Membrane pressing mechanism and diaphragm wet extraction device

Abstract

The utility model discloses a diaphragm pressing mechanism and a diaphragm wet extraction device, which comprise a pressing roller, a supporting roller, a first driving device for driving the supporting roller to rotate and a second driving device for driving the pressing roller to be close to or far away from the supporting roller, and the two ends of the supporting roller are respectively and rotatably connected to the two sides of an extraction tank. The pressing roller and the supporting roller are arranged in parallel, a diaphragm moves and passes through a gap between the pressing roller and the supporting roller, and the diameter of the middle of the pressing roller is smaller than the diameters of the two sides of the pressing roller. According to the utility model, white oil on the diaphragm can be prevented from entering the extraction tank, the extraction efficiency is improved, meanwhile, the residue of an extracting agent on the diaphragm can be reduced, the quality of the diaphragm is improved, and the extruded extracting agent flows back into the extraction tank, so that the using amount of the extracting agent can be saved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of diaphragm extraction, in particular to a film pressing mechanism and a diaphragm wet extraction device. Background Art

[0002] In a lithium battery, a diaphragm is one of the key inner components in the structure of the lithium battery. The main material of the diaphragm is a porous polymer membrane. The diaphragm has the functions of separating the positive and negative electrode plates and conducting lithium ions. The production process of the diaphragm is divided into a dry process and a wet process.

[0003] Among them, the wet process for preparing the diaphragm uses polyethylene as the main material and white oil as the diluent. Polyethylene is dissolved in white oil under high temperature and high pressure, and after rapid cooling, polyethylene crystallizes and precipitates, and white oil droplets are dispersed therein. Then, the white oil is removed. The commonly used process for removing white oil is to use dichloromethane as the extractant for extraction. The film is conveyed to an extraction tank filled with the extractant, the film is immersed in the extraction liquid, and then conveyed to a drying device for drying. Through the extraction and drying process, the replacement of dichloromethane with white oil and air with dichloromethane occurs successively, and finally a polyethylene microporous membrane is obtained. The extraction process mainly utilizes the characteristics that white oil is soluble in dichloromethane and dichloromethane has a low boiling point to extract white oil from the microporous structure of the film.

[0004] However, in the existing production process, when extracting white oil on the film, it is difficult to extract the white oil on both sides of the film completely. The film needs to be immersed in the extractant for a long path to be extracted completely. Thus, the production efficiency and the quality of the film are affected, and the consumption of the extractant also increases. Summary of the Utility Model

[0005] In order to overcome the deficiencies of the prior art, the utility model provides a film pressing mechanism and a diaphragm wet extraction device, which can reduce the entry of white oil on the diaphragm into the extraction tank, improve the extraction efficiency. At the same time, it can reduce the residue of the extractant on the diaphragm, improve the quality of the diaphragm. Moreover, the extruded extractant flows back into the extraction tank, which can save the amount of the extractant used and reduce the production cost.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] A film pressing mechanism includes a pressure roller, a support roller, a first driving device for driving the support roller to rotate, and a second driving device for driving the pressure roller to approach or separate from the support roller. Both ends of the support roller are respectively rotatably connected to both sides of the extraction tank. The pressure roller is arranged parallel to the support roller. The diaphragm moves through the gap between the pressure roller and the support roller. The diameter of the middle part of the pressure roller is smaller than the diameters of both sides of the pressure roller.

[0008] As a further improvement of the above technical solution, two second driving devices are provided, and the two driving devices are respectively connected to the two ends of the pressing roller.

[0009] As a further improvement of the above technical solution, the second driving device includes a cylinder and a transmission assembly, and the transmission assembly is arranged between the cylinder and the pressure roller.

[0010] As a further improvement of the above technical solution, the transmission assembly includes a rotating shaft, a first swing arm and a second swing arm respectively arranged at both ends of the rotating shaft, the rotating shaft is rotatably connected to the extraction tank, the first swing arm is located outside the extraction tank and is hinged to the telescopic end of the cylinder, the second swing arm is located inside the extraction tank and is connected to the end of the pressure roller, and the cylinder body of the cylinder is hinged to the outside of the extraction tank.

[0011] As a further improvement of the above technical solution, the rotating shaft is rotatably connected to the extraction tank via two first bearings.

[0012] As a further improvement of the above technical solution, a seal is further provided between the rotating shaft and the extraction tank, and the seal is located between the two first bearings.

[0013] As a further improvement of the above technical solution, the sealing element is a PTFE oil seal.

[0014] As a further improvement of the above technical solution, the first driving device includes a motor and a reducer, the output end of the motor is connected to the input end of the reducer, and the output end of the reducer is connected to one end of the supporting roller.

[0015] As a further improvement of the above technical solution, the support roller is rotatably connected to the extraction tank via a second bearing.

[0016] A membrane wet extraction device comprises an extraction tank filled with an extractant and a plurality of rollers, wherein the membrane pressing mechanism is arranged on the extraction tank.

[0017] The beneficial effects of the utility model are as follows: the utility model provides a film pressing mechanism and a diaphragm wet extraction device, by arranging a pressing roller, a supporting roller, a first driving device and a second driving device, the diaphragm moves through the gap between the pressing roller and the supporting roller, the second driving device drives the pressing roller to approach the supporting roller, and the diaphragm can be pressed against the supporting roller, then the first driving device drives the supporting roller to rotate, which can drive the diaphragm for transportation, and can squeeze out the excess white oil and the mixture of white oil and extractant on both sides of the diaphragm, thereby reducing the amount of white oil on the diaphragm entering the extraction tank and improving the extraction efficiency. At the same time, it can reduce the residue of the extractant on the diaphragm and improve the quality of the diaphragm. Moreover, the extruded extractant flows back into the extraction tank, which can save the amount of extractant used and reduce the production cost. Brief Description of the Drawings

[0018] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0019] Figure 1 is a schematic structural diagram provided by an embodiment of the present utility model;

[0020] Figure 2 is Figure 1 a side view of

[0021] Figure 3 is Figure 1 a top view of

[0022] Figure 4 is Figure 3 an enlarged view of part A in

[0023] Reference numerals: 1 - pressure roller, 2 - support roller, 3 - first driving device, 4 - second driving device, 5 - extraction tank, 6 - diaphragm, 7 - transmission component, 8 - over roller, 9 - cylinder, 21 - second bearing, 31 - motor, 32 - reducer, 71 - rotating shaft, 72 - first swing arm, 73 - second swing arm, 74 - first bearing, 75 - seal. Detailed Description of the Preferred Embodiments

[0024] The concept, specific structure and technical effects of the present utility model will be clearly and completely described below in conjunction with the embodiments and the drawings, so as to fully understand the purpose, features and effects of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present utility model. In addition, all the connection / connection relationships involved in the patent do not simply refer to the direct connection of components, but refer to the more optimal connection structure that can be formed by adding or reducing connection accessories according to the specific implementation situation. Each technical feature in the present utility model can be combined with each other without conflicting with each other.

[0025] Referring to Figures 1 to 3 , a diaphragm wet extraction device provided by an embodiment of the present utility model includes an extraction tank 5 and a plurality of over rollers 8. The plurality of over rollers 8 are arranged in the extraction tank 5, and the plurality of over rollers 8 are used to support the diaphragm 6. An extraction agent is contained in the extraction tank 5.

[0026] An example of the present utility model further provides a film pressing mechanism, which is arranged on the extraction tank 5 and includes a pressing roller 1, a supporting roller 2, a first driving device 3 for driving the supporting roller 2 to rotate, and a second driving device 4 for driving the pressing roller 1 to approach or move away from the supporting roller 2. Both ends of the supporting roller 2 are respectively rotatably connected to both sides of the extraction tank 5. The pressing roller 1 is arranged parallel to the supporting roller 2, and the diaphragm 6 moves through the gap between the pressing roller 1 and the supporting roller 2.

[0027] It can be understood that when the second driving device 4 drives the pressing roller 1 to approach the supporting roller 2, the diaphragm 6 can be pressed tightly on the supporting roller 2. Then, the first driving device 3 drives the supporting roller 2 to rotate, which can drive the diaphragm 6 to be conveyed. Thus, the excess white oil and the mixture of white oil and extractant on both sides of the diaphragm 6 can be extruded, and further, the extraction efficiency of the diaphragm 6 can be improved.

[0028] It should be noted that the number of the film pressing mechanisms is two. The two film pressing mechanisms are respectively arranged at the feeding end and the discharging end of the extraction tank 5. One film pressing mechanism can extrude the white oil on the diaphragm 6 when it enters the extraction tank 5, so as to reduce the white oil on the diaphragm 6 from entering the extraction tank 5, reduce the extraction time of the diaphragm 6, and improve the extraction efficiency. The other film pressing mechanism can extrude the white oil and the extractant on the diaphragm 6 when it moves out of the extraction tank 5. Thus, the residue of the extractant on the diaphragm 6 can be reduced, and the quality of the diaphragm 6 can be improved. Moreover, the extruded extractant flows back into the extraction tank 5, which can save the dosage of the extractant and reduce the production cost.

[0029] Further, the diameter of the middle part of the pressing roller 1 is smaller than the diameters of both sides of the pressing roller 1, which can prevent the overall diameter size of the pressing roller 1 from being uneven due to the processing error of the pressing roller 1 and resulting in incomplete contact with both sides of the diaphragm 6. Thus, the extrusion effect of the pressing roller 1 on both sides of the diaphragm 6 can be ensured.

[0030] Further, there are two second driving devices 4, and the two second driving devices 4 are respectively connected to both ends of the pressing roller 1. Thus, both ends of the pressing roller 1 can be stressed simultaneously, and when the pressing roller 1 presses the diaphragm 6 tightly on the supporting roller 2, the force is uniform. Further, the fitting degree between the larger diameter roller surfaces on both sides of the pressing roller 1 and the diaphragm 6 can be improved.

[0031] In some preferred embodiments, the second driving device 4 includes a cylinder 9 and a transmission assembly 7, and the transmission assembly 7 is arranged between the cylinder 9 and the pressing roller 1.

[0032] Further, the transmission assembly 7 includes a rotating shaft 71, a first swing arm 72 and a second swing arm 73 respectively arranged at both ends of the rotating shaft 71. The rotating shaft 71 is rotatably connected to the extraction tank 5. The first swing arm 72 is located outside the extraction tank 5 and is hinged to the telescopic end of the cylinder 9. The second swing arm 73 is located inside the extraction tank 5 and is connected to the end of the pressing roller 1. The cylinder body of the cylinder 9 is hinged to the outside of the extraction tank 5.

[0033] During operation, the telescopic end of the cylinder 9 extends to drive the first swing arm 72 to swing. The first swing arm 72 drives the rotating shaft 71 to rotate, and the rotating shaft 71 drives the second swing arm 73 to swing. The second swing drives the pressure roller 1 close to the support roller 2, and then presses the diaphragm 6 against the support roller 2, squeezing out the white oil and the mixture of white oil and extractant on the diaphragm 6. Thus, the cylinder 9 is arranged outside the extraction tank 5, which is convenient for the installation of the cylinder 9. Moreover, it can prevent the extractant in the extraction tank 5 from splashing onto the cylinder 9 and affecting the operation.

[0034] Refer to Figure 3 and Figure 4 Furthermore, the rotating shaft 71 is rotatably connected to the extraction tank 5 through two first bearings 74. A seal 75 is also provided between the rotating shaft 71 and the extraction tank 5. The seal 75 is located between the two first bearings 74. Thus, the sealing performance of the extraction tank 5 can be improved, preventing the extractant in the extraction tank 5 from overflowing.

[0035] Specifically, the seal 75 is a PTFE oil seal. The PTFE oil seal has good heat resistance and corrosion resistance. At the same time, the surface layer of the PTFE raw material has prominent self-lubricity. Thus, when the extractant contacts the seal 75, physical or chemical changes can be prevented, improving the service life of the seal 75. At the same time, the self-lubricity of the PTFE oil seal can reduce the friction force between the seal 75 and the rotating shaft 71, facilitating the rotation of the rotating shaft 71.

[0036] In some preferred embodiments, the first driving device 3 includes a motor 31 and a speed reducer 32. The output end of the motor 31 is connected to the input end of the speed reducer 32. By adjusting the reduction ratio of the speed reducer 32, the rotation speed of the support roller 2 can be adjusted, thus facilitating the adjustment of the speed when the diaphragm 6 moves.

[0037] Furthermore, the support roller 2 is rotatably connected to the extraction tank 5 through a second bearing 21, which can reduce the friction coefficient of the support roller 2, thus improving the service life of the support roller 2.

[0038] The above is a specific description of the preferred embodiments of the present invention. However, the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A film pressing mechanism, characterized in that, It includes a pressure roller, a support roller, a first driving device for driving the support roller to rotate, and a second driving device for driving the pressure roller to approach or move away from the support roller. Both ends of the support roller are respectively rotatably connected to both sides of the extraction tank. The pressure roller is arranged parallel to the support roller. The diaphragm moves through the gap between the pressure roller and the support roller. The diameter of the middle part of the pressure roller is smaller than the diameters of both sides of the pressure roller.

2. The film pressing mechanism according to claim 1, characterized in that, There are two second driving devices, and the two driving devices are respectively connected to both ends of the pressure roller.

3. A film pressing mechanism according to claim 1 or 2, characterized in that, The second driving device includes a cylinder and a transmission component, and the transmission component is arranged between the cylinder and the pressure roller.

4. A film pressing mechanism according to claim 3, characterized in that, The transmission component includes a rotating shaft, a first swing arm and a second swing arm respectively arranged at both ends of the rotating shaft. The rotating shaft is rotatably connected to the extraction tank. The first swing arm is located outside the extraction tank and is hinged to the telescopic end of the cylinder. The second swing arm is located inside the extraction tank and is connected to the end of the pressure roller. The cylinder block of the cylinder is hinged to the outside of the extraction tank.

5. A film pressing mechanism according to claim 4, characterized in that, The rotating shaft is rotatably connected to the extraction tank through two first bearings.

6. The film pressing mechanism according to claim 5, wherein, A seal is further arranged between the rotating shaft and the extraction tank, and the seal is located between the two first bearings.

7. The film pressing mechanism according to claim 6, characterized in that, The seal is a PTFE oil seal.

8. A film pressing mechanism according to claim 1, wherein, The first driving device includes a motor and a reducer. The output end of the motor is connected to the input end of the reducer, and the output end of the reducer is connected to one end of the support roller.

9. A film pressing mechanism according to claim 1, characterized in that, The support roller is rotatably connected to the extraction tank through a second bearing.

10. A wet diaphragm extraction device, comprising an extraction tank filled with an extractant and a number of over-rollers, characterized in that, The pressure film mechanism according to any one of claims 1 to 9 is arranged on the extraction tank.

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