A discharge port die for high pressure foaming kettle

Abstract

The utility model discloses a discharge port die for a high-pressure foaming kettle, belongs to the field of foaming technology, comprises a connecting component and a pressure relief component, the pressure relief component is installed on the high-pressure foaming kettle through the connecting component, the pressure relief component comprises a capillary port die, a pressure relief channel with a diameter smaller than that of raw material particles is arranged in the capillary port die, a discharge port is arranged at the lower end of the capillary port die, because the size of the pressure relief channel is smaller than that of the raw material particles, the particles are subjected to greater resistance when being pressed through the capillary port die, presenting a flow state in which a mixed solution of polymer particles, water and foaming agent appear alternately, which is equivalent to a slightly blocked pressure relief process, so that the pressure drop and the temperature drop become slow, and then the particles after discharge are more uniform, and the problem that in the discharge stage of kettle pressure foaming in the prior art, the size of the foamed particles is difficult to maintain uniformity due to the sudden drop of pressure is solved.

Description

Technical Field

[0001] The utility model relates to the field of foaming equipment, in particular to a discharge port die for a high-pressure foaming kettle. Background Art

[0002] Foaming materials is an effective way to reduce their density and expand their functional applications. Supercritical fluid high-pressure foaming technology is an effective method for preparing polymer foam materials that has developed rapidly in the past 20 years. As one of the commonly used supercritical fluid foaming processes, kettle pressure foaming is essentially an intermittent foaming technology. It has many advantages such as simple equipment structure, wide application of polymer systems, and easy control of the processing process. It is beneficial to stabilize product quality, improve production efficiency, and has extremely high industrial value.

[0003] In the existing autoclave foaming production process, it is still difficult to maintain the uniformity of the size and cell stability of the foaming beads in the same autoclave, which reduces the production efficiency and product qualification rate. There are several main reasons for this: first, water is used as a dispersion medium. Under the action of vertical stirring equipment, it is impossible to ensure that the raw material particles are heated uniformly and the foaming agent is dispersed uniformly; second, pressure is the main factor that determines the particle foaming ratio. It is difficult to maintain uniformity in the previous and next stages during the discharge and pressure relief process; finally, during the rapid pressure relief process, the temperature drops sharply, and it is difficult to keep the foaming state consistent.

[0004] The problem of polymer particle dispersion can be easily solved by modifying the foaming kettle or the stirring device. For example, Chinese patent CN111992138A discloses a horizontal supercritical fluid foaming autoclave with a built-in stirring device. The reactor is horizontally arranged, and the stirring shaft of the stirring drive crosses the kettle body and is connected to the stirring paddle located inside the kettle body. The horizontal stirring paddle rotates to drive the fluid inside the kettle body to produce convection circulation, drive the raw material particles to flow evenly, and improve the product yield. Another Chinese patent CN 209552286U uses an oblique stirring device with a crescent-shaped blade. The stirring paddle is at an angle of 40.5° to the horizontal direction. Vertical vortices are easily formed during the stirring process, which can also ensure that the raw material particles are evenly dispersed. However, the disadvantage of the above patent is that during the discharge and pressure relief process, due to the change in pressure, it is difficult to keep the foaming particles uniform. Utility Model Content

[0005] The utility model aims to overcome the problem in the prior art that it is difficult to keep the size of foamed particles uniform due to a sudden drop in pressure during the discharge stage of the kettle pressure foaming, and provides a discharge port die for a high-pressure foaming kettle, which can improve the uniformity of the foamed bead foam.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] The utility model discloses a discharge port die for a high-pressure foaming kettle, comprising a connecting component and a pressure relief component, wherein the pressure relief component is installed on the high-pressure foaming kettle through the connecting component, the pressure relief component comprises a capillary port die, a pressure relief channel with a diameter smaller than that of raw material particles is arranged in the capillary port die, and a discharge port is arranged at the lower end of the capillary port die.

[0008] In the utility model, since the size of the pressure relief channel is smaller than the size of the raw material particles, the particles will encounter greater resistance when they are pressed through the capillary die, presenting a flow state in which a mixed solution of polymer particles, water and foaming agent appears alternately, which is equivalent to a slight blockage pressure relief process, making the pressure drop slow, thereby making the particles after discharge more uniform.

[0009] Preferably, the present application further comprises a heating component, the heating component is located between the connecting component and the pressure relief component, a heating channel is provided in the heating component, the heating component comprises a heating interlayer, and a temperature sensor connected to the heating channel, and the lower end of the heating channel is connected to the pressure relief channel. The heating component can maintain the thermal stability of the material during the pressure release process, achieve a uniform discharge temperature, and also ensure that the foaming bead pore morphology is stable and consistent.

[0010] Preferably, the heating interlayer is a spiral heating wire sleeve, and the outside of the heating interlayer is coated with a heat insulation layer, which can prevent heat from being lost to the outside.

[0011] Preferably, the thermal insulation layer is made of rock wool.

[0012] Preferably, a connecting channel is provided in the connecting assembly, the connecting channel is connected to an anti-blocking air inlet, and the anti-blocking air inlet is provided with an anti-blocking air inlet valve. When the pressure relief channel is blocked, compressed air can be introduced through the air inlet to flush the blocked channel.

[0013] Preferably, a discharge valve is further provided on the connecting channel, and the discharge valve is used to control the switch of the discharge process.

[0014] Preferably, the pressure relief assembly includes a positioning sleeve, the capillary die is installed in the positioning sleeve, and the heating assembly includes a positioning sleeve connector, and the positioning sleeve connector is detachably connected to the positioning sleeve. The capillary die can be quickly replaced by removing the positioning sleeve, so as to cope with different situations of discharge particles.

[0015] Preferably, a limit stop ring is provided in the positioning sleeve and is located at the lower side of the capillary die. The limit stop ring can prevent the capillary die from moving due to air pressure.

[0016] Preferably, an elastic pad is provided between the capillary die and the positioning sleeve connector, and the elastic pad can play a sealing role.

[0017] Preferably, the pressure relief assembly further comprises a baffle plate located below the discharge port, which can prevent the high-pressure water from splashing onto the capillary die, causing the discharge temperature to drop rapidly.

[0018] Therefore, the utility model has the following beneficial effects: (1) it can ensure that the raw material particles in the same kettle are subjected to the same pressure and pressure reduction rate before discharge, thereby ensuring that the size of the foamed beads is uniform; (2) the material is heated while being discharged slowly to achieve a uniform discharge temperature, thereby ensuring that the pore morphology of the foamed beads is stable and consistent; (3) the problem of die blockage can be cleared at any time through the air inlet, including during the production process, in conjunction with the air inlet valve at the upper end of the kettle body to form a circulating airflow in the kettle, thereby achieving efficient and comprehensive cleaning; (4) the pressure relief component is easy to replace and adjust to meet different discharge needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model installed on a foaming kettle.

[0020] Figure 2 It is a structural schematic diagram of the first embodiment of the utility model.

[0021] Figure 3 It is a structural schematic diagram of the second embodiment of the utility model.

[0022] Figure 4 It is a structural schematic diagram of the third embodiment of the present utility model.

[0023] In the figure: high-pressure foaming kettle 1 kettle bottom discharge port 2 discharge port die 3 kettle body air inlet 4 kettle body feed port 5 kettle internal pressure gauge 6 kettle internal thermometer 7 kettle body connector 8 discharge valve mounting seat 9 discharge valve connector 10 discharge valve 11 mounting flange 12 positioning sleeve connector 13 heating interlayer 14 temperature detector 15 positioning sleeve 16 capillary die 17 baffle 18 limit retaining ring 19 elastic pad 20. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0025] Embodiment 1, as Figure 1-2 As shown, a discharge port mold 3 for a high-pressure foaming kettle 1 is installed on the discharge port 2 at the bottom of the high-pressure foaming kettle 1. The high-pressure foaming kettle 1 is provided with a kettle body air inlet 4 and a kettle body feed port 5. The high-pressure foaming kettle 1 is also equipped with an inner kettle pressure gauge 6 and an inner kettle thermometer 7.

[0026] The discharge port die 3 includes a connection component, a heating component, and a pressure relief component from top to bottom. A discharge channel is provided in the connection component, a heating channel is provided in the heating component, and a pressure relief channel is provided in the pressure relief component. The discharge channel, the heating channel, and the pressure relief channel are connected in sequence. The connection component is connected to the discharge port 2 at the bottom of the kettle. The connection component includes a kettle body connector 8, a discharge valve mounting seat 9, and a discharge valve connector 10 from top to bottom. A discharge valve 11 is installed on the discharge valve mounting seat 9. Threaded holes are provided on the upper and lower sides of the discharge valve mounting seat 9, and the threaded holes on the upper and lower sides are threadedly connected to the kettle body connector 8 and the discharge valve connector 10, respectively.

[0027] The heating assembly includes a mounting flange 12 and a positioning sleeve connector 13. The mounting flange 12 and the discharge valve connector 10 are also connected by threads for easy disassembly. When encountering large-particle raw material slices or materials with low pressure and temperature stability requirements, the mounting flange 12 and the lower components can be disassembled, and only the connecting components are retained. Discharging is performed through the connecting components to achieve more efficient production. A heating interlayer 14 is provided on the outside of the mounting flange 12. The heating interlayer 14 is a spiral heating pipe sleeve, and the outside of the heating interlayer 14 is covered with an insulation layer made of rock wool. A temperature detector 15 connected to the heating channel is installed in the positioning sleeve connector 13.

[0028] The pressure relief assembly includes a positioning sleeve 16 and a capillary die 17 installed in the positioning sleeve 16. The pressure relief channel includes a transition section located at the upper part thereof and a capillary section at the lower part thereof, wherein the transition section is a funnel-shaped channel with a funnel opening of 60°. The diameter of the capillary die 17 is 1-20 mm and the length is 0.5-80 mm. The size of the capillary die 17 and the size of the corresponding positioning sleeve 16 can be adjusted according to different materials and pressure drops. The positioning sleeve 16 is also connected to the positioning sleeve connector 13 by threads.

[0029] The working process of the utility model is as follows: when the high-pressure foaming kettle 1 equipped with the discharge port die 3 is used, the material slices to be foamed are placed in the lower kettle cavity through the feed port and an appropriate amount of water and dispersion medium are injected, supercritical carbon dioxide is charged through the air inlet at the upper end of the kettle body, the amount of gas charged is monitored and controlled by a pressure gauge, and at the same time the kettle body is heated to the required temperature, the temperature in the kettle is monitored and adjusted by the temperature detector 15 at the upper end of the kettle body, and the pressure-maintaining saturation infiltration operation is performed when the required pressure and temperature are reached. After the saturation stage, discharge begins. The kettle discharge valve 11 is opened, and the fully wetted polymer particles flow from the kettle into the discharge channel and then into the heating channel. At this time, the high-pressure ball valve at the air inlet on the discharge valve connector 10 is in a closed state, and the configured temperature detector 15 feeds back real-time signals. If the temperature is lower than the kettle temperature in the gas saturation stage, the external spiral heating sleeve starts to heat, and the temperature is maintained equal to or slightly higher than the kettle temperature in the gas saturation stage to ensure that the polymer particles in the channel are thermally stable. The material continues to pass through the heating channel to reach the pressure relief channel. Due to the plasticizing effect of the gas foaming agent, the polymer particles have a certain elasticity. Although the particle size is larger than the diameter of the capillary die 173, they flow into the capillary die 17 one by one under the action of high pressure. In this process, the particles are subject to greater resistance, which is equivalent to slight blockage. At this time, the air inlet valve at the upper end of the foaming kettle is opened at the same time, and the supercritical fluid is continuously filled into the kettle to ensure that the pressure is equal to the processing pressure in the gas saturation stage. All particles are extruded through the capillary die 17 under the same internal pressure, and undergo the same pressure drop process to complete the foaming process.

[0030] Embodiment 2, as Figure 3 As shown, a discharge port mold 3 for a high-pressure foaming kettle 1 is installed on the discharge port 2 at the bottom of the high-pressure foaming kettle 1. The high-pressure foaming kettle 1 is provided with a kettle body air inlet 4 and a kettle body feed port 5. The high-pressure foaming kettle 1 is also equipped with an inner kettle pressure gauge 6 and an inner kettle thermometer 7.

[0031] The discharge port die 3 includes a connection component, a heating component, and a pressure relief component from top to bottom. A discharge channel is provided in the connection component, a heating channel is provided in the heating component, and a pressure relief channel is provided in the pressure relief component. The discharge channel, the heating channel, and the pressure relief channel are connected in sequence. The connection component is connected to the discharge port 2 at the bottom of the kettle. The connection component includes a kettle body connector 8, a discharge valve mounting seat 9, and a discharge valve connector 10 from top to bottom. A discharge valve 11 is installed on the discharge valve mounting seat 9. Threaded holes are provided on the upper and lower sides of the discharge valve mounting seat 9, and the threaded holes on the upper and lower sides are threadedly connected to the kettle body connector 8 and the discharge valve connector 10, respectively.

[0032] The heating assembly includes a mounting flange 12 and a positioning sleeve connector 13. The mounting flange 12 and the discharge valve connector 10 are also connected by threads for easy disassembly. When encountering large-particle raw material slices or materials with low pressure and temperature stability requirements, the mounting flange 12 and the lower components can be disassembled, and only the connecting components are retained. Discharging is performed through the connecting components to achieve more efficient production. A heating interlayer 14 is provided on the outside of the mounting flange 12. The heating interlayer 14 is a spiral heating pipe sleeve, and the outside of the heating interlayer 14 is covered with an insulation layer made of rock wool. A temperature detector 15 connected to the heating channel is installed in the positioning sleeve connector 13.

[0033] The pressure relief assembly includes a positioning sleeve 16 and a capillary die 17 installed in the positioning sleeve 16. The pressure relief channel includes a transition section located at the upper part thereof and a capillary section at the lower part thereof, wherein the transition section is a funnel-shaped channel with a funnel opening of 60°. The diameter of the capillary die 17 is 1-20 mm and the length is 0.5-80 mm. The size of the capillary die 17 and the size of the corresponding positioning sleeve 16 can be adjusted according to different materials and pressure drops. The positioning sleeve 16 is also connected to the positioning sleeve connector 13 by threads.

[0034] In this embodiment, in order to prevent water from splashing onto the capillary die 17 and the foaming kettle under high pressure during discharge, causing a drop in temperature and affecting the quality stability of the bead foam, a trumpet-shaped baffle 18 is installed under the positioning sleeve 16, and its diameter exceeds the width of the kettle.

[0035] The working process of the utility model is as follows: when the high-pressure foaming kettle 1 equipped with the discharge port die 3 is used, the material slices to be foamed are placed in the lower kettle cavity through the feed port and an appropriate amount of water and dispersion medium are injected, supercritical carbon dioxide is charged through the air inlet at the upper end of the kettle body, the amount of gas charged is monitored and controlled by a pressure gauge, and at the same time the kettle body is heated to the required temperature, the temperature in the kettle is monitored and adjusted by the temperature detector 15 at the upper end of the kettle body, and the pressure-maintaining saturation infiltration operation is performed when the required pressure and temperature are reached. After the saturation stage, discharge begins. The kettle discharge valve 11 is opened, and the fully wetted polymer particles flow from the kettle into the discharge channel and then into the heating channel. At this time, the high-pressure ball valve at the air inlet on the discharge valve connector 10 is in a closed state, and the configured temperature detector 15 feeds back real-time signals. If the temperature is lower than the kettle temperature in the gas saturation stage, the external spiral heating sleeve starts to heat, and the temperature is maintained equal to or slightly higher than the kettle temperature in the gas saturation stage to ensure that the polymer particles in the channel are thermally stable. The material continues to pass through the heating channel to reach the pressure relief channel. Due to the plasticizing effect of the gas foaming agent, the polymer particles have a certain elasticity. Although the particle size is larger than the diameter of the capillary die 173, they flow into the capillary die 17 one by one under the action of high pressure. In this process, the particles are subject to greater resistance, which is equivalent to slight blockage. At this time, the air inlet valve at the upper end of the foaming kettle is opened at the same time, and the supercritical fluid is continuously filled into the kettle to ensure that the pressure is equal to the processing pressure in the gas saturation stage. All particles are extruded through the capillary die 17 under the same internal pressure, and undergo the same pressure drop process to complete the foaming process.

[0036] Embodiment three, as Figure 4 As shown, a discharge port mold 3 for a high-pressure foaming kettle 1 is installed on the discharge port 2 at the bottom of the high-pressure foaming kettle 1. The high-pressure foaming kettle 1 is provided with a kettle body air inlet 4 and a kettle body feed port 5. The high-pressure foaming kettle 1 is also equipped with an inner kettle pressure gauge 6 and an inner kettle thermometer 7.

[0037] The discharge port die 3 includes a connection component, a heating component, and a pressure relief component from top to bottom. A discharge channel is provided in the connection component, a heating channel is provided in the heating component, and a pressure relief channel is provided in the pressure relief component. The discharge channel, the heating channel, and the pressure relief channel are connected in sequence. The connection component is connected to the discharge port 2 at the bottom of the kettle. The connection component includes a kettle body connector 8, a discharge valve mounting seat 9, and a discharge valve connector 10 from top to bottom. A discharge valve 11 is installed on the discharge valve mounting seat 9. Threaded holes are provided on the upper and lower sides of the discharge valve mounting seat 9, and the threaded holes on the upper and lower sides are threadedly connected to the kettle body connector 8 and the discharge valve connector 10, respectively.

[0038] The heating assembly includes a mounting flange 12 and a positioning sleeve connector 13. The mounting flange 12 and the discharge valve connector 10 are also connected by threads for easy disassembly. When encountering large-particle raw material slices or materials with low pressure and temperature stability requirements, the mounting flange 12 and the lower components can be disassembled, and only the connecting components are retained. Discharging is performed through the connecting components to achieve more efficient production. A heating interlayer 14 is provided on the outside of the mounting flange 12. The heating interlayer 14 is a spiral heating pipe sleeve, and the outside of the heating interlayer 14 is covered with an insulation layer made of rock wool. A temperature detector 15 connected to the heating channel is installed in the positioning sleeve connector 13.

[0039] The pressure relief assembly includes a positioning sleeve 16 and a capillary die 17 installed in the positioning sleeve 16. The pressure relief channel includes a transition section located at the upper part thereof and a capillary section at the lower part thereof, wherein the transition section is a funnel-shaped channel with a funnel opening of 60°. The diameter of the capillary die 17 is 1-20 mm and the length is 0.5-80 mm. The size of the capillary die 17 and the size of the corresponding positioning sleeve 16 can be adjusted according to different materials and pressure drops. The positioning sleeve 16 is also connected to the positioning sleeve connector 13 by threads. In the present embodiment, a limit stop ring 19 located at the lower side of the capillary die 17 is provided in the positioning sleeve 16 to prevent the capillary die 17 from moving due to air pressure. An elastic pad 20 is provided between the capillary die 17 and the positioning sleeve connector 13 to play a sealing role.

[0040] In this embodiment, in order to prevent water from splashing onto the capillary die 17 and the foaming kettle under high pressure during discharge, causing a drop in temperature and affecting the quality stability of the bead foam, a trumpet-shaped baffle 18 is installed under the positioning sleeve 16, and its diameter exceeds the width of the kettle.

[0041] The working process of the utility model is as follows: when the high-pressure foaming kettle 1 equipped with the discharge port die 3 is used, the material slices to be foamed are placed in the lower kettle cavity through the feed port and an appropriate amount of water and dispersion medium are injected, supercritical carbon dioxide is charged through the air inlet at the upper end of the kettle body, the amount of gas charged is monitored and controlled by a pressure gauge, and at the same time the kettle body is heated to the required temperature, the temperature in the kettle is monitored and adjusted by the temperature detector 15 at the upper end of the kettle body, and the pressure-maintaining saturation infiltration operation is performed when the required pressure and temperature are reached. After the saturation stage, discharge begins. The kettle discharge valve 11 is opened, and the fully wetted polymer particles flow from the kettle into the discharge channel and then into the heating channel. At this time, the high-pressure ball valve at the air inlet on the discharge valve connector 10 is in a closed state, and the configured temperature detector 15 feeds back real-time signals. If the temperature is lower than the kettle temperature in the gas saturation stage, the external spiral heating sleeve starts to heat, and the temperature is maintained equal to or slightly higher than the kettle temperature in the gas saturation stage to ensure that the polymer particles in the channel are thermally stable. The material continues to pass through the heating channel to reach the pressure relief channel. Due to the plasticizing effect of the gas foaming agent, the polymer particles have a certain elasticity. Although the particle size is larger than the diameter of the capillary die 173, they flow into the capillary die 17 one by one under the action of high pressure. In this process, the particles are subject to greater resistance, which is equivalent to slight blockage. At this time, the air inlet valve at the upper end of the foaming kettle is opened at the same time, and the supercritical fluid is continuously filled into the kettle to ensure that the pressure is equal to the processing pressure in the gas saturation stage. All particles are extruded through the capillary die 17 under the same internal pressure, and undergo the same pressure drop process to complete the foaming process.

Claims

1. A discharge die for a high pressure foaming kettle, characterized in that: It includes a connecting component and a pressure relief component. The pressure relief component is installed on the high-pressure foaming kettle through the connecting component. The pressure relief component includes a capillary die. The capillary die is provided with a pressure relief channel with a diameter smaller than that of the raw material particles. The lower end of the capillary die is provided with a discharge port.

2. A discharge die for a high pressure foaming kettle according to claim 1, characterized in that: It also includes a heating component, which is located between the connecting component and the pressure relief component. A heating channel is provided in the heating component. The heating component includes a heating interlayer and a temperature sensor connected to the heating channel. The lower end of the heating channel is connected to the pressure relief channel.

3. A discharge die for a high pressure foaming kettle according to claim 2, characterized in that: The heating interlayer is a spiral heating wire tube sleeve, and the outside of the heating interlayer is coated with a heat insulation layer.

4. A discharge die for a high pressure foaming kettle according to claim 3, characterized in that: The material of the heat insulation layer is rock wool.

5. The discharge die for a high pressure foaming kettle according to claim 1, characterized in that: A connecting channel is provided in the connecting component, an anti-blocking air inlet is connected to the connecting channel, and an anti-blocking air inlet valve is provided on the anti-blocking air inlet.

6. A discharge die for a high pressure foaming kettle according to claim 5, characterized in that: The connecting channel is also provided with a discharge valve.

7. A discharge die for a high pressure foaming kettle according to claim 2, characterized in that: The pressure relief component comprises a positioning sleeve, the capillary die is installed in the positioning sleeve, and the heating component comprises a positioning sleeve connector, and the positioning sleeve connector is detachably connected to the positioning sleeve.

8. A discharge die for a high pressure foaming kettle according to claim 7, characterized in that: A limiting retaining ring is arranged in the positioning sleeve and is located at the lower side of the capillary die.

9. A discharge die for a high pressure foaming kettle according to claim 8, characterized in that: An elastic pad is arranged between the capillary die and the positioning sleeve connector.

10. A discharge die for a high pressure foaming reactor according to any one of claims 1 to 9, characterized in that: The pressure relief assembly also includes a baffle located below the discharge port.

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