PVDF powder cleaning and drying equipment

Abstract

The utility model provides a kind of PVDF powder cleaning and drying equipment, including tank body, hollow interlayer is arranged in tank body;Tank body inner chamber is separated into drying cavity located upper portion and filter cavity located lower portion with filter assembly, filter cavity is communicated with vacuum pump assembly and is provided with liquid outlet in the bottom of filter cavity;Several fan-shaped nozzles are arranged in drying cavity, and liquid inlet is opened in the side of drying cavity.The utility model separates the solution with impurities from the separated PVDF powder wet material by separating tank body into drying cavity and filter cavity and applying filter assembly, and then completes the aggregation and flushing of PVDF powder wet material by the fan-shaped nozzle arranged, vacuum pump assembly can be applied to suction filtration and drying process, so that the equipment meets all the needs of PVDF powder from cleaning to drying at the same time, and the weight of PVDF powder on filter assembly is fed back in time through weighing assembly, which can judge the drying condition of PVDF powder.

Description

Technical Field

[0001] This utility model relates to the field of drying and cleaning equipment technology, and in particular to a PVDF powder cleaning and drying equipment. Background Technology

[0002] Industrially produced virgin PVDF powder may contain impurities such as polymerization residues, inorganic salts, metal ions, and organic solvents. For cleaning and drying PVDF powder, a classic, efficient, and reliable process route is "dissolution-reprecipitation" combined with "vacuum drying." Current processes require dividing the cleaning and drying of PVDF powder into numerous steps, each carried out in different equipment. For example, specialized cleaning equipment is needed for cleaning, while the drying process requires manual collection of wet material and transfer to drying equipment. Therefore, a continuous cleaning and drying process for PVDF powder cannot be directly achieved. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the defects of the existing technology. This utility model proposes a method in which the PVDF powder after treatment can continuously complete the cleaning and drying process in the equipment, and the resulting PVDF powder has extremely high purity.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a PVDF powder cleaning and drying equipment, including a tank, with a hollow jacket provided in the tank; the inner cavity of the tank is divided into an upper drying chamber and a lower filtering chamber by a filter assembly, the filtering chamber is connected to a vacuum pump assembly and has a liquid outlet at the bottom of the filtering chamber; a plurality of fan-shaped nozzles are arranged in an array in the drying chamber, and a liquid inlet is opened on the side of the drying chamber.

[0005] Furthermore, in order to separate the precipitated PVDF powder particles from the solvent containing impurities, the filtration assembly includes a ring fixed in the tank and several layers of first filter screens disposed in the ring.

[0006] Furthermore, to confirm whether the PVDF powder is completely dry during the drying process, a weighing component is fixedly installed below the filter component, with the projection of the first filter screen located above the weighing component, and the bottom surface of the filter component in contact with the top side of the weighing component.

[0007] Furthermore, to ensure that the weighing component can obtain the weight of the PVDF powder blocked by the filter component, the weighing component includes a fixed frame, on which a pressure sensor and a support plate are sequentially arranged, and the support plate is in contact with the bottom surface of the filter component.

[0008] Furthermore, rinsing conditions are provided for the precipitated PVDF powder, and the PVDF powder adhering to the inner wall of the tank is flushed onto the filter assembly to complete the agglomeration. The fan-shaped nozzles are arranged in a ring along the inner wall of the tank, and any one of the fan-shaped nozzles points to the geometric center of the filter assembly.

[0009] Furthermore, to ensure the filtration process of wet PVDF powder and the maintenance of the vacuum environment inside the tank during the drying process, the vacuum pump assembly includes a Roots pump and a liquid ring pump connected in sequence to the filter chamber, and the output end of the liquid ring pump is connected to the condensation assembly.

[0010] Furthermore, in order to separate PVDF virgin powder and insoluble impurities and to detect blockage at the inlet in a timely manner, a dissolving tank is connected to the inlet, a filter screen is fixedly installed at the output end of the dissolving tank, and a flow sensor is installed between the filter screen and the inlet.

[0011] Furthermore, in order to achieve rapid drying of PVDF powder wet material during the drying process, the temperature of the heat exchange medium circulating in the hollow jacket is 80-100℃, and the vacuum degree in the tank is not less than -0.095MPa.

[0012] Compared with the prior art, the beneficial effects of this utility model include: 1) By dividing the tank into a drying chamber and a filtration chamber, and using a filtration assembly to separate the precipitated PVDF powder wet material from the solution containing impurities, the PVDF powder wet material is then collected and washed through a fan-shaped nozzle. The vacuum pump assembly can be used for the filtration and drying processes, so that the equipment can simultaneously meet all the requirements of PVDF powder from cleaning to drying. 2) By installing a weighing component below the filter assembly to provide timely feedback on the weight of the PVDF powder located above the filter assembly, the drying status of the PVDF powder can be determined. 3) By installing a filter screen and a flow sensor between the dissolving tank and the inlet, the status of insoluble impurities filtered through the filter screen can be fed back, facilitating timely cleaning and ensuring the cleaning and drying process of PVDF powder. Attached Figure Description

[0013] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts. Wherein: Figure 1 The schematic diagram shows a cross-sectional view of a PVDF powder washing and drying equipment; Figure 2 The schematic diagram shows the cross-sectional structure of the filter component; Figure 3 The diagram schematically shows the cross-sectional structure of a PVDF powder cleaning and drying device during the precipitation process of PVDF powder, with sufficient deionized water placed in the tank at this time; Figure 4 The schematic diagram shows the perspective structure of the weighing assembly.

[0014] Numbering in the diagram: 1-Tank body, 2-Hollow jacket, 3-Drying chamber, 4-Filter chamber, 5-Inlet, 6-Outlet, 7-Fan-shaped nozzle, 8-Filter assembly, 81-Ring body, 82-First filter screen, 9-Weighing assembly, 91-Fixing frame, 92-Pressure sensor, 93-Panel, 10-Vacuum pump assembly, 101-Roots pump, 102-Liquid ring pump, 11-Dissolving tank, 12-Condensation assembly. Detailed Implementation

[0015] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0016] A PVDF powder washing and drying device, such as Figure 1 As shown, the device includes a tank 1. The inner cavity of the tank 1 is divided into a drying chamber 3 and a filtering chamber 4 by a filter assembly 8. The drying chamber 3 is located in the upper part of the tank 1, while the filtering chamber 4 is located in the lower part of the tank 1. The filtering chamber 4 is connected to a vacuum pump assembly 10 and has a liquid outlet 6 at the bottom. The vacuum pump provides a vacuum environment for the filtering chamber 4 and even the entire tank 1. The liquid outlet 6 allows for the timely discharge of liquid inside the tank 1. A liquid inlet 5 is provided on the side of the drying chamber 3 to allow PVDF powder dissolved in a highly polar organic solvent to enter the tank 1 along with the solvent to complete the subsequent processing.

[0017] The following combination Figure 1 and Figure 2 Filter component 8 will be described in detail. For example... Figure 2 As shown, the filter assembly 8 includes a ring 81 fixed within the tank 1 and several layers of first filter screens 82 disposed within the ring 81. Specifically, the edges of the first filter screens 82 are fixed by the ring 81, which provides support for the first filter screens 82 and simultaneously secures them to a fixed position within the tank 1. The multiple layers of first filter screens 82 ensure the integrity of the first filter screens 82 even when their elasticity is poor, thus guaranteeing the filtration effect. In practical use, such as... Figure 3As shown, sufficient deionized water can be injected into the tank 1 first. At this time, the filter assembly 8 is immersed in the deionized water. When the PVDF powder dissolved in the organic solvent comes into contact with a large amount of deionized water, its solubility drops sharply, thus instantly precipitating fine and uniform particles. These particles can be blocked by the first filter screen 82 in the filter assembly 8, while the solvent can pass through the first filter screen 82. That is, the filter assembly 8 can capture the high-purity PVDF powder particles. Then, the liquid outlet 6 located at the bottom of the filter chamber 4 can be opened to obtain the wet PVDF powder.

[0018] Because the filter assembly 8 is immersed in deionized water during the PVDF powder precipitation process, the precipitated PVDF powder does not completely fall onto the first filter screen 82; some may adhere to the inner wall of the drying chamber 3. Furthermore, after the PVDF powder precipitates, it needs to undergo multiple rinsing processes. Therefore, several fan-shaped nozzles 7 are arranged in a circular array along the inner wall of the tank 1 within the drying chamber 3, with each fan-shaped nozzle 7 pointing towards the geometric center of the filter assembly 8, i.e., the area where the first filter screen 82 is located. The rinsing process is completed by spraying deionized water onto the wet PVDF powder using the fan-shaped nozzles 7. Simultaneously, the fan-shaped nozzles 7 can also cover the inner wall area of ​​the drying chamber 3, washing the PVDF powder particles adhering to the inner wall of the drying chamber 3 onto the first filter screen 82, thus agglomerating the PVDF powder particles. During the rinsing process, the PVDF can first be sprayed and washed through the fan-shaped nozzle 7. Then, the fan-shaped nozzle 7 stops spraying and the vacuum pump assembly 10 is turned on to complete a filtration-like process. After that, the vacuum pump assembly 10 is turned off and the fan-shaped nozzle 7 is turned on again. The aforementioned opening and closing of the fan-shaped nozzle 7 and the vacuum pump assembly 10 are repeated multiple times to complete the multiple rinsing process of the wet PVDF powder.

[0019] The following combination Figure 1 and Figure 4 The weighing component 9 is described in detail below. The weighing component 9 includes a mounting frame 91, on which a pressure sensor 92 and a support plate 93 are sequentially mounted. The support plate 93 contacts the bottom surface of the filter assembly 8, and the projection of the first filter screen 82 constituting the filter assembly 8 is located above the weighing component 9. By maintaining the contact state between the first filter screen 82 and the weighing component 9, if the pressure data obtained by the weighing component 9 does not change for a period of time during the drying process, the PVDF powder can be considered completely dried.

[0020] It is worth noting that the aforementioned vacuum pump assembly 10 includes a Roots pump 101 and a liquid ring pump 102 connected in sequence to the filter chamber 4. The output end of the liquid ring pump 102 is connected to the condensation assembly 12, which is used to remove the gas discharged by the Roots pump 101 and process the large amount of condensable vapor contained therein. After condensation by the condensation assembly 12, it can be combined with the solution discharged from the liquid outlet 6 for subsequent processing.

[0021] like Figure 3 As shown, before the virgin PVDF powder enters tank 1, a dissolution process is performed. NMP or DMF at a temperature of 60-80℃ is added to the dissolution tank 11, followed by stirring. The stirring process can be carried out using a servo motor in conjunction with a stirring shaft. The powder is then introduced into tank 1 through inlet 5 to complete the subsequent precipitation, cleaning, and drying processes. It is worth noting that a second filter screen is fixedly installed at the output end of the solution tank. The particle size of this second filter screen is larger than that of the first filter screen 82 in the filter assembly 8. A flow sensor is installed between the second filter screen and inlet 5. The aforementioned second filter screen filters out large-volume impurities in the virgin PVDF powder that are difficult to dissolve in strongly polar solvents, ensuring that only liquid enters tank 1. The flow sensor is used to monitor the liquid inlet 5 in real time to prevent excessive blockage of the second filter screen by large-volume impurities, which could affect the liquid inlet process.

[0022] A hollow jacket 2 is also provided within the tank body 1 to allow the introduction of a heat exchange medium at a temperature of 80-100℃, thereby regulating the internal temperature of the tank body 1 to 80-100℃. During the drying process of the wet PVDF powder, on the one hand, the heat exchange medium is introduced into the hollow jacket 2 of the tank body 1 to ensure a constant temperature inside the tank body 1; on the other hand, the vacuum pump assembly 10 adjusts the internal environment of the tank body 1 to a vacuum degree of not less than -0.095MPa, significantly reducing the boiling point of the solvent, allowing it to evaporate rapidly at a temperature far below the atmospheric pressure boiling point, thus avoiding damage to the material from high temperatures. In some embodiments, a vibrator can also be provided at the bottom of the ring body 81, which is intermittently activated during the drying process to vibrate the ring body 81, thereby indirectly driving the vibration of the first filter screen 82 constituting the filter assembly 8. This can, to a certain extent, agitate the wet PVDF powder, preventing the PVDF powder from clumping and ensuring complete drying. After drying, it can be collected manually.

[0023] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. A PVDF powder washing and drying device, characterized in that, Includes a tank (1), in which a hollow interlayer (2) is provided; the inner cavity of the tank (1) is divided into a drying chamber (3) located at the top and a filtering chamber (4) located at the bottom by a filter assembly (8), the filtering chamber (4) is connected to a vacuum pump assembly (10) and has a liquid outlet (6) at the bottom of the filtering chamber (4); a number of fan-shaped nozzles (7) are arranged in an array in the drying chamber (3), and a liquid inlet (5) is opened on the side of the drying chamber (3).

2. The PVDF powder cleaning and drying equipment according to claim 1, characterized in that, The filter assembly (8) includes a ring (81) fixed in the tank (1) and several layers of first filter screens (82) disposed in the ring (81).

3. The PVDF powder cleaning and drying equipment according to claim 2, characterized in that, A weighing component (9) is fixedly disposed below the filter component (8), the projection of the first filter screen (82) is located above the weighing component (9), and the bottom surface of the filter component (8) is in contact with the top side of the weighing component (9).

4. The PVDF powder cleaning and drying equipment according to claim 3, characterized in that, The weighing component (9) includes a fixed frame (91), on which a pressure sensor (92) and a tray (93) are sequentially arranged, and the tray (93) is in contact with the bottom surface of the filter component (8).

5. The PVDF powder cleaning and drying equipment according to claim 1, characterized in that, The fan-shaped nozzles (7) are arranged in a ring along the inner wall of the tank (1), and any one of the fan-shaped nozzles (7) points to the geometric center of the filter assembly (8).

6. The PVDF powder cleaning and drying equipment according to claim 1, characterized in that, The vacuum pump assembly (10) includes a Roots pump (101) and a liquid ring pump (102) connected in sequence to the filter chamber (4), and the output end of the liquid ring pump (102) is connected to the condenser assembly (12).

7. The PVDF powder cleaning and drying equipment according to claim 1, characterized in that, A dissolving tank (11) is connected to the liquid inlet (5), a second filter screen is fixedly installed at the output end of the dissolving tank (11), and a flow sensor is installed between the filter screen and the liquid inlet (5).

8. The PVDF powder cleaning and drying equipment according to claim 1, characterized in that, During the drying process, the temperature of the heat exchange medium circulating in the hollow jacket (2) is 80-100℃, and the vacuum degree in the tank (1) is not less than -0.095MPa.

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