A depolymerization liquid preparation device

Abstract

The utility model discloses a kind of depolymerization liquid blending devices, including controller, analyzer and at least one blending unit, the blending unit includes depolymerization kettle, output pump, liquid level meter, first feed pipeline, second feed pipeline, circulation branch, sampling branch and discharge branch, the liquid level meter is connected with the depolymerization kettle and is used to detect the liquid level height in the depolymerization kettle, the first feed pipeline is connected with the depolymerization kettle and is used to access crude depolymerization liquid, the second feed pipeline is connected with the depolymerization kettle and is used to access methanol, first feed valve is connected in the first feed pipeline, second feed valve is connected in the second feed pipeline, the inlet of the output pump is connected with the outlet of the depolymerization kettle.The utility model can automatically control blending process, reduce manual participation, can analyze concentration on line and realize real-time closed-loop control, and then can reduce labor cost, improve blending efficiency, also can avoid to improve security by avoiding to empty and liquid level.

Description

Technical Field

[0001] This utility model relates to a depolymerization solution preparation device. Background Technology

[0002] Currently, in the glyphosate production process, the crude depolymerization solution (i.e., crude formaldehyde solution) needs to be prepared in a mixing device to meet the concentration requirements of downstream processes. Chinese patent CN219424370U discloses a device for producing paraformaldehyde depolymerization solution using a 50% formaldehyde solution. However, existing mixing devices rely heavily on manual operation throughout the process, requiring manual intervention. Furthermore, concentration analysis depends on offline laboratory sampling, making real-time closed-loop control impossible. The operation is extremely cumbersome, inefficient, and labor-intensive. In addition, manual operation is prone to dangerous situations such as overflow and liquid level depletion, increasing safety risks. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a depolymerization liquid preparation device that can automatically control the preparation process, reduce manual intervention, analyze the concentration online and realize real-time closed-loop control, thereby reducing labor costs, improving preparation efficiency, and avoiding overflow and liquid level cavitation to improve safety.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is: a depolymerization liquid preparation device, including a controller, an analyzer and at least one preparation unit, wherein the preparation unit includes a depolymerization kettle, an output pump, a level gauge, a first feed pipe, a second feed pipe, a circulation branch, a sampling branch and a discharge branch;

[0005] The level gauge is connected to the depolymerization vessel and is used to detect the liquid level in the depolymerization vessel.

[0006] The first feed line is connected to the depolymerization reactor and is used to feed crude depolymerization liquid; the second feed line is connected to the depolymerization reactor and is used to feed methanol; a first feed valve is connected to the first feed line; and a second feed valve is connected to the second feed line.

[0007] The inlet of the output pump is connected to the outlet of the depolymerization reactor;

[0008] The outlet of the output pump is connected to the circulation inlet of the depolymerization reactor through the circulation branch;

[0009] The outlet of the output pump is connected to the inlet of the analyzer through the sampling branch;

[0010] The outlet of the output pump is also connected to the discharge branch;

[0011] A circulation valve is connected to the circulation branch, a sampling valve is connected to the sampling branch, and a discharge valve is connected to the discharge branch.

[0012] The level gauge and the analyzer are respectively connected to the input terminal of the controller, and the controller is respectively connected to the output pump, the first feed valve, the second feed valve, the circulation valve, the sampling valve and the discharge valve.

[0013] Furthermore, the dispatching unit also includes an alarm, and the controller is connected to the alarm.

[0014] Furthermore, the dispensing unit also includes a condenser;

[0015] The condenser has an inlet for receiving cooling water, an outlet for discharging cooling water, an inlet connected to the exhaust port of the depolymerization vessel and for receiving gas discharged from the depolymerization vessel, a liquid phase outlet connected to the reflux port of the depolymerization vessel and for discharging condensate into the depolymerization vessel, and a gas phase outlet for discharging uncondensed gas.

[0016] Furthermore, in order to inject nitrogen into the depolymerization reactor, the preparation unit also includes a third feed line, which is connected to the depolymerization reactor and used to introduce nitrogen. A third feed valve is connected to the third feed line.

[0017] Furthermore, in order to inject the catalyst into the depolymerization reactor, the preparation unit also includes a fourth feed line, which is connected to the depolymerization reactor and used to connect the catalyst. The fourth feed line is connected to a fourth feed valve.

[0018] Furthermore, a flow meter is connected to the inlet of the analyzer.

[0019] Furthermore, in order to control the temperature in the depolymerization reactor, the mixing unit also includes an inlet steam pipe, an outlet steam pipe, an inlet cooling water pipe, and an outlet cooling water pipe;

[0020] The depolymerization reactor is equipped with a jacket, and a temperature control chamber is provided in the jacket;

[0021] The steam inlet pipe, the steam outlet pipe, the cooling water inlet pipe, and the cooling water outlet pipe are respectively connected to the temperature control chamber on the corresponding depolymerization reactor;

[0022] Valves are connected to the steam inlet pipeline, the steam outlet pipeline, the cooling water inlet pipeline, and the cooling water outlet pipeline.

[0023] Furthermore, a pressure gauge and a self-regulating valve are connected to the depolymerization reactor.

[0024] Furthermore, a thermometer is connected to the depolymerization reactor.

[0025] Furthermore, it also includes a transfer pump, a raw material tank for storing the crude depolymerization liquid, and an elevated tank for storing methanol;

[0026] The first feed pipeline is connected to the outlet of the transfer pump, and the inlet of the transfer pump is connected to the raw material tank;

[0027] The second feed pipe is connected to the high-level tank.

[0028] Using the above technical solution, each mixing unit can be independently controlled. Taking one mixing unit as an example, initially, the controller controls the first feed valve to open so that crude depolymerization liquid can be injected into the depolymerization vessel through the first feed pipeline. When the level gauge detects that the liquid level in the depolymerization vessel has risen to a set height, the level gauge will send a high liquid level signal to the controller. After receiving the high liquid level signal, the controller will control the first feed valve to close, control the output pump to start, control the stirring device in the depolymerization vessel to start, control the circulation valve to open, and control the sampling valve and discharge valve to close. At this time, the liquid in the depolymerization vessel will flow out of the outlet of the depolymerization vessel under the pumping of the output pump, flow through the output pump and the circulation branch, and then flow back into the depolymerization vessel from the circulation inlet of the depolymerization vessel, realizing the circulation flow of the liquid. After the circulation flow has lasted for a period of time, the controller controls the sampling valve to open so that a part of the liquid flowing through the output pump flows into the analyzer from the sampling branch. Then, the analyzer analyzes the concentration of the liquid and sends the concentration information to the controller. Then, the controller controls the sampling valve to close. If the concentration information received by the controller is between 44.8% and 45.2%, the liquid at this point meets the concentration requirements of the downstream process, meaning the mixing is complete and the discharge step can be executed. The discharge step is as follows: the controller shuts off the stirring device, opens the discharge valve, and closes the circulation valve, allowing the liquid in the depolymerization reactor to flow through the output pump and be discharged from the discharge branch. The discharged liquid can then be stored in a storage tank. The liquid level in the depolymerization reactor will decrease as the liquid is discharged until the level gauge detects that the liquid level in the depolymerization reactor is below 18%. At this point, the level gauge sends a low-level signal to the controller. Upon receiving the low-level signal, the controller closes the discharge valve and stops the output pump. If the concentration information received by the controller is higher than 45.2%, the controller will open the second feed valve to add a certain amount of methanol to the depolymerization vessel for reaction. Then, the controller will close the second feed valve. At this time, the output pump and circulation valve remain open, and the liquid in the depolymerization vessel will continue to circulate under the pumping of the output pump. After circulating for a period of time, the controller will open the sampling valve again to allow a portion of the liquid to flow from the sampling branch into the analyzer. The analyzer will then analyze the liquid concentration again and send the new concentration information to the controller. After that, the controller will close the sampling valve again. If the new concentration information received by the controller is between 44.8% and 45.2%, the preparation is complete, and the discharge step described above can be executed. If the new concentration information received by the controller is still higher than 45.2%, methanol will be added to the depolymerization vessel again until the concentration is adjusted to between 44.8% and 45.2%, and then the discharge step will be executed. If the concentration information received by the controller is lower than 44.75% or the moisture content is higher than 2%, the controller will activate the corresponding alarm. Then, the staff will manually add paraformaldehyde solid to the depolymerization reactor until the concentration is adjusted to between 44.8% and 45.2%, and then proceed with the discharge step.In this embodiment, the controller can automatically control the entire mixing process, reducing manual intervention. The analyzer can analyze the liquid concentration online and realize real-time closed-loop control, reducing labor costs and improving mixing efficiency. The level gauge can monitor the liquid level in the depolymerization vessel, significantly reducing the risk of overflow and liquid level evacuation, and improving production safety. Attached Figure Description

[0029] Figure 1 This is a process flow diagram of the depolymerization solution preparation device of this utility model;

[0030] Figure 2 This is a process flow diagram of one of the mixing units of this utility model;

[0031] In the diagram: 1. Analyzer; 2. Depolymerization vessel; 3. Output pump; 4. Level gauge; 5. First feed line; 6. Second feed line; 7. Circulation branch; 8. Sampling branch; 9. Discharge branch; 10. First feed valve; 11. Second feed valve; 12. Circulation valve; 13. Sampling valve; 14. Discharge valve; 15. Stirring device; 16. Condenser; 17. Third feed line; 18. Third feed valve; 19. Fourth feed line; 20. Fourth feed valve; 21. Steam inlet line; 22. Steam outlet line; 23. Cooling water inlet line; 24. Cooling water outlet line; 25. Temperature control chamber. Detailed Implementation

[0032] To make the contents of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0033] like Figure 1 , 2 As shown, a depolymerization solution preparation device includes a controller, an analyzer 1, and at least one preparation unit. The preparation unit includes a depolymerization vessel 2, an output pump 3, a level gauge 4, a first feed pipe 5, a second feed pipe 6, a circulation branch 7, a sampling branch 8, and a discharge branch 9.

[0034] The level gauge 4 is connected to the depolymerization vessel 2 and is used to detect the liquid level in the depolymerization vessel 2;

[0035] The first feed pipe 5 is connected to the depolymerization vessel 2 and is used to feed crude depolymerization liquid. The second feed pipe 6 is connected to the depolymerization vessel 2 and is used to feed methanol. The first feed pipe 5 is connected to a first feed valve 10, and the second feed pipe 6 is connected to a second feed valve 11.

[0036] The inlet of the output pump 3 is connected to the outlet of the depolymerization reactor 2;

[0037] The outlet of the output pump 3 is connected to the circulation inlet of the depolymerization reactor 2 through the circulation branch 7;

[0038] The outlet of the output pump 3 is connected to the inlet of the analyzer 1 through the sampling branch 8;

[0039] The outlet of the output pump 3 is also connected to the discharge branch 9;

[0040] A circulation valve 12 is connected to the circulation branch 7, a sampling valve 13 is connected to the sampling branch 8, and a discharge valve 14 is connected to the discharge branch 9.

[0041] The level gauge 4 and the analyzer 1 are respectively connected to the input terminal of the controller, and the controller is respectively connected to the output pump 3, the first feed valve 10, the second feed valve 11, the circulation valve 12, the sampling valve 13 and the discharge valve 14;

[0042] The dispatching unit may also include an alarm, and the controller is connected to the alarm.

[0043] Specifically, each of the mixing units can be controlled independently. Taking one mixing unit as an example, initially the controller controls the first feed valve 10 to open so that crude depolymerization liquid can be injected into the depolymerization vessel 2 through the first feed pipe 5. When the level gauge 4 detects that the liquid level in the depolymerization vessel 2 has risen to a set height, the level gauge 4 will send a high liquid level signal to the controller. After receiving the high liquid level signal, the controller will control the first feed valve 10 to close, control the output pump 3 to start, control the stirring device 15 in the depolymerization vessel 2 to start, control the circulation valve 12 to open, and control the sampling valve 13 and the discharge valve 14 to close. At this time, the liquid in the depolymerization vessel 2 will flow out of the outlet of the depolymerization vessel 2 under the pumping of the output pump 3, then flow through the output pump 3 and the circulation branch 7, and then flow back into the depolymerization vessel 2 from the circulation inlet of the depolymerization vessel 2, realizing the circulation flow of the liquid. After circulating for a period of time, the controller controls the sampling valve 13 to open so that a portion of the liquid flowing through the output pump 3 flows from the sampling branch 8 into the analyzer 1. The analyzer 1 then analyzes the concentration of the liquid and sends the concentration information to the controller. The controller then controls the sampling valve 13 to close.

[0044] If the concentration information received by the controller is between 44.8% and 45.2%, the liquid at this time meets the concentration requirements of the downstream process, meaning that the mixing is complete and the discharge step can be executed. The discharge step is as follows: the controller controls the stirring device 15 to close, controls the discharge valve 14 to open, and controls the circulation valve 12 to close, so that the liquid in the depolymerization vessel 2 flows through the output pump 3 and is discharged from the discharge branch 9. The discharged liquid can be stored in the storage tank. The liquid level in the depolymerization vessel 2 will decrease as the liquid is discharged, until the level gauge 4 detects that the liquid level in the depolymerization vessel 2 is lower than 18%. At this time, the level gauge 4 sends a low liquid level signal to the controller. After receiving the low liquid level signal, the controller controls the discharge valve 14 to close and controls the output pump 3 to stop.

[0045] If the concentration information received by the controller is higher than 45.2%, the controller will open the second feed valve 11 to add a certain amount of methanol to the depolymerization vessel 2 for reaction. Then, the controller will close the second feed valve 11. At this time, the output pump 3 and the circulation valve 12 remain open, and the liquid in the depolymerization vessel 2 will continue to circulate under the pumping of the output pump 3. After circulating for a period of time, the controller will open the sampling valve 13 again to allow a portion of the liquid to flow from the sampling branch 8 into the analyzer 1. The analyzer 1 will then analyze the liquid concentration again and send the new concentration information to the controller. After that, the controller will close the sampling valve 13 again. If the new concentration information received by the controller is between 44.8% and 45.2%, the preparation is complete and the discharge step described above can be executed. If the new concentration information received by the controller is still higher than 45.2%, methanol will be added to the depolymerization vessel 2 again until the concentration is adjusted to between 44.8% and 45.2%, and then the discharge step will be executed.

[0046] If the concentration information received by the controller is below 44.75% or the moisture content is above 2%, the controller will activate the corresponding alarm. Then, the operator will manually add paraformaldehyde solid to the depolymerization reactor 2 until the concentration is adjusted to between 44.8% and 45.2%, and then proceed with the discharge step. In this embodiment, the controller can automatically control the entire mixing process, reducing manual intervention. The analyzer 1 can analyze the liquid concentration online and achieve real-time closed-loop control, reducing labor costs and improving mixing efficiency. The level gauge 4 can monitor the liquid level in the depolymerization reactor 2, significantly reducing the risk of overflow and liquid level evacuation, and improving production safety.

[0047] In this embodiment, there are two or more mixing units, all of which share one analyzer 1. Each mixing unit is equipped with a sampling valve 13. Under the control of the controller, only one sampling valve 13 in one mixing unit can be opened at any given time. Of course, in some embodiments, each mixing unit may be equipped with its own analyzer 1.

[0048] In this embodiment, the analyzer 1 can be an existing online concentration analyzer 1, the controller can be a PLC controller, and the specific structure of the stirring device 15 in the depolymerization vessel 2 is existing technology well known to those skilled in the art, and will not be described in detail in this embodiment.

[0049] like Figure 1 , 2 As shown, the mixing unit may also include a condenser 16;

[0050] The condenser 16 has an inlet for receiving cooling water, an outlet for discharging cooling water, an inlet connected to the exhaust port of the depolymerization vessel 2 for receiving gas discharged from the depolymerization vessel 2, a liquid phase outlet connected to the reflux port of the depolymerization vessel 2 for discharging condensate into the depolymerization vessel 2, and a gas phase outlet for discharging uncondensed gas. Specifically, the gas generated in the reaction in the depolymerization vessel 2 flows into the condenser 16 from the inlet, and then exchanges heat with the cooling water in the condenser 16 to condense and liquefy. The condensed water flows out from the liquid phase outlet of the condenser 16 and flows back into the depolymerization vessel 2 from the reflux port of the depolymerization vessel 2. The uncondensed gas is discharged from the gas phase outlet of the condenser 16.

[0051] like Figure 1 , 2 As shown, the mixing unit may also include a third feed line 17, which is connected to the depolymerization vessel 2 and used to introduce nitrogen gas. A third feed valve 18 is connected to the third feed line 17. Specifically, opening the third feed valve 18 can inject nitrogen gas into the depolymerization vessel 2 from the third feed line 17 to create an inert reaction environment.

[0052] like Figure 1 , 2 As shown, the mixing unit may also include a fourth feed line 19, which is connected to the depolymerization vessel 2 and used to feed the catalyst. A fourth feed valve 20 is connected to the fourth feed line 19. Specifically, opening the fourth feed valve 20 can inject the catalyst into the depolymerization vessel 2 from the fourth feed line 19.

[0053] Specifically, the inlet of the analyzer 1 can be connected to a flow meter. After the sampling valve 13 is opened, a portion of the liquid will flow into the analyzer 1 from the sampling branch 8. When the flow rate detected by the flow meter is greater than the set value, the analyzer 1 will analyze the concentration of the liquid and send the concentration information to the controller to avoid the instability of the liquid flow into the analyzer 1, which may lead to detection deviation.

[0054] like Figure 1 , 2As shown, the dispensing unit may also include a steam inlet pipe 21, a steam outlet pipe 22, a cooling water inlet pipe 23, and a cooling water outlet pipe 24;

[0055] The depolymerization vessel 2 is equipped with a jacket, and a temperature control chamber 25 is provided in the jacket;

[0056] The steam inlet pipe 21, the steam outlet pipe 22, the cooling water inlet pipe 23, and the cooling water outlet pipe 24 are respectively connected to the temperature control chamber 25 on the corresponding depolymerization reactor 2;

[0057] Valves are connected to the steam inlet pipe 21, the steam outlet pipe 22, the cooling water inlet pipe 23, and the cooling water outlet pipe 24. Specifically, when it is necessary to heat the liquid in the depolymerization reactor 2, the valves in the steam inlet pipe 21 and the steam outlet pipe 22 can be opened, while the valves in the cooling water inlet pipe 23 and the cooling water outlet pipe 24 can be closed. This allows steam to flow from the steam inlet pipe 21 into the temperature control chamber 25 and heat the liquid in the depolymerization reactor 2. The steam then mixes with condensate and is discharged from the steam outlet pipe 22. When it is necessary to cool the liquid in the depolymerization reactor 2, the valves in the cooling water inlet pipe 23 and the cooling water outlet pipe 24 can be opened, while the valves in the steam inlet pipe 21 and the steam outlet pipe 22 can be closed. This allows cooling water to flow from the cooling water inlet pipe 23 into the temperature control chamber 25 and cool the liquid in the depolymerization reactor 2. The cooling water then is discharged from the cooling water outlet pipe 24.

[0058] Specifically, a pressure gauge and a self-regulating valve can be connected to the depolymerization vessel 2. The pressure gauge can monitor the pressure in the depolymerization vessel 2, and the self-regulating valve can automatically adjust the pressure in the depolymerization vessel 2. The specific structure of the self-regulating valve is prior art well known to those skilled in the art, and will not be described in detail in this embodiment. A thermometer can also be connected to the depolymerization vessel 2 to monitor the temperature in the depolymerization vessel 2. In this embodiment, a thermometer, a pressure gauge, and a self-regulating valve are respectively connected to the depolymerization vessel 2 in each mixing unit.

[0059] Specifically, the depolymerization solution preparation device may further include a transfer pump, a raw material tank for storing crude depolymerization solution, and an elevated tank for storing methanol. The first feed pipe 5 is connected to the outlet of the transfer pump, the inlet of the transfer pump is connected to the raw material tank, and the second feed pipe 6 is connected to the elevated tank. In each preparation unit, the first feed pipe 5 is connected to the outlet of the transfer pump, and the second feed pipe 6 is connected to the elevated tank. When the first feed valve 10 is opened, the transfer pump can pump the crude depolymerization solution from the raw material tank to the depolymerization reactor 2. When the second feed valve 11 is opened, the methanol in the elevated tank can flow into the depolymerization reactor 2.

[0060] In summary, each of the aforementioned mixing units can be controlled independently. Taking one mixing unit as an example, initially, the controller controls the first feed valve 10 to open so that crude depolymerization liquid can be injected into the depolymerization vessel 2 through the first feed pipe 5. When the level gauge 4 detects that the liquid level in the depolymerization vessel 2 has risen to a set height, the level gauge 4 will send a high liquid level signal to the controller. After receiving the high liquid level signal, the controller will control the first feed valve 10 to close, control the output pump 3 to start, control the stirring device 15 in the depolymerization vessel 2 to start, control the circulation valve 12 to open, and control the sampling valve 13 and the discharge valve 14 to close. At this time, the liquid in the depolymerization vessel 2 will flow out of the outlet of the depolymerization vessel 2 under the pumping of the output pump 3, then flow through the output pump 3 and the circulation branch 7, and then flow back into the depolymerization vessel 2 from the circulation inlet of the depolymerization vessel 2, realizing the circulation flow of the liquid. After a period of circulation, the controller opens the sampling valve 13 to allow a portion of the liquid flowing through the output pump 3 to flow from the sampling branch 8 into the analyzer 1. The analyzer 1 then analyzes the concentration of the liquid and sends the concentration information to the controller. The controller then closes the sampling valve 13. If the concentration information received by the controller is between 44.8% and 45.2%, the liquid at this point meets the concentration requirements of the downstream process, meaning the mixing is complete and the discharge step can be performed. The discharge step is as follows: the controller closes the stirring device 15, opens the discharge valve 14, and closes the circulation valve 12, so that the liquid in the depolymerization vessel 2 flows through the output pump 3 and is discharged from the discharge branch 9. The discharged liquid can be stored in a storage tank. The liquid level in the depolymerization vessel 2 will decrease as the liquid is discharged until the level gauge 4 detects that the liquid level in the depolymerization vessel 2 is below 18%. At this point, the level gauge 4 sends a low liquid level signal to the controller. Upon receiving the low liquid level signal, the controller closes the discharge valve 14 and stops the output pump 3. If the concentration information received by the controller is higher than 45.2%, the controller will open the second feed valve 11 to add a certain amount of methanol to the depolymerization vessel 2 for reaction. Then, the controller will close the second feed valve 11. At this time, the output pump 3 and the circulation valve 12 remain open, and the liquid in the depolymerization vessel 2 will continue to circulate under the pumping of the output pump 3. After circulating for a period of time, the controller will open the sampling valve 13 again to allow a portion of the liquid to flow from the sampling branch 8 into the analyzer 1. The analyzer 1 will then analyze the liquid concentration again and send the new concentration information to the controller. After that, the controller will close the sampling valve 13 again. If the new concentration information received by the controller is between 44.8% and 45.2%, the preparation is complete and the discharge step described above can be executed. If the new concentration information received by the controller is still higher than 45.2%, methanol will be added to the depolymerization vessel 2 again until the concentration is adjusted to between 44.8% and 45.2%, and then the discharge step will be executed.If the concentration information received by the controller is below 44.75% or the moisture content is above 2%, the controller will activate the corresponding alarm. Then, the operator will manually add paraformaldehyde solid to the depolymerization reactor 2 until the concentration is adjusted to between 44.8% and 45.2%, and then proceed with the discharge step. In this embodiment, the controller can automatically control the entire mixing process, reducing manual intervention. The analyzer 1 can analyze the liquid concentration online and achieve real-time closed-loop control, reducing labor costs and improving mixing efficiency. The level gauge 4 can monitor the liquid level in the depolymerization reactor 2, significantly reducing the risk of overflow and liquid level evacuation, and improving production safety.

[0061] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A depolymerization solution preparation device, characterized in that, It includes a controller, an analyzer (1) and at least one mixing unit, wherein the mixing unit includes a depolymerization vessel (2), an output pump (3), a level gauge (4), a first feed line (5), a second feed line (6), a circulation branch (7), a sampling branch (8) and a discharge branch (9). The level gauge (4) is connected to the depolymerization vessel (2) and is used to detect the liquid level in the depolymerization vessel (2); The first feed line (5) is connected to the depolymerization vessel (2) and is used to feed crude depolymerization liquid. The second feed line (6) is connected to the depolymerization vessel (2) and is used to feed methanol. The first feed line (5) is connected to a first feed valve (10), and the second feed line (6) is connected to a second feed valve (11). The inlet of the output pump (3) is connected to the outlet of the depolymerization vessel (2); The outlet of the output pump (3) is connected to the circulation inlet of the depolymerization vessel (2) through the circulation branch (7); The outlet of the output pump (3) is connected to the inlet of the analyzer (1) through the sampling branch (8); The outlet of the output pump (3) is also connected to the discharge branch (9); A circulation valve (12) is connected to the circulation branch (7), a sampling valve (13) is connected to the sampling branch (8), and a discharge valve (14) is connected to the discharge branch (9). The level gauge (4) and the analyzer (1) are respectively connected to the input terminal of the controller, and the controller is respectively connected to the output pump (3), the first feed valve (10), the second feed valve (11), the circulation valve (12), the sampling valve (13) and the discharge valve (14).

2. The depolymerization solution preparation device according to claim 1, characterized in that, The dispatching unit also includes an alarm, and the controller is connected to the alarm.

3. The depolymerization solution preparation device according to claim 1, characterized in that, The mixing unit also includes a condenser (16). The condenser (16) has an inlet for receiving cooling water, an outlet for discharging cooling water, an inlet connected to the exhaust port of the depolymerization vessel (2) and for receiving gas discharged from the depolymerization vessel (2), a liquid phase outlet connected to the reflux port of the depolymerization vessel (2) and for discharging condensate into the depolymerization vessel (2), and a gas phase outlet for discharging uncondensed gas.

4. The depolymerization solution preparation device according to claim 1, characterized in that, The mixing unit also includes a third feed pipe (17), which is connected to the depolymerization vessel (2) and used to introduce nitrogen gas. A third feed valve (18) is connected in the third feed pipe (17).

5. The depolymerization solution preparation device according to claim 1, characterized in that, The mixing unit also includes a fourth feed pipe (19), which is connected to the depolymerization vessel (2) and used to feed the catalyst. A fourth feed valve (20) is connected in the fourth feed pipe (19).

6. The depolymerization solution preparation device according to claim 1, characterized in that, The inlet of the analyzer (1) is connected to a flow meter.

7. The depolymerization solution preparation device according to claim 1, characterized in that, The distribution unit also includes a steam inlet pipe (21), a steam outlet pipe (22), a cooling water inlet pipe (23), and a cooling water outlet pipe (24). The depolymerization vessel (2) is provided with a jacket, and the jacket is provided with a temperature control chamber (25). The steam inlet pipe (21), the steam outlet pipe (22), the cooling water inlet pipe (23), and the cooling water outlet pipe (24) are respectively connected to the temperature control chamber (25) on the corresponding depolymerization vessel (2); Valves are connected to the steam inlet pipe (21), the steam outlet pipe (22), the cooling water inlet pipe (23), and the cooling water outlet pipe (24).

8. The depolymerization solution preparation device according to claim 1, characterized in that, The depolymerization vessel (2) is connected to a pressure gauge and a self-regulating valve.

9. The depolymerization solution preparation device according to claim 1, characterized in that, A thermometer is connected to the depolymerization vessel (2).

10. The depolymerization solution preparation device according to claim 1, characterized in that, It also includes a transfer pump, a raw material tank for storing crude depolymerization liquid, and an elevated tank for storing methanol; The first feed pipe (5) is connected to the outlet of the transfer pump, and the inlet of the transfer pump is connected to the raw material tank; The second feed pipe (6) is connected to the high-level tank.

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