Screw for extruder and double-screw mixing extruder

Abstract

The utility model discloses a screw for extruder and twin-screw mixing extruder, relates to reaction intensification technical field, including driving device, mixing chamber and two screw body, screw body axial distribution first thread section, second thread section and third thread section in proper order, and the thread on the second thread section is equipped with the groove, and the screw body is equipped with the first thread section, the second thread section and the third thread section. The depth of the groove extends from the top to the bottom of the thread, the groove penetrates through the thread in the thickness direction of the thread so as to divide the thread of the second thread section into multiple sections, the two screws can be rotationally arranged in the mixing cavity, and the driving device is connected with the screw body and used for driving the screw body to rotate. According to the double-screw mixing extruder provided by the utility model, the mixing capacity of the extruder can be improved, and materials can be mixed more uniformly.

Description

Technical Field

[0001] The utility model relates to the technical field of reaction intensification, in particular to a screw for an extruder and a twin-screw mixing extruder. Background Art

[0002] A twin-screw extruder is an efficient extrusion device, which is a material processing device that can fully plasticize and mix materials and form them through a die. It occupies an important position in the processing industries of raw materials such as plastics, rubbers, and chemical fibers. However, the shape and parameters of the threads in the screw elements of a twin-screw extruder are crucial for the mixing and plasticization of materials. The screw not only provides the physical space for material mixing, but also the rotation of the screw can achieve the shearing, extrusion, and redistribution of materials, so as to achieve the purpose of material mixing.

[0003] Patent application (CN104411473A) discloses a twin-screw extruder, and the threads on the screw are of the same type. In the process of material mixing, the distribution of the shear force field and velocity field of a single-thread screw is relatively regular, resulting in poor material mixing effect when the two screws in the device mix materials. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a screw for an extruder and a twin-screw mixing extruder to solve the problems existing in the above-mentioned prior art, improve the mixing ability of the extruder, and strengthen the mixing effect.

[0005] To achieve the above purpose, the utility model provides the following scheme:

[0006] The utility model provides a screw for an extruder, including a screw body. The screw body includes a first thread section, a second thread section, and a third thread section that are sequentially distributed in the axial direction. Grooves are provided on the threads of the second thread section. The depth of the grooves extends from the top to the bottom of the threads, and the grooves penetrate the threads in the thickness direction of the threads to divide the threads of the second thread section into multiple segments.

[0007] Preferably, the lengths of the first thread section and the third thread section of the two screw bodies are both smaller than the length of the second thread section.

[0008] Preferably, the screw body is a conical screw, and the large end of the screw body is used to be close to the feed port.

[0009] Preferably, a driving device, a mixing chamber, and two screws for an extruder as described above are provided. The two screw bodies are rotatably arranged in the mixing chamber. The driving device is connected to the screw body and is used to drive the screw body to rotate. The mixing chamber is provided with a feed port and a discharge port.

[0010] Preferably, the two screw bodies are meshed with each other.

[0011] Preferably, the feed inlet is arranged at the top of the mixing chamber and above the first threaded section, and the discharge outlet is arranged at the end face of the mixing chamber.

[0012] Preferably, it further comprises a heating device, a temperature sensor and a pressure sensor. The heating device is arranged outside the mixing chamber for heating the mixing chamber. The temperature sensor is arranged inside the mixing chamber for measuring the temperature inside the mixing chamber. The pressure sensor is arranged inside the mixing chamber for measuring the pressure inside the mixing chamber.

[0013] Preferably, the heating device comprises a heat medium channel spirally wound around the outside of the mixing chamber, and heat-conducting oil is used to be introduced into the heat medium channel.

[0014] Preferably, the driving device comprises a motor and a transmission device. The output member of the motor is fixedly connected to the input member of the transmission device. The output member of the transmission device is connected to the two screw bodies and can drive the two screw bodies to rotate synchronously in opposite directions.

[0015] Preferably, it further comprises a controller, and the driving device, the heating device, the temperature sensor and the pressure sensor are all electrically connected to the controller.

[0016] The utility model has achieved the following technical effects compared with the prior art:

[0017] The utility model provides a screw for an extruder and a twin-screw mixing extruder. By changing the thread shape of part of the screw, the second section of the screw is provided with grooves. Compared with a screw only provided with threads, the grooves can form an additional pressure on the material when the screw rotates, so that the pressure distribution of the material changes during the mixing process, thereby changing the material flow, enhancing the exchange between materials, being beneficial to material mixing. At the same time, changing the thread shape can reduce the high shear force during the mixing process, make the shear rate distribution more uniform, thereby improving the mixing ability of the extruder and strengthening the mixing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic structural diagram of a twin-screw mixing extruder in an embodiment of the present utility model;

[0020] Figure 2 Schematic structural diagram of a screw for an extruder in an embodiment of the present utility model;

[0021] Figure 3 Schematic groove structure diagram of a screw for an extruder in an embodiment of the present utility model;

[0022] Wherein: 1 - pressure sensor; 2 - temperature sensor; 3 - stirring barrel; 4 - transmission device; 5 - driving device; 6 - controller; 7 - screw body; 8 - thread; 9 - groove; Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0024] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0025] In a more preferred embodiment of the present utility model, the screw for the extruder includes a screw body 7. As Figure 2 shown, the screw body 7 includes a first thread section, a second thread section, and a third thread section that are sequentially distributed in the axial direction. A groove 9 is provided on the thread 8 of the second thread section. As Figure 3 shown, the depth of the groove 9 extends from the top to the bottom of the thread 8, and the groove 9 penetrates the thread 8 in the thickness direction A of the thread 8 to divide the thread 8 of the second thread section into multiple segments. By changing the shape and parameters of part of the thread 8 of the screw, a groove 9 is provided on the second thread 8 of the screw body 7, which can form an additional pressure when the screw body 7 rotates, change the pressure distribution during the mixing of the material, thereby changing the flow of the material, enhancing the exchange between the materials, being beneficial to the mixing of the materials. At the same time, changing the shape of the thread 8 can reduce the high shear force during the mixing process, make the shear rate distribution more uniform, thereby improving the mixing ability of the extruder and strengthening the mixing efficiency.

[0026] In a more preferred embodiment of the present utility model, the lengths of the first thread section and the third thread section of the two screw bodies 7 are both smaller than the length of the second thread section. The first thread section and the third thread section are mainly used for conveying materials, and the second thread section is mainly used for strengthening the mixing of materials. The length of the second thread section is relatively long, making the mixing area of the materials larger, more conducive to the mixing of materials, and enhancing the mixing effect of the materials.

[0027] In a more preferred embodiment of the present utility model, the screw body 7 is a conical screw, and the large end of the screw body 7 is used to be close to the feed inlet. The screw body 7 is conical. When the conical screw rotates, it can make the material be extruded in an "8" shape in the mixing cavity, increasing the plasticization time and reducing the friction between the material and the screw body 7, thereby improving the plasticization quality of the material.

[0028] In another more preferred embodiment of the present utility model, the twin-screw mixing extruder includes a driving device 5, a mixing cavity, and two screws for the extruder as described above. The two screw bodies 7 are rotatably arranged in the mixing cavity 3. The driving device 5 is connected to the screw body 7 and is used to drive the screw body 7 to rotate. The mixing cavity 3 is provided with a feed inlet and a discharge outlet. By changing the shape and parameters of part of the thread 8 of the screw, a groove 9 is provided on the second section of the thread 8 on the screw body 7. When the screw body 7 rotates, compared with a screw only provided with threads, the groove can form an additional pressure on the material, changing the pressure distribution of the material during the mixing process, thereby changing the flow of the material, enhancing the exchange between the materials, being beneficial to material mixing. At the same time, changing the shape of the thread 8 can reduce the high shear force during the mixing process, making the shear rate distribution more uniform, thereby improving the mixing ability of the extruder and enhancing the mixing efficiency.

[0029] In a more preferred embodiment of the present utility model, the two screw bodies 7 are meshed. The meshing of the two screw bodies 7 can improve the uniformity of material mixing, enhance the material conveying ability, and improve the production efficiency.

[0030] In a more preferred embodiment of the present utility model, the feed inlet is arranged at the top of the mixing cavity 3 and above the first thread section, and the discharge outlet is arranged at the end face of the mixing cavity 3. The feed inlet is used to convey the material into the mixing cavity 3, and the discharge outlet is used to output the mixed material.

[0031] In a more preferred embodiment of the present utility model, it further includes a heating device, a temperature sensor 2, and a pressure sensor 1. The heating device is arranged outside the mixing cavity 3 for heating the mixing cavity 3. The temperature sensor 2 is arranged inside the mixing cavity 3 for measuring the temperature inside the mixing cavity 3. The pressure sensor 1 is arranged inside the mixing cavity 3 for measuring the pressure inside the mixing cavity 3. By arranging the heating device, the temperature sensor 2, and the pressure sensor 1, the temperature and pressure inside the mixing cavity 3 are always within the set range, thereby ensuring the product quality and improving the production efficiency.

[0032] In a preferred embodiment of the utility model, the heating device includes a heat medium channel spirally wound around the outside of the mixing chamber, and the heat medium channel is used to pass heat transfer oil. The heat medium channel heats the heat transfer oil to increase the temperature in the mixing chamber 3. When the material reacts and needs to be cooled, the heat transfer oil is discharged and ethylene glycol is passed in, which can reduce the temperature in the mixing chamber 3.

[0033] In a preferred embodiment of the utility model, the driving device 4 includes a motor and a transmission device 4, the output member of the motor is fixedly connected to the input member of the transmission device 4, and the output member of the transmission device 4 is connected to the two screw bodies 7 and can drive the two screw bodies 7 to rotate synchronously in the opposite direction. The motor drives the screw body 7 to rotate through the transmission device 4, and supplies the torque and speed required by the screw body 7 during the rotation process, thereby completing the extrusion of the material, and the transmission device is preferably a gear box.

[0034] In a preferred embodiment of the utility model, a controller 6 is further included, and the driving device, the heating device, the temperature sensor 2 and the pressure sensor 1 are all electrically connected to the controller 6. The controller 6 in the extruder accurately controls the pressure and temperature in the mixing chamber 3 and controls the drive of the motor, so that the extruder can operate efficiently and stably to meet the requirements of the extruder process.

[0035] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A screw for an extruder, characterized in that: It includes a screw body, which includes a first thread segment, a second thread segment and a third thread segment distributed in sequence in the axial direction. A groove is provided on the thread of the second thread segment, the depth of the groove extends from the top of the thread to the bottom, and the groove penetrates the thread in the thickness direction of the thread to divide the thread of the second thread segment into multiple segments.

2. The screw for an extruder according to claim 1, characterized in that: The lengths of the first thread segment and the third thread segment of the two screw bodies are both smaller than the length of the second thread segment.

3. The screw for an extruder according to claim 1, characterized in that: The screw body is a conical screw, and the large end of the screw body is used to be close to the feed port.

4. A twin-screw mixing extruder, characterized in that: include: A driving device, a mixing chamber and two screws for an extruder as described in any one of claims 1 to 3, wherein the two screw bodies are rotatably arranged in the mixing chamber, the driving device is connected to the screw bodies and is used to drive the screw bodies to rotate, and the mixing chamber is provided with a feed port and a discharge port.

5. The twin-screw mixing extruder according to claim 4, characterized in that: The two screw bodies are meshed.

6. The twin-screw mixing extruder according to claim 5, characterized in that: The feed port is arranged at the top of the mixing chamber and is located above the first thread segment, and the discharge port is arranged at the end surface of the mixing chamber.

7. The twin-screw mixing extruder according to claim 4, characterized in that: It also includes a heating device, a temperature sensor and a pressure sensor. The heating device is arranged outside the mixing chamber to heat the mixing chamber, the temperature sensor is arranged inside the mixing chamber to measure the temperature inside the mixing chamber, and the pressure sensor is arranged inside the mixing chamber to measure the pressure inside the mixing chamber.

8. The twin-screw mixing extruder according to claim 7, characterized in that: The heating device comprises a heat medium channel spirally wound around the outside of the mixing chamber, and the heat medium channel is used for passing heat transfer oil.

9. The twin-screw mixing extruder according to claim 8, characterized in that: The driving device comprises a motor and a transmission device, wherein the output member of the motor is fixedly connected to the input member of the transmission device, and the output member of the transmission device is connected to the two screw bodies and can drive the two screw bodies to rotate synchronously in opposite directions.

10. The twin-screw mixing extruder according to claim 9, characterized in that: It also includes a controller, and the driving device, the heating device, the temperature sensor and the pressure sensor are all electrically connected to the controller.

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