates 504 are alternately arranged. A first downcomer 501 connects the laminar flow plate 504 to the tray 502, and the second downcomers 505 are staggered from the first downcomer 501. There are at least three laminar flow plates 504 and at least nine trays 502. The tray 502 has non-uniformly distributed strip-shaped holes 507; the laminar flow plate 504 has inverted conical holes 506, with the diameter of the conical holes 506 near the water collection box 7 being smaller than the diameter of the conical holes 506 near the defoaming unit 9.

[0054] The gas distributor 6 includes a circular connecting plate 601, which is adapted to the inner wall of the tower body 1. A plurality of vent holes 602 are evenly opened on the connecting plate 601. The connecting plate 601 is connected to a distribution pipe 603 through the vent holes 602. The end of the distribution pipe 603 away from the connecting plate 601 is connected to a circular top cover plate 605 through a connecting rod 604. The top cover plate 605 is connected to an annular expansion plate 606. The expansion plate 606 is set at an angle of 90 to 180° with the top cover plate 605. The top cover plate 605 is set close to the distribution pipe 603.

[0055] The side wall of the overflow pipe 8 is connected to the connecting plate 601, and the top cover plate 605 is 110mm away from the end of the overflow pipe 8 away from the water collection box 7.

[0056] The defoaming unit 9 includes two L-shaped foam traps 901. One end of each foam trap 901 is connected to the inner wall of the tower body 1. The foam traps 901 are set at an angle of 40 to 50 degrees to the inner wall of the tower body 1. The other ends of the two foam traps 901 form a rectangular space. It also includes a first nozzle 902 and a second nozzle 903. Both the first nozzle 902 and the second nozzle 903 penetrate the side wall of the tower body 1 and are connected to a defoamer tank 403. The first nozzle 902 is located between the top of the tower body 1 and the foam trap 901 and faces the rectangular space. The second nozzle 903 is located between the foam trap 901 and the tower plate unit 5 and faces the tower plate unit 5.

[0057] The foam trap 901 forms a 20° angle with the side wall of the tower body 1, and the two foam traps 901 are at a 45° angle.

[0058] This invention has been successfully applied in the 35,000-ton / year special nitrile rubber unit of Lanzhou Petrochemical. From the unit's start-up in March 2022 to July 2023, the degassing tower operated stably without any cleaning or rubber residue buildup. The acrylonitrile content in the degassed rubber solution was 298 ppm, and the unit's steam consumption was reduced by approximately 120 tons per year compared to similar units. While ensuring stable operation, energy conservation and clean production were achieved.

Claims

1. A degassing tower for preparing nitrile rubber, characterized in that, The tower includes a tower body (1), a steam tank (2) connected to the bottom of the tower body (1), a condenser (3) connected to the top of the tower body (1), an input unit (4) connected to the top of the tower body (1), a columnar tray unit (5) provided inside the tower body (1), the tray unit (5) being adapted to the inner wall of the tower body (1), and the tray unit (5) being located between the input unit (4) and the steam tank (2); a gas distributor (6) provided inside the tower body (1), the gas distributor (6) being located between the steam tank (2) and the tray unit (5); a fan-shaped water collection box (7) connected to the inner wall of the bottom of the tower body (1), the water collection box (7) being located away from the steam tank (2), and the water collection box (7) being connected to the gas distributor (6) through an overflow pipe (8); and a defoaming unit (9) provided at the top of the tower body (1).

2. The degassing tower for preparing nitrile rubber according to claim 1, characterized in that, The input unit (4) includes an undegassed latex tank (401), a demineralized water tank (402), and a defoamer tank (403).

3. The degassing tower for preparing nitrile rubber according to claim 1, characterized in that, The tray unit (5) includes a tray (502) away from the gas distributor (6), both ends of the tray (502) are provided with vertically connected overflow weirs (503), and a second downcomer (505) is connected between every two adjacent trays (502), and every two adjacent second downcomers (505) are staggered; it also includes a laminar flow plate (504), both ends of the laminar flow plate (504) are vertically connected to the overflow weirs (503), the trays (502) and laminar flow plates (504) are arranged alternately, a first downcomer (501) is provided between the laminar flow plate (504) and the tray (502), and the second downcomer (505) is staggered from the first downcomer (501).

4. The degassing tower for preparing nitrile rubber according to claim 3, characterized in that, There are no fewer than three laminar flow plates (504) and no fewer than nine tower plates (502).

5. The degassing tower for preparing nitrile rubber according to claim 4, characterized in that, The tower plate (502) has non-uniformly distributed strip holes (507), and the laminar flow plate (504) has inverted conical holes (506). The diameter of the conical hole (506) near the water collection box (7) is smaller than the diameter of the conical hole (506) near the defoaming unit (9).

6. The degassing tower for preparing nitrile rubber according to claim 1, characterized in that, The gas distributor (6) includes a circular connecting plate (601), which is adapted to the inner wall of the tower body (1). A plurality of ventilation holes (602) are evenly opened on the connecting plate (601). The connecting plate (601) is connected to a distribution pipe (603) through the ventilation holes (602). The end of the distribution pipe (603) away from the connecting plate (601) is connected to a circular top cover plate (605) through a connecting rod (604). The top cover plate (605) is connected to an annular expansion plate (606). The expansion plate (606) and the top cover plate (605) are set at an angle of 90 to 180 degrees. The top cover plate (605) is set close to the distribution pipe (603).

7. The degassing tower for preparing nitrile rubber according to claim 6, characterized in that, The side wall of the overflow pipe (8) is connected to the connecting plate (601), and the top cover plate (605) is not less than 100mm away from the end of the overflow pipe (8) away from the water collection box (7).

8. The degassing tower for preparing nitrile rubber according to claim 2, characterized in that, The defoaming unit (9) includes two L-shaped foam traps (901), one end of which is connected to the inner wall of the tower body (1). The foam traps (901) are set at an angle of 40-50° to the inner wall of the tower body (1). The other ends of the two foam traps (901) form a rectangular space. The unit also includes a first nozzle (902) and a second nozzle (903). The first nozzle (902) and the second nozzle (903) both penetrate the side wall of the tower body (1) and are connected to a defoamer tank (403). The first nozzle (902) is located between the top of the tower body (1) and the foam trap (901) and faces the rectangular space. The second nozzle (903) is located between the foam trap (901) and the tower plate unit (5) and faces the tower plate unit (5).

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