Circulating pump cooling system of rectifying tower

Abstract

The utility model discloses a circulating pump cooling system of a rectifying tower in the technical field of caprolactam rectification. The circulating pump cooling system comprises the rectifying tower, a cooling tank, a circulating pump, a heat preservation jacket and a slag discharging device, a discharge port of the rectifying tower is connected with a suction port of the circulating pump, a discharge port of the circulating pump is connected with the heater, a mechanical sealing cavity of the circulating pump is communicated with the cooling tank through the cooling pipe, the cooling tank is wrapped with the heat preservation jacket, the heat preservation jacket is communicated with an external high-temperature water vapor pipeline, and the cooling pipe is connected to the outside of the sealing cavity. And the cooling medium is the caprolactam aqueous solution, so that the caprolactam mixed solution in the rectifying tower is not influenced even if the mechanical seal and the external cooling medium are mutually permeated, and the caprolactam mixed solution in the rectifying tower is not influenced even if the mechanical seal and the external cooling medium are mutually permeated. And the external cooling medium is not influenced by the dissolution of caprolactam, and the cooling liquid does not need to be continuously supplemented.

Description

TECHNICAL FIELD

[0001] The utility model relates to caprolactam rectification technical field especially relates to a circulating pump cooling system of rectifying column. BACKGROUND

[0002] As the rectifying column of separating caprolactam, need to set up circulating pump cooperation to use, to keep the sustained flow of caprolactam, avoid its precipitation and condensation, the vast majority of caprolactam in rectifying column reaches the purpose of heating separation after being heated by heater and returning to the inside of rectifying column, a small part of caprolactam is slagged by slag remover, circulating pump provides power, accelerates caprolactam circulation, heater provides heat, so that the caprolactam in rectifying column completes rectification.

[0003] Rectification circulating pump is mainly to the caprolactam in rectifying column circulation, heating, slagging, because the caprolactam in rectifying column needs to be heated continuously, and the inside needs to be cooled down, so that the working environment of circulating pump is in high temperature state for a long time, and due to the process production demand, the caprolactam circulation amount of rectification circulating pump is relatively large, and the power demand of circulating pump is also relatively large, especially the medium pumped by it is caprolactam, and the whole rectification system is absolutely vacuum, so the use environment of circulating pump is very high.

[0004] At present, the centrifugal circulating pump is selected, and the mechanical seal needs to be used for the mechanical seal, and the mechanical seal is mainly used to prevent caprolactam leakage, and if the packing seal is used, the caprolactam will seep out to cause the packing seal to be frozen and blocked, which not only cannot achieve the sealing effect, but also will cause the driving shaft to be scratched and damaged, and the mechanical seal has good effect and long service life.

[0005] The rotating shaft of this high-power circulating pump will heat due to high-speed rotation, the mechanical seal has a sealing surface, and the dynamic sealing purpose is achieved through the relative rotation of the dynamic ring and the static ring, therefore, the sealing surface of the mechanical seal will also rotate synchronously with the circulating pump, and the heat generation is very large, in order to solve the heating problem of the mechanical seal, the mechanical seal needs to be cooled, and the cooling liquid of the mechanical seal is water or silicon oil at present, and this cooling method has defects, the mechanical seal cannot be absolutely isolated, and once the mutual mixing occurs, the abnormality will exist, when the cooling liquid mixes into the rectifying column, the separation purity of the caprolactam in the rectifying column will be seriously affected, and when the caprolactam in the rectifying column mixes into the outside, the mechanical seal will be blocked, and a large amount of particulate matter will exist in the water, if the silicon oil is used, the flowability is poor, the temperature fluctuation is large, and the silicon oil will crack at high temperature, which will cause the quality of the separated caprolactam in the rectifying column to be degraded, and the silicon oil is a consumable, and needs to be added for a long time, if the caprolactam in the rectifying column seeps out to cause the emulsification, the mechanical seal and the separation system of the rectifying column will be replaced, and these conditions will cause the abnormality of the mechanical seal and the separation system of the rectifying column, and this problem is difficult to be effectively solved.

[0006] Based on this, the utility model discloses a circulating pump cooling system of rectifying tower to solve above -mentioned problem. Utility model content

[0007] The utility model discloses a circulating pump cooling system of rectifying tower, the mechanical seal of the circulating pump of this rectifying tower uses, and the cooling pipe is connected outside the sealed cavity, and through the circulating flow cooling of cooling tank and cooling pipe to mechanical seal, reaches the purpose of circulating cooling, and the medium of cooling is caprolactam aqueous solution, even if mechanical seal and external cooling medium mutually permeate, also will not influence each other, neither will influence caprolactam mixed solution in rectifying tower, and the cooling medium of external also will not be influenced by caprolactam solution, and need not constantly supplement cooling liquid, and the cooling liquid of this device can be self -adaptation.

[0008] The utility model is such realization: a circulating pump cooling system of rectifying tower, include:

[0009] Rectifying tower, cooling tank, circulating pump and heat preservation jacket are set up.

[0010] The discharge port of rectifying tower is connected with the suction port of circulating pump, and the discharge port of circulating pump is connected with the heater, and the discharge pipe of heater is arranged in the inner chamber of rectifying tower.

[0011] The cooling tank is closed tank body, and the top of cooling tank is connected with pressure valve, and cooling tank is communicated with high pressure nitrogen gas pipeline through pressure valve, and temperature meter is also set up on cooling tank, and charging pipe is also set up on the top of cooling tank.

[0012] The drive device of circulating pump is externally provided with drive motor, and mechanical seal is arranged at the connecting place of the drive shaft of drive motor and circulating pump.

[0013] The bottom of cooling tank is connected with cooling pipe, and the other end of cooling pipe is connected at the top of the inner chamber of cooling tank, and two openings are arranged on the sealed cavity outside mechanical seal, and the two openings of the sealed cavity of mechanical seal are communicated with the inner chamber of cooling tank through separate cooling pipe.

[0014] The heat preservation jacket is closed hollow casing, and the heat preservation jacket is wrapped outside cooling tank, and heat preservation outlet pipe and heat preservation inlet pipe are connected on the heat preservation jacket, and the heat preservation inlet pipe is communicated with the water vapor pipeline of external connection, and the heat preservation outlet pipe is connected with heating device.

[0015] Further, one control valve is arranged on the inlet and outlet of circulating pump.

[0016] Further, vacuum pump is also set up on the top of rectifying tower, and the suction port of vacuum pump is sealed and arranged at the top of the inner chamber of rectifying tower, and the gas outlet of vacuum pump is arranged outside rectifying tower.

[0017] Further, the temperature of the caprolactam water solution inside the cooling tank is kept between 65-90℃.

[0018] Further, the nitrogen pipeline connected with the pressurizing valve is 6bar, and the pressurizing valve is an adjusting valve.

[0019] The beneficial effects of the present application are as follows: 1. The device is specially increased with a cooling tank, which is filled with a certain concentration of caprolactam water solution, which will not be viscous, and will not affect the separation operation in the rectifying tower due to impurities. At the same time, because the water in the cooling tank contains a certain concentration of caprolactam, even if the external cooling liquid is mixed into the rectifying tower, it has little effect on the quality of the separated product.

[0020] 2. The device is also increased with a heat preservation jacket, which can keep the cooling liquid in the cooling tank stable, ensure that the caprolactam inside will not condense, and the caprolactam permeated on the mechanical seal will not condense into blocks, keep the cooling liquid completely in a liquid state, and also can dissolve and clean the caprolactam leaked from the circulating pump, improve the sealing effect of the mechanical seal on the caprolactam. BRIEF DESCRIPTION OF DRAWINGS

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 It is a schematic diagram of the overall structure of the present application.

[0023] In the drawings, the component list represented by each reference numeral is as follows:

[0024] 1-rectifying tower, 11-control valve, 12-heater, 13-vacuum pump, 2-cooling tank, 21-thermometer, 22-pressurizing valve, 23-cooling pipe, 3-circulating pump, 31-mechanical seal, 32-driving motor, 4-heat preservation jacket, 41-heat preservation outlet pipe, 42-heat preservation inlet pipe. DETAILED DESCRIPTION

[0025] Please refer to Figure 1 The present application provides a circulating pump cooling system of a rectifying tower, in order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the description of the drawings and specific embodiments.

[0026] In one specific embodiment of the technical scheme of the present application:

[0027] It comprises a rectifying tower 1, a cooling tank 2, a circulating pump 3, a heat preservation jacket 4 and a slag discharger 5.

[0028] The outlet of the rectifying tower 1 is connected with the suction port of the circulating pump 3, the outlet of the circulating pump 3 is connected with the heater 12 and the slag discharger 5 through a three-way joint, the outlet pipe of the heater 12 is arranged in the inner cavity of the rectifying tower 1; the slag discharger 5 is communicated with a sewage pipe; the slag discharger 5 is used to occasionally discharge the impurities in the pipeline, and the slag discharger 5 is a conventional structure in the rectifying tower; the inlet and outlet of the circulating pump 3 are respectively provided with a control valve 11.

[0029] A vacuum pump 13 is further arranged at the top of the rectifying tower 1, the suction port of the vacuum pump 13 is sealingly arranged at the top of the inner cavity of the rectifying tower 1, and the gas outlet of the vacuum pump 13 is arranged outside the rectifying tower 1.

[0030] The cooling tank 2 is a closed tank body, the top of the cooling tank 2 is connected with a pressurizing valve 22, and the cooling tank 2 is communicated with a high-pressure nitrogen pipeline through the pressurizing valve 22; the nitrogen pipeline connected with the pressurizing valve 22 is 6bar, and the pressurizing valve 22 is an adjusting valve.

[0031] A thermometer 21 is further arranged on the cooling tank 2, and a feeding pipe is further arranged at the top of the cooling tank 2.

[0032] An external driving motor 32 is arranged on the driving device of the circulating pump 3, and a mechanical seal 31 is arranged at the connection position between the driving shaft of the driving motor 32 and the circulating pump 3.

[0033] The bottom of the cooling tank 2 is connected with a cooling pipe 23, the other end of the cooling pipe 23 is connected with the inner cavity of the cooling tank 2, two openings are arranged on the outer sealing cavity of the mechanical seal 31, and the two openings of the sealing cavity of the mechanical seal 31 are communicated with the inner cavity of the cooling tank 2 through separate cooling pipes 23.

[0034] The heat preservation jacket 4 is a closed hollow shell, the heat preservation jacket 4 is wrapped outside the cooling tank 2, the heat preservation jacket 4 is connected with the heat preservation outlet pipe 41 and the heat preservation inlet pipe 42, the heat preservation inlet pipe 42 is communicated with the high-temperature steam pipeline, the heat preservation outlet pipe 41 is connected with the heating device, and the heat preservation outlet pipe 41 and the heat preservation inlet pipe 42 are all provided with a separate control valve. The inside of the cooling tank 2 is the caprolactam aqueous solution, and the concentration is 20%-40%; the temperature of the caprolactam aqueous solution in the cooling tank 2 is kept between 65-90 DEG C. The temperature of the cooling liquid in the cooling tank 2 is kept by the heat preservation jacket 4, the high-temperature water vapor is injected into the heat preservation jacket 4, the temperature of the cooling liquid in the cooling tank 2 is kept, and the temperature of the cooling liquid is continuously detected by the thermometer 21, so that the temperature is kept stable, the temperature of the circulating cooling liquid in the sealing cavity of the mechanical seal 31 is kept above 50 DEG C, the caprolactam is prevented from condensing, and the mechanical seal 31 is prevented from being affected by the condensed crystals.

[0035] In use, the steam condensate valve of the heat preservation outlet pipe 41 and the steam valve of the heat preservation inlet pipe 42 are opened first, the heat preservation jacket is preheated and heated by the high-temperature water vapor connected outside, and then the cooling tank 2 is heated and kept warm.

[0036] When the temperature reaches 70 DEG C or above, the caprolactam aqueous solution with a concentration of 30% is added into the cooling tank 2, the caprolactam aqueous solution is continuously injected into the cooling tank 2, the gas in the cooling tank 2 is discharged, and then the caprolactam aqueous solution is fully flowed in, the liquid level of the cooling tank 2 is kept appropriate, and the adding is stopped.

[0037] The pressurizing valve of the nitrogen pipeline is slightly opened, a small amount of positive pressure is generated, the air is discharged outside, and the caprolactam aqueous solution is fully circulated.

[0038] The rectification circulating pump 3 is started, the rectification tower is produced, the operation of the circulating pump 3 is observed, the temperature of the cooling liquid is observed by the thermometer 21 on the cooling tank 2, the opening degree of the steam valve on the heat preservation inlet pipe 42 is adjusted, and the circulating temperature of the cooling tank 2 is kept at about 80 DEG C.

[0039] Although the specific embodiments of the utility model are described above, those skilled in the art should understand that the specific examples described by us are only illustrative, and are not used to limit the scope of the utility model, and equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the utility model should be covered in the scope of protection of the claims of the utility model.

Claims

1. A circulating pump cooling system for a rectification column, characterized by, The utility model relates to a rectifying tower, cooling tank, circulating pump and heat preservation jacket, which are connected to each other. The outlet of the rectifying tower (1) is connected to the suction port of the circulating pump (3), the outlet of the circulating pump (3) is connected to a heater (12), and the outlet pipe of the heater (12) is arranged in the inner cavity of the rectifying tower (1). The cooling tank (2) is a closed tank body, the top of the cooling tank (2) is connected to a pressurizing valve (22), the cooling tank (2) is in communication with a high-pressure nitrogen pipeline through the pressurizing valve (22), a thermometer (21) is arranged on the cooling tank (2), and a feeding pipe is arranged on the top of the cooling tank (2). The driving device of the circulating pump (3) is externally provided with a driving motor (32), a mechanical seal (31) is arranged at the connection between the driving shaft of the driving motor (32) and the circulating pump (3). The bottom of the cooling tank (2) is connected to a cooling pipe (23), the other end of the cooling pipe (23) is connected to the inner cavity of the cooling tank (2), two openings are arranged on the outer sealing cavity of the mechanical seal (31), and the two openings of the sealing cavity of the mechanical seal (31) are in communication with the inner cavity of the cooling tank (2) through separate cooling pipes (23). The heat preservation jacket (4) is a closed hollow shell, the heat preservation jacket (4) is wrapped outside the cooling tank (2), the heat preservation jacket (4) is connected to a heat preservation outlet pipe (41) and a heat preservation inlet pipe (42), the heat preservation inlet pipe (42) is in communication with an external water vapor pipeline, and the heat preservation outlet pipe (41) is connected to a heating device. The inlet and outlet of the circulating pump (3) are each provided with a control valve (11).

2. A circulating pump cooling system for a distillation column as defined in claim 1, characterized in that: The top of the rectifying tower (1) is further provided with a vacuum pump (13), the suction port of the vacuum pump (13) is sealingly arranged at the top of the inner cavity of the rectifying tower (1), and the gas outlet of the vacuum pump (13) is arranged outside the rectifying tower (1).

3. A circulating pump cooling system for a distillation column as defined in claim 1, wherein: The nitrogen pipeline connected to the pressurizing valve (22) is 6 bar, and the pressurizing valve (22) is an adjusting valve.

4. A circulating pump cooling system for a distillation column as defined in claim 1, wherein: ​

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