Sampling and recycling device for nylon 66 salt solution

Abstract

The utility model belongs to the technical field of chemical equipment, and particularly relates to a sampling and recycling device for nylon 66 salt liquid. Comprising a recovery tank, a discharge port of the recovery tank is connected to a spray tower, and a discharge port of the spray tower is connected to a salifying reactor; a recovery hopper is arranged above the recovery tank, a filler layer is filled in the recovery tank, and a heat preservation device, a replacement system and a monitoring unit are further arranged on the recovery tank; eDI desalted water pipelines are connected to the recovery tank and a spraying branch pipe of the spraying tower, and a gas outlet of the spraying tower is connected to the water-sealed tank; a control system is further included. By arranging the large-capacity recovery tank, batch continuous recovery of the salt liquid is realized, and the operation frequency is obviously reduced; due to the double-isolation design of the nitrogen replacement system and the sealing cover, oxidation and yellowing of the salt liquid are effectively inhibited; the jacket type heat preservation device is arranged on the outer wall of the recovery tank, the temperature in the tank is maintained to be 50 DEG C or above, and salt liquid crystallization is effectively prevented; the activated carbon filler layer is filled in the tank to adsorb impurities and decolor, so that the quality of the recovered salt solution is guaranteed.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to a sampling and recovery device for nylon 66 salt solution. Background Technology

[0002] Nylon 66, a major product in the nylon series, is synthesized from adipic acid and hexamethylenediamine. The process involves an equimolar reaction of these two substances to first form a nylon 66 salt solution with a concentration of approximately 57 wt.%, followed by concentration and polymerization to obtain the final product. It is widely used in engineering plastics and synthetic fibers, and its quality is closely related to the performance of downstream products. During nylon 66 production, it is necessary to sample and monitor the salt solution concentration, UV value, and other indicators every 2 hours. These indicators directly affect key performance parameters such as viscosity and color value of the product and are therefore key areas for production control.

[0003] Traditional recycling devices typically use simple recycling tanks with small volumes, which have the following drawbacks: First, due to insufficient capacity, frequent recycling operations are required every day, resulting in low efficiency; second, the brine is easily oxidized and discolored when in contact with air, leading to an increase in UV value and product color value; third, the brine is prone to crystallization into solids when the temperature is below 50℃, causing blockage of the recycling port and making cleaning difficult; fourth, oxygen is easily introduced during the recycling process, causing the system brine to turn yellow, which seriously affects product quality.

[0004] Therefore, there is an urgent need to design a sampling and recovery device that can overcome the above-mentioned defects and achieve efficient, stable, and high-quality recovery of nylon 66 salt solution. Utility Model Content

[0005] To address the shortcomings of the existing technology, the present invention aims to provide a sampling and recovery device for nylon 66 brine. By using a large-capacity recovery tank, it achieves continuous batch recovery of the brine, significantly reducing the frequency of operations. The dual isolation design, employing a nitrogen replacement system and a sealed cap, effectively inhibits the oxidation and yellowing of the brine. A jacketed insulation device is installed on the outer wall of the recovery tank, dynamically maintaining the tank temperature above 50°C through hot water circulation, effectively preventing brine crystallization. An activated carbon packing layer inside the tank adsorbs impurities and decolorizes, ensuring the quality of the recovered brine.

[0006] This utility model is achieved using the following technical solution:

[0007] The nylon 66 brine sampling and recovery device includes a recovery tank, the outlet of which is connected to a spray branch pipe of a spray tower via a pipeline, and the outlet of the spray tower is connected to a salt-forming reactor via a pipeline. A recovery hopper is located above the recovery tank, and the interior of the recovery tank is filled with a packing layer. The recovery tank is also equipped with a heat preservation device, a displacement system, and a monitoring unit. EDI demineralized water pipelines are connected to both the recovery tank and the spray branch pipe of the spray tower. A first flow meter is installed on the EDI demineralized water pipeline, and a second flow meter is installed on the pipeline from the recovery tank to the spray tower. The air outlet of the spray tower is connected to a water seal tank via a pipeline. The device also includes a control system.

[0008] The heat preservation device includes a jacket installed on the outer wall of the recovery tank and a hot water pipeline connected to the jacket. A first regulating valve is installed on the hot water pipeline, and the first regulating valve is electrically connected to the control system.

[0009] The replacement system includes a nitrogen pipeline and a venting pipeline connected to the recovery tank. A second regulating valve and a third regulating valve are respectively installed on the nitrogen pipeline and the venting pipeline. The second regulating valve and the third regulating valve are electrically connected to the control system.

[0010] The monitoring unit includes a thermometer and a pressure gauge installed on the recovery tank, and the thermometer and pressure gauge are electrically connected to the control system.

[0011] The spray tower is equipped with a pressure sensor, which is electrically connected to the control system.

[0012] The inlet of the recycling hopper is equipped with a sealing cover, and the inside of the recycling hopper is equipped with a filter screen.

[0013] A fourth regulating valve is installed on the pipeline from the spray tower to the water seal tank, and a fifth regulating valve is installed on the EDI demineralized water pipeline. The fourth and fifth regulating valves are electrically connected to the control system.

[0014] The recycling tank has a sampling port on its outlet pipeline.

[0015] A first on / off valve is provided on the branch line from the EDI demineralized water pipeline to the recovery tank, and a second on / off valve is provided on the branch line from the EDI demineralized water pipeline to the spray tower. The first and second on / off valves are electrically connected to the control system.

[0016] The recycling tank has a capacity of 150L, ​​which allows for a large recycling volume and can effectively reduce the frequency of recycling operations.

[0017] The working principle of the nylon 66 brine sampling and recovery device is as follows:

[0018] The operator opens the sealed cover of the recovery hopper and pours the Nylon 66 brine to be recovered into the hopper. After the brine is initially filtered through the filter screen inside the hopper to remove large particulate impurities, it flows into the recovery tank. The packing layer (such as activated carbon) inside the recovery tank further adsorbs the brine to remove fine impurities and achieve decolorization. After closing the sealed cover, the control system opens the fifth regulating valve and the first on / off valve, adding EDI demineralized water into the recovery tank through the EDI demineralized water pipeline. Based on the actual amount of recovered material, the first flow meter monitors the amount of demineralized water added, diluting the material in the recovery tank to approximately 40 wt.%.

[0019] Subsequently, the control system controls the opening and closing of the second regulating valve (nitrogen pipeline) and the third regulating valve (venting pipeline) of the replacement system, introducing nitrogen into the recovery tank for replacement to remove air from the tank. During this process, the pressure inside the tank is monitored in real time using a pressure gauge to ensure complete replacement. At the same time, the control system regulates the first regulating valve (hot water pipeline) of the insulation device, and based on the temperature data fed back by the thermometer, stabilizes the temperature inside the recovery tank above 50°C to prevent salt crystallization.

[0020] The material inside the tank is sampled through the sampling port on the outlet pipeline of the recovery tank to test the color value, concentration and UV value. After the indicators are qualified, the discharge valve is opened and the material enters the spray tower through the spray branch pipe. The spray tower is set above the salt formation reactor. The material flows into the salt formation reactor under the action of gravity. During this period, the amount of material entering the spray tower is monitored by the second flow meter.

[0021] After the material is discharged, the control system opens the second regulating valve to purge with nitrogen gas, which is then vented through the salt-forming reactor. Once purging is complete, the second regulating valve is closed, and the fifth regulating valve and the second on / off valve are opened. EDI deionized water, equivalent to 1-1.5 times the amount of material measured by the second flow meter, is added to the spray tower to flush the pipelines and the spray tower, ensuring that any remaining material completely enters the salt-forming reactor.

[0022] The pressure sensor on the spray tower monitors the pressure inside the tower in real time. When the pressure exceeds the preset value, the control system automatically opens the fourth regulating valve (the pipeline from the spray tower to the water seal tank) to discharge the gas inside the tower to the water seal tank, so as to maintain the stability of the system pressure and ensure the safe and orderly progress of the recovery process.

[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0024] (1) By setting up a large-capacity recovery tank, the batch continuous recovery of brine was achieved. Combined with an automated control system, the frequent operation of traditional small-capacity devices was avoided, the workload was reduced, and the recovery efficiency was improved.

[0025] (2) The dual isolation design of nitrogen replacement system and sealing cap can effectively remove the air brought in during the recycling process, reduce the contact between brine and air, avoid oxidation and discoloration of brine and increase UV value and color value, and ensure the quality of brine.

[0026] (3) Large particles of impurities can be initially filtered through the filter screen in the recycling hopper, and the packing layer in the recycling tank can further adsorb impurities and decolorize them, reducing the risk of brine contamination and ensuring the purity of the recycled brine.

[0027] (4) By using the jacket insulation device on the outer wall of the recycling tank and the control system to adjust the valve of the hot water pipeline, the temperature of the brine can be stably controlled above 50°C, preventing the recycling port from being blocked due to low temperature crystallization of the brine and reducing the difficulty of cleaning. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the nylon 66 salt solution sampling and recovery device of this utility model;

[0029] In the diagram: 1. Recovery tank; 2. Spray tower; 3. Salt-forming reactor; 4. Recovery hopper; 5. Packing layer; 6. EDI desalination water pipeline; 7. First flow meter; 8. Second flow meter; 9. Water seal tank; 10. Jacket; 11. First regulating valve; 12. Second regulating valve; 13. Third regulating valve; 14. Pressure sensor; 15. Thermometer; 16. Pressure gauge; 17. Sealing cover; 18. Filter screen; 19. Fourth regulating valve; 20. Fifth regulating valve; 21. Sampling port; 22. First on / off valve; 23. Second on / off valve. Detailed Implementation

[0030] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0031] Example 1

[0032] like Figure 1 As shown, the sampling and recovery device for nylon 66 brine includes a recovery tank 1 with a capacity of 150L. The outlet of the recovery tank 1 is connected to the spray branch pipe of the spray tower 2 via a pipeline, and the outlet of the spray tower 2 is connected to the salt-forming reactor 3 via a pipeline. A recovery hopper 4 is provided above the recovery tank 1, and the interior of the recovery tank 1 is filled with a packing layer 5. The recovery tank 1 is also equipped with a heat preservation device, a displacement system, and a monitoring unit. EDI demineralized water pipelines 6 are connected to both the recovery tank 1 and the spray branch pipe of the spray tower 2. A first flow meter 7 is provided on the EDI demineralized water pipeline 6, and a second flow meter 8 is provided on the pipeline from the recovery tank 1 to the spray tower 2. The air outlet of the spray tower 2 is connected to a water seal tank 9 via a pipeline. The device also includes a control system.

[0033] The heat preservation device includes a jacket 10 installed on the outer wall of the recovery tank 1 and a hot water pipeline connected to the jacket 10. A first regulating valve 11 is provided on the hot water pipeline, and the first regulating valve 11 is electrically connected to the control system.

[0034] The replacement system includes a nitrogen pipeline and a venting pipeline connected to the recovery tank 1. A second regulating valve 12 and a third regulating valve 13 are respectively installed on the nitrogen pipeline and the venting pipeline. The second regulating valve 12 and the third regulating valve 13 are electrically connected to the control system.

[0035] The monitoring unit includes a thermometer 15 and a pressure gauge 16 installed on the recovery tank 1, and the thermometer 15 and the pressure gauge 16 are electrically connected to the control system.

[0036] The spray tower 2 is equipped with a pressure sensor 14, which is electrically connected to the control system.

[0037] The inlet of the recycling hopper 4 is equipped with a sealing cover 17, and the inside of the recycling hopper 4 is equipped with a filter screen 18.

[0038] A fourth regulating valve 19 is provided on the pipeline from the spray tower 2 to the water seal tank 9, and a fifth regulating valve 20 is provided on the EDI demineralized water pipeline 6. The fourth regulating valve 19 and the fifth regulating valve 20 are electrically connected to the control system.

[0039] The outlet pipeline of the recycling tank 1 is equipped with a sampling port 21.

[0040] A first on / off valve 22 is provided on the branch line from the EDI demineralized water pipeline 6 to the recovery tank 1, and a second on / off valve 23 is provided on the branch line from the EDI demineralized water pipeline 6 to the spray tower 2. The first on / off valve 22 and the second on / off valve 23 are electrically connected to the control system respectively.

[0041] The specific steps for doing this are as follows:

[0042] The operator first opens the sealing cover 17 of the recovery hopper 4 and slowly pours the nylon 66 brine solution to be recovered generated during the production process into the recovery hopper 4. Under the action of gravity, the brine solution passes through the filter screen 18 inside the hopper, initially filtering out large particulate impurities, and then flows smoothly into the recovery tank 1. The brine solution is adsorbed by the packing layer 5 (activated carbon) inside the recovery tank 1, effectively removing fine impurities and completing the decolorization treatment. After the operator closes the sealing cover 17, the control system starts working. According to the amount of material in the recovery tank 1, the control system opens the fifth regulating valve 20 and the first on / off valve 22, adding EDI demineralized water into the recovery tank 1 through the EDI demineralized water pipeline 6. The amount of demineralized water added is monitored by the first flow meter 7, diluting the material in the recovery tank 1 to a concentration of 40 wt.%. After dilution is completed, the fifth regulating valve 20 and the first on / off valve 22 are closed. Next, the control system opens the second regulating valve 12 on the nitrogen pipeline and the third regulating valve 13 on the vent pipeline to purge nitrogen into the recovery tank 1. During this process, the pressure change inside the tank is monitored in real time by the pressure gauge 16 on the recovery tank 1. After the purging is completed, the third regulating valve 13 and the second regulating valve 12 are closed. At the same time, the control system adjusts the first regulating valve 11 on the hot water pipeline according to the value fed back by the thermometer 15 to keep the hot water circulation in the jacket 10 of the recovery tank 1 stable and maintain the temperature inside the recovery tank 1 above 50°C to prevent material crystallization. Subsequently, the operator extracts a small amount of material through the sampling port 21 on the outlet pipeline of the recovery tank 1 to test its color value, concentration, and UV value. After confirming that all indicators are qualified, the control system opens the discharge valve of the recovery tank 1, and the material enters the spray tower 2 through the spray branch pipe. At this time, the second flow meter 8 monitors the amount of material entering the spray tower 2 in real time. Under the action of gravity, the material flows from the spray tower 2 into the salt-forming reactor 3 below. After the material in spray tower 2 is completely discharged, the control system reopens the second regulating valve 12 on the nitrogen pipeline for purging. Exhaust gas is then released through the salt-forming reactor 3. After purging, the second regulating valve 12 is closed, and the fifth regulating valve 20 and the second on / off valve 23 are opened. EDI demineralized water equivalent to 1.5 times the amount of material in spray tower 2 is added through the EDI demineralized water pipeline 6 to flush the pipeline and spray tower 2, ensuring that residual material is completely carried into the salt-forming reactor 3. After flushing, the fifth regulating valve 20 and the second on / off valve 23 are closed, and the second regulating valve 12 on the nitrogen pipeline is opened to introduce nitrogen into spray tower 2 for pressurized purging, further removing residual material. The pressure sensor 14 on spray tower 2 continuously monitors the pressure inside the tower. When the pressure exceeds a preset value, the control system automatically opens the fourth regulating valve 19 to discharge excess gas into the tower through the pipeline to the water seal tank 9 to maintain system pressure stability, ultimately completing a full brine recovery process.

Claims

1. A sampling and recovery device for nylon 66 brine, characterized in that, The system includes a recovery tank (1), the outlet of which is connected to the spray branch pipe of the spray tower (2) via a pipeline, and the outlet of the spray tower (2) is connected to the salt-forming reactor (3) via a pipeline; a recovery hopper (4) is provided above the recovery tank (1), and the inside of the recovery tank (1) is filled with a packing layer (5). The recovery tank (1) is also equipped with a heat preservation device, a replacement system and a monitoring unit; an EDI demineralized water pipeline (6) is connected to both the recovery tank (1) and the spray branch pipe of the spray tower (2), a first flow meter (7) is provided on the EDI demineralized water pipeline (6), a second flow meter (8) is provided on the pipeline from the recovery tank (1) to the spray tower (2), and the air outlet of the spray tower (2) is connected to the water seal tank (9) via a pipeline; and a control system is also included.

2. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, The heat preservation device includes a jacket (10) installed on the outer wall of the recovery tank (1) and a hot water pipeline connected to the jacket (10). A first regulating valve (11) is provided on the hot water pipeline, and the first regulating valve (11) is electrically connected to the control system.

3. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, The replacement system includes a nitrogen pipeline and a venting pipeline connected to the recovery tank (1). A second regulating valve (12) and a third regulating valve (13) are respectively provided on the nitrogen pipeline and the venting pipeline. The second regulating valve (12) and the third regulating valve (13) are electrically connected to the control system.

4. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, The monitoring unit includes a thermometer (15) and a pressure gauge (16) installed on the recovery tank (1), and the thermometer (15) and the pressure gauge (16) are electrically connected to the control system.

5. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, The spray tower (2) is equipped with a pressure sensor (14), which is electrically connected to the control system.

6. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, The inlet of the recycling hopper (4) is provided with a sealing cover (17), and the inside of the recycling hopper (4) is provided with a filter screen (18).

7. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, A fourth regulating valve (19) is provided on the pipeline from the spray tower (2) to the water seal tank (9), and a fifth regulating valve (20) is provided on the EDI demineralized water pipeline (6). The fourth regulating valve (19) and the fifth regulating valve (20) are electrically connected to the control system respectively.

8. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, The recycling tank (1) is equipped with a sampling port (21) on its outlet pipeline.

9. The sampling and recovery device for nylon 66 brine according to claim 1, characterized in that, A first on / off valve (22) is provided on the branch line from the EDI demineralized water pipeline (6) to the recovery tank (1), and a second on / off valve (23) is provided on the branch line from the EDI demineralized water pipeline (6) to the spray tower (2). The first on / off valve (22) and the second on / off valve (23) are electrically connected to the control system respectively.

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