Polymer supercritical fluid foaming system

Abstract

The utility model provides a polymer supercritical fluid foaming system, and belongs to the field of high polymer material processing. According to the technical scheme, a foaming kettle is connected with a gas storage tank through a high-pressure pipeline, a sealing cover is not directly opened after the foaming kettle is subjected to heat preservation and pressure preservation, a second stop valve on the high-pressure pipeline of the gas storage tank is opened, nitrogen or carbon dioxide flows into the gas storage tank from the foaming kettle under the action of pressure difference, and when the pressure of the foaming kettle and the gas storage tank is balanced or the pressure of the foaming kettle is 2 MPa, the nitrogen or the carbon dioxide flows into the gas storage tank. And closing the second stop valve, opening the sealing cover of the foaming kettle, pouring out the foaming material, and entering the next foaming period. The system disclosed by the utility model has the beneficial effects that the one-way stop valve can be opened when heat preservation and pressure preservation are finished in the foaming process, and nitrogen or carbon dioxide enters the gas storage tank for cyclic utilization, so that gas emission is reduced, and materials are saved.

Description

Technical Field

[0001] The utility model relates to the field of polymer material processing, in particular to a polymer supercritical fluid foaming system. Background Art

[0002] The kettle type foaming is widely used due to its simple process, convenience, reliability and wide adaptability. The specific process is as follows: add the thermoplastic resin material to the high-pressure foaming kettle, and then seal it. Fill the high-pressure foaming kettle with nitrogen or carbon dioxide through an air compressor. At this time, the foaming kettle is heated by heat-conducting oil. The temperature in the kettle needs to be raised to above 100°C according to different materials, and the pressure is raised to 30-40MPa, and then the temperature and pressure are kept constant for 3-4 hours. Then, the foaming agent and the foaming material are discharged from the foaming kettle together, and the foaming material is directly foamed or enters the foaming chamber for foaming and shaping, and the nitrogen or carbon dioxide is discharged into the atmosphere. During the entire production process, a large amount of excess nitrogen or carbon dioxide in the foaming kettle is discharged into the air, resulting in material waste. For this purpose, the present application document provides a polymer supercritical fluid foaming system. Utility Model Content

[0003] The utility model aims to provide a polymer supercritical fluid foaming system. When the heat preservation and pressure preservation in the foaming process of the system are finished, the one-way stop valve is opened, and nitrogen or carbon dioxide enters the gas storage tank for recycling, thereby reducing gas emissions and saving materials.

[0004] The utility model is achieved through the following measures:

[0005] A polymer supercritical fluid foaming system, characterized in that it comprises an air circuit system and an oil circuit system;

[0006] The gas circuit system includes a gas preparation machine, which is connected to a compressor, a buffer and a foaming kettle in sequence through a high-pressure pipeline, the gas outlet of the foaming kettle is connected to a gas storage tank through a high-pressure pipeline, and the gas outlet of the gas storage tank is connected to the high-pressure pipeline between the gas preparation machine and the compressor through a high-pressure pipeline. The gas circuit system is a flow channel for nitrogen or carbon dioxide, constituting a nitrogen or carbon dioxide recovery and utilization system;

[0007] The oil system includes an oil storage tank, the oil outlet of the oil storage tank is sequentially connected to a thermal oil furnace, a flow pump and a foaming kettle through an oil pipe, and the oil outlet of the foaming kettle is connected to the oil inlet of the oil storage tank through an oil pipe;

[0008] The specific features of the utility model also include:

[0009] The gas preparation machine is a nitrogen preparation machine or a carbon dioxide preparation machine, and the working medium in the gas circuit system is nitrogen or carbon dioxide;

[0010] The working medium in the oil system is heat transfer oil.

[0011] A first stop valve is provided on the high-pressure pipeline between the gas preparation machine and the compressor, and the high-pressure pipeline connected to the gas outlet of the gas storage tank is connected to the high-pressure pipeline between the first stop valve and the compressor;

[0012] A fourth stop valve is arranged in the high-pressure pipeline connected to the gas outlet of the gas storage tank, and the valve is kept normally open during production.

[0013] A safety valve, a pressure gauge, a second stop valve and a pressure reducing valve are sequentially arranged in the high-pressure pipeline between the foaming kettle and the gas storage tank. Before the foaming is completed, the second stop valve is in a closed state. After the insulation and pressure maintenance of the foaming material is completed and before unloading, the safety valve and the second stop valve are opened, and the nitrogen or carbon dioxide that is not integrated into the foaming material enters the gas storage tank and is stored under the action of the pressure difference. When the reading of the pressure gauge is 2MPa, the safety valve and the second stop valve are closed to stop exhausting.

[0014] A first proportional solenoid valve is arranged in the high-pressure pipeline between the buffer and the foaming kettle.

[0015] A third stop valve is arranged in the oil pipe between the oil storage tank and the foaming kettle.

[0016] A second proportional solenoid valve and a temperature sensor 1 are sequentially arranged in the oil pipe between the flow pump and the foaming kettle;

[0017] The foaming kettle is provided with a second temperature sensor.

[0018] The volume of the gas storage tank is 20 times the volume of the foaming kettle, ensuring that when the foaming pressure is 40 MPa, the gas storage tank can recover 95% of the foaming agent.

[0019] The operating steps of this system are as follows:

[0020] S1, adding the foaming material into the foaming kettle and covering it with a sealing cover;

[0021] S2, open all valves except the second stop valve;

[0022] S3, the gas preparation machine and the compressor start working, nitrogen or carbon dioxide is filled into the foaming kettle through the buffer, and the valve is closed to maintain pressure after the pressure reaches a certain value;

[0023] S4, the heat-conducting oil in the oil storage tank is heated to the required temperature by the heat-conducting oil furnace, and enters the interlayer of the foaming kettle through the flow pump to heat the foaming material and nitrogen or carbon dioxide in the foaming kettle. The temperature in the foaming kettle can be maintained at the desired temperature by the temperature control system composed of the temperature sensor, etc. During this period, the pressure increase caused by the temperature rise can be adjusted by the second stop valve;

[0024] S5. Maintain the temperature and pressure at a constant value for about 3-4 hours;

[0025] S6, close the gas system and the oil system, open the second stop valve, and the gas not mixed with the material flows from the foaming kettle into the gas storage tank through the pressure reducing valve;

[0026] S7. When the pressure gauge points to 2MPa, close the second stop valve, open the fourth stop valve, and enter the next production cycle.

[0027] The utility model provides a polymer supercritical fluid foaming system, which adds a pressure relief process after heat preservation and pressure maintenance and before unloading. Specifically, the foaming kettle is connected to the gas storage tank through a high-pressure pipeline. After the foaming kettle is heat-insulated and pressure-maintained, the sealing cover is no longer opened directly, but the second stop valve on the high-pressure pipeline to the gas storage tank is opened, and nitrogen or carbon dioxide flows from the foaming kettle into the gas storage tank under the action of the pressure difference. When the pressures of the two are balanced or the pressure of the foaming kettle is 2MPa, the second stop valve is closed, and then the sealing cover of the foaming kettle is opened to pour out the foaming material, and enter the next foaming cycle.

[0028] The beneficial effects of the utility model are as follows: the system can realize opening the one-way stop valve during the foaming agent injection process and when the heat preservation and pressure maintenance in the foaming process is finished, nitrogen or carbon dioxide enters the gas storage tank for recycling, thereby reducing gas emissions and saving materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the connection of various components of an embodiment of the utility model.

[0030] Among them, the accompanying drawings are marked as: 1. gas preparation machine; 2. first stop valve; 3. compressor; 4. buffer; 5. first proportional solenoid valve; 6. foaming kettle; 7. temperature sensor 2; 8. pressure gauge; 9. second stop valve; 10. pressure reducing valve; 11. gas storage tank; 13. oil storage tank; 14. third stop valve; 15. temperature sensor 1; 16. second proportional solenoid valve; 17. flow pump; 18. thermal oil furnace; 19. fourth stop valve; 20. safety valve. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0032] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0034] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0035] Example 1

[0036] See also Figure 1 , a polymer supercritical fluid foaming system, including an air circuit system and an oil circuit system;

[0037] The gas circuit system includes a gas preparation machine 1, which is connected to a compressor 3, a buffer 4 and a foaming kettle 6 in sequence through a high-pressure pipeline. The gas outlet of the foaming kettle 6 is connected to a gas storage tank 11 through a high-pressure pipeline. The gas outlet of the gas storage tank 11 is connected to the high-pressure pipeline between the gas preparation machine 1 and the compressor 3 through a high-pressure pipeline. The gas circuit system is a flow channel for nitrogen or carbon dioxide, constituting a nitrogen or carbon dioxide recovery and utilization system;

[0038] The oil system includes an oil storage tank 13, the oil outlet of the oil storage tank 13 is connected to a thermal oil furnace 18, a flow pump 17 and a foaming kettle 6 in sequence through an oil pipe, and the oil outlet of the foaming kettle 6 is connected to the oil inlet of the oil storage tank 13 through an oil pipe;

[0039] The gas preparation machine 1 is a nitrogen preparation machine or a carbon dioxide preparation machine, and the working medium in the gas circuit system is nitrogen or carbon dioxide;

[0040] The working medium in the oil system is heat transfer oil.

[0041] A first stop valve 2 is provided on the high-pressure pipeline between the gas preparation machine 1 and the compressor 3, and a high-pressure pipeline connected to the gas outlet of the gas storage tank 11 is connected to the high-pressure pipeline between the first stop valve 2 and the compressor 3;

[0042] A fourth stop valve 19 is provided in the high-pressure pipeline connected to the gas outlet of the gas storage tank 11, and the valve is kept normally open during production.

[0043] A safety valve 20, a pressure gauge 8, a second stop valve 9 and a pressure reducing valve 10 are sequentially arranged in the high-pressure pipeline between the foaming kettle 6 and the gas storage tank 11. Before the foaming is completed, the second stop valve 9 is in a closed state. After the insulation and pressure maintenance of the foaming material is completed, before unloading, the safety valve 20 and the second stop valve 9 are opened, and the nitrogen or carbon dioxide that is not integrated into the foaming material enters the gas storage tank 11 and is stored under the action of the pressure difference. When the reading of the pressure gauge 8 is 2MPa, the safety valve 20 and the second stop valve 9 are closed to stop exhausting.

[0044] A first proportional solenoid valve 5 is provided in the high-pressure pipeline between the buffer 4 and the foaming kettle 6 .

[0045] A third stop valve 14 is provided in the oil pipe between the oil storage tank 13 and the foaming kettle 6 .

[0046] A second proportional solenoid valve 16 and a temperature sensor 15 are sequentially arranged in the oil pipe between the flow pump 17 and the foaming kettle 6;

[0047] A temperature sensor 7 is provided on the foaming kettle 6.

[0048] The volume of the gas storage tank 11 is 20 times the volume of the foaming kettle 6, ensuring that when the foaming pressure is 40 MPa, the gas storage tank can recover 95% of the foaming agent.

[0049] The operating steps of this system are as follows:

[0050] S1, add the foaming material into the foaming kettle 6, and cover the sealing cover;

[0051] S2, open all valves except the second stop valve 9;

[0052] S3, the gas preparation machine 1 and the compressor 3 start working, and nitrogen or carbon dioxide is charged into the foaming kettle 6 through the buffer 4. When the pressure reaches a certain value, the valve is closed to maintain the pressure;

[0053] S4, the heat-conducting oil in the oil storage tank 13 is heated to the required temperature by the heat-conducting oil furnace 18, and enters the interlayer of the foaming kettle 6 through the flow pump 17 to heat the foaming material and nitrogen or carbon dioxide in the foaming kettle 6. The temperature in the foaming kettle 6 can be maintained at the desired temperature by a temperature control system composed of a temperature sensor 7, etc. During this period, the pressure increases due to the increase in temperature, which can be adjusted by the second stop valve 9;

[0054] S5. Maintain the temperature and pressure at a constant value for about 3-4 hours;

[0055] S6, close the gas system and the oil system, open the second stop valve 9, and the gas not mixed with the material flows from the foaming kettle 6 through the pressure reducing valve 10 into the gas storage tank 11;

[0056] S7. When the pressure gauge 8 points to 2MPa, close the second stop valve 9, open the fourth stop valve 19, and enter the next production cycle.

[0057] The utility model provides a polymer supercritical fluid foaming system, which adds a pressure relief process after heat preservation and pressure maintenance and before unloading. Specifically, the foaming kettle 6 is connected to the gas storage tank 11 through a high-pressure pipeline. After the foaming kettle 6 is heat-insulated and pressure-maintained, the sealing cover is no longer opened directly, but the second stop valve 9 on the high-pressure pipeline to the gas storage tank 11 is opened, and nitrogen or carbon dioxide flows from the foaming kettle 6 into the gas storage tank 11 under the action of the pressure difference. When the pressures of the two are balanced or the pressure of the foaming kettle 6 is 2MPa, the second stop valve 9 is closed, and then the sealing cover of the foaming kettle 6 is opened to pour out the foaming material, and enter the next foaming cycle.

[0058] Example 2

[0059] See also Figure 1 , taking the foaming raw material as TPU and the foaming agent as nitrogen as an example, the specific implementation process of the present invention is optimized and explained. The system includes a nitrogen preparation machine 1, a first stop valve 2, a compressor 3, a buffer 4, a first proportional solenoid valve 5, a foaming kettle 6, a temperature sensor 2 7, a pressure gauge 8, a second stop valve 9, a pressure reducing valve 10, a gas storage tank 11, an oil storage tank 13, a third stop valve 14, a temperature sensor 15, a first proportional solenoid valve 16, a flow pump 17, a thermal oil furnace 18, a fourth stop valve 19, a safety valve 20 and pressure pipes and communication wires or cables connecting the above components, wherein the nitrogen preparation machine 1, the first stop valve 2, the compressor 3, the buffer 4, the first proportional solenoid valve 5, the foaming kettle 6, the temperature sensor 2 7, the pressure gauge 8, the fourth stop valve 19, the pressure reducing valve 10 and the gas storage tank 11 are sequentially connected in series with a pressure pipe to form a nitrogen flow channel, forming a nitrogen recovery and utilization system. In this embodiment: the foaming kettle 6 has a diameter of 1 meter and a volume of 6m 3. First, add 500 kg of TPU pellets, cover the end caps and seal. The gas preparation machine 1 is a nitrogen generator. The nitrogen generator and the compressor 3 start working, and open all valves in the above-mentioned device system except the second stop valve 9. The heat-conducting oil in the oil storage tank 13 flows into the heat-conducting oil furnace 18 and is heated in the heat-conducting oil furnace 18. It enters the interlayer of the foaming kettle 6 through the high-pressure pipeline. The heat-conducting oil circulates back and forth in the heat-conducting oil furnace 18 and the foaming kettle 6, and the material in the foaming kettle 6 is heated to 155°C; at the same time, nitrogen is injected into the foaming kettle 6 through the high-pressure gas nozzle, and the pressure sensor collects signals to control the opening of the first proportional solenoid valve 5, and the pressure in the foaming kettle 6 is controlled at 40 MPa. Under the conditions of a pressure of 40 MPa and a temperature of 155°C in the foaming kettle 6, the material is kept warm and pressurized in the foaming kettle 6 for 4 hours. Then open the second stop valve 9, and the nitrogen that has not penetrated into the TPU raw material enters the gas storage tank 11 through the pressure reducing valve 10 under the action of the pressure difference. Generally, the gas storage tank 11 is set to be 20 times the volume of the foaming kettle 6. When the reading of the pressure gauge 8 is 2MPa, close all valves, unload the raw materials in the foaming kettle 6, and directly foam them into foaming materials or enter the foaming chamber for further foaming treatment. At this point, one production batch is completed and the next production batch can be started immediately. At the beginning of the next batch, 500 kg of TPU raw material is added to the foaming kettle 6. All valves except the second stop valve 9 are opened. At this time, the nitrogen in the gas storage tank 11 can meet the gas source demand of the compressor 3. The nitrogen generator can be used as a supplementary gas source. The pressure sensor is used to control the start and stop of the nitrogen generator and the opening of the first proportional solenoid valve 5 to maintain the air pressure in the foaming kettle at 40 MPa. Similarly, the heat transfer oil is pushed by the flow pump 17 to circulate and heat between the heat transfer oil furnace 18 and the foaming kettle 6, and the temperature in the foaming kettle 6 is heated to 155°C, and then the material in the foaming kettle 6 is kept at 155°C for 4 hours under a pressure of 40 MPa. After that, the second stop valve 9 is opened, and the nitrogen that has not penetrated into the TPU raw material enters the gas storage tank 11 through the pressure reducing valve 10 under the action of the pressure difference. The general gas storage tank 11 is set to be 20 times the volume of the foaming kettle. When the reading of the pressure gauge 8 is 2MPa, all valves are closed, and the raw materials in the foaming kettle 6 are discharged and directly foamed into foaming materials or enter the foaming room for further foaming treatment. At this point, the second production batch is completed. The subsequent batches replicate the process of the previous batch until the entire production cycle is completed.

[0060] Example 3

[0061] Taking TPU as the foaming raw material and carbon dioxide as the foaming agent as an example, the specific implementation process of the present invention is optimized and explained. Figure 1The system includes a carbon dioxide preparation machine, a first stop valve 2, a compressor 3, a buffer 4, a first proportional solenoid valve 5, a foaming kettle 6, a temperature sensor 2 7, a pressure gauge 8, a second stop valve 9, a pressure reducing valve 10, a gas storage tank 11, an oil storage tank 13, a third stop valve 14, a temperature sensor 15, a first proportional solenoid valve 16, a flow pump 17, a thermal oil furnace 18, a fourth stop valve 19, a safety valve 20, and pressure pipes and communication wires or cables connecting the above components, wherein the carbon dioxide preparation machine 1, the first stop valve 2, the compressor 3, the buffer 4, the first proportional solenoid valve 5, the foaming kettle 6, the temperature sensor 2 7, the pressure gauge 8, the fourth stop valve 19, the pressure reducing valve 10 and the gas storage tank 11 are sequentially connected in series with a pressure pipe to form a flow channel for carbon dioxide, thereby forming a carbon dioxide recovery and utilization system. In this embodiment: the foaming kettle 6 has a diameter of 1 meter and a volume of 6m 3. First, add 500 kg of TPU pellets, cover the end caps and seal. The carbon dioxide preparation machine and compressor 3 start working, and open all valves in the above-mentioned device system except the second stop valve 9. The heat-conducting oil in the oil storage tank 13 flows into the heat-conducting oil furnace 18 and is heated in the heat-conducting oil furnace 18. It enters the interlayer of the foaming kettle 6 through the high-pressure pipeline. The heat-conducting oil is pushed by the flow pump 17 to circulate back and forth in the heat-conducting oil furnace 18 and the foaming kettle 6, and the material in the foaming kettle 6 is heated to 120°C; at the same time, carbon dioxide is injected into the foaming kettle 6 through the high-pressure gas nozzle, and the pressure sensor collects signals to control the opening of the first proportional solenoid valve 5, and the pressure in the foaming kettle 6 is controlled at 40 MPa. Under the conditions of a pressure of 40 MPa and a temperature of 120°C in the foaming kettle 6, the material is kept warm and pressurized in the foaming kettle 6 for 2 hours. Afterwards, open the second stop valve 9, and the carbon dioxide that has not penetrated into the TPU raw material enters the gas storage tank 11 through the pressure reducing valve 10 under the action of the pressure difference. Generally, the gas storage tank 11 is set to be 20 times the volume of the foaming kettle 6. When the reading of the pressure gauge 8 is 2MPa, close all valves, unload the raw materials in the foaming kettle 6, and directly foam them into foaming materials or enter the foaming chamber for further foaming treatment. At this point, one production batch is completed and the next production batch can be started immediately. At the beginning of the next batch, 500 kg of TPU raw material is added to the foaming kettle 6. All valves except the second stop valve 9 are opened. At this time, the carbon dioxide in the gas tank 11 can meet the gas source demand of the compressor. The carbon dioxide preparation machine can be used as a gas source supplement. The pressure sensor is used to control the start and stop of the carbon dioxide preparation machine and the opening of the first proportional solenoid valve 5 to keep the air pressure in the foaming kettle 6 at 40 MPa. Similarly, the heat transfer oil is pushed by the flow pump 17 to circulate and heat between the heat transfer oil furnace 18 and the foaming kettle 6, and the temperature in the foaming kettle 6 is heated to 120°C, and then the material in the foaming kettle 6 is kept at 120°C under a pressure of 40 MPa for 4 hours. After that, the second stop valve 9 is opened, and the carbon dioxide that has not penetrated into the TPU raw material enters the gas storage tank 11 through the pressure reducing valve 10 under the action of the pressure difference. Generally, the gas storage tank 11 is set to be 20 times the volume of the foaming kettle 6. When the reading of the pressure gauge 8 is 2MPa, all valves are closed, and the raw materials in the foaming kettle 6 are discharged and directly foamed into foaming materials or enter the foaming room for further foaming treatment. At this point, the second production batch is completed. The subsequent batches replicate the process of the previous batch until the entire production cycle is completed.

[0062] Technical features not described in the present invention can be achieved through or by adopting existing technologies, and will not be elaborated here. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A polymer supercritical fluid foaming system, characterized in that: Including gas system and oil system; The gas circuit system comprises a gas preparation machine (1), the gas preparation machine (1) being connected to a compressor (3), a buffer (4) and a foaming kettle (6) in sequence through a high-pressure pipeline, the gas outlet of the foaming kettle (6) being connected to a gas storage tank (11) through a high-pressure pipeline, and the gas outlet of the gas storage tank (11) being connected to the high-pressure pipeline between the gas preparation machine (1) and the compressor (3) through a high-pressure pipeline; The oil circuit system comprises an oil storage tank (13), the oil outlet of the oil storage tank (13) being connected in sequence to a thermal oil furnace (18), a flow pump (17) and a foaming kettle (6) via an oil pipe, and the oil outlet of the foaming kettle (6) being connected to the oil inlet of the oil storage tank (13) via an oil pipe.

2. The polymer supercritical fluid foaming system according to claim 1, characterized in that: The gas preparation machine (1) is a nitrogen preparation machine or a carbon dioxide preparation machine, and the working medium in the gas circuit system is nitrogen or carbon dioxide; The working medium in the oil system is heat transfer oil.

3. The polymer supercritical fluid foaming system according to claim 1, characterized in that: A first stop valve (2) is provided on the high-pressure pipeline between the gas preparation machine (1) and the compressor (3), and a high-pressure pipeline connected to the gas outlet of the gas storage tank (11) is connected to the high-pressure pipeline between the first stop valve (2) and the compressor (3); A fourth stop valve (19) is provided in the high-pressure pipeline connected to the gas outlet of the gas storage tank (11).

4. The polymer supercritical fluid foaming system according to claim 1, characterized in that: A safety valve (20), a pressure gauge (8), a second stop valve (9) and a pressure reducing valve (10) are sequentially arranged in the high-pressure pipeline between the foaming kettle (6) and the gas storage tank (11).

5. The polymer supercritical fluid foaming system according to claim 1, characterized in that: A first proportional solenoid valve (5) is arranged in the high-pressure pipeline between the buffer (4) and the foaming kettle (6).

6. The polymer supercritical fluid foaming system according to claim 1, characterized in that: A third stop valve (14) is provided in the oil pipe between the oil storage tank (13) and the foaming kettle (6).

7. The polymer supercritical fluid foaming system according to claim 1, characterized in that: A second proportional solenoid valve (16) and a temperature sensor (15) are sequentially arranged in the oil pipe between the flow pump (17) and the foaming kettle (6); The foaming kettle (6) is provided with a second temperature sensor (7).

8. The polymer supercritical fluid foaming system according to claim 1, characterized in that: The volume of the gas storage tank (11) is 20 times the volume of the foaming kettle (6).

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