A filter press drying device

Abstract

The present application discloses a filter press drying device. The filter press drying device comprises a feeding system, a filter press, an extrusion system and a vacuum system; the filter press comprises a plurality of filter press units, the filter press units comprise a first filter plate, a second filter plate, a first diaphragm and a filter cloth; the second filter plate and the first filter plate are enclosed to form a chamber; the filter cloth is arranged in the chamber, the part of the chamber between the filter cloth and the second filter plate is a filter chamber, the part between the filter cloth and the first filter plate is a drainage chamber, and the first diaphragm is arranged in the filter chamber; a first diaphragm cavity is formed between the first diaphragm and the second filter plate, or the first diaphragm has a first diaphragm cavity; the feeding system and the vacuum system are both connected to the filter chamber, and the vacuum system is used to evacuate the filter chamber; the extrusion system is connected to the first diaphragm cavity to supply high-pressure cold fluid or high-pressure hot fluid to the first diaphragm cavity. The device can shorten the process flow of slurry filter press drying, reduce the space occupied by the equipment and the time of filter press drying treatment, and improve work efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of filtration and drying, and in particular to a filter press drying device. Background Art

[0002] Lithium battery positive electrode materials are usually separated by wet solid-liquid separation using a filter press, such as a vertical filter press. A filter press generally includes a number of filter plates, with filter chambers formed between adjacent filter plates and a diaphragm disposed in the filter chamber. When in use, slurry can be introduced into the filter chamber, and high-pressure water is used to expand the diaphragm to squeeze the slurry inside the filter chamber to achieve solid-liquid separation of the slurry, and obtain a wet filter cake and a filtrate. The wet filter cake usually contains a lot of water and needs to be further dried before subsequent use.

[0003] In the related art, the filter press only has the filtering function, and the wet filter cake obtained by filtering needs to be sent to a special dryer for drying. In this way, since the wet filter cake material needs to be sent to the dryer, the process flow is relatively long, occupies more space, takes more time, and has low work efficiency.

[0004] Therefore, how to provide a solution to overcome or alleviate the above-mentioned defects is still a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] The purpose of the present application is to provide a filter press drying device to shorten the process flow of slurry filter press drying, reduce the space occupied by the equipment and the time of filter press drying treatment, and improve work efficiency.

[0006] In order to solve the above technical problems, the present application provides a filter press drying device, comprising a feeding system, a filter press, an extrusion system and a vacuum system;

[0007] The filter press comprises a plurality of filter press units, each of which comprises a first filter plate, a second filter plate, a first diaphragm and a filter cloth; the second filter plate and the first filter plate together form a chamber;

[0008] The filter cloth is arranged in the chamber, the part of the chamber between the filter cloth and the second filter plate is a filter chamber, and the part between the filter cloth and the first filter plate is a drainage chamber, the first diaphragm is arranged in the filter chamber; a first diaphragm cavity is formed between the first diaphragm and the second filter plate, or the first diaphragm has a first diaphragm cavity;

[0009] The feeding system and the vacuum system are both connected to the filter chamber, and the vacuum system is used to evacuate the filter chamber; the extrusion system is connected to the first diaphragm cavity to supply high-pressure cold fluid or high-pressure hot fluid to the first diaphragm cavity.

[0010] Optionally, the filter press unit further includes a second diaphragm;

[0011] The second diaphragm is arranged in the drainage chamber; a second diaphragm cavity is formed between the second diaphragm and the first filter plate, or the second diaphragm has a second diaphragm cavity; the extrusion system is connected to the second diaphragm cavity to supply the high-pressure cold fluid or the high-pressure hot fluid to the second diaphragm cavity.

[0012] Optionally, the filter press is a vertical filter press, and the second filter plate is located above the first filter plate.

[0013] Optionally, the drainage chamber has a first side and a second side opposite to each other, and the first side and the second side are each provided with at least one drainage port;

[0014] When the high-pressure cold fluid or the high-pressure hot fluid is introduced into the second diaphragm cavity, the second diaphragm can expand toward the side close to the filter cloth, and the outer surface of the second diaphragm facing the filter cloth can form two downward-inclined filtering slopes, and the two filtering slopes extend from the middle of the second diaphragm to the first side and the second side respectively.

[0015] Optionally, at least one of the drainage ports on the first side and at least one of the drainage ports on the second side are symmetrically arranged with respect to a vertical cross section passing through the center of the drainage chamber.

[0016] Optionally, a plurality of convex strips are provided on one side of the second diaphragm close to the filter cloth, and the plurality of convex strips extend from the middle portion to the edge of the second diaphragm, and drainage grooves are formed between adjacent convex strips.

[0017] Optionally, the extrusion system includes an extrusion tank, a mold temperature controller and a high-pressure pump connected in sequence;

[0018] The squeeze tank is used to store fluid, the first diaphragm cavity has a first inlet and a first outlet, the second diaphragm cavity has a second inlet and a second outlet, the first inlet and the second inlet are both connected to the high-pressure pump, and the first outlet and the second outlet are both connected to the squeeze tank.

[0019] Optionally, an air blowing system is also included;

[0020] The air blowing system comprises an air compressor and a heater connected to each other. The air blowing system is connected to the filter chamber and is used to supply back-blowing gas to the filter chamber.

[0021] Optionally, the feed system and the filter chamber are connected via a feed pipe, and the air blowing system is connected to the feed pipe.

[0022] Optionally, the vacuum system includes a condenser, a liquid collecting tank and a vacuum pump connected in sequence;

[0023] The filter chamber has an air outlet, and the condenser is connected to the air outlet.

[0024] The filter pressing and drying device provided by the present application is provided with a feeding system, a filter press, an extrusion system and a vacuum system, the filter pressing unit of the filter press forms a chamber between the first filter plate and the second filter plate, a filter cloth is arranged in the chamber, the filter cloth separates the chamber into a filter chamber and a drainage chamber, a first diaphragm cavity is formed between the first diaphragm and the second filter plate or the first diaphragm itself, the feeding system and the vacuum system are both connected to the filter chamber, and the extrusion system is connected to the first diaphragm cavity. When in use, the slurry can be passed into the filter chamber by the feeding system, and the high-pressure cold fluid can be passed into the first diaphragm cavity by the extrusion system to expand the first diaphragm toward the filter cloth to filter the slurry, and the vacuum system can also be used to evacuate the filter chamber after the filter pressing, and the high-pressure hot fluid can be passed into the first diaphragm cavity by the extrusion system to expand the first diaphragm toward the filter cloth to heat the wet filter cake, vaporize the water in the wet filter cake, and extract it by the vacuum system to achieve the drying of the slurry. In this way, the slurry filtration and drying can be integrated in the same equipment, which can shorten the process flow of slurry filtration and drying, reduce the space occupied by the equipment and the time of filtration and drying treatment, improve work efficiency, and use a vacuum system to evacuate the filter chamber during drying to reduce the boiling point of water and enhance the drying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural principle diagram of the filter press drying device of the embodiment provided in this application;

[0026] Figure 2 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when not in operation;

[0027] Figure 3 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when a high-pressure cold fluid is passed through the second diaphragm;

[0028] Figure 4 This is a schematic diagram of the structure of the filter press unit in the filter press drying device of the embodiment provided in the present application when the slurry is introduced into the filter chamber;

[0029] Figure 5 This is a schematic structural diagram of a filter press unit in a filter press drying device according to an embodiment of the present application when a high-pressure cold fluid is introduced into the first diaphragm to filter the slurry;

[0030] Figure 6 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when high-pressure hot fluid is passed through the first diaphragm and the second diaphragm to dry the wet filter cake;

[0031] Figure 7This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when unloading after the high-pressure hot fluid is discharged from the first diaphragm and the second diaphragm.

[0032] The reference numerals in the above drawings are described as follows:

[0033] 1-feeding system, 11-slurry tank, 12-feeding pump, 13-feeding pipe, 14-feeding valve;

[0034] 2-filter press, 2a-filter press unit, a-chamber, a1-filter chamber, a2-drainage chamber, 21-first filter plate, 22-second filter plate, 23-first diaphragm, 23a-first diaphragm cavity, 24-second diaphragm, 24a-second diaphragm cavity, 25-filter cloth, 26-drainage port;

[0035] 3-extrusion system, 31-extrusion tank, 32-mold temperature controller, 33-high pressure pump, 34-inlet pipe, 35-outlet pipe, 36-inlet valve, 37-outlet valve, 38-supplement pipe, 39-supplement valve;

[0036] 4- vacuum system, 41- condenser, 42- liquid collecting tank, 43- vacuum pump;

[0037] 5-air blowing system, 51-heater, 52-intake pipe, 53-intake valve;

[0038] b1-slurry, b2-wet filter cake, b3-dry filter cake, c1-high-pressure cold fluid, c2-high-pressure hot fluid. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0040] It should be specially noted that the words “first”, “second”, etc. in this application are only used to facilitate the description of two or more structures or components with the same or similar structures and / or functions, and do not imply any special limitation on the order and / or importance.

[0041] The term “several” as used in this application refers to an indefinite number of multiples, usually more than two; and when “several” is used to indicate the number of certain components, it does not indicate the quantitative relationship between these components.

[0042] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] Please refer to Figure 1 to Figure 2 , Figure 1 This is a structural principle diagram of the filter press drying device of the embodiment provided in this application, Figure 2 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when not in operation.

[0044] In the examples provided in this application, please refer to Figure 1 The filter press drying device includes a feed system 1, a filter press 2, an extrusion system 3 and a vacuum system 4. The filter press 2 includes a plurality of filter press units 2a, please refer to Figure 2 The filter press unit 2a includes a first filter plate 21, a second filter plate 22, a first diaphragm 23 and a filter cloth 25; the second filter plate 22 and the first filter plate 21 together form a chamber a; the filter cloth 25 is arranged in the chamber a, the part of the chamber a between the filter cloth 25 and the second filter plate 22 is the filter chamber a1, the part between the filter cloth 25 and the first filter plate 21 is the drainage chamber a2, the first diaphragm 23 is arranged in the filter chamber a1; the first diaphragm 23 has a first diaphragm cavity 23a. The feed system 1 and the vacuum system 4 are both connected to the filter chamber a1, and the vacuum system 4 is used to evacuate the filter chamber a1; the extrusion system 3 is connected to the first diaphragm cavity 23a, so as to supply the first diaphragm cavity 23a with a high-pressure cold fluid c1 or a high-pressure hot fluid c2.

[0045] When in use, the slurry b1 can be introduced into the filter chamber a1 using the feeding system 1, and the high-pressure cold fluid c1 can be introduced into the first diaphragm cavity 23a using the extrusion system 3 to make the first diaphragm 23 expand toward the filter cloth 25 to filter the slurry b1 to obtain a wet filter cake b2 and a filtrate. After the filtration, the filter chamber a1 can be evacuated using the vacuum system 4, and the high-pressure hot fluid c2 can be introduced into the first diaphragm cavity 23a using the extrusion system 3 to make the first diaphragm 23 expand toward the filter cloth 25 to heat the wet filter cake b2, so that the water in the wet filter cake b2 is vaporized and extracted using the vacuum system 4 to obtain a dry filter cake b3, thereby drying the slurry b1.

[0046] In this way, the solid-liquid separation and vacuum drying processes of slurry b1 can be integrated in the same equipment, which can shorten the process flow of filter pressing and drying of slurry b1, realize the short-term process, reduce the space occupied by the equipment and the time of filter pressing and drying treatment, improve work efficiency, and reduce equipment and production line investment.

[0047] Moreover, compared with the related art that uses a dryer to utilize high-temperature oil or other heat to dry the wet filter cake b2, which results in higher energy consumption, the filter press drying device provided in the embodiment of the present application uses a vacuum system 4 to evacuate the filter chamber a1 during drying, which can reduce the boiling point of water and enhance the drying effect. At the same time, it can reduce the temperature of the high-pressure hot fluid c2 used to heat the wet filter cake b2, thereby reducing energy consumption.

[0048] In addition, compared with the related art in which the filter press only has a filtering function, which causes the wet filter cake to easily remain in the filter chamber during unloading and easily stick to the inner wall of the pipe during transportation, the filter press 2 provided in the embodiment of the present application has a drying function, and the obtained dry filter cake b3 has a lower water content. The material is not likely to remain in the filter chamber a1 during unloading, and is not likely to stick to the inner wall of the pipe during subsequent transportation, which can reduce the cleaning operations of the filter chamber and the pipe.

[0049] It can be understood that the high-pressure cold fluid c1 is used to expand and swell the corresponding diaphragm to squeeze and dehydrate the slurry b1, and the high-pressure hot fluid c2 is used to expand and swell the corresponding diaphragm to heat and dry the slurry b1. The two can be gases or liquids, and this application does not limit them. In the embodiment of this application, the fluid can be water, which has a lower cost. The temperatures corresponding to "cold" and "hot" here are relative. The temperature of the high-pressure hot fluid c2 can make the moisture inside the wet filter cake b2 vaporize when the wet filter cake b2 is heated, and the temperature of the high-pressure cold fluid c1 will not vaporize the moisture.

[0050] In the embodiments provided in this application, please combine Figure 2 It is understood that the filter press unit 2a also includes a second diaphragm 24; the second diaphragm 24 is arranged in the drainage chamber a2; the second diaphragm 24 has a second diaphragm cavity 24a; the extrusion system 3 is connected to the second diaphragm cavity 24a to supply high-pressure cold fluid c1 or high-pressure hot fluid c2 to the second diaphragm cavity 24a.

[0051] In this way, when the slurry b1 needs to be filtered, the extrusion system 3 can be used to pass high-pressure cold fluid c1 into the second diaphragm cavity 24a, so that the second diaphragm 24 expands toward the filter cloth 25 to support the filter cloth 25, and can cooperate with the expanded first diaphragm 23 to filter the slurry b1 inside the filter chamber a1, which can improve the filtering effect. At the same time, after the second diaphragm 24 expands, its outer surface facing the filter cloth 25 can form a filtering slope inclined from the middle to the edge, which is conducive to guiding the filtrate generated by the filtering, making it easier to discharge the filtrate, and can further reduce the moisture in the filtering process and improve the filtering effect.

[0052] Furthermore, when the wet filter cake b2 needs to be dried, the extrusion system 3 can be used to introduce high-pressure hot fluid c2 into the second diaphragm cavity 24a, so that the second diaphragm 24 expands toward the filter cloth 25, and cooperates with the expanded first diaphragm 23 to heat the wet filter cake b2 inside the filter chamber a1 from both sides, thereby improving the efficiency of water vaporization in the wet filter cake b2 and enhancing the drying effect.

[0053] It is worth noting that in the above embodiment of the present application, the first diaphragm 23 and the second diaphragm 24 are both hollow structures, and form corresponding diaphragm cavities by themselves. In fact, the first diaphragm 23 and the second diaphragm 24 can also be a layer of membrane structure. The first diaphragm 23 and the second filter plate 22 can form a first diaphragm cavity 23a, and the second diaphragm 24 and the first filter plate 21 can form a second diaphragm cavity 24a. When in use, a high-pressure cold fluid c1 or a high-pressure hot fluid c2 can be introduced between the first diaphragm 23 and the second filter plate 22 to expand the first diaphragm 23, and a high-pressure cold fluid c1 or a high-pressure hot fluid c2 can be introduced between the second diaphragm 24 and the first filter plate 21 to expand the second diaphragm 24. In the specific setting, the structure of the first diaphragm 23 and the second diaphragm 24 is not limited.

[0054] When in use, the materials of the first diaphragm 23 and the second diaphragm 24 are not limited. As an optional solution, the first diaphragm 23 and the second diaphragm 24 can both be made of rubber material to have good heat resistance and toughness, further ensuring the filter pressing effect and drying effect.

[0055] In actual configuration, the structure of the filter press 2 is not limited, and it can be a horizontal filter press or a vertical filter press.

[0056] As an alternative, please refer to Figure 2 , the filter press 2 is a vertical filter press, the second filter plate 22 is located above the first filter plate 21, and correspondingly, the drainage chamber a2 is located below the filter chamber a1, the first diaphragm 23 is located above the filter cloth 25, the first diaphragm 23 can be fixed to the second filter plate 22, the second diaphragm 24 is located below the filter cloth 25, and the second diaphragm 24 can be fixed to the first filter plate 21. In this way, after the second diaphragm 24 expands, it can support the filter cloth 25 from bottom to top, and the slurry b1 on the filter cloth 25 is subjected to the downward force applied by the first diaphragm 23 and the upward force applied by the second diaphragm 24, which can further improve the filter pressing effect. Obviously, after the second diaphragm 24 expands, the above-mentioned filter slope formed by it can be tilted downward from the middle to the edge, which has a better diversion effect on the filtrate, can further improve the discharge efficiency of the filtrate, and improve the filter pressing effect.

[0057] It is not difficult to understand that the filter press 2 can be a vertical automatic plate and frame filter press, and its filtration process is almost continuously operated. The filter cake storage tank can be much smaller than the storage tank of the horizontal automatic plate and frame filter press, thereby reducing the thickness of a single filter cake and making it easier to control the moisture content of the filter cake, making it easier to meet the requirements.

[0058] In the examples provided in this application, please refer to Figure 2 The drainage chamber a2 has a first side and a second side opposite to each other, and each of the first side and the second side is provided with at least one drainage port 26; when the high-pressure cold fluid c1 or the high-pressure hot fluid c2 is introduced into the second diaphragm cavity 24a, the second diaphragm 24 can expand toward the side close to the filter cloth 25, and the outer surface of the second diaphragm 24 facing the filter cloth 25 can form two downwardly inclined filtering slopes, and the two filtering slopes extend from the middle of the second diaphragm 24 to the first side and the second side, respectively.

[0059] In this way, the two filtering slopes can be tilted downward from the middle of the second diaphragm 24 to the edges of the first side and the second side respectively, so that the filtrate can quickly enter the discharge ports 26 on the first side and the second side under the guidance of the two filtering slopes and be quickly discharged, which can further improve the discharge efficiency of the filtrate and improve the filter press effect.

[0060] At the same time, compared with the one-sided drainage method in the related art, which results in more water near the drain port 26, resulting in uneven water distribution, which is not conducive to the discharge of the filtrate, the second diaphragm 24 in the filter press drying device provided in the embodiment of the present application forms the above-mentioned two filtering slopes, which can make the filtrate distributed more evenly on both sides, which is more conducive to the discharge of the filtrate.

[0061] Moreover, compared with the related art in which the overall filter plate of the filter press needs to be thickened in order to have enough space to set a drainage chute under the filter cloth for drainage, the filter press drying device provided in the embodiment of the present application has the above-mentioned filtering slope to guide the liquid discharge port 26, and there is no need to set a drainage chute on the filter plate, so that the thickness of the first filter plate 21 and the second filter plate 22 can be thinner, which can reduce the weight of the device and save manufacturing costs.

[0062] In the specific configuration, the number of the first side and the second side drainage ports 26 is not limited, and can be as follows: Figure 2 As shown, one is set respectively, and more than two can also be set.

[0063] When specifically configured, the arrangement of the drainage ports 26 on the first side and the second side is not limited. As an optional solution, at least one drainage port 26 on the first side and at least one drainage port 26 on the second side can be symmetrically arranged about the vertical cross section through the center of the drainage chamber a2, so that the filtrate is more evenly distributed when discharged and the discharge efficiency is higher.

[0064] In the embodiment provided in the present application, a plurality of convex strips (not shown in the figure) are provided on one side of the second diaphragm 24 close to the filter cloth 25, and the plurality of convex strips extend from the middle part to the edge of the second diaphragm 24, and drainage grooves (not shown in the figure) are formed between adjacent convex strips, and each drainage groove can enhance the diversion effect on the filtrate to enhance the filter pressing effect.

[0065] In actual configuration, the structure of the extrusion system 3 is not limited.

[0066] As an alternative, please refer to Figure 1 The extrusion system 3 may include an extrusion tank 31, a mold temperature controller 32 and a high-pressure pump 33 connected in sequence; the extrusion tank 31 is used to store the extrusion fluid, which may be water, the first diaphragm cavity 23a has a first inlet and a first outlet, the second diaphragm cavity 24a has a second inlet and a second outlet, the first inlet and the second inlet are both connected to the high-pressure pump 33, and the first outlet and the second outlet are both connected to the extrusion tank 31. The high-pressure pump 33 may be a high-pressure water pump, which is used to pressurize water before transporting it; the specific structure of the mold temperature controller 32 is not limited, for example, it may be a water-type mold temperature controller, which can be used to heat the transported water.

[0067] During use, when high-pressure cold fluid c1 is required for filter pressing, the mold temperature controller 32 does not work, and the high-pressure pump 33 pumps high-pressure cold fluid c1 to the first diaphragm cavity 23a and the second diaphragm cavity 24a respectively. After the filter pressing is completed, the high-pressure cold fluid c1 inside the first diaphragm cavity 23a and the second diaphragm cavity 24a can flow back to the squeeze tank 31 through the first outlet and the second outlet respectively; when high-pressure hot fluid c2 is required for drying, the mold temperature controller 32 works, and after heating the cold fluid, the high-pressure hot fluid c2 is pumped to the first diaphragm cavity 23a and the second diaphragm cavity 24a respectively through the high-pressure pump 33. During the drying process, the high-pressure hot fluid c2 inside the first diaphragm cavity 23a and the second diaphragm cavity 24a can flow back to the squeeze tank 31 through the first outlet and the second outlet respectively. In this way, a heat flow cycle can be formed to relatively ensure that the first diaphragm cavity 23a and the second diaphragm cavity 24a have a stable temperature to ensure the drying effect of the wet filter cake b2 inside the filter chamber a1.

[0068] In the embodiments provided in this application, Figure 1 As shown, the filter press drying device also includes an air blowing system 5; the air blowing system 5 includes an air compressor and a heater 51 connected to each other, the air blowing system 5 is connected to the filter chamber a1, and the air blowing system 5 is used to supply back-blowing gas to the filter chamber a1. The air compressor can be used to provide compressed air, and the form of the heater 51 is not limited, for example, it can be an electric heater, which can heat the compressed air.

[0069] During use, after the filter press is completed, the heater 51 does not work, and the air blowing system 5 can be used to introduce compressed air into the filter chamber a1 to purge the wet filter cake b2, and the residual filtrate in the drainage chamber a2 and the drainage hose connected thereto can be discharged to ensure the filter press effect; after the drying is completed, the heater 51 works to heat the compressed air, and the air blowing system 5 can introduce hot compressed air into the filter chamber a1 to purge the dry filter cake b3. The air flow purge temperature can be consistent with the temperature of the high-pressure hot fluid c2, so that the residual moisture in the gap of the dry filter cake b3 can be vaporized, and extracted by the vacuum system 4 to ensure the drying effect.

[0070] In the embodiment of the present application, the feeding system 1 can be connected to the filter chamber a1 through the feeding pipe 13, and the air blowing system 5 can be connected to the feeding pipe 13. In this way, after the feeding is completed, the air blowing system 5 can be used to introduce compressed air into the feeding pipe 13 to backflush the feeding pipe 13 and clean the residual slurry in the feeding pipe 13, so that the slurry is not easy to stick to and block the feeding pipe 13, thereby ensuring the smooth progress of the next feeding work of the feeding system 1.

[0071] In the embodiments provided in this application, Figure 1 As shown, the vacuum system 4 includes a condenser 41, a liquid collecting tank 42 and a vacuum pump 43 which are connected in sequence; the filter chamber a1 has an air outlet, the inlet of the condenser 41 can be connected to the air outlet of the filter chamber a1 through a hose, the outlet of the condenser 41 can be connected to the inlet of the liquid collecting tank 42, and the outlet of the liquid collecting tank 42 can be connected to the inlet of the vacuum pump 43 through a pipeline.

[0072] When in use, the vacuum pump 43 can be used to evacuate the filter chamber a1 to reduce the boiling point of water and ensure the drying effect. After the water inside the wet filter cake b2 is vaporized, it can be pumped out by the vacuum pump 43 and first enter the condenser 41 for condensation, and then sent to the liquid collecting tank 42 for collection.

[0073] In the embodiment of the present application, the filter chamber a1 may have a feed inlet and an air outlet. Figure 1 The feeding system 1 may include a slurry tank 11 and a feed pump 12 which are connected to each other. The inlet of the slurry tank 11 may be connected to the outlet of the water-washed slurry of the upstream equipment, and the outlet of the slurry tank 11 may be connected to the inlet of the feed pump 12 through a pipeline. The feed pump 12 may be a high-pressure feed pump, and the feed pipe 13 may be a high-pressure hose. The outlet of the feed pump 12 may be connected to the feed port of the filter chamber a1 through the feed pipe 13, and a feed valve 14 may be provided on the feed pipe 13; in the air blowing system 5, the heater 51 may be connected to the feed pipe 13 through the air inlet pipe 52, and share the same pipeline with the feeding system 1 to supply air to the filter chamber a1. The air inlet pipe 52 may be provided with an air inlet valve 53, and the feeding and air intake can be switched by switching the feed valve 14 and the air inlet valve 53.

[0074] In the extrusion system 3, the high-pressure pump 33 can be specifically connected to the first inlet and the second inlet through the inlet pipe 34, the inlet pipe 34 can be specifically connected to the first inlet and the second inlet through two inlet branch pipes, the extrusion tank 31 can be specifically connected to the first outlet and the second outlet through the outlet pipe 35, the outlet pipe 35 can be specifically connected to the first outlet and the second outlet through two outlet branch pipes, an inlet valve 36 can be arranged on the inlet pipe 34, an outflow valve 37 can be arranged on the outflow pipe 35, the two inlet branch pipes can be respectively provided with inlet branch valves, the two outflow branch pipes can be respectively provided with outflow branch valves, the extrusion tank 31 can be connected to the fluid source through the replenishing pipe 38, and the replenishing valve 39 can be arranged on the replenishing pipe 38.

[0075] In actual use, a controller can be provided for the filter press drying device, and the controller can be connected to the above-mentioned feed valve 14, air intake valve 53, inlet valve 36, outlet valve 37, inlet branch valve, outflow branch valve, replenishing valve 39 and feed pump 12, heater 51, mold temperature controller 32, and high-pressure pump 33 to realize the automatic feeding, cold backflush, hot backflush, cold fluid inlet, cold fluid exhaust, hot fluid inlet, and heat fluid exhaust of the device, which can improve the effect of filter press and drying.

[0076] Please refer to Figures 3 to 7 , Figure 3 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when a high-pressure cold fluid is passed through the second diaphragm. Figure 4 This is a schematic diagram of the structure of the filter press unit in the filter press drying device of the embodiment provided in the present application when the slurry is passed into the filter chamber. Figure 5 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when a high-pressure cold fluid is passed through the first diaphragm to filter the slurry. Figure 6 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when high-pressure hot fluid is passed through the first diaphragm and the second diaphragm to dry the wet filter cake. Figure 7 This is a schematic structural diagram of the filter press unit in the filter press drying device of the embodiment provided in the present application when unloading after the high-pressure hot fluid is discharged from the first diaphragm and the second diaphragm.

[0077] Taking the filtration and drying of the washed slurry of lithium battery positive electrode materials as an example, the working process of the filtration and drying device provided in the embodiment of the present application is described in conjunction with the accompanying drawings:

[0078] Closing the filter plates: starting the hydraulic cylinder of the filter press 2 to control the first filter plate 21 and the second filter plate 22 to close;

[0079] Preparation for filter pressing: Start the high-pressure pump 33 of the extrusion system 3, and open the inlet valve 36 and the inlet valve corresponding to the second diaphragm 24. The high-pressure pump 33 pressurizes the fluid inside the extrusion tank 31 to form a high-pressure cold fluid c1, and pumps it into the second diaphragm cavity 24a. Figure 3 As shown, the second diaphragm 24 expands and bulges upward, propping up the filter cloth 25 and forming a filtering slope at the same time;

[0080] Feeding: Start the feed pump 12 of the feed system 1 and open the feed valve 14. The feed pump 12 pressurizes the slurry b1 in the slurry tank 11 and evenly feeds it into the filter chamber a1 through the feed port of the filter chamber a1. Figure 4 As shown, the slurry b1 gradually fills the filter chamber a1, and when the pressure inside the feed pipe 13 reaches the preset pressure, the feed valve 14 is closed to stop feeding;

[0081] Feed pipe backflush: Start the air compressor and open the air inlet valve 53 to introduce compressed air into the feed pipe 13 to backflush the slurry b1 remaining inside the feed pipe 13 into the filter chamber a1;

[0082] Pressure filtration: Open the inlet branch valve corresponding to the first diaphragm 23, and the high-pressure pump 33 introduces high-pressure cold fluid c1 into the first diaphragm cavity 23a. The first diaphragm 23 expands downward continuously to squeeze the slurry b1 inside the filter chamber a1. After the pressure inside the inlet branch pipe corresponding to the first diaphragm 23 reaches the preset pressure, the inlet branch valve corresponding to the first diaphragm 23 is closed to stop the flow of fluid. The water in the slurry b1 passes through the filter holes of the filter cloth 25 under the pressure of the first diaphragm 23, enters the drainage groove of the second diaphragm 24 in the drainage chamber a2, and converges on both sides along the filter slope, and then is discharged through the drainage ports 26 on both sides; the material in the slurry b1 cannot pass through the filter holes of the filter cloth 25 and is intercepted on the filter cloth 25, such as Figure 5 As shown, a wet filter cake b2 is formed;

[0083] Wet filter cake backflush: Open the air inlet valve 53, and introduce cold compressed air into the filter chamber a1 to purge the wet filter cake b2, and discharge the residual filtrate in the drainage chamber a2 and its connected drainage hose;

[0084] Vacuuming: Start the vacuum pump 43 to evacuate the filter chamber a1;

[0085] Drying: When the vacuum degree of the filter chamber a1 reaches the preset vacuum degree, the mold temperature controller 32 is started to heat the extruded fluid. When the temperature of the extruded fluid reaches the preset temperature, a high-pressure hot fluid c2 is formed. The inlet valve 36 and the outlet valve 37 are opened to pass the high-pressure hot fluid c2 into the first diaphragm cavity 23a and the second diaphragm cavity 24a to form a cycle. Figure 6 As shown, the second diaphragm 24 expands and bulges upward, and the first diaphragm 23 expands and bulges downward, and the wet filter cake b2 is evenly heated from both sides, and the water inside the wet filter cake b2 is vaporized to obtain the following Figure 7 The gaseous water produced by the vaporization of the dry filter cake b3 is extracted by the vacuum pump 43, condensed by the condenser 41 and collected in the liquid collecting tank 42;

[0086] Back-flushing of dry filter cake: When the drying time of wet filter cake b2 reaches the preset drying time, turn off the vacuum pump 43, start the heater 51, heat the compressed air to the same temperature as the high-pressure hot fluid c2, introduce hot compressed air into the filter chamber a1, blow the dry filter cake b3, and vaporize the residual water in the dry filter cake b3. Then, turn on the vacuum pump 43 to extract the vaporized water.

[0087] In the above process, since drying is carried out in a vacuum environment, the boiling point of water is relatively low, for example, it can reach below 90°C. In this way, the temperature of the high-pressure thermal fluid c2 and the hot compressed air provided only needs to be around 90°C. Compared with the high-temperature drying in the related technology which requires a temperature of around 150°C, it greatly reduces the energy consumption of the equipment, saves energy, and reduces the drying cost.

[0088] In the embodiment of the present application, double drying is performed by the above-mentioned vacuum drying and hot compressed air purging, and the moisture content of the finally obtained dry filter cake b3 can be reduced to below 950 ppm, meeting the drying requirements and greatly improving the drying effect.

[0089] The principles and implementation methods of the present application are described in this article using specific examples. The description of the above embodiments is only used to help understand the device and its core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A filter press drying device, characterized in that: It includes a feeding system (1), a filter press (2), an extrusion system (3) and a vacuum system (4); The filter press (2) comprises a plurality of filter press units (2a), wherein the filter press units (2a) comprise a first filter plate (21), a second filter plate (22), a first diaphragm (23) and a filter cloth (25); the second filter plate (22) and the first filter plate (21) together form a chamber (a); The filter cloth (25) is arranged in the chamber (a); the portion of the chamber (a) between the filter cloth (25) and the second filter plate (22) is a filter chamber (a1); the portion of the chamber (a) between the filter cloth (25) and the first filter plate (21) is a drainage chamber (a2); the first diaphragm (23) is arranged in the filter chamber (a1); a first diaphragm cavity (23a) is formed between the first diaphragm (23) and the second filter plate (22), or the first diaphragm (23) has a first diaphragm cavity (23a); The feeding system (1) and the vacuum system (4) are both connected to the filter chamber (a1), and the vacuum system (4) is used to evacuate the filter chamber (a1); the extrusion system (3) is connected to the first diaphragm cavity (23a) to supply high-pressure cold fluid (c1) or high-pressure hot fluid (c2) to the first diaphragm cavity (23a).

2. The filter press drying device according to claim 1, characterized in that: The filter press unit (2a) further comprises a second diaphragm (24); The second diaphragm (24) is arranged in the drainage chamber (a2); a second diaphragm cavity (24a) is formed between the second diaphragm (24) and the first filter plate (21), or the second diaphragm (24) has a second diaphragm cavity (24a); the extrusion system (3) is connected to the second diaphragm cavity (24a) to supply the high-pressure cold fluid (c1) or the high-pressure hot fluid (c2) to the second diaphragm cavity (24a).

3. The filter press drying device according to claim 2, characterized in that: The filter press (2) is a vertical filter press, and the second filter plate (22) is located above the first filter plate (21).

4. The filter press drying device according to claim 3, characterized in that: The drainage chamber (a2) has a first side and a second side opposite to each other, and the first side and the second side are each provided with at least one drainage port (26); When the high-pressure cold fluid (c1) or the high-pressure hot fluid (c2) is introduced into the second diaphragm cavity (24a), the second diaphragm (24) can expand toward the side close to the filter cloth (25), and the outer surface of the second diaphragm (24) facing the filter cloth (25) can form two downwardly inclined filtering slopes, and the two filtering slopes extend from the middle of the second diaphragm (24) to the first side and the second side respectively.

5. The filter press drying device according to claim 4, characterized in that: At least one of the drainage openings (26) on the first side and at least one of the drainage openings (26) on the second side are symmetrically arranged with respect to a vertical cross section passing through the center of the drainage chamber (a2).

6. The filter press drying device according to claim 2, characterized in that: A plurality of convex strips are provided on one side of the second diaphragm (24) close to the filter cloth (25), the plurality of convex strips extending from the middle portion to the edge of the second diaphragm (24), and drainage grooves are formed between adjacent convex strips.

7. The filter press drying device according to claim 2, characterized in that: The extrusion system (3) comprises an extrusion tank (31), a mold temperature controller (32) and a high-pressure pump (33) which are connected in sequence; The squeeze tank (31) is used to store fluid, the first diaphragm cavity (23a) has a first inlet and a first outlet, the second diaphragm cavity (24a) has a second inlet and a second outlet, the first inlet and the second inlet are both connected to the high-pressure pump (33), and the first outlet and the second outlet are both connected to the squeeze tank (31).

8. The filter press drying device according to any one of claims 1 to 7, characterized in that: Also includes an air blowing system (5); The air blowing system (5) comprises an air compressor and a heater (51) which are connected to each other. The air blowing system (5) is connected to the filter chamber (a1). The air blowing system (5) is used to supply back-blowing gas to the filter chamber (a1).

9. The filter press drying device according to claim 8, characterized in that: The feed system (1) and the filter chamber (a1) are connected via a feed pipe (13), and the air blowing system (5) is connected to the feed pipe (13).

10. The filter press drying device according to any one of claims 1 to 7, characterized in that: The vacuum system (4) comprises a condenser (41), a liquid collecting tank (42) and a vacuum pump (43) which are connected in sequence; The filter chamber (a1) has an air outlet, and the condenser (41) is connected to the air outlet.

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