Afosetyl-aluminum reactive crystallization device

Abstract

The utility model belongs to the technical field of separation devices, and particularly relates to a fosetyl-aluminum reaction crystallization device which comprises a double decomposition reaction unit, the double decomposition reaction unit is sequentially connected with a cooling crystallization unit and a centrifugal separation unit and comprises a reaction tank, and the top end of the reaction tank is connected with a first metering tank and a second metering tank. The cooling crystallization unit comprises a cooling chamber, the top end of the cooling chamber is connected with an overflow pipeline, and one end, away from the cooling chamber, of the overflow pipeline is connected with a crystallization tower. The centrifugal separation unit comprises a centrifugal machine, the side wall of the centrifugal machine is connected with a double-effect evaporator, and the bottom end of the centrifugal machine is connected with a washing tank. A distilled water storage tank is arranged between the double-effect evaporator and the washing tank, the bottom end of the washing tank is connected with a negative pressure suction filter, and the bottom end of the negative pressure suction filter is connected with a mother liquor tank. According to the utility model, fosetyl-aluminum crystals can be more accurately separated out in the fosetyl-aluminum production process, the product purity is improved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of separation devices, and in particular relates to an ethylphosphine aluminum reaction crystallization device. Background Art

[0002] The reaction crystallization integrated kettle in the preparation process of ethyl phosphine aluminum is a special chemical equipment that combines the two processes of reaction and crystallization into one. It mainly achieves the goal of crystallization separation based on the characteristic that the solubility of ethyl phosphine aluminum, ammonium sulfate and ammonium phosphate at different temperatures is quite different. Inside the reaction crystallization integrated kettle, a chemical reaction will first occur to generate substances such as ethanol, ethyl phosphine aluminum and ammonium sulfate. After that, the reaction crystallization integrated kettle will be heated to 86°C to cause ethanol and part of the water to evaporate. Then, the reaction crystallization integrated kettle will be cooled to 70°C, which will cause ethyl phosphine aluminum to precipitate in the supersaturated solution.

[0003] However, compared with traditional separate equipment, the integrated reaction and crystallization reactor has higher costs and more complicated maintenance and repair work. At the same time, since the reaction and crystallization are carried out in the same equipment, it is difficult to control the quality of ethyl phosphine aluminum crystals. In certain specific concentration ranges, the solubility difference of different salts is not obvious, which can easily lead to the simultaneous crystallization of ethyl phosphine aluminum and impurities, thereby affecting the purity of ethyl phosphine aluminum products. Utility Model Content

[0004] The purpose of the utility model is to provide an ethyl phosphine aluminum reaction crystallization device, which can make ethyl phosphine aluminum crystals precipitate more accurately during the ethyl phosphine aluminum production process, improve the product purity, while increasing the yield of ethyl phosphine aluminum and reducing production costs.

[0005] To achieve the above purpose, the technical solution of the utility model is:

[0006] The aluminum phosphite reaction crystallization device comprises a double decomposition reaction unit, which is sequentially connected to a cooling crystallization unit and a centrifugal separation unit, and the double decomposition reaction unit comprises a reaction tank, which is equipped with a stirring shaft, a steam heating tube and a thermometer, and the top of the reaction tank is respectively connected to a metering tank 1 and a metering tank 2;

[0007] The cooling crystallization unit comprises a cooling chamber, the side wall of the cooling chamber is connected to the bottom of the reaction tank, the top of the cooling chamber is connected to an overflow pipe, the end of the overflow pipe away from the cooling chamber is connected to a crystallization tower, the side wall of the crystallization tower is connected to the bottom of the cooling chamber through a circulation pipe, and a circulation pump is arranged on the circulation pipe;

[0008] The centrifugal separation unit includes a centrifuge, the top of the centrifuge is connected to the bottom of the side wall of the crystallization tower away from the circulation pump, the side wall of the centrifuge is connected to a double-effect evaporator, the bottom of the centrifuge is connected to a washing tank, the top of the double-effect evaporator is connected to the top of the washing tank, a distilled water storage tank is arranged between the double-effect evaporator and the washing tank, the bottom of the washing tank is connected to a negative pressure filter, the bottom of the negative pressure filter is connected to a mother liquid tank, the side wall of the mother liquid tank is connected to the side wall of the cooling chamber, and a feeding pump is arranged between the mother liquid tank and the cooling chamber.

[0009] in:

[0010] The top of the reaction tank is provided with an air outlet pipe, and one end of the air outlet pipe away from the reaction tank is connected with a primary condenser and a secondary condenser in sequence.

[0011] The outlet pipe is provided with a vacuum pump 1, which is located between the reaction tank and the primary condenser. The top of the secondary condenser is connected with a tail gas treatment pipe, on which a vacuum pump 2 is provided.

[0012] The side wall of the primary condenser and the side wall of the secondary condenser are commonly connected with an ethanol storage tank, the top of the ethanol storage tank is connected with a tail gas treatment pipe, and the bottom of the ethanol storage tank is connected with a distillation treatment device.

[0013] The crystallization tower comprises a crystallization chamber, a reflux chamber is arranged outside the crystallization chamber, the bottom end of the crystallization chamber is connected to a sedimentation chamber, the reflux chamber is located above the sedimentation chamber, and the side wall of the reflux chamber is connected to a circulation pipeline.

[0014] The top of the crystallization chamber is higher than the top of the reflux chamber. An air guide tube is arranged at the top of the reflux chamber. One end of the air guide tube away from the reflux chamber is connected to the side wall of the crystallization chamber.

[0015] An exhaust pipe is arranged at the top of the mother liquid tank, one end of the exhaust pipe away from the mother liquid tank is connected to the tail gas treatment pipe, and a vacuum pump three is arranged on the exhaust pipe.

[0016] A vent pipe is arranged at the top of the crystallization tower, and one end of the vent pipe away from the crystallization tower is connected to the tail gas treatment pipe.

[0017] The bottom end of the double-effect evaporator is connected with concentrated salt solution processing equipment.

[0018] The side wall of the negative pressure filter is connected with ethyl phosphine aluminum product collecting equipment.

[0019] The beneficial effects of the utility model are:

[0020] By setting a cooling chamber and a crystallization tower, the liquid material discharged from the reaction tank can be quickly and evenly cooled, the precipitation efficiency of aluminum phosphite crystals in the liquid material is improved, the crystallization time of aluminum phosphite is shortened, the aggregation of aluminum phosphite crystals is avoided, and the overall yield of aluminum phosphite crystals is improved; at the same time, the cooling process is optimized to promote the uniform growth of aluminum phosphite crystals, so that the aluminum phosphite crystal particles have better consistency in shape and particle size, reduce the influence of impurities, reduce the occurrence of co-precipitation, and improve the purity of aluminum phosphite crystals; by setting a double-effect evaporator and a washing tank, the aluminum phosphite that has not been precipitated in the material can be fully recovered, the waste of raw materials can be reduced, and the resource recovery rate can be improved. The washing tank can remove impurities attached to the crude aluminum phosphite, and the purity of the final product can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the utility model;

[0022] Figure 2 It is a structural schematic diagram of the crystallization tower in the utility model;

[0023] In the figure:

[0024] 1. Reaction tank; 2. Metering tank one; 3. Metering tank two; 4. Cooling chamber; 5. Overflow pipe; 6. Crystallization tower; 601. Crystallization chamber; 602. Sedimentation chamber; 603. Reflux chamber; 604. Air duct; 7. Circulation pump; 8. Centrifuge; 9. Double-effect evaporator; 10. Distilled water storage tank; 11. Washing tank; 12. Negative pressure filter; 13. Mother liquor tank; 14. Feed pump; 15. Primary condenser; 16. Secondary condenser; 17. Vacuum pump one; 18. Tail gas treatment pipe; 19. Vacuum pump two; 20. Ethanol storage tank; 21. Distillation processing equipment; 22. Vacuum pump three; 23. Concentrated salt solution processing equipment; 24. Ethyl phosphine aluminum product collection equipment. DETAILED DESCRIPTION

[0025] The present invention will be specifically described and illustrated below in conjunction with the embodiments.

[0026] Example 1

[0027] like Figure 1-2 As shown, the phosphine-aluminum reactive crystallization device of the utility model comprises a double decomposition reaction unit, which is sequentially connected to a cooling crystallization unit and a centrifugal separation unit, and the double decomposition reaction unit comprises a reaction tank 1, on which a stirring shaft, a steam heating tube and a thermometer are provided, and the top of the reaction tank 1 is respectively connected to a metering tank 1 2 and a metering tank 2 3;

[0028] The cooling crystallization unit includes a cooling chamber 4, the side wall of the cooling chamber 4 is connected to the bottom end of the reaction tank 1, the top of the cooling chamber 4 is connected to an overflow pipe 5, the end of the overflow pipe 5 away from the cooling chamber 4 is connected to a crystallization tower 6, the side wall of the crystallization tower 6 is connected to the bottom end of the cooling chamber 4 through a circulation pipe, and a circulation pump 7 is arranged on the circulation pipe;

[0029] The centrifugal separation unit includes a centrifuge 8, the top of the centrifuge 8 is connected to the bottom of the side wall of the crystallization tower 6 away from the circulation pump 7, the side wall of the centrifuge 8 is connected to a double-effect evaporator 9, the bottom of the centrifuge 8 is connected to a washing tank 11, the top of the double-effect evaporator 9 is connected to the top of the washing tank 11, a distilled water storage tank 10 is arranged between the double-effect evaporator 9 and the washing tank 11, the bottom of the washing tank 11 is connected to a negative pressure filter 12, the bottom of the negative pressure filter 12 is connected to a mother liquid tank 13, the side wall of the mother liquid tank 13 is connected to the side wall of the cooling chamber 4, and a feeding pump 14 is arranged between the mother liquid tank 13 and the cooling chamber 4.

[0030] An air outlet pipe is arranged at the top of the reaction tank 1 , and one end of the air outlet pipe away from the reaction tank 1 is connected to a primary condenser 15 and a secondary condenser 16 in sequence.

[0031] A vacuum pump 17 is provided on the gas outlet pipe, and the vacuum pump 17 is located between the reaction tank 1 and the primary condenser 15. The top of the secondary condenser 16 is connected to a tail gas treatment pipe 18, and a vacuum pump 2 19 is provided on the tail gas treatment pipe 18.

[0032] The side wall of the primary condenser 15 and the side wall of the secondary condenser 16 are commonly connected to an ethanol storage tank 20 , the top of the ethanol storage tank 20 is connected to the tail gas treatment pipe 18 , and the bottom of the ethanol storage tank 20 is connected to a distillation processing device 21 .

[0033] The crystallization tower 6 includes a crystallization chamber 601, a reflux chamber 603 is arranged outside the crystallization chamber 601, the bottom of the crystallization chamber 601 is connected to the sedimentation chamber 602, the reflux chamber 603 is located above the sedimentation chamber 602, and the side wall of the reflux chamber 603 is connected to the circulation pipeline.

[0034] The top of the crystallization chamber 601 is higher than the top of the reflux chamber 603 . An air guide tube 604 is provided at the top of the reflux chamber 603 . One end of the air guide tube 604 away from the reflux chamber 603 is connected to the side wall of the crystallization chamber 601 .

[0035] An exhaust pipe is arranged at the top of the mother liquid tank 13, and one end of the exhaust pipe away from the mother liquid tank 13 is connected to the tail gas treatment pipe 18, and a vacuum pump 22 is arranged on the exhaust pipe.

[0036] A ventilation pipe is provided at the top of the crystallization tower 6 , and one end of the ventilation pipe away from the crystallization tower 6 is connected to the tail gas treatment pipe 18 .

[0037] The bottom end of the double-effect evaporator 9 is connected to a concentrated salt solution processing device 23 .

[0038] The side wall of the negative pressure filter 12 is connected to an ethyl phosphine aluminum product collecting device 24 .

[0039] Operation process and principle:

[0040] 1. Feeding and mixing

[0041] A predetermined amount of ammoniated liquid is added into the reaction tank 1 through the metering tank 2. After the addition of the ammoniated liquid is completed, the feeding port of the metering tank 2 is quickly closed, and the stirring shaft of the reaction tank 1 is started to mix the ammoniated liquid evenly. Then, a predetermined amount of aluminum sulfate is added into the reaction tank 1 through the metering tank 2 3. After the addition of aluminum sulfate is completed, the feeding port of the metering tank 2 3 is quickly closed.

[0042] 2. Double decomposition reaction

[0043] The vacuum pump 17 is turned on to maintain the negative pressure inside the reaction tank 1 between 100 and 200 Pa, and then the mixed gas is slowly introduced into the reaction tank 1 through the steam heating tube. The mixed gas includes ethanol gas and water vapor. During the ventilation process, the mixed gas pressure is controlled to be lower than 0.2 MPa, and the mixed gas flow rate is controlled to prevent the reaction tank 1 from heating up too quickly. The internal temperature of the reaction tank 1 is monitored by a thermometer. When the temperature of the reaction tank 1 exceeds 75°C, the flow rate of the mixed gas is reduced. The reacted gas in the reaction tank 1 is extracted by the vacuum pump 17 and sent to the primary condenser 15 and the secondary condenser 16 for condensation and separation. The primary condenser 15 is cooled by circulating water, and the secondary condenser 16 is cooled by 5°C water. The condensate of the primary condenser 15 and the condensate of the secondary condenser 16 are sent to the ethanol storage tank 20 for storage. The ethanol storage tank 20 sends the condensate to the distillation treatment equipment 21 for recovery. The non-condensable gas of the primary condenser 15 and the secondary condenser 16 is sent to the tail gas treatment through the tail gas treatment pipe 18.

[0044] 3. Crystallization and Sedimentation

[0045] When the temperature of the reaction tank 1 rises to above 86°C, stop introducing the mixed gas into the reaction tank 1, and keep the reaction tank 1 at this temperature for 30 minutes. Then, the liquid material after the reaction in the reaction tank 1 is sent to the cooling chamber 4, the liquid material is rapidly cooled in the cooling chamber 4, and then sent to the crystallization tower 6 through the overflow pipe 5; the liquid material precipitates ethyl phosphine aluminum crude salt crystals in the crystallization chamber 601 in the crystallization tower 6, and the ethyl phosphine aluminum crude salt crystals settle into the sedimentation chamber 602 under the action of gravity. In this process, the supersaturated ethyl phosphine aluminum crude salt crystals in the liquid material are precipitated again to form a high-concentration solid-liquid mixture, and the clearer brine in the liquid material flows into the reflux chamber 603, and enters the cooling chamber 4 again through the circulation pump 7 to further precipitate ethyl phosphine aluminum crude salt crystals.

[0046] 4. Centrifugal separation and washing

[0047] The high-concentration solid-liquid mixture at the bottom of the crystallization tower 6 is sent to the centrifuge 8 for centrifugal separation, the crude ethyl phosphine aluminum after centrifugation is sent to the washing tank 11, the separated secondary brine is sent to the double-effect evaporator 9 for concentration, the concentrated salt solution is sent to the concentrated salt solution treatment equipment 23, and the distilled water in the double-effect evaporator 9 is sent to the washing tank 11 through the distilled water storage tank 10 for washing the crude ethyl phosphine aluminum. When the crude ethyl phosphine aluminum is washed, the distilled water is fully in contact with the crude ethyl phosphine aluminum to remove impurities on the surface of the crude ethyl phosphine aluminum. After washing, the washing liquid is filtered through the negative pressure suction filter 12 to obtain refined ethyl phosphine aluminum, which is sent to the ethyl phosphine aluminum product collection equipment 24, and the mother liquor in the negative pressure suction filter 12 is sent to the mother liquor tank 13, and is sent to the cooling chamber 4 again through the feed pump 14.

[0048] 5. Exhaust gas treatment

[0049] The gas discharged from the crystallization tower 6 and the gas discharged from the mother liquid tank 13 are sent to tail gas treatment through the tail gas treatment pipe 18.

Claims

1. A phosphite-aluminum reactive crystallization device, comprising a double decomposition reaction unit, characterized in that: The double decomposition reaction unit is connected to the cooling crystallization unit and the centrifugal separation unit in sequence, and the double decomposition reaction unit comprises a reaction tank (1), on which a stirring shaft, a steam heating tube and a thermometer are provided, and the top of the reaction tank (1) is respectively connected to a metering tank 1 (2) and a metering tank 2 (3); The cooling crystallization unit comprises a cooling chamber (4), the side wall of the cooling chamber (4) is connected to the bottom end of the reaction tank (1), the top end of the cooling chamber (4) is connected to an overflow pipe (5), the end of the overflow pipe (5) away from the cooling chamber (4) is connected to a crystallization tower (6), the side wall of the crystallization tower (6) is connected to the bottom end of the cooling chamber (4) via a circulation pipe, and a circulation pump (7) is arranged on the circulation pipe; The centrifugal separation unit comprises a centrifuge (8), the top of the centrifuge (8) is connected to the bottom of the side wall of the crystallization tower (6) away from the circulation pump (7), the side wall of the centrifuge (8) is connected to a double-effect evaporator (9), the bottom of the centrifuge (8) is connected to a washing tank (11), the top of the double-effect evaporator (9) is connected to the top of the washing tank (11), a distilled water storage tank (10) is arranged between the double-effect evaporator (9) and the washing tank (11), the bottom of the washing tank (11) is connected to a negative pressure filter (12), the bottom of the negative pressure filter (12) is connected to a mother liquid tank (13), the side wall of the mother liquid tank (13) is connected to the side wall of the cooling chamber (4), and a feed pump (14) is arranged between the mother liquid tank (13) and the cooling chamber (4).

2. The phosphite-aluminum reactive crystallization device according to claim 1, characterized in that: An air outlet pipe is provided at the top of the reaction tank (1), and an end of the air outlet pipe away from the reaction tank (1) is connected to a primary condenser (15) and a secondary condenser (16) in sequence.

3. The ethyl phosphine aluminum reactive crystallization device according to claim 2, characterized in that: A vacuum pump 1 (17) is provided on the gas outlet pipe, and the vacuum pump 1 (17) is located between the reaction tank (1) and the first-stage condenser (15). The top end of the second-stage condenser (16) is connected to an exhaust gas treatment pipe (18), and a vacuum pump 2 (19) is provided on the exhaust gas treatment pipe (18).

4. The ethyl phosphine aluminum reactive crystallization device according to claim 2, characterized in that: The side wall of the primary condenser (15) and the side wall of the secondary condenser (16) are commonly connected to an ethanol storage tank (20), the top end of the ethanol storage tank (20) is connected to an exhaust gas treatment pipe (18), and the bottom end of the ethanol storage tank (20) is connected to a distillation treatment device (21).

5. The phosphite-aluminum reactive crystallization device according to claim 1, characterized in that: The crystallization tower (6) comprises a crystallization chamber (601), a reflux chamber (603) is arranged outside the crystallization chamber (601), the bottom end of the crystallization chamber (601) is connected to the sedimentation chamber (602), the reflux chamber (603) is located above the sedimentation chamber (602), and the side wall of the reflux chamber (603) is connected to the circulation pipeline.

6. The phosphite-aluminum reactive crystallization device according to claim 5, characterized in that: The top of the crystallization chamber (601) is higher than the top of the reflux chamber (603). An air guide tube (604) is provided at the top of the reflux chamber (603). One end of the air guide tube (604) away from the reflux chamber (603) is connected to the side wall of the crystallization chamber (601).

7. The phosphite-aluminum reactive crystallization device according to claim 1, characterized in that: An exhaust pipe is provided at the top of the mother liquid tank (13), one end of the exhaust pipe away from the mother liquid tank (13) is connected to the tail gas treatment pipe (18), and a vacuum pump three (22) is provided on the exhaust pipe.

8. The ethyl phosphine aluminum reactive crystallization device according to claim 3, characterized in that: A ventilation pipe is provided at the top of the crystallization tower (6), and one end of the ventilation pipe away from the crystallization tower (6) is connected to the tail gas treatment pipe (18).

9. The phosphite-aluminum reactive crystallization device according to claim 1, characterized in that: The bottom end of the double-effect evaporator (9) is connected to a concentrated salt solution processing device (23).

10. The phosphite-aluminum reactive crystallization device according to claim 1, characterized in that: The side wall of the negative pressure filter (12) is connected to an ethyl phosphine aluminum product collecting device (24).

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