Crystallization kettle for producing sodium p-nitrophenolate

Abstract

The utility model belongs to the technical field of production of chemical intermediates, and particularly discloses a crystallization kettle for producing sodium paranitrophenolate, which comprises a crystallization kettle body and a jacket, a heat exchange layer is reserved between the jacket and the kettle body, a stirring mechanism is mounted in the kettle body, a scraper is fixedly connected onto the stirring mechanism through a connecting rod, a water inlet and a water outlet are formed in the heat exchange layer, and the water inlet and the water outlet are communicated with the jacket. The stirring mechanisms are communicated through a circulating pipeline, a stop valve, a water pump and a heat exchanger are mounted on the circulating pipeline, the heat exchanger is communicated with a steam supply source through a first electromagnetic valve and is communicated with a cold water supply source through a second electromagnetic valve, and a temperature sensor is fixedly connected to the lower end of each stirring mechanism. According to the utility model, the heat exchanger is arranged on the circulating pipeline, the temperature of circulating water in the circulating pipeline is controlled by the heat exchanger to carry out heat exchange and cooling on the kettle body of the crystallization kettle, and the temperature sensor is arranged in the kettle body to monitor the change of the temperature in the kettle body in real time, so that the condition that the temperature of the crystallization kettle is rapidly reduced is prevented, and the wall hanging phenomenon is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical intermediate production, in particular to a crystallization kettle for the production of sodium p-nitrophenolate. Background Art

[0002] Sodium p-nitrophenolate is a commonly used chemical raw material, commonly used to prepare intermediates for fine chemicals such as pesticides, medicines, and dyes. The industrial preparation of sodium p-nitrophenolate is mostly done by mixing a dilute alkaline solution with p-nitrochlorobenzene and heating it, performing a hydrolysis reaction, and then cooling, crystallizing, and separating to obtain the finished product. In the current production process of sodium p-nitrophenolate, after the raw material completes the reaction in the hydrolysis kettle, the product is directly transferred to the crystallization kettle, where the temperature is cooled from 75°C to 38-40°C and then filtered to separate the solid and liquid. After filtration, the solid sodium p-nitrophenolate finished product is obtained, and the mother liquor is sent to the acidification process for subsequent treatment. However, when using a crystallization kettle to crystallize the product, the product material is rapidly cooled in the crystallization kettle, and some of the material quickly crystallizes on the walls of the crystallization kettle, resulting in serious wall adhesion in the crystallization kettle. The wall adhesion affects the heat transfer of the crystallization kettle, causing the material cooling rate in the crystallization kettle to decrease, ultimately reducing the working efficiency of the crystallization process. Therefore, it is necessary to design a crystallization kettle for sodium p-nitrophenolate production that prevents wall adhesion during the crystallization process. Utility Model Content

[0003] In view of the above technical problems, the utility model provides a crystallization kettle for the production of sodium p-nitrophenolate, which is designed to prevent the wall hanging phenomenon from occurring during the crystallization process.

[0004] In order to solve the above technical problems, the technical solution of the utility model is as follows: a crystallization kettle for the production of sodium p-nitrophenolate, comprising a crystallization kettle body and a jacket, the jacket being arranged on the periphery of the kettle body, a heat exchange layer being left between the jacket and the kettle body, a feed port being fixedly connected to the upper end of the kettle body, and a discharge port being fixedly connected to the lower end, a stirring mechanism being installed in the kettle body, a scraper being fixedly connected to the stirring mechanism through a connecting rod, the outer side of the scraper being in contact with the inner wall of the kettle body, a water inlet and a water outlet being provided in the heat exchange layer, and the water inlet and the discharge port being fixedly connected to the lower end of the kettle body. The inlet and outlet are connected by a circulation pipe, and a stop valve, a water pump, and a heat exchanger are installed on the circulation pipe. The heat exchanger is provided with a steam inlet, a steam outlet, a cold water inlet, and a cold water outlet. A first solenoid valve is installed on the steam inlet and is connected to the steam supply source, and a second solenoid valve is installed on the cold water inlet and is connected to the cold water supply source. A temperature sensor is fixedly connected to the lower end of the stirring mechanism, and the temperature sensor is communicated with the controller. The first solenoid valve and the second solenoid valve are controlled by the controller.

[0005] Furthermore, the stirring mechanism includes a stirring motor, a stirring shaft, and a stirring blade. The stirring motor is fixedly connected to the top of the kettle body, the output end of the stirring motor extends into the kettle body and is fixedly connected to the upper end of the stirring shaft, one end of the stirring blade is fixedly connected to the stirring shaft, the stirring shaft is fixedly connected to a scraper through a connecting rod, and the temperature sensor is fixedly connected to the lower end of the stirring shaft.

[0006] Furthermore, a liquid inlet pipe is fixedly connected to the upper end of the kettle body, a liquid inlet valve is installed on the liquid inlet pipe, and the liquid inlet pipe is connected to the mother liquid delivery pipeline.

[0007] Compared with the prior art, the present invention has the following advantages:

[0008] 1. The utility model arranges a heat exchanger on the circulation pipe, controls the temperature of the circulating water in the circulation pipe through the heat exchanger to exchange heat and cool the body of the crystallization kettle, installs a temperature sensor in the kettle body to monitor the temperature change in the kettle body in real time, prevents the crystallization kettle temperature from dropping rapidly, avoids the occurrence of wall hanging phenomenon, ensures the working efficiency of the crystallization process, and arranges a scraper on the stirring mechanism to stir the material in the kettle body and scrape the material on the kettle wall at the same time, prevents the material from accumulating and agglomerating on the kettle wall, and further avoids the occurrence of wall hanging phenomenon.

[0009] 2. The utility model provides a liquid inlet pipe connected to the mother liquor delivery pipe after filtration at the upper end of the kettle body, so that the mother liquor can be added to the crystallization kettle body before the crystallization process to preheat the crystallization kettle body, thereby avoiding the rapid cooling of the low-temperature kettle wall when the product material is added to the kettle body to form crystals attached to the kettle wall, further avoiding the occurrence of wall hanging phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural diagram of the present utility model.

[0011] Figure 2 It is a schematic diagram of the internal top-view cross-sectional structure of the present invention.

[0012] In the figure: 1. kettle body, 2. heat exchange layer, 3. feed port, 4. discharge port, 5. stirring mechanism, 51. stirring motor, 52. stirring shaft, 53. stirring blade, 6. connecting rod, 7. scraper, 8. water inlet, 9. water outlet, 10. circulation pipe, 11. stop valve, 12. water pump, 13. heat exchanger, 131. steam inlet, 132. steam outlet, 133. cold water inlet, 134. cold water outlet, 14. first solenoid valve, 15. second solenoid valve, 16. temperature sensor, 17. liquid inlet pipe, 18. liquid inlet valve. DETAILED DESCRIPTION

[0013] The present invention will be further described below with reference to the accompanying drawings.

[0014] like Figures 1 to 2 The crystallization kettle for producing sodium p-nitrophenol shown in the figure comprises a crystallization kettle body 1 and a jacket. The jacket is arranged on the outer periphery of the kettle body 1, and the connection between the jacket and the kettle body 1 is sealed. A heat exchange layer 2 is left between the jacket and the kettle body 1. A baffle is provided in the heat exchange layer 2 to guide the direction of water flow. An observation window is provided on the kettle body 1. A feed port 3 is fixedly connected to the upper end of the kettle body 1, and a discharge port 4 is fixedly connected to the lower end. A sealing cover is provided on the feed port 3, and a valve is installed on the discharge port 4. A stirring mechanism 5 is installed in the kettle body 1. A scraper 7 is fixedly connected to the stirring mechanism 5 through a connecting rod 6. The outer side of the scraper 7 is in contact with the inner wall of the kettle body 1. A water inlet 8 and a water outlet 9 are provided in the heat exchange layer 2. A drain port is also provided on the other side of the heat exchange layer 2, which can be used for both drainage and water injection. The water inlet 8 and the water outlet 9 They are connected through an external circulation pipe 10, and a stop valve 11, a water pump 12, and a heat exchanger 13 are installed on the circulation pipe 10. The heat exchanger 13 adopts a tubular heat exchanger, and the heat exchanger 13 is provided with a steam inlet 131, a steam outlet 132, a cold water inlet 133, and a cold water outlet 134. A first solenoid valve 14 is installed on the steam inlet 131 and is connected to a high-pressure steam supply source. A second solenoid valve 15 is installed on the cold water inlet 133 and is connected to a high-pressure cold water supply source. A temperature sensor 16 is fixedly connected to the lower end of the stirring mechanism 5, and the temperature sensor 16 is communicated with the controller. The first solenoid valve 14 and the second solenoid valve 15 are controlled by the controller. The controller adopts a PLC controller, and the PLC controller is communicated with a matching display.

[0015] In order to stir the product materials in the kettle body 1, ensure uniform heat transfer between the materials, and prevent the materials from accumulating and agglomerating, the stirring mechanism 5 includes a stirring motor 51, a stirring shaft 52, and a stirring blade 53. The stirring motor 51 is fixedly connected to the top of the kettle body 1, and the output end of the stirring motor 51 extends into the kettle body 1 and is fixedly connected to the upper end of the stirring shaft 52. One end of the stirring blade 53 is fixedly connected to the stirring shaft 52. The stirring shaft 52 is fixedly connected to the scraper 7 through the connecting rod 6, and the temperature sensor 16 is fixedly connected to the lower end of the stirring shaft 52.

[0016] In order to preheat the crystallization kettle body 1 before adding the product material, and prevent the product material from directly crystallizing and forming a wall-clinging phenomenon when it encounters the low-temperature kettle wall when it is added to the kettle body 1, a liquid inlet pipe 17 is fixedly connected to the upper end of the kettle body 1. The liquid inlet pipe 17 is installed on the liquid inlet valve 18, and the liquid inlet pipe 18 is connected to the mother liquor delivery pipeline. By injecting a portion of the filtered mother liquor into the crystallization kettle body 1 and then preheating the kettle body 1, the probability of the wall-clinging phenomenon is reduced.

[0017] The specific working process of this utility model is as follows:

[0018] Open the liquid inlet valve 18 and add the filtered mother liquor into the kettle body 1 through the liquid inlet pipe 17 until it just covers the temperature sensor 16. Then close the liquid inlet valve 18 and start the water pump 12. The circulating water begins to circulate in the circulating pipe 10, the heat exchanger 13 and the heat exchange layer 2. The controller controls the first solenoid valve 14 to open, and high-pressure steam enters the heat exchanger 13 from the steam inlet 131. After heat exchange with the circulating water, it is discharged from the heat exchanger 13 through the steam outlet 132. The temperature in the kettle body 1 is continuously increased by heat exchange until the temperature sensor 16 detects that the temperature in the kettle body 1 reaches 70°C. At this time, the controller controls the first solenoid valve 14 to close, and preheating is completed. The hydrolyzate is fed into the preheated crystallization kettle 1 through the feed inlet 3. The stirring motor 51 is started to rotate the stirring shaft 52, which in turn rotates the stirring blades 53 and the scraper 7. The scraper 7 continuously scrapes off the material adhering to the kettle wall to prevent accumulation and crystallization. The stirring blades 53 continuously stir the material to uniformly dissipate heat from the material. At this time, the controller activates the second solenoid valve 15. Cold water enters the cold water inlet 133 from the water supply source, then enters the heat exchanger 13 to exchange heat with the circulating water, and is discharged through the cold water outlet 134. The heat exchange continuously reduces the temperature in the kettle 1. The temperature sensor 16 detects the temperature in the kettle 1 in real time and sends a data signal to the controller. The controller transmits the received temperature data signal to the display for display. The operator controls the opening and closing of the second solenoid valve 15 in real time based on the displayed temperature value. If the temperature drop is large, the second solenoid valve 15 is closed in time to prevent a sudden temperature drop. After the material in the kettle 1 is linearly cooled to the crystallization temperature, the cooled material is discharged from the discharge port 4 for the next process.

Claims

1. A crystallization kettle for producing sodium p-nitrophenolate, comprising a crystallization kettle body (1) and a jacket, wherein the jacket is arranged on the outer periphery of the kettle body (1), a heat exchange layer (2) is left between the jacket and the kettle body (1), the upper end of the kettle body (1) is fixedly connected to a feed port (3), and the lower end is fixedly connected to a discharge port (4), and a stirring mechanism (5) is installed in the kettle body (1), characterized in that: The stirring mechanism (5) is fixedly connected to a scraper (7) via a connecting rod (6), and the outer side of the scraper (7) is in contact with the inner wall of the kettle body (1). The heat exchange layer (2) is provided with a water inlet (8) and a water outlet (9), and the water inlet (8) and the water outlet (9) are connected via a circulation pipe (10). The circulation pipe (10) is equipped with a stop valve (11), a water pump (12), and a heat exchanger (13). The heat exchanger (13) is provided with a steam inlet (131), a steam outlet (132), and a steam pump (133). (132), a cold water inlet (133), and a cold water outlet (134); a first solenoid valve (14) is installed on the steam inlet (131) and is connected to a steam supply source; a second solenoid valve (15) is installed on the cold water inlet (133) and is connected to a cold water supply source; a temperature sensor (16) is fixedly connected to the lower end of the stirring mechanism (5); the temperature sensor (16) is communicatively connected to a controller; the first solenoid valve (14) and the second solenoid valve (15) are controlled by the controller.

2. The crystallization kettle for producing sodium p-nitrophenolate according to claim 1, wherein: The stirring mechanism (5) comprises a stirring motor (51), a stirring shaft (52), and a stirring blade (53); the stirring motor (51) is fixedly connected to the top of the kettle body (1); the output end of the stirring motor (51) extends into the kettle body (1) and is fixedly connected to the upper end of the stirring shaft (52); one end of the stirring blade (53) is fixedly connected to the stirring shaft (52); the stirring shaft (52) is fixedly connected to a scraper (7) via a connecting rod (6); and the temperature sensor (16) is fixedly connected to the lower end of the stirring shaft (52).

3. The crystallization kettle for producing sodium p-nitrophenolate according to claim 1, wherein: The upper end of the kettle body (1) is fixedly connected with a liquid inlet pipe (17), a liquid inlet valve (18) is installed on the liquid inlet pipe (17), and the liquid inlet pipe (17) is connected with the mother liquid delivery pipeline.

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