Kneader

Abstract

To provide a kneader that raises a material viscosity in returning parts to increase a returning force of the returning parts, and thereby enables prevention of a material from intruding to seal parts of material.SOLUTION: A kneader has: a chamber 2 having a kneading chamber 18 in which a material is kneaded; rotors 3 provided in the chamber 2; and returning parts 14 and 15. The returning parts 14 and 15 are formed with screws. The returning parts 14 and 15 are configured to push out the material from the returning parts 14 and 15 to the kneading chamber side by rotating with the rotors 3. A chamber 2 or the returning parts 14 and 15 or both are equipped with a cooling mechanism (cooling device 17) for cooling the material present between the chamber 2 and the returning parts 14 and 15.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a kneader that kneads materials in the presence of a working fluid in a supercritical or subcritical state. [Background technology]

[0002] Supercritical CO2 enables high dispersion and low-temperature kneading, which was difficult with conventional batch processes, in a supercritical atmosphere, making it possible to produce higher quality rubber products than with conventional processes.However, creating a supercritical atmosphere requires greater airtightness than conventional batch processes.

[0003] Patent document 1 discloses a molding processing device and a sealing method that can prevent the intrusion of the kneading object into the shaft seal section by forming multiple spiral grooves between the continuous shaft seal and the kneading section.

[0004] Patent Document 2 discloses a continuous mixer that can prevent the material to be mixed from entering the bearing section by providing a twisted blade section on the outer periphery between the continuous bearing and the material discharge section that is inclined in a direction that pushes the mixed material to the other end of the chamber as the rotor rotates. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-248115 [Patent Document 2] Japanese Patent Application Publication No. 11-333831 Summary of the Invention [Problem to be solved by the invention]

[0006] In the kneader of Patent Document 1, packing is used as a sealing material, and in order to prevent the material from entering the area where the packing is installed, multiple spiral grooves (return sections) are formed between the packing and the kneading chamber, and the material seals it. However, when a low-viscosity material is used or the screw rotation speed is reduced, if the return force (sealing ability) of the return section decreases, there is a risk that it will become difficult to maintain the sealing ability.

[0007] In the kneader of Patent Document 2, in order to prevent the material from entering the bearing installation area, twisted blades are provided on the outer periphery, which are inclined in a direction that pushes the kneaded material out to the other end of the chamber as the rotor rotates. However, as with the above, there is a possibility that the return force of the return section will decrease, and this may cause oil from the bearing to mix with the material, deteriorating the physical properties of the material.

[0008] An object of the present invention is to provide a kneader capable of increasing the returning force of the returning section by increasing the viscosity of the material in the returning section. [Means for solving the problem]

[0009] The kneading machine disclosed in the present application is a kneading machine that kneads materials in the presence of a working fluid in a supercritical or subcritical state, and has a chamber having a kneading chamber in which the materials are kneaded, a rotor provided within the chamber, and a return section, the return section having a screw formed therein and configured to rotate together with the rotor to push the materials from the return section toward the kneading chamber, and a cooling mechanism that cools the materials present between the chamber and the return section is provided within one or both of the chamber and the return section.

[0010] According to the above configuration, the material in the return section is cooled and the viscosity of the material is increased, thereby increasing the return force of the return section, preventing the material from entering the sealing section, and maintaining the sealing performance of the return section.

[0011] The cooling mechanism may be provided both inside the chamber and inside the return section.

[0012] According to the above configuration, the material in the return section is cooled and the viscosity of the material is increased, thereby further increasing the return force of the return section, further preventing the material from entering the sealing section, and maintaining the sealing performance of the return section.

[0013] The cooling mechanism may be provided between a center of the return portion in the axial direction of the rotor and an end portion of the return portion on the kneading chamber side in the axial direction of the rotor.

[0014] According to the above configuration, since the portion of the return section from the center to the kneading chamber side in the axial direction of the rotor is close to the kneading chamber where the material is kneaded, the material on the kneading chamber side in the return section can be cooled to increase the viscosity of the material, thereby suppressing the material from entering the return section. Also, by reducing the area cooled by the cooling device, an increase in the power consumption of the cooling device can be suppressed.

[0015] In the kneading machine disclosed in the present application, the cooling mechanism is a cooling mechanism that uses a cooling medium, and the cooling mechanism includes a flow meter that measures the flow rate of the cooling medium, a flow rate adjustment mechanism that adjusts the flow rate of the cooling medium, a thermometer that measures the temperature of the cooling medium, a cooling medium temperature adjustment mechanism that adjusts the temperature of the cooling medium, and a pressure gauge that measures the pressure between the chamber and the return section, and when the pressure value measured by the pressure gauge is greater than a predetermined set pressure, the flow rate adjustment mechanism performs one or both of an operation to increase the flow rate of the cooling medium and an operation to lower the temperature of the cooling medium by the cooling medium temperature adjustment mechanism.

[0016] According to the above configuration, the cooling mechanism is provided with sensors, and the presence or absence of material between the chamber and the return section is determined based on the pressure between the chamber and the return section, and the flow rate and temperature of the cooling medium are adjusted as necessary, thereby enabling the material in the return section to be efficiently cooled. As a result, by increasing the viscosity of the material in the return section, the return force of the return section is increased, preventing the material from entering the seal section and maintaining the sealing performance of the return section.

[0017] When the pressure value measured by the pressure meter is greater than the set pressure, the flow rate control mechanism may increase the flow rate of the cooling medium, and when the flow rate value measured by the flow meter becomes the maximum flow rate value that can be adjusted by the flow rate control mechanism, the cooling medium temperature control mechanism may lower the temperature of the cooling medium.

[0018] According to the above configuration, the material present between the chamber and the return section can be cooled more efficiently.

[0019] The measurement position of the pressure gauge may be located closer to the kneading chamber than a position that is one pitch of the screw away from the end of the return section on the side opposite the kneading chamber in the axial direction of the rotor.

[0020] According to the above configuration, the pressure gauge can detect the entry of the material before the material reaches the vicinity of the end of the return section on the side opposite to the kneading chamber.

[0021] The measurement position of the pressure gauge may be located at a position on the opposite side of the kneading chamber from the kneading chamber side end of the return section in the axial direction of the rotor, the position being one pitch of the screw on the opposite side of the kneading chamber.

[0022] According to the above configuration, if the pressure detection position is too close to the kneading chamber side, the material will be detected too frequently, but at this position, the intrusion of the material can be detected appropriately.

[0023] The measurement position of the pressure gauge may be located closer to the kneading chamber than a position away from the end of the return section on the kneading chamber side in the axial direction of the rotor by a distance equivalent to one pitch of the screw toward the opposite side of the kneading chamber.

[0024] According to the above configuration, if the pressure gauge value is greater than atmospheric pressure, it is determined that the material is clogged, and the flow rate of the cooling medium in the cooling mechanism is increased to lower the temperature, thereby increasing the return force of the return section and thereby discharging the material from the return section. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a kneader that can increase the viscosity of the material in the return section, thereby increasing the return force of the return section and preventing the material from entering the seal section. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a block diagram showing a kneading device. [Figure 2] 1 is a cross-sectional view of a kneader according to a first embodiment. [Figure 3] FIG. 10 is a cross-sectional view of a kneader according to a second embodiment. [Figure 4] FIG. 10 is a cross-sectional view of a kneader according to a third embodiment. [Figure 5] FIG. 10 is an explanatory diagram of a cooling device for a kneader according to a third embodiment. [Figure 6] FIG. 10 is an explanatory diagram of a modified example of the cooling device for the kneader in the third embodiment. [Figure 7] FIG. 10 is an explanatory diagram of a sensor used in a cooling mechanism of the returning section during kneading. [Figure 8] 10 is a flowchart showing a cooling mechanism of the returning section during kneading. [Figure 9] FIG. 10 is an explanatory diagram of a sensor used in a cooling mechanism of the returning section after kneading is completed. [Figure 10] 10 is a flowchart showing a cooling mechanism of the returning section after kneading is completed. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0028] [First embodiment] (Configuration of the kneading device) The kneader in the first embodiment of the present invention kneads materials in the presence of a working fluid in a supercritical state or a subcritical state. As shown in FIG. 1, which is a block diagram showing the kneading device 20, the kneader 1 is provided in the kneading device 20. In this embodiment, the material is rubber, but it may be resin, food, or the like. The kneading device 20 of this embodiment kneads in a batch manner.

[0029] Here, the supercritical state refers to a state where the temperature is equal to or higher than the critical temperature (Tc) of the working fluid and the pressure is equal to or higher than the critical pressure (Pc) of the working fluid. The subcritical state is a state close to the supercritical state. The temperature (T) and pressure (P) of the subcritical state satisfy, for example, any of the following conditions. The units of the temperature (T) and the critical temperature (Tc) in each of the following examples are in degrees Celsius. [Example 1 of subcritical state] Satisfies T≧Tc and P<Pc. [Example 2 of subcritical state] Satisfies T<Tc, P<Pc, T is sufficiently higher than room temperature, and P is sufficiently higher than normal pressure (atmospheric pressure). [Example 3 of subcritical state] Satisfies 0.5<T / Tc<1.0 and 0.5<P / Pc. [Example 4 of subcritical state] Satisfies 0.5<T / Tc and 0.5<P / Pc<1.0. [Example 5 of subcritical state] When the critical temperature (Tc) is 0°C or lower, satisfies 0.5<P / Pc.

[0030] Examples of the substance constituting the working fluid include carbon dioxide, nitrogen, hydrogen, xenon, ethane, ammonia, methanol, water, and the like. Among these, carbon dioxide and nitrogen are suitable for kneading rubber.

[0031] In this embodiment, carbon dioxide (CO2) is used as the working fluid, and kneading is performed in the presence of supercritical carbon dioxide (supercritical CO2). Note that kneading may be performed in the presence of other supercritical working fluids or in the presence of a subcritical working fluid.

[0032] The kneading device 20 has a manufacturing unit 21 and a kneading unit 22.

[0033] <The production unit 21 produces supercritical CO2. The production unit 21 has a tank 31, a first heat exchanger 32, a pump 33, and a second heat exchanger .

[0034] The tank 31 stores CO2 gas. The first heat exchanger 32 cools the CO2 gas supplied from the tank 31 to turn it into liquid CO2 (liquid CO2).

[0035] The pump 33 pressurizes the liquid CO2. Pressurizing the liquid CO2 requires less power than pressurizing the CO2 gas. The pump 33 pumps the pressurized liquid CO2 downstream.

[0036] The second heat exchanger 34 heats the pressurized liquid CO2 to vaporize it. The second heat exchanger 34 pressurizes the CO2 by vaporizing the liquid CO2 in the container. This causes the CO2 to become supercritical CO2.

[0037] The kneading section 22 kneads the materials in the presence of supercritical CO 2. The kneading section 22 includes a kneader 1, an adjusting valve 42, and a separation filter 43.

[0038] The materials and additives are supplied to a flow path connecting the production section 21 and the kneading section 22. The materials and additives supplied to the flow path are transferred into the kneader 1 together with supercritical CO2.

[0039] The kneader 1 kneads the materials and additives in the presence of supercritical CO2 inside. The materials and additives are dissolved in supercritical CO2, so they are kneaded quickly.

[0040] When the material is a polymer material such as rubber or resin, the additives are additives, kneaded rubber, plant-derived materials including cellulose nanofibers, etc. When the material is food, the additives are food additives, etc. Note that additives do not necessarily have to be used.

[0041] When mixing in the mixer 1 is completed, the mixture of the materials and additives is separated from the supercritical CO2 within the mixer 1. The mixture is discharged from the mixer 1. The adjustment valve 42 adjusts the flow rate of the supercritical CO2 discharged from the mixer 1. In this embodiment, the adjustment valve 42 reduces the pressure of the supercritical CO2 discharged from the mixer 1 to form CO2 gas. The separation filter 43 separates the additives remaining in the CO2 gas.

[0042] The kneading device 20 also has a return flow path 23. CO2 gas separated from the kneaded product after the materials are kneaded flows through the return flow path 23. The upstream end of the return flow path 23 is connected to the separation filter 43 of the kneading section 22. The downstream end of the return flow path 23 is connected to a flow path connecting the tank 31 and the first heat exchanger 32.

[0043] The CO2 gas separated from the kneaded material in the kneading section 22 is returned to the production section 21 through the return flow path 23. This allows the CO2 gas separated from the kneaded material to be reused.

[0044] (Configuration of the kneading machine) Fig. 2 is a cross-sectional view of the mixer according to the first embodiment. As shown in Fig. 2, the mixer 1 has a chamber 2, a pair of rotors 3, and return portions 14 and 15, and each of the return portions 14 and 15 is formed with a screw.

[0045] (Chamber) The materials are mixed in the chamber 2. The chamber 2 is provided with an inlet / outlet 2a. The inlet / outlet 2a is provided in each of the fixing parts 7, which will be described later. Supercritical CO2 is supplied into the chamber 2 from the inlet / outlet 2a. The supercritical CO2 in the chamber 2 is also discharged from the inlet / outlet 2a.

[0046] A cylindrical fixing portion 7 is connected to the side wall of the chamber 2. The fixing portion 7 is provided for each of the pair of rotors 3.

[0047] (Rotor) The pair of rotors 3 are rotatably provided in the chamber 2. When each of the pair of rotors 3 is rotated, the material in the chamber 2 is kneaded in the presence of supercritical CO2.

[0048] The rotor 3 has a rotor body 11, a rotor shaft 12, and return portions 14 and 15. The rotor body 11 is provided with spiral teeth (not shown). The rotor shaft 12 is one axial end of the rotor 3 and is the shaft portion of the rotor 3.

[0049] (return part) The return section 14 is provided between the rotor body 11 and the rotor shaft 12. The return section 15 is provided at the end of the rotor 3 opposite to the side where the rotor shaft 12 is provided. Each of the return sections 14, 15 is formed with a thread, and the thread of the return section 14 is formed in the opposite direction to the twisting direction of the return section 15. The return sections 14, 15 are configured to rotate together with the rotor, thereby pushing the material from the return sections 14, 15 toward the kneading chamber. The kneaded material that attempts to move toward the rotor shaft 12 is pushed back toward the kneading chamber 18, which is the center of the chamber 2, by the action of the return section 14. This prevents the kneaded material from moving toward the bearing 4. Furthermore, the kneaded material that attempts to move toward the end of the rotor 3 opposite to the side where the rotor shaft 12 is provided is pushed back toward the kneading chamber 18, which is the center of the chamber 2, by the action of the return section 15. This prevents the kneaded material from moving toward the end of the rotor 3 opposite to the side where the rotor shaft 12 is provided.

[0050] (cooling device) The cooling device 17 is a cooling mechanism that uses a cooling medium. Examples of the cooling medium include air, gases such as nitrogen, water, oil, and water-soluble coolants. In this embodiment, an example in which water is used as the cooling medium will be described.

[0051] 2, the cooling device 17 is provided to cool the material present between the chamber 2 and the return sections 14, 15. The cooling device 17 is provided in the chamber 2. In this embodiment, the cooling device 17 can increase the viscosity of the material in the return section 14, thereby increasing the return force of the return section 14. As a result, it is possible to prevent the material from entering the seal section 6, and the sealing performance of the return sections 14, 15 can be maintained.

[0052] The bearing 4 rotatably supports the rotor shaft 12. The bearing 4 is, for example, a bearing. The bearing 4 is disposed inside the fixed portion .

[0053] The seal portion 6 is a member that prevents (suppresses) fluid leakage from gaps. The seal portion 6 prevents working fluid from leaking from the center of the chamber 2 (kneading chamber 18) to the motor side. The seal portion 6 prevents fluid (for example, lubricating oil used in the bearing 4) from leaking from the motor side of the seal portion 6 to the chamber 2. The seal portion 6 is arranged inside the fixed portion 7. The seal portion 6 is provided on the motor side of the chamber 2. The seal portion 6 is provided on the chamber 2 side of the bearing 4. The seal portion 6 is arranged between the bearing 4 and the chamber 2.

[0054] 3 is a cross-sectional view of a kneader according to the second embodiment. In the kneader 1 of the first embodiment, the cooling device 17 is provided in the chamber 2, whereas in the kneader 101 of this embodiment, the cooling device 17 is provided inside the returning sections 14, 15. In this embodiment, as in the first embodiment, the viscosity of the material in the returning sections 14, 15 is increased to increase the returning force of the returning sections 14, 15, thereby preventing the material from entering the sealing section 6 and maintaining the sealing performance of the returning sections 14, 15.

[0055] 4 is a cross-sectional view of a kneader according to a third embodiment. In a kneader 201 according to this embodiment, cooling devices 17 are provided both inside the chamber 2 and the return sections 14, 15. In this embodiment, the viscosity of the material in the return sections 14, 15 is increased to further increase the return force of the return sections 14, 15, which further prevents the material from entering the seal section 6 and maintains the sealing performance of the return sections 14, 15.

[0056] 5 and 6 are explanatory diagrams of the cooling device 17 provided in the chamber 2 of the kneader 201 shown in FIG. 4. As shown in FIGS. 5 and 6, the cooling device 17 provided in the chamber 2 is provided between the kneading chamber side end and the opposite kneading chamber side end of the return sections 14, 15 in the axial direction of the rotor 3. The cooling device 17 provided in the chamber 2 is provided between the center of the return sections 14, 15 in the axial direction of the rotor 3 and the kneading chamber side end of the return sections 14, 15 in the axial direction of the rotor 3. As shown in FIGS. 5 and 6, the kneading chamber side of the center of the return sections 14, 15 in the axial direction of the rotor 3 is close to the kneading chamber 18 that kneads the material. Therefore, by cooling the material on the kneading chamber side in the return sections 14, 15 and increasing the viscosity of the material, it is possible to suppress the material from entering the return sections 14, 15. In addition, in the mixer 201 shown in FIG. 6, the area cooled by the cooling device 17 is reduced, so that an increase in the power consumption of the cooling device 17 can be suppressed.

[0057] Next, each sensor used in the cooling mechanism will be described.

[0058] FIG. 7 is an explanatory diagram of sensors used in the cooling mechanism of the return sections 14, 15 during kneading. The kneader 201 in FIG. 7 includes flow meters FL1, FL2 that measure the flow rate of the cooling medium, a flow rate adjustment mechanism (valves V1, V2) that adjusts the flow rate of the cooling medium, thermometers T1, T2 that measure the temperature of the cooling medium, a cooling medium temperature adjustment mechanism (cooling device 17) that adjusts the temperature of the cooling medium, and first pressure gauges P1, P2 that measure the pressure in the chamber 2. The detection positions of the first pressure gauges P1, P2 are located closer to the kneading chamber than a position that is one pitch of the screw away from the end of the return sections 14, 15 on the opposite side of the kneading chamber in the axial direction of the rotor 3. This allows each pressure gauge to detect the intrusion of the material before it reaches the vicinity of the end of the return sections 14, 15 on the opposite side of the kneading chamber. Furthermore, the detection positions of the first pressure gauges P1, P2 are provided at positions on the opposite side of the kneading chamber 18 from the kneading chamber side ends of the return sections 14, 15 in the axial direction of the rotor 3, which are one pitch of the screw away from the kneading chamber 18. According to this, if the pressure detection position is too close to the kneading chamber, the material will be detected too frequently, but at this position, the intrusion of the material can be detected appropriately.

[0059] 8 is a flow chart showing the cooling mechanism of the return sections 14, 15 during kneading. The control described below may be performed by a controller or manually by a person. First, kneading of the material is started (S1), and the value of the first pressure gauge P1 is equal to the atmospheric pressure P A It is determined whether the value of the first pressure gauge P1 is greater than the atmospheric pressure P A If it is greater than this (S2: Yes), it is determined that material exists between the chamber 2 and the return section 14, and it is determined whether the cooling water flow rate is at its maximum based on the value of the flow meter FL1 (S3). Here, maximum cooling water flow rate means the maximum flow rate value that can be adjusted by the flow rate adjustment mechanism (the same applies below). If the cooling water flow rate is at its maximum (S3: Yes), the cooling water temperature is lowered (S4). In this way, by improving the cooling capacity, the return force of the return section 14 is increased. Thereafter, when the value of the first pressure gauge P1 is again equal to atmospheric pressure P AIt is determined whether the pressure is greater than the atmospheric pressure (S2) to confirm whether the material is present. At this time, if the cooling water flow rate is not at its maximum (S3: No), the cooling water flow rate is increased by opening the cooling water flow path valve V1 (S5). This control is performed until the first pressure gauge P1 is below atmospheric pressure. If the first pressure gauge P1 is below atmospheric pressure (S2: No), the value of the first pressure gauge P2 is equal to or greater than atmospheric pressure P A It is determined whether the value of the first pressure gauge P2 is greater than the atmospheric pressure P A If it is greater than this (S6: Yes), it is determined that material exists between the chamber 2 and the return section 15, and it is determined whether the cooling water flow rate is at its maximum based on the value of the flow meter FL2 (S7). If the cooling water flow rate is at its maximum (S7: Yes), the cooling water temperature is lowered (S8). In this way, by improving the cooling capacity, the return force of the return section 15 is increased. After that, when the value of the first pressure gauge P2 reaches atmospheric pressure P A The presence or absence of material is confirmed by determining whether the cooling water flow rate is greater than the atmospheric pressure (S6). If the cooling water flow rate is not at its maximum (S7: No), the cooling water flow rate is increased by opening the cooling water flow path valve V2 (S9). This control is continued until the first pressure gauge P2 is below atmospheric pressure. If the first pressure gauge P2 is below atmospheric pressure (S6: No) and kneading of the material is to be terminated (S10: Yes), pressure reduction within the chamber 2 is initiated. After kneading is terminated and pressure reduction is initiated, the viscosity of the material increases, so the cooling water temperature is increased to maintain the viscosity of the material, thereby preventing the material in the return sections 14, 15 (which are not sufficiently kneaded) from mixing with the material in the kneading chamber 18. If kneading of the material is not to be terminated (S10: No), the cooling water temperature is increased (S11) and adjusted to an appropriate temperature, and then the value of the first pressure gauge P1 is reduced to atmospheric pressure P A It is determined whether it is greater than (S2).

[0060] Next, a pressure gauge used for controlling the cooling of the returning sections 14 and 15 after the kneading of the material is explained.

[0061] FIG. 9 is an explanatory diagram of sensors used in the cooling mechanism of the return sections 14, 15 during kneading. The kneader 201 in FIG. 9 further includes second pressure gauges P3, P4 in addition to the kneader 201 shown in FIG. 7. The second pressure gauges P3, P4 are located closer to the kneading chamber than a position one pitch of the screw away from the kneading chamber side end of the return sections 14, 15 in the axial direction of the rotor 3. According to this, if the readings of the second pressure gauges P3, P4 are greater than atmospheric pressure, it is determined that the material is clogged. If necessary, the flow rate and temperature of the cooling medium can be adjusted to increase the returning force of the return sections 14, 15, thereby discharging the material from the return sections 14, 15.

[0062] 10 is a flowchart showing the cooling control of the return sections 14, 15 after the kneading is completed. The control described below may be performed by a controller or manually by a person. The control starts after the material is discharged (S13), and the value of the second pressure gauge P3 reaches the atmospheric pressure P A It is determined whether the value of the second pressure gauge P3 is greater than the atmospheric pressure P A If it is greater than this (S14: Yes), it is determined that material exists between the chamber 2 and the return section 14, and it is determined whether the cooling water flow rate is at its maximum based on the value of the flow meter FL1 (S15). If the cooling water flow rate is at its maximum (S15: Yes), the cooling water temperature is lowered (S16). In this way, by improving the cooling capacity, the return force of the return section 14 is increased, and the material in the return section 14 is discharged. After that, when the value of the second pressure gauge P3 is again equal to the atmospheric pressure P A It is determined whether the value of the second pressure gauge P4 is greater than the atmospheric pressure (S14) to confirm whether the material is present. If the cooling water flow rate is not at its maximum (S15: No), the cooling water flow path valve V1 is opened to increase the cooling water flow rate (S17). This control is performed until the second pressure gauge P3 is below atmospheric pressure. If the second pressure gauge P3 is below atmospheric pressure (S14: No), the value of the second pressure gauge P4 is below atmospheric pressure P A It is determined whether the value of the second pressure gauge P4 is greater than the atmospheric pressure P AIf it is greater than this (S18: Yes), it is determined that material exists between the chamber 2 and the return section 15, and it is determined whether the cooling water flow rate is at its maximum based on the value of the flow meter FL2 (S19). If the cooling water flow rate is at its maximum (S19: Yes), the cooling water temperature is lowered (S20). In this way, by improving the cooling capacity, the return force of the return section 15 is increased, and the material in the return section 15 is discharged. After that, when the value of the second pressure gauge P4 is again equal to the atmospheric pressure P A The presence or absence of material is confirmed by determining whether the cooling water flow rate is greater than the maximum (S18). If the cooling water flow rate is not at its maximum (S19: No), the cooling water flow rate is increased by opening the cooling water flow path valve V2 (S21). This control is continued until the second pressure gauge P4 reaches atmospheric pressure or below. If the second pressure gauge P4 reaches atmospheric pressure or below (S18: No), it can be finally confirmed that no material is present in the return sections 14, 15, so the material is discharged from the kneading chamber 18 and this control is completed.

[0063] (Effects of the first invention) The effects of the kneader 1 shown in Figure 2 are as follows. The kneader 1 kneads materials in the presence of a working fluid in a supercritical or subcritical state. The kneader 1 includes a chamber 2 in which the materials are kneaded, a rotor 3 provided in the chamber 2, return sections 14 and 15, and a cooling device 17. The return section 14 is provided between the rotor 3 and the rotor shaft 12.

[0064] [Configuration 1-1] The return sections 14, 15 are formed with screws, and are configured to rotate together with the rotor, thereby pushing the material from the return sections 14, 15 toward the kneading chamber.

[0065] [Configuration 1-2] A cooling device 17 (cooling mechanism) for cooling the material present between the chamber 2 and the return sections 14, 15 is provided inside one or both of the chamber 2 and the return sections 14, 15.

[0066] The above [Configuration 1-1] provides the following effects: When the material is being kneaded in the kneading chamber 18, the material can be prevented from entering the opposite side of the kneading chamber from the return portions 14, 15.

[0067] The above [Configuration 1-2] provides the following effects. By increasing the viscosity of the material present between the chamber 2 and the return sections 14, 15, the return force of the return sections 14, 15 is increased, making it possible to prevent the material from entering the seal section 6 and maintain the sealing performance. The return force of the return sections 14, 15 can be secured even under low rotation speed conditions, and the operating conditions for the rotation speed can be expanded more than ever before.

[0068] (Effects of the second invention) [Configuration 2] The cooling mechanism is provided both inside the chamber 2 and the return sections 14 and 15.

[0069] In the above [Configuration 2], the material in the return sections 14, 15 is cooled and the viscosity of the material is increased, thereby further increasing the return force of the return sections 14, 15, further preventing the material from entering the sealing section 6, and maintaining the sealing performance of the return sections 14, 15.

[0070] (Effect of the third invention) [Configuration 3] The cooling mechanism (cooling device 17) is provided between the center of the return sections 14, 15 in the axial direction of the rotor 3 and the kneading chamber side end sections of the return sections 14, 15 in the axial direction of the rotor 3.

[0071] In the above [Configuration 3], the portion of the return sections 14, 15 on the kneading chamber side in the axial direction of the rotor 3 from the center thereof is close to the kneading chamber 18 in which the material is kneaded, and therefore, by cooling the material on the kneading chamber side in the return sections 14, 15 and increasing the viscosity of the material, it is possible to suppress the material from entering the return sections 14, 15. In addition, by reducing the area cooled by the cooling device 17, it is possible to suppress an increase in the power consumption of the cooling device 17.

[0072] (Effect of the fourth invention) [Configuration 4] The cooling mechanism uses a cooling medium. The kneader 201 includes flow meters FL1 and FL2 that measure the flow rate of the cooling medium, a flow rate adjustment mechanism (valves V1 and V2) that adjusts the flow rate of the cooling medium, thermometers T1 and T2 that measure the temperature of the cooling medium, a cooling medium temperature adjustment mechanism (cooling device 17) that adjusts the temperature of the cooling medium, and pressure gauges P1 and P2 that measure the pressure within the chamber 2. When the pressure values ​​measured by the pressure gauges P1 and P2 are greater than a predetermined set pressure, the flow rate adjustment mechanisms (valves V1 and V2) perform one or both of the following operations: increasing the flow rate of the cooling medium; and the cooling medium temperature adjustment mechanism (cooling device 17) performs one or both of the following operations.

[0073] According to the above [Configuration 4], sensors are provided in the cooling mechanism, and based on the pressure between the chamber 2 and the return sections 14, 15, it is determined whether or not material is present between the chamber 2 and the return sections 14, 15, and the flow rate and temperature of the cooling medium are adjusted as necessary, thereby making it possible to efficiently cool the material in the return sections 14, 15. As a result, by increasing the viscosity of the material in the return sections 14, 15, the return force of the return sections 14, 15 is increased, making it possible to prevent the material from entering the seal section 6 and maintain the sealing performance of the return sections 14, 15.

[0074] (Effect of the fifth invention) [Configuration 5] When the pressure value measured by the pressure gauges P1 and P2 is greater than the set pressure, the flow rate adjustment mechanism (valves V1 and V2) increases the flow rate of the cooling medium, and when the flow rate value measured by the flow meters reaches the maximum flow rate value that the flow rate adjustment mechanism (valves V1 and V2) can adjust, the cooling medium temperature adjustment mechanism (cooling device 17) lowers the temperature of the cooling medium.

[0075] By the above [Configuration 5], the material present between the chamber 2 and the return portions 14, 15 can be cooled more efficiently.

[0076] (Effect of the sixth aspect of the invention) [Configuration 6] The measurement positions of the pressure gauges P1 and P2 are located closer to the kneading chamber than a position that is one pitch of the screw away from the end of the return section 14, 15 on the opposite side of the kneading chamber in the axial direction of the rotor 3 toward the kneading chamber.

[0077] By the above [Configuration 6], the pressure gauges P1 and P2 can detect the intrusion of the material before the material reaches the vicinity of the end of the return sections 14 and 15 on the side opposite to the kneading chamber.

[0078] (Effect of the seventh invention) [Configuration 7] The measurement position of the pressure gauge is set at a position on the opposite side of the kneading chamber from the kneading chamber side end of the return section in the axial direction of the rotor, which is a distance of one pitch of the screw on the opposite side of the kneading chamber 18.

[0079] According to the above [Configuration 7], if the pressure detection position is too close to the kneading chamber side, the material will be detected too frequently, but at this position, the intrusion of the material can be detected appropriately.

[0080] (Effect of the 8th invention) [Configuration 8] The measurement positions of the pressure gauges P3 and P4 are located closer to the kneading chamber than a position that is one pitch of the screw away from the kneading chamber side end of the return sections 14 and 15 in the axial direction of the rotor 3 toward the opposite side of the kneading chamber.

[0081] According to the above [Configuration 8], if the pressure gauge value is greater than atmospheric pressure, it is determined that the material is clogged, and by increasing the flow rate of the cooling medium in the cooling mechanism to lower the temperature, the returning force of the return sections 14, 15 is increased, thereby allowing the material in the return sections 14, 15 to be discharged.

[0082] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and other aspects can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferred actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention. [Explanation of symbols]

[0083] 1, 101, 201 Kneader 2 chambers 2a Supply / exhaust port 3 rotors 4 Bearings 6 Seal part 7 Fixed part 11 Rotor body 12 rotor shaft 14, 15 Return section 17 Cooling device 18 Mixing Room 20 Kneading equipment 21 Manufacturing Department 22 Mixing section 23 Return flow path 31 Tank 32 1st heat exchanger 33 Pump 34 Second heat exchanger 42 Regulating valve 43 Separation Filter

Claims

1. A kneader that kneads materials in the presence of a working fluid in a supercritical state or a subcritical state, a chamber having a kneading chamber in which the material is kneaded; a rotor disposed within the chamber; A return portion; and a screw is formed in the return portion, and the return portion is configured to rotate together with the rotor to push out the material from the return portion toward the kneading chamber, A kneader characterized in that a cooling mechanism for cooling the material present between the chamber and the returning section is provided in one or both of the chamber and the returning section.

2. 2. The kneader according to claim 1, wherein the cooling mechanism is provided both inside the chamber and inside the return section.

3. The kneader according to claim 1, characterized in that the cooling mechanism is provided between the center of the return section in the axial direction of the rotor and the end of the return section on the kneading chamber side in the axial direction of the rotor.

4. the cooling mechanism is a cooling mechanism that uses a cooling medium, The cooling mechanism includes: a flow meter for measuring the flow rate of the cooling medium; a flow rate adjusting mechanism for adjusting the flow rate of the cooling medium; a thermometer for measuring the temperature of the cooling medium; a cooling medium temperature adjustment mechanism for adjusting the temperature of the cooling medium; a pressure gauge for measuring the pressure between the chamber and the return section; Equipped with 2. The kneader according to claim 1, wherein, when the pressure value measured by the pressure gauge is greater than a predetermined set pressure, the flow rate adjustment mechanism performs one or both of an operation to increase the flow rate of the cooling medium and an operation to decrease the temperature of the cooling medium by the cooling medium temperature adjustment mechanism.

5. When the pressure value measured by the pressure gauge is greater than the predetermined set pressure, the flow rate adjustment mechanism increases the flow rate of the cooling medium, 5. The kneader according to claim 4, wherein the cooling medium temperature adjustment mechanism lowers the temperature of the cooling medium when the flow rate value measured by the flow meter reaches a maximum flow rate value that can be adjusted by the flow rate adjustment mechanism.

6. A kneader as described in claim 4, characterized in that the measurement position of the pressure gauge is located closer to the kneading chamber than a position that is one pitch of the screw away from the end of the return section on the opposite side of the kneading chamber in the axial direction of the rotor.

7. A kneader as described in claim 4 or 5, characterized in that the measurement position of the pressure gauge is located on the opposite side of the kneading chamber from the kneading chamber side end of the return section in the axial direction of the rotor, a distance of one pitch of the screw on the opposite side of the kneading chamber.

8. A kneader as described in claim 4 or 5, characterized in that the measurement position of the pressure gauge is located closer to the kneading chamber than a position that is one pitch of the screw away from the kneading chamber side end of the return section in the axial direction of the rotor toward the opposite kneading chamber.

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