A lithium iron phosphate dewatering device and process

Abstract

The present application provides a dewatering device and process for lithium iron phosphate, and relates to the technical field of lithium iron phosphate production. A dewatering device for lithium iron phosphate includes a drying tank shell composed of an inner shell and an interlayer sleeve, and the cavity formed by the inner shell and the interlayer sleeve constitutes a heat transfer oil chamber A. The two opposite side walls of the drying tank shell are respectively rotatably provided with a mounting assembly A and fixed with a mounting assembly B, and the drying tank shell can be driven to rotate by the mounting assembly B. The mounting assembly A includes a fixed shaft that is rotationally sealed with the side wall of the drying tank shell and extends to the inside thereof, and a heat transfer oil chamber B is provided in the fixed shaft, and through holes are provided on the upper and lower side walls of the fixed shaft, and the oil in the heat transfer oil chamber A and the oil in the heat transfer oil chamber B are merged through the through holes. The oil in the heat transfer oil chamber B and the oil in the heat transfer oil chamber A are merged through the through holes, which expands the heat conduction area, improves the efficiency of drying and dewatering the lithium iron phosphate powder, and saves costs.

Description

Technical Field

[0001] The present application relates to the technical field of lithium iron phosphate production, and in particular to a lithium iron phosphate water removal device and process. Background Art

[0002] Lithium iron phosphate, also known as lithium iron phosphate, is a lithium-ion battery electrode material with the chemical formula LiFePO4 (LFP for short), which is mainly used in various lithium-ion batteries.

[0003] At present, the mainstream preparation process of lithium iron phosphate positive electrode materials can be divided into two major routes: solid phase method and liquid phase method. The main process flow of preparing lithium iron phosphate by solid phase method is: mixing → spray drying → sintering → crushing → mixed classification → baking. In the baking process, the qualified lithium iron phosphate powder after mixing and classification is mainly baked to remove moisture. Generally, a dryer (or double cone dryer) is used as a dehydration device.

[0004] When drying lithium iron phosphate powder, in order to speed up the evaporation of water vapor inside, the dryer in the related technology usually designs an interlayer on the tank body to contain heating media such as heat transfer oil / steam / water, and uses the above heating medium to transfer heat to the inside of the tank body, so that the lithium iron phosphate powder absorbs heat and evaporates, and uses a vacuum suction structure to quickly extract water vapor, thereby achieving the dehydration process of the lithium iron phosphate powder. However, only filling the heating medium outside the tank body to transfer heat inside, the transfer effect is insufficient, and if a separate heat conduction path is opened inside the tank body and not connected to the interlayer, the cost is too high. Therefore, how to increase the heat conduction effect while reducing costs has become a technical problem to be solved in this application. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a dehydration device and process for lithium iron phosphate, which introduces a heat transfer chamber connected to the inner chamber of the interlayer into the dryer, increases the contact area between the lithium iron phosphate powder and the heat source during the turning process inside the dryer, improves the heat conduction efficiency, and relatively reduces the heat conduction cost.

[0006] The technical solution adopted by the embodiment of the present application to solve the technical problem is: a dehydration device for lithium iron phosphate, comprising a drying tank shell composed of an inner shell and an interlayer sleeve arranged on the outer side thereof for accommodating lithium iron phosphate powder, and the cavity formed by the inner shell and the interlayer sleeve on the outer side constitutes a heat transfer oil chamber A, and the two opposite side walls of the drying tank shell are respectively rotatably connected with a mounting assembly A and fixedly connected with a mounting assembly B, and the drying tank shell can be driven to rotate through the mounting assembly B, so as to drive the lithium iron phosphate powder to turn over and dry in the drying tank shell. The mounting assembly B is provided with a vacuum suction assembly extending into the inner shell for absorbing drying steam, a base is installed at the bottom of the mounting assembly A and the mounting assembly B, the mounting assembly A includes a fixed shaft which is rotatably sealed with the side wall of the drying tank shell and extends into the interior thereof, and a heat transfer oil cavity B for conducting heat to the outside is provided in the fixed shaft, and through holes which communicate with the heat transfer oil cavity B are provided on the upper and lower side walls of the fixed shaft, and the oil in the heat transfer oil cavity A and the heat transfer oil cavity B are merged through the through holes.

[0007] According to some embodiments of the present application, the inner shell and the interlayer sleeve are connected to the fixed shaft at a mounting opening, and a rotating seal A is provided at the connection between the mounting opening and the outer wall of the fixed shaft;

[0008] The rotating seal A includes a mounting sleeve fixed to the inner wall of the mounting port, and a bearing A whose inner and outer rings are respectively connected to the outer wall of the fixed shaft and the inner wall of the mounting sleeve. Sealing rings A symmetrically about the bearing A are installed at both ends of the inner ring of the mounting sleeve, and the inner wall of the sealing ring A is pressed against the outer wall of the fixed shaft.

[0009] According to some embodiments of the present application, the openings at both ends of the mounting sleeve are designed to be in an inwardly retracted state, and limiting rings symmetrically designed with respect to the bearing A are installed on both sides of the inner ring of the mounting sleeve, and the sealing ring A is installed in a limited manner between the inner opening of the mounting sleeve and the limiting ring.

[0010] According to some embodiments of the present application, the lithium iron phosphate water removal device further includes a heat transfer oil circulation component;

[0011] The heat transfer oil circulation component includes a natural gas heat medium furnace and an oil inlet pipe and an oil return pipe connected to the upper and lower side walls thereof. The oil inlet pipe and the oil return pipe both penetrate the fixed shaft and enter the heat transfer oil chamber B therein. The oil return pipe also separately penetrates the upper side wall of the fixed shaft from the heat transfer oil chamber B and extends to the top of the heat transfer oil chamber A. The oil inlet pipe is also sequentially installed with a stop valve A and a circulating oil pump for providing oil injection power, and an oil inlet temperature detector for detecting the oil injection temperature.

[0012] According to some embodiments of the present application, the area of ​​the oil inlet pipeline located between the circulating oil pump and the oil inlet temperature detector is also connected to a bypass pipeline, and stop valves B are installed at both upper and lower ends of the bypass pipeline. A thermal oil cooler is installed in the area of ​​the bypass pipeline located between the two stop valves B, and stop valves C are installed on the oil inlet pipeline near the upper and lower ends of the bypass pipeline.

[0013] According to some embodiments of the present application, the mounting assembly A further includes a box shell A fixed to one side of the upper surface of the base, and both ends of the fixed axis penetrate and are fixed to two side walls of the box shell A.

[0014] According to some embodiments of the present application, the mounting assembly B includes a box shell B fixed to the other side of the upper surface of the base, a rotating shaft rotatably connected to the two side walls of the box shell B, and a driving part provided in the box shell B for driving the rotating shaft to rotate, and one end of the rotating shaft penetrates and is fixed to the inner shell and the interlayer sleeve;

[0015] The driving part includes a servo motor fixed on the upper surface of the base and a right-angle reducer installed on the middle plate inside the box shell B. The output shaft of the servo motor and one of the shafts of the right-angle reducer are driven by a belt. The master and slave sprockets are respectively installed on the outer ring of the rotating shaft and the other shaft of the right-angle reducer, and are driven by a ring chain.

[0016] According to some embodiments of the present application, the vacuum suction assembly includes a vacuum pump and an exhaust pipe A connected to the exhaust end thereof, a hollow cavity is provided inside the rotating shaft, and an interpenetrating connection with the exhaust pipe A is achieved through the hollow cavity, and a rotating seal B is installed in the hollow cavity to realize the rotation of the rotating shaft and fix the exhaust pipe A;

[0017] The rotating seal B comprises a bearing B with two inner and outer rings respectively connected to the two sides of the inner wall of the hollow cavity and the two sides of the outer wall of the exhaust pipe A, and a sealing ring B installed at both ends of the inner wall of the hollow cavity, and the inner ring of the sealing ring B is pressed tightly against the outer wall of the exhaust pipe A;

[0018] One end of the exhaust pipe A extends to the interior of the inner shell and is installed with a vacuum filter head. A condenser, a buffer tank and a check valve are also installed on the exhaust pipe A in sequence. The water vapor evaporated from the inner shell is discharged along the exhaust pipe A through the vacuum filter head, the condenser, the buffer tank and the check valve and the vacuum pump in sequence.

[0019] According to some embodiments of the present application, an inlet and a discharge port are respectively provided at the upper and lower ends of the drying tank shell, and a sealing cover and a butterfly valve are respectively installed at the inlet and the discharge port.

[0020] In addition, the present application also provides a dehydration process of a lithium iron phosphate dehydration device, including the above-mentioned lithium iron phosphate dehydration device, and the following steps:

[0021] S1. Feeding, opening the sealing cover, and putting the lithium iron phosphate powder after the mixing and grading process into the inner shell;

[0022] S2. Rotate and stir, start the servo motor and the right-angle reducer, and indirectly drive the drying tank shell to rotate through the cooperation of the rotating shaft, so that the lithium iron phosphate powder put into it turns over;

[0023] S3. Heating, starting the circulating oil pump, the stop valve A and the stop valve C, and the stop valve B is in a closed state, the oil heated in the natural gas heat medium furnace is introduced into the heat transfer oil chamber B and the heat transfer oil chamber A through the oil inlet pipe, the hot oil passes through the two chambers to transfer heat to the inner shell, and the lithium iron phosphate powder absorbs moisture and evaporates water vapor to become dry;

[0024] S4. Vacuum evacuation, start the vacuum pump and the condenser, and open the check valve. The water vapor evaporated after the lithium iron phosphate powder absorbs moisture is discharged along the exhaust pipe A through the vacuum filter head, the condenser, the buffer tank, the check valve and the vacuum pump in sequence, thereby completing the drying of the lithium iron phosphate powder;

[0025] S5. Cool the thermal oil, close the stop valve C, and open the stop valve B. The oil in the oil inlet pipeline changes its flow direction and enters the thermal oil cooler from the bypass pipeline for cooling, and then is sent to the thermal oil chamber B and the thermal oil chamber A through the oil inlet pipeline;

[0026] S6. Discharging the material: turn off the servo motor and the right-angle reducer, and make the discharge port face downward, and open the butterfly valve to discharge the dried lithium iron phosphate powder.

[0027] In the above-mentioned lithium iron phosphate dehydration device, heat is conducted inside the inner shell through the heat transfer oil chamber A and the heat transfer oil chamber B. The heat in a short period of time is difficult to quickly reach the specified requirements. At the same time, due to the high water content and viscosity of the lithium iron phosphate powder, it is easy to cause the moisture in the material to fail to evaporate in a short period of time and cause wall sticking.

[0028] According to some embodiments of the present application, a scraper assembly A that cooperates with the heat transfer oil chamber B is installed inside the fixed shaft;

[0029] The scraper assembly A comprises a piston portion sealed with the inner wall of the heat transfer oil chamber B and extending to the outside of the fixed shaft, a connecting rod mechanism A connected between the fixed shaft and the piston portion, and an arc-shaped scraper plate A installed at the outer end of the connecting rod mechanism A and movably fitted with the inner wall of the inner shell;

[0030] The piston part comprises a piston block A sealed in the heat transfer oil chamber B, and a piston rod arranged at the outer end of the piston block A, and the outer end of the fixed shaft is provided with an insertion opening for the piston rod to pass through;

[0031] The connecting rod mechanism A includes connecting rods A respectively hinged on both sides of the outer wall of the fixed shaft, and two connecting rods B with a cross design and hinged at the intersection to the piston rod near the outer end. The outer end of the connecting rod A is hinged to one end of the connecting rod B, and the ends of the connecting rods B are slidably connected to the inner wall of the arc-shaped scraper plate A.

[0032] According to some embodiments of the present application, a avoidance opening cooperating with the vacuum suction assembly is opened in the middle of the arc-shaped scraper plate A.

[0033] According to some embodiments of the present application, the piston block A is provided with an air cavity toward the piston rod, and a piston block B is sealed therein, and the piston block A is also provided with an air path structure communicating with the air cavity;

[0034] The air path structure includes an air intake pipe and an air exhaust pipe B, both of which are connected to the air cavity and sealably penetrate the piston block A and the fixed shaft and extend to the outside of the fixed shaft. The end of the air intake pipe is connected to an air intake pump and an air intake valve is installed thereon. The end of the air exhaust pipe B is connected to an air exhaust pump and an air exhaust valve is installed thereon. The air intake pipe and the air exhaust pipe B are also installed with air pressure sensors.

[0035] The piston rod is provided with a scraper assembly B matched with the gas path structure;

[0036] The scraper assembly B includes a connecting rod mechanism B installed on the piston rod, and arc-shaped scraper plates B hinged on both sides of the outer wall of the fixed shaft. The connecting rod mechanism B is slidably connected with the arc-shaped scraper plates B, and the piston rod is moved backward so that the connecting rod mechanism B can push the arc-shaped scraper plates B to fit the inner wall of the inner shell;

[0037] The connecting rod mechanism B is composed of two connecting rods C hinged on both sides of the piston rod, and the ends of the two connecting rods C are both slidably connected to the inner wall of the arc-shaped scraper plate B.

[0038] According to some embodiments of the present application, the piston block A is in a tightened state toward the outside near the outer end of the air cavity to limit the piston block B.

[0039] When both the heat transfer oil chamber B and the heat transfer oil chamber A are filled with heat transfer oil, the oil will squeeze and push the piston part located in the heat transfer oil chamber B forward, that is, directly push the piston block A forward, and indirectly push the piston rod forward. When the piston rod moves forward, the lateral angle between the two hinged connecting rods B will open, driving the arc-shaped scraper plate A that is slidably connected to the end of the connecting rod B to move toward the inner wall of the inner shell until it fits with the inner wall of the inner shell. Since the fixed shaft does not move during the rotation of the drying tank shell, the static arc-shaped scraper plate A can scrape the inner wall of the inner shell at a position close to halfway.

[0040] An air cavity is designed inside the piston block A and matched with the air path structure. When the piston rod moves forward, the air intake pump is turned on and the air intake pipe is used to fill the air cavity with gas to make it a positive pressure state, thereby reducing the possibility of the piston rod moving backward and further strengthening the position of the arc-shaped scraper plate A.

[0041] When it is necessary to scrape the other half of the inner wall of the inner shell, turn off the air intake pump and turn on the air extraction pump. Use the air extraction pipe B to extract gas from the air cavity to make it a negative pressure state, so that the piston rod retreats, driving the connecting rod mechanism B hinged to it to move backward, and pushing the arc-shaped scraper plate B slidably connected to its end to contact the other side of the inner wall of the inner shell. In this way, scraping of the other half of the drying tank shell can be achieved during the rotation of the drying tank shell.

[0042] To summarize the advantages of operating the above process: 1. The present application can achieve a more comprehensive wall-sticking treatment by allowing the scraper structure to contact the inner wall of the dryer with the help of the heat transfer oil in the heat transfer oil chamber B and the gas; 2. During the treatment process, since the arc-shaped scraper plate A is designed with a avoidance opening for the exhaust pipe A to extend to the inside of the inner shell, the forward and backward movement of the arc-shaped scraper plate A does not interfere with the vacuum suction operation; 3. During the alternating operation of the scraper assembly A and the scraper assembly B, the connecting rod mechanism B cooperates with the arc-shaped scraper plate B, and the connecting rod mechanism A cooperates with the arc-shaped scraper plate A to stir the material; 4. During the alternating operation of the scraper assembly A and the scraper assembly B, the disadvantage of the lithium iron phosphate powder being stuck on the sides of the arc-shaped scraper plate A and the arc-shaped scraper plate B and being difficult to flip and dry is reduced.

[0043] In the above-mentioned lithium iron phosphate dewatering device, although the scraper assembly A and the scraper assembly B play a role in stirring the lithium iron phosphate powder during the alternating operation, they are unable to cut up the agglomerated materials that are not adhered to the inner shell.

[0044] According to some embodiments of the present application, an upwardly inclined stirring mechanism is equidistantly provided on the outer wall of the fixed shaft, and the stirring mechanism includes a stirring shaft designed in a curved shape and fixed to the fixed shaft, and blades for crushing agglomerated lithium iron phosphate powder are equidistantly connected to the stirring shaft.

[0045] According to some embodiments of the present application, the stirring shaft is designed to be hollow, and the inner chamber is connected to the heat transfer oil chamber B.

[0046] Curved stirring shafts are designed at equal intervals on the outer wall of the fixed shaft. During the flipping process, part of the lithium iron phosphate powder will fall on the stirring shaft, so the existence of the stirring shaft can assist in stirring the material inside it. Blades are designed on the stirring shaft, so that the agglomerated lithium iron phosphate powder can be chopped into pieces when it falls on the stirring shaft.

[0047] In addition, a cavity is designed inside the stirring shaft to be connected to the heat transfer oil cavity B, so that the heat transfer oil can pass through the heat transfer oil cavity B and connect to the inside of the stirring shaft, further expanding the heat transfer surface of the heat transfer oil and accelerating the drying efficiency of the lithium iron phosphate powder.

[0048] The advantages of the embodiments of the present application are:

[0049] By opening a heat transfer oil chamber B inside the fixed shaft, and the oil in the heat transfer oil chamber B and the oil in the heat transfer oil chamber A are merged through the through hole, the powder will partially contact the outer wall of the fixed shaft and the inner wall of the drying tank shell during the flipping process. This not only facilitates the heat transfer from the outside of the drying tank shell to the lithium iron phosphate powder inside, but also allows the heat source to extend into the inside of the drying tank shell to transfer heat to the lithium iron phosphate powder, thereby expanding the heat conduction area, improving the heat conduction efficiency, and improving the drying and water removal efficiency of the lithium iron phosphate powder. In this way, there is no need to open up and design a heat transfer oil circulation path separately, which also saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of the external structure of a lithium iron phosphate water removal device provided in an embodiment of the present application;

[0051] Figure 2 Provided for the implementation of this application Figure 1 The schematic diagram of the structure after the drive unit is exposed on the right;

[0052] Figure 3 Provided for the implementation of this application Figure 1 Schematic diagram of the structure after the upper semicircle of the interlayer is cut open;

[0053] Figure 4 A schematic diagram of the connection relationship between the drying tank shell, the fixed shaft, the scraper assembly A, the scraper assembly B and the stirring mechanism provided in the embodiment of the present application;

[0054] Figure 5 This is one of the schematic diagrams of the connection relationship between the drying tank shell, the fixed shaft, the scraper assembly A and the scraper assembly B provided in the embodiment of the present application;

[0055] Figure 6The second schematic diagram of the connection relationship between the drying tank shell, the fixed shaft, the scraper assembly A and the scraper assembly B provided in the embodiment of the present application;

[0056] Figure 7 Provided for the implementation of this application Figure 6 A local enlarged structural diagram of the part;

[0057] Figure 8 A schematic diagram of the positional relationship between the connecting rod B, the arc-shaped scraper plate A and the exhaust pipe A provided in the embodiment of the present application;

[0058] Fig. 9 A schematic diagram of the connection relationship between the exhaust pipe A and the rotating shaft provided in the embodiment of the present application;

[0059] Fig.10 A schematic diagram of the drying tank shell structure provided in an embodiment of the present application;

[0060] Fig.11 A schematic diagram of the structure of a rotating seal A provided in an embodiment of the present application;

[0061] Fig.12 A schematic diagram of the structure of a stirring mechanism provided in an embodiment of the present application;

[0062] Fig.13 This is a process flow chart of a lithium iron phosphate water removal device provided in an embodiment of the present application.

[0063] icon:

[0064] 1. Drying tank shell; 11. Inner shell; 12. Interlayer sleeve; 13. Heat transfer oil chamber A; 14. Rotating seal A; 141. Mounting sleeve; 142. Bearing A; 143. Sealing ring A; 144. Stop ring; 15. Inlet; 16. Discharge port; 2. Mounting assembly A; 21. Fixed shaft; 211. Heat transfer oil chamber B; 212. Through hole; 22. Shell A; 3. Mounting assembly B; 31. Shell B; 32 , rotating shaft; 33, driving unit; 331, servo motor; 332, right angle reducer; 4, base; 5, thermal oil circulation assembly; 51, natural gas heat medium furnace; 52, oil inlet pipeline; 53, oil return pipeline; 54, circulating oil pump; 55, stop valve A; 56, oil inlet temperature detector; 57, bypass pipeline; 58, stop valve B; 59, thermal oil cooler; 510, stop valve C; 6, vacuum suction assembly; 61. Vacuum pump; 62. Suction pipe A; 63. Vacuum filter head; 64. Condenser; 65. Buffer tank; 66. Check valve; 7. Scraper assembly B; 71. Connecting rod mechanism B; 72. Arc scraper plate B; 8. Stirring mechanism; 81. Stirring shaft; 82. Blade; 9. Rotating seal B; 91. Bearing B; 92. Sealing ring B; 10. Scraper assembly A; 101. Piston; 1011. Piston block A ; 10111, air cavity; 1012, piston rod; 1013, piston block B; 102, connecting rod mechanism A; 1021, connecting rod A; 1022, connecting rod B; 103, arc-shaped scraper plate A; 104, air path structure; 1041, air intake pipe; 1042, air exhaust pipe B; 1043, air intake pump; 1044, air exhaust pump; 1045, air exhaust valve; 1046, air pressure sensor; 1047, air intake valve. Implementation

[0065] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0066] In order to make the purpose, technical solutions and advantages of the implementation methods of this application clearer, the technical solutions in the implementation methods of this application will be clearly and completely described below in conjunction with the drawings in the implementation methods of this application. Obviously, the described implementation methods are part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0067] The following describes a water removal device and process for lithium iron phosphate according to an embodiment of the present application with reference to the accompanying drawings. Example

[0068] See also Figure 1-Figure 4A dehydration device for lithium iron phosphate includes a drying tank shell 1 composed of an inner shell 11 and an interlayer sleeve 12 arranged on the outer side thereof for accommodating lithium iron phosphate powder, and the cavity formed by the inner shell 11 and the interlayer sleeve 12 on the outer side constitutes a heat transfer oil cavity A13, and the two opposite side walls of the drying tank shell 1 are respectively rotatably connected with a mounting assembly A2 and fixedly connected with a mounting assembly B3, and the drying tank shell 1 can be driven to rotate through the mounting assembly B3, so as to drive the lithium iron phosphate powder to turn over and dry in the drying tank shell 1, and the mounting assembly B3 is provided with an extension A vacuum suction component 6 for absorbing drying steam is provided in the inner shell 11, and a base 4 is installed at the bottom of the mounting component A2 and the mounting component B3. The mounting component A2 includes a fixed shaft 21 which is rotatably sealed with the side wall of the drying tank shell 1 and extends to the inside thereof, and a heat transfer oil chamber B211 for conducting heat to the outside is provided in the fixed shaft 21. The upper and lower side walls of the fixed shaft 21 are also provided with through holes 212 which are communicated with the heat transfer oil chamber B211, and the oil in the heat transfer oil chamber A13 and the heat transfer oil chamber B211 are merged through the through holes 212. By opening a heat transfer oil chamber B211 inside the fixed shaft 21, and the oil in the heat transfer oil chamber B211 and the oil in the heat transfer oil chamber A13 are merged through the through hole 212, the powder will partially contact the outer wall of the fixed shaft 21 and the inner wall of the drying tank shell 1 during the flipping process. This not only facilitates the heat transfer from the outside of the drying tank shell 1 to the lithium iron phosphate powder inside, but also allows the heat source to extend into the inside of the drying tank shell 1 to transfer heat to the lithium iron phosphate powder, thereby expanding the heat conduction area, improving the heat conduction efficiency, and improving the drying and dehydration efficiency of the lithium iron phosphate powder. In this way, there is no need to open up and design a heat transfer oil circulation path separately, which also saves costs.

[0069] See also Figure 1 , Fig.10 and Fig.11 The inner shell 11 and the interlayer sleeve 12 are connected to the fixed shaft 21 at the connection points, and a rotating seal A14 is provided at the connection points between the installation opening and the outer wall of the fixed shaft 21.

[0070] The rotating seal A14 includes a mounting sleeve 141 fixed to the inner wall of the mounting port, and a bearing A142 whose inner and outer rings are respectively connected to the outer wall of the fixed shaft 21 and the inner wall of the mounting sleeve 141. Sealing rings A143 symmetrical to the bearing A142 are mounted at both ends of the inner ring of the mounting sleeve 141, and the inner wall of the sealing ring A143 is pressed against the outer wall of the fixed shaft 21. The purpose of designing the mounting sleeve 141 is to facilitate the coordination of the bearing A142 and the sealing ring A143 to connect the fixed shaft 21 and the drying tank shell 1 in rotation. Specifically, the design of the bearing A142 does not affect the use of the fixed shaft 21 inside the drying tank shell 1 when the drying tank shell 1 is in a rotating state, so that the fixed shaft 21 maintains a stable position and does not interfere with the movement of the drying tank shell 1. The design of the two sealing rings A143 symmetrical to the bearing A142 can maintain a good sealing state during the rotation and fixing process between the drying tank shell 1 and the fixed shaft 21.

[0071] The openings at both ends of the mounting sleeve 141 are designed to be inwardly retracted, and limiting rings 144 designed symmetrically with respect to the bearing A142 are installed on both sides of the inner ring of the mounting sleeve 141, and the sealing ring A143 is limitedly installed between the inner opening of the mounting sleeve 141 and the limiting ring 144. The sealing ring A143 can be limited between the two ends of the mounting sleeve 141 by the inwardly retracted design and the limiting ring 144, thereby reducing the probability of the position displacement of the sealing ring A143 during the rotation and fixing process of the drying tank shell 1 and the fixed shaft 21.

[0072] See also Figure 1 , Figure 3 and Fig.13 The lithium iron phosphate water removal device also includes a heat transfer oil circulation component 5.

[0073] The heat transfer oil circulation assembly 5 includes a natural gas heat medium furnace 51 and an oil inlet pipe 52 and an oil return pipe 53 connected to the upper and lower side walls thereof. The oil inlet pipe 52 and the oil return pipe 53 both penetrate the fixed shaft 21 and enter the heat transfer oil chamber B211 therein. The oil return pipe 53 also penetrates the upper side wall of the fixed shaft 21 from the heat transfer oil chamber B211 and extends to the top of the heat transfer oil chamber A13. A high temperature resistant window matching the shape of the inner shell 11 and the interlayer sleeve 12 is fixed at the corresponding position of the inner shell 11 and the interlayer sleeve 12 to facilitate observation of the oil amount in the heat transfer oil chamber A13. In addition, the oil return pipe 53 A stop valve D is installed on it to control the reflux of oil. A stop valve A55 and a circulating oil pump 54 for providing oil injection power, and an oil inlet temperature detector 56 for detecting the oil injection temperature are also installed in sequence on the oil inlet pipeline 52. The oil inlet temperature detector 56 can detect the temperature of the oil transported in the oil pipe, and feed the oil temperature back to the control system of the natural gas heat medium furnace 51. When the temperature is low, the heating device in the natural gas heat medium furnace 51 is controlled to continue heating the oil in the furnace. When the temperature is high, the heating device in the natural gas heat medium furnace 51 is controlled to stop the heating operation.

[0074] The area of ​​the oil inlet pipeline 52 between the circulating oil pump 54 and the oil inlet temperature detector 56 is also connected to a bypass pipeline 57, and stop valves B58 are installed at both ends of the bypass pipeline 57. A thermal oil cooler 59 is installed in the area of ​​the bypass pipeline 57 between the two stop valves B58, and stop valves C510 are installed on the oil inlet pipeline 52 near the upper and lower ends of the bypass pipeline 57.

[0075] When the lithium iron phosphate is in the drying process, the circulating oil pump 54, the stop valve A55 and the stop valve C510 are started, and the stop valve B58 is in the closed state, and the oil heated in the natural gas heat medium furnace 51 is introduced into the heat transfer oil chamber B211 and the heat transfer oil chamber A13 through the oil inlet pipe 52. The hot oil maintains a temperature of about 300°C. The hot oil transfers heat to the inner shell 11 through the above two chambers. The lithium iron phosphate powder absorbs moisture and evaporates water vapor to become dry. The hot oil that enters is then returned to the natural gas heat medium furnace 51 through the return oil pipe 53 for circulation.

[0076] When the lithium iron phosphate powder is completely dried, in order to reduce oxidation during the feeding of the lithium iron phosphate powder, the stop valve C510 is closed and the stop valve B58 is opened. The oil in the oil inlet pipe 52 changes its flow direction and enters the thermal oil cooler 59 from the bypass pipe 57 for cooling. It is then sent to the thermal oil chamber B211 and the thermal oil chamber A13 through the oil inlet pipe 52, and the circulation of the return oil pipe 53 is coordinated to cool the lithium iron phosphate powder inside the inner shell 11 to a temperature of about 60 degrees Celsius.

[0077] See also Figure 1-Figure 3 The mounting assembly A2 further includes a box shell A22 fixed to one side of the upper surface of the base 4, and both ends of the fixed shaft 21 are fixedly penetrated through the two side walls of the box shell A22, and the box shell A22 can play a role in fixing and supporting the fixed shaft 21.

[0078] Please continue reading Figure 1-Figure 3 The mounting assembly B3 includes a box shell B31 fixed on the other side of the upper surface of the base 4, a rotating shaft 32 rotatably connected to the two side walls of the box shell B31, and a driving part 33 arranged in the box shell B31 for driving the rotating shaft 32 to rotate. One end of the rotating shaft 32 is fixed through the inner shell 11 and the interlayer sleeve 12, that is, one end of the rotating shaft 32 is integrally designed with the inner shell 11 and the interlayer sleeve 12, and the inner end surface of the rotating shaft 32 is adapted to the shape of the inner wall of the inner shell 11, thereby reducing the influence of the rotating shaft 32 on the scraping position of the arc scraper plate A103.

[0079] The driving part 33 includes a servo motor 331 fixed on the upper surface of the base 4, and a right angle reducer 332 installed on the middle plate inside the box shell B31. The output shaft of the servo motor 331 and one of the shafts of the right angle reducer 332 are driven by a belt. The outer ring of the rotating shaft 32 and the other shaft of the right angle reducer 332 are respectively installed with master and slave sprockets, and the transmission is carried out through an annular chain. The servo motor 331 and the right angle reducer 332 driven by the belt are started, and the master and slave sprockets and the annular chain are matched to make the drying tank shell 1 connected to the rotating shaft 32 rotate, so that the lithium iron phosphate powder put into it is turned over, so that the drying of the lithium iron phosphate becomes more uniform and the drying efficiency of the lithium iron phosphate powder is improved.

[0080] See also Figure 1 , Figure 8 , Fig. 9 and Fig.13 The vacuum suction assembly 6 includes a vacuum pump 61 and an air extraction pipe A62 connected to the air extraction end thereof. A hollow cavity is provided inside the rotating shaft 32, and an interpenetrating connection with the air extraction pipe A62 is realized through the hollow cavity. A rotating seal B9 is installed in the hollow cavity to realize the rotation of the rotating shaft 32 and fix the air extraction pipe A62;

[0081] The rotating seal B9 includes two inner and outer rings of a bearing B91 respectively connected to both sides of the inner wall of the hollow cavity and both sides of the outer wall of the exhaust pipe A62, and a sealing ring B92 installed at both ends of the inner wall of the hollow cavity. The inner ring of the sealing ring B92 is pressed against the outer wall of the exhaust pipe A62. The design of the bearing B91 can prevent the inner ring exhaust pipe A62 from rotating during the movement of the rotating shaft 32, thereby indirectly making the vacuum filter head 63 always face upward, which is beneficial to the absorption and filtration of water vapor. The design of the sealing ring B92 can improve the sealing of the rotating position and reduce the probability of the lithium iron phosphate powder inside the dryer blocking the bearing B91 and affecting the operation of the machine.

[0082] In addition, both ends of the hollow cavity of the rotating shaft 32 are designed to be tightened inwardly. At the same time, an annular limiting structure (not shown) with the same function structure as the above-mentioned limiting ring 144 is provided on both sides of the hollow cavity of the rotating shaft 32 near the end. The limiting structure and the end tightening design facilitate maintaining the stability of the position of the sealing ring B92.

[0083] One end of the exhaust pipe A62 extends to the interior of the inner shell 11 and is installed with a vacuum filter head 63. The exhaust pipe A62 is also installed with a condenser 64, a buffer tank 65 and a check valve 66 in sequence. The water vapor evaporated from the inner shell 11 is discharged through the vacuum filter head 63, the condenser 64, the buffer tank 65, the check valve 66 and the vacuum pump 61 in sequence along the exhaust pipe A62. When the vacuum pump 61 and the condenser 64 are started, when the evaporated water vapor is sucked through the vacuum filter head 63 and the exhaust pipe A62, the water vapor is liquefied into water through the condenser 64 and enters the buffer tank 65. The excess gas in the buffer tank 65 is discharged to the outside through the exhaust end of the vacuum pump 61.

[0084] See also Figure 1 , Figure 2 and Figure 4 The upper and lower ends of the drying tank shell 1 are respectively provided with a feed inlet 15 and a discharge port 16, and a sealing cover and a butterfly valve are respectively installed at the feed inlet 15 and the discharge port 16. The feed inlet 15 and the discharge port 16 can be sealed by the sealing cover and the butterfly valve to control the input and discharge of the lithium iron phosphate powder inside the drying tank shell 1, so as to ensure a more rigorous whole drying process.

[0085] In addition, the present application also provides a dehydration process of a lithium iron phosphate dehydration device, including the above-mentioned lithium iron phosphate dehydration device, and the following steps:

[0086] S1. Feeding, open the sealing cover, and put an appropriate amount of lithium iron phosphate powder after the mixing and grading process into the inner shell 11;

[0087] S2. Rotation stirring, start the servo motor 331 and the right-angle reducer 332, and indirectly drive the drying tank shell 1 to rotate through the cooperation of the rotating shaft 32, so that the lithium iron phosphate powder put into it will flip over;

[0088] S3. Heating, start the circulating oil pump 54, stop valve A55 and stop valve C510, and the stop valve B58 is in the closed state, the oil heated in the natural gas heat medium furnace 51 is introduced into the heat transfer oil chamber B211 and the heat transfer oil chamber A13 through the oil inlet pipe 52, the hot oil transfers heat to the inner shell 11 through the two chambers, and the lithium iron phosphate powder absorbs moisture and evaporates water vapor to become dry;

[0089] S4. Vacuum evacuation, start the vacuum pump 61 and the condenser 64, and open the check valve 66. The water vapor evaporated after the lithium iron phosphate powder absorbs moisture is discharged along the exhaust pipe A62 through the vacuum filter head 63, the condenser 64, the buffer tank 65 and the check valve 66 and the vacuum pump 61 in sequence, thus completing the drying of the lithium iron phosphate powder;

[0090] S5. Cool the thermal oil, close the stop valve C510, and open the stop valve B58, the oil in the oil inlet pipe 52 changes its flow direction, enters the thermal oil cooler 59 from the bypass pipe 57 for cooling, and then is sent to the thermal oil chamber B211 and the thermal oil chamber A13 through the oil inlet pipe 52;

[0091] S6. Discharging the material, turning off the servo motor 331 and the right-angle reducer 332, and making the discharge port 16 face downward, and opening the butterfly valve to discharge the dried lithium iron phosphate powder.

[0092] In the above-mentioned lithium iron phosphate dehydration device, heat is conducted inside the inner shell 11 through the heat transfer oil chamber A13 and the heat transfer oil chamber B211. The heat in a short period of time is difficult to quickly reach the specified requirements. At the same time, due to the high water content and viscosity of the lithium iron phosphate powder, it is easy to cause the moisture in the material to fail to evaporate in a short period of time and cause wall sticking.

[0093] See also Figure 4-Figure 8 A scraper assembly A10 that cooperates with the heat transfer oil chamber B211 is installed inside the fixed shaft 21.

[0094] The scraper assembly A10 includes a piston portion 101 sealed to the inner wall of the heat transfer oil chamber B211 and extending to the outside of the fixed shaft 21, a connecting rod mechanism A102 connected between the fixed shaft 21 and the piston portion 101, and an arc-shaped scraper plate A103 installed at the outer end of the connecting rod mechanism A102 and movably fitted to the inner wall of the inner shell 11.

[0095] The piston part 101 includes a piston block A1011 sealed in the heat transfer oil chamber B211, a piston rod 1012 arranged at the outer end of the piston block A1011, and an insertion opening for the piston rod 1012 to penetrate the outer end of the fixed shaft 21;

[0096] The connecting rod mechanism A102 includes a connecting rod A1021 respectively hinged on both sides of the outer wall of the fixed shaft 21, and two connecting rods B1022 which are cross-designed and hinged at the intersection with the piston rod 1012 near the outer end. The outer end of the connecting rod A1021 is hinged to one end of the adjacent connecting rod B1022, and the ends of the connecting rod B1022 are both slidably connected to the inner wall of the arc scraper plate A103, wherein the inner wall of the arc scraper plate A103 is designed with a sliding track adapted to the connecting rod B1022, so that the opening or contraction of the two intersecting connecting rods B1022 can be realized on the arc scraper plate A103.

[0097] See also Figure 8The arc scraper A103 has a relief opening in the middle thereof for cooperating with the vacuum suction assembly 6. Furthermore, the arc scraper A103 has a relief opening for the air extraction pipe A62 to extend to the inner shell 11, and the connecting rod B1022 and the air extraction pipe A62 are staggered, so that the telescopic movement of the connecting rod B1022 and the arc scraper A103 does not interfere with the air extraction pipe A62 and the vacuum filter head 63 at its end, and the drying tank body 1 can be scraped over a wider area.

[0098] See also Figure 4-Figure 8 , Fig.13 The piston block A1011 is provided with an air cavity 10111 toward the piston rod 1012, and a piston block B1013 is sealed inside the air cavity 10111. The piston block A1011 is also provided with an air path structure 104 connected to the air cavity 10111.

[0099] The air path structure 104 includes an air intake pipe 1041 and an air exhaust pipe B1042, both of which are connected to the air cavity 10111 and sealably penetrate the piston block A1011 and the fixed shaft 21, and extend to the outside of the fixed shaft 21. The end of the air intake pipe 1041 is connected to an air intake pump 1043, and an air intake valve 1047 is also installed on it. The end of the air exhaust pipe B1042 is connected to an air exhaust pump 1044, and an air exhaust valve 1045 is installed on it. The air intake pipe 1041 and the air exhaust pipe B1042 are also installed with an air pressure sensor 1046. The air pressure sensor 1046 can be used to measure the air pressure intensity in the air intake pipe 1041 or the air exhaust pipe B1042, and indirectly measure the air pressure value in the air cavity 10111, and timely feedback is given to the air exhaust pump 1044 or the air intake pump 1043 to control the start or stop of the corresponding air path.

[0100] It should also be noted that if Figure 3 Cooperate Figure 7 It can be observed that the air inlet pipe 1041 and the air exhaust pipe B1042 are provided with excess length in the heat transfer oil chamber B211, and an extra length for the piston block A1011 to move, so as not to affect the operation of the present application.

[0101] See also Figure 4-Figure 6 , Fig.11 A scraper assembly B7 that cooperates with the air path structure 104 is installed on the piston rod 1012.

[0102] The scraper assembly B7 includes a connecting rod mechanism B71 installed on the piston rod 1012, and an arc-shaped scraper plate B72 hinged on both sides of the outer wall of the fixed shaft 21. The connecting rod mechanism B71 is slidably connected with the arc-shaped scraper plate B72, and the piston rod 1012 is moved backward so that the connecting rod mechanism B71 can push the arc-shaped scraper plate B72 to fit the inner wall of the inner shell 11. Among them, the outer wall of the fixed shaft 21 is installed with bumps on both sides near the rotating seal A14, and the top position of the upper bump and the bottom position of the lower bump are consistent with the top position of the outer side of the mounting sleeve 141. The arc-shaped scraper plate B72 is hinged at the outer end of the bump, such as Figure 6 shown.

[0103] The connecting rod mechanism B71 is composed of two connecting rods C hinged on both sides of the piston rod 1012, and the ends of the two connecting rods C are slidably connected to the inner wall of the arc scraper plate B72, wherein the inner wall of the arc scraper plate B72 is provided with a sliding track compatible with the ends of the connecting rod C, so that when the piston rod 1012 moves back and forth, the connecting rod C can make a certain displacement on the arc scraper plate B72.

[0104] The piston block A1011 is in a tightened state near the outer end of the air cavity 10111, which is used to limit the piston block B1013 and reduce the situation where it is accidentally separated from the piston block A1011 during launch.

[0105] When the heat transfer oil chamber B211 and the heat transfer oil chamber A13 are both filled with heat transfer oil, the oil will squeeze and push the piston part 101 located in the heat transfer oil chamber B211 forward, that is, directly push the piston block A1011 forward, and indirectly push the piston rod 1012 forward. When the piston rod 1012 moves forward, the lateral angle between the two hinged connecting rods B1022 will open, driving the arc scraper plate A103 slidably connected to the end of the connecting rod B1022 to move toward the inner wall of the inner shell 11 until it fits with the inner wall of the inner shell 11. Since the fixed shaft 21 does not move during the rotation of the drying tank shell 1, the static arc scraper plate A103 can scrape the inner wall of the inner shell 11 at a position close to halfway.

[0106] An air cavity 10111 is designed inside the piston block A1011 and matched with the air path structure 104. When the piston rod 1012 moves forward, the air intake pump 1043 is turned on and the air intake pipe 1041 is used to fill the air cavity 10111 with gas to make it a positive pressure state, thereby reducing the possibility of the piston rod 1012 moving backward and further reinforcing the position of the arc scraper A103.

[0107] When it is necessary to scrape the other half of the inner wall of the inner shell 11, the air intake pump 1043 is turned off and the air exhaust pump 1044 is turned on. The air is extracted from the air cavity 10111 by the air exhaust pipe B1042 to make it into a negative pressure state, so that the piston rod 1012 retreats, driving the connecting rod mechanism B71 hinged to it to move backward, and pushing the arc-shaped scraper plate B72 slidably connected to its end to contact the other side of the inner wall of the inner shell 11. In this way, the scraping of the other half of the drying tank shell 1 can be achieved during the rotation of the drying tank shell 1.

[0108] The advantages of using the above-mentioned process can be summarized as follows: 1. The present application can achieve a more comprehensive wall-sticking treatment by contacting the scraper structure with the inner wall of the dryer with the help of the heat transfer oil in the heat transfer oil chamber B211 and the gas; 2. During the treatment process, since the arc-shaped scraper plate A103 is designed with an escape port for the exhaust pipe A62 to extend to the inside of the inner shell 11, the forward and backward movement of the arc-shaped scraper plate A103 does not interfere with the vacuum suction operation; 3. During the alternating operation of the scraper assembly A10 and the scraper assembly B7, the connecting rod mechanism B71 cooperates with the arc-shaped scraper plate B72, and the connecting rod mechanism A102 cooperates with the arc-shaped scraper plate A103 to stir the material; 4. During the alternating operation of the scraper assembly A10 and the scraper assembly B7, the disadvantage that the lithium iron phosphate powder is stuck on the sides of the arc-shaped scraper plate A103 and the arc-shaped scraper plate B72 and is difficult to flip and dry is reduced.

[0109] In the above-mentioned lithium iron phosphate dewatering device, although the scraper assembly A10 and the scraper assembly B7 play a role in stirring the lithium iron phosphate powder during the alternating operation, they are unable to cut up the agglomerated materials that are not adhered to the inner shell 11.

[0110] See also Figure 4 and Fig.12 The outer wall of the fixed shaft 21 is equidistantly provided with a stirring mechanism 8 inclined upward, the stirring mechanism 8 includes a stirring shaft 81 designed in a curved shape and fixed to the fixed shaft 21, and a blade 82 for crushing agglomerated lithium iron phosphate powder is equidistantly connected to the stirring shaft 81.

[0111] The stirring shaft 81 is designed to be hollow inside, and the inner chamber is connected to the heat transfer oil chamber B211.

[0112] A curved stirring shaft 81 is designed at equal intervals on the outer wall of the fixed shaft 21. During the flipping process, part of the lithium iron phosphate powder will fall on the stirring shaft 81, so that the existence of the stirring shaft 81 can assist in stirring the material inside it; a blade 82 is designed on the stirring shaft 81, so that the agglomerated lithium iron phosphate powder can be chopped up when it falls on the stirring shaft 81.

[0113] In addition, a cavity is designed inside the stirring shaft 81 to communicate with the heat transfer oil cavity B211, so that the heat transfer oil can pass through the heat transfer oil cavity B211 and connect to the inside of the stirring shaft 81, further expanding the heat transfer surface of the heat transfer oil and accelerating the drying efficiency of the lithium iron phosphate powder.

[0114] The lithium iron phosphate powder after mixing and grading in the previous process enters the drying and dehydration process. The specific working principle of this process is: open the sealing cover, put the lithium iron phosphate powder after the mixing and grading process into the inner shell 11, start the servo motor 331 and the right-angle reducer 332 driven by the belt, and use the transmission cooperation through the master and slave sprockets and the ring chain to drive the drying tank shell 1 to rotate through the rotating shaft 32, so that the lithium iron phosphate powder put in it will turn over, start the circulating oil pump 54, the stop valve A55 and the stop valve C510, and the stop valve B58 is in a closed state. The oil in the natural gas heat medium furnace 51 is introduced into the heat transfer oil chamber B211 and the heat transfer oil chamber A13 and the internal chamber of the stirring shaft 81 through the oil inlet pipe 52. When the heat transfer oil chamber B211 and the heat transfer oil chamber A13 are filled with heat transfer oil, the oil will squeeze and push the piston part 101 located in the heat transfer oil chamber B211 forward, that is, directly push the piston block A1011 forward, and indirectly push the piston rod 1012 forward. When the piston rod 1012 moves forward, the lateral angle between the two hinged connecting rods B1022 will open, driving the arc portion 1012 slidingly connected to the end of the connecting rod B1022. The arc-shaped scraper plate A103 moves toward the inner wall of the inner shell 11 until it fits with the inner wall of the inner shell 11. Since the fixed shaft 21 does not move with the rotation of the drying tank shell 1, the static arc-shaped scraper plate A103 can scrape the inner wall of the inner shell 11 at a position close to halfway. The air cavity 10111 is designed inside the piston block A1011 and cooperates with the air path structure 104. During the forward movement of the piston rod 1012, the air intake pump 1043 is turned on, and the air intake pipe 1041 is used to fill the air cavity 10111 with gas to make it a positive pressure state, thereby reducing the possibility of the piston rod 1012 retreating. and when the other half of the inner wall of the inner shell 11 needs to be scraped, the air inlet pump 1043 is turned off and the air exhaust pump 1044 is turned on. The air is extracted from the air cavity 10111 by the air exhaust pipe B1042 to make it into a negative pressure state, so that the piston rod 1012 retreats, driving the connecting rod mechanism B71 hinged to it to move backward, pushing the arc scraper plate B72 slidably connected to its end to contact the other side of the inner wall of the inner shell 11, so that the scraping of the other half of the inner wall of the inner shell 11 can be achieved during the rotation of the drying tank shell 1.

[0115] The water vapor in the lithium iron phosphate powder can be quickly dried by conducting heat through the heat-conducting oil and coordinating with the rotation of the drying tank shell 1. The water vapor evaporated after the lithium iron phosphate powder absorbs moisture is discharged along the exhaust pipe A62 through the vacuum filter head 63, the condenser 64, the buffer tank 65, the check valve 66 and the vacuum pump 61 in sequence, thereby completing the drying of the lithium iron phosphate powder.

[0116] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A dehydration device for lithium iron phosphate, comprising a drying tank shell (1) composed of an inner shell (11) and an interlayer sleeve (12) arranged on the outer side thereof for accommodating lithium iron phosphate powder, wherein the cavity formed by the inner shell (11) and the interlayer sleeve (12) on the outer side constitutes a heat transfer oil cavity A (13), the two opposite side walls of the drying tank shell (1) are rotatably connected to a mounting assembly A (2) and fixedly connected to a mounting assembly B (3), and the drying tank shell (1) can be driven to rotate by the mounting assembly B (3), thereby driving the lithium iron phosphate powder to turn over and dry in the drying tank shell (1), the mounting assembly B (3) is provided with a vacuum suction assembly (6) extending into the inner shell (11) for absorbing drying steam, the mounting assembly A (2) and the mounting assembly B (3) are jointly provided with a base (4) at the bottom, characterized in that: The mounting assembly A (2) comprises a fixed shaft (21) which is rotatably sealed with the side wall of the drying tank shell (1) and extends into the interior thereof, and a heat transfer oil chamber B (211) for conducting heat to the outside is provided in the fixed shaft (21), and through holes (212) which are in communication with the heat transfer oil chamber B (211) are also provided on the upper and lower side walls of the fixed shaft (21), and the oil in the heat transfer oil chamber A (13) and the heat transfer oil chamber B (211) are allowed to merge through the through holes (212); A scraper assembly A (10) that cooperates with the heat transfer oil chamber B (211) is installed inside the fixed shaft (21); The scraper assembly A (10) comprises a piston portion (101) which is sealed against the inner wall of the heat transfer oil chamber B (211) and extends to the outside of the fixed shaft (21), a connecting rod mechanism A (102) connected between the fixed shaft (21) and the piston portion (101), and an arc-shaped scraper plate A (103) which is mounted on the outer end of the connecting rod mechanism A (102) and movably fits against the inner wall of the inner shell (11); The piston part (101) comprises a piston block A (1011) sealed in the heat transfer oil chamber B (211), and a piston rod (1012) arranged at the outer end of the piston block A (1011); the outer end of the fixed shaft (21) is provided with a through hole for the piston rod (1012) to pass through; The connecting rod mechanism A (102) comprises connecting rods A (1021) respectively hinged to the outer wall of the fixed shaft (21), and two connecting rods B (1022) which are cross-designed and hinged to the piston rod (1012) at the intersection, the outer end of the connecting rod A (1021) and one end of the connecting rod B (1022) being hinged, and the ends of the connecting rods B (1022) are both slidably connected to the inner wall of the arc-shaped scraper plate A (103); The arc-shaped scraper plate A (103) has a middle portion provided with an escape opening that cooperates with the vacuum suction assembly (6); The piston block A (1011) is provided with an air cavity (10111) at a position facing the piston rod (1012), and a piston block B (1013) is provided in a sealed manner therein; the piston block A (1011) is also provided with an air path structure (104) communicating with the air cavity (10111); The air path structure (104) comprises an air intake pipe (1041) and an air exhaust pipe B (1042), both of which are in communication with the air cavity (10111) and sealably penetrate the piston block A (1011) and the fixed shaft (21), and extend to the outside of the fixed shaft (21); the end of the air intake pipe (1041) is connected to an air intake pump (1043), and an air intake valve (1047) is also installed thereon; the end of the air exhaust pipe B (1042) is connected to an air exhaust pump (1044), and an air exhaust valve (1045) is installed thereon; and air pressure sensors (1046) are also installed on the air intake pipe (1041) and the air exhaust pipe B (1042); A scraper assembly B (7) that cooperates with the gas path structure (104) is installed on the piston rod (1012); The scraper assembly B (7) comprises a connecting rod mechanism B (71) mounted on the piston rod (1012), and arc-shaped scraper plates B (72) hinged on both sides of the outer wall of the fixed shaft (21); the connecting rod mechanism B (71) is slidably connected to the arc-shaped scraper plates B (72), and the piston rod (1012) moves backward so that the connecting rod mechanism B (71) can push the arc-shaped scraper plates B (72) to fit against the inner wall of the inner shell (11); The connecting rod mechanism B (71) comprises two connecting rods C hinged on both sides of the piston rod (1012), and the ends of the two connecting rods C are slidably connected to the inner wall of the arc-shaped scraper plate B (72).

2. The dehydration device for lithium iron phosphate according to claim 1, characterized in that: The inner shell (11) and the interlayer sleeve (12) are connected to the fixed shaft (21) with mounting openings, and the connection between the mounting opening and the outer wall of the fixed shaft (21) is provided with a rotating seal A (14); The rotating seal A (14) comprises a mounting sleeve (141) fixed to the inner wall of the mounting opening, and a bearing A (142) respectively connected to the outer wall of the fixed shaft (21) and the inner wall of the mounting sleeve (141), and sealing rings A (143) symmetrically about the bearing A (142) are mounted at both ends of the inner ring of the mounting sleeve (141), and the inner wall of the sealing ring A (143) is pressed against the outer wall of the fixed shaft (21).

3. The dehydration device for lithium iron phosphate according to claim 2, characterized in that: The openings at both ends of the mounting sleeve (141) are designed to be in an inwardly contracted state, and limiting rings (144) designed symmetrically with respect to the bearing A (142) are also installed on both sides of the inner ring of the mounting sleeve (141), and the sealing ring A (143) is installed in a limited position between the inner opening of the mounting sleeve (141) and the limiting ring (144).

4. The dehydration device for lithium iron phosphate according to claim 3, characterized in that: Also included is a heat transfer oil circulation component (5); The heat transfer oil circulation assembly (5) comprises a natural gas heat medium furnace (51) and an oil inlet pipe (52) and an oil return pipe (53) communicating with the upper and lower side walls thereof. The oil inlet pipe (52) and the oil return pipe (53) both penetrate the fixed shaft (21) and enter the heat transfer oil chamber B (211) therein. The oil return pipe (53) also penetrates the upper side wall of the fixed shaft (21) from the heat transfer oil chamber B (211) and extends to the top of the heat transfer oil chamber A (13). The oil inlet pipe (52) is also successively installed with a stop valve A (55) for providing oil injection power and a circulating oil pump (54), and an oil inlet temperature detector (56) for detecting the oil injection temperature.

5. The dehydration device for lithium iron phosphate according to claim 4, characterized in that: The oil inlet pipeline (52) is also connected to a bypass pipeline (57) in an area between the circulating oil pump (54) and the oil inlet temperature detector (56). Stop valves B (58) are installed at both upper and lower ends of the bypass pipeline (57). A heat transfer oil cooler (59) is installed in an area between the two stop valves B (58) of the bypass pipeline (57). Stop valves C (510) are installed at positions on the oil inlet pipeline (52) close to both upper and lower ends of the bypass pipeline (57).

6. The lithium iron phosphate dewatering device according to claim 5, characterized in that: The mounting assembly A (2) further comprises a box shell A (22) fixed to one side of the upper surface of the base (4), and the two ends of the fixed shaft (21) penetrate and are fixed to two side walls of the box shell A (22).

7. The lithium iron phosphate dewatering device according to claim 6, characterized in that: The mounting assembly B (3) comprises a box shell B (31) fixed to the other side of the upper surface of the base (4), a rotating shaft (32) rotatably connected to the two side walls of the box shell B (31), and a driving part (33) disposed in the box shell B (31) for driving the rotating shaft (32) to rotate, and one end of the rotating shaft (32) penetrates and is fixed to the inner shell (11) and the interlayer sleeve (12); The driving part (33) comprises a servo motor (331) fixed to the upper surface of the base (4), and a right-angle reducer (332) mounted on the middle plate inside the housing B (31); the output shaft of the servo motor (331) and one of the shafts of the right-angle reducer (332) are driven by a belt; the outer ring of the rotating shaft (32) and the other shaft of the right-angle reducer (332) are respectively mounted with master and slave sprockets, and the transmission is carried out by an annular chain.

8. The lithium iron phosphate dewatering device according to claim 7, characterized in that: The vacuum suction assembly (6) comprises a vacuum pump (61) and an air extraction pipe A (62) connected to the air extraction end thereof; a hollow cavity is provided inside the rotating shaft (32) and is connected to the air extraction pipe A (62) through the hollow cavity; a rotating seal B (9) is installed in the hollow cavity to realize the rotation of the rotating shaft (32) and fix the air extraction pipe A (62); The rotating seal B (9) comprises a bearing B (91) having two inner and outer rings respectively connected to two sides of the inner wall of the hollow cavity and two sides of the outer wall of the exhaust pipe A (62), and a sealing ring B (92) installed at both ends of the inner wall of the hollow cavity, wherein the inner ring of the sealing ring B (92) is pressed tightly against the outer wall of the exhaust pipe A (62); One end of the exhaust pipe A (62) extends to the interior of the inner shell (11) and is installed with a vacuum filter head (63). A condenser (64), a buffer tank (65) and a check valve (66) are also installed in sequence on the exhaust pipe A (62). Water vapor evaporated from the interior of the inner shell (11) is discharged along the exhaust pipe A (62) through the vacuum filter head (63), the condenser (64), the buffer tank (65), the check valve (66) and the vacuum pump (61) in sequence.

9. The lithium iron phosphate dewatering device according to claim 8, characterized in that: The drying tank shell (1) is provided with a feed inlet (15) and a discharge outlet (16) at the upper and lower ends thereof, respectively, and a sealing cover and a butterfly valve are installed at the feed inlet (15) and the discharge outlet (16), respectively.

10. A dehydration process for a lithium iron phosphate dehydration device, characterized in that: The invention comprises the lithium iron phosphate dehydration device as claimed in claim 9, and the following steps: S1. Feeding, opening the sealing cover, and feeding the lithium iron phosphate powder after the mixing and grading process into the inner shell (11); S2. Rotational stirring, starting the servo motor (331) and the right-angle reducer (332), and indirectly driving the drying tank shell (1) to rotate through the cooperation of the rotating shaft (32), so that the lithium iron phosphate powder put into the drying tank shell is turned over; S3. Heating, starting the circulating oil pump (54), the stop valve A (55) and the stop valve C (510), and the stop valve B (58) is in a closed state, and the oil heated in the natural gas heat medium furnace (51) is introduced into the heat transfer oil chamber B (211) and the heat transfer oil chamber A (13) through the oil inlet pipe (52), and the hot oil passes through the two chambers to transfer heat to the inner shell (11), and the lithium iron phosphate powder absorbs moisture and evaporates water vapor to become dry; S4. Vacuum extraction, start the vacuum pump (61) and the condenser (64), and open the check valve (66). The water vapor evaporated after the lithium iron phosphate powder absorbs moisture is discharged along the exhaust pipe A (62) through the vacuum filter head (63), the condenser (64), the buffer tank (65), the check valve (66) and the vacuum pump (61) in sequence, thereby completing the drying of the lithium iron phosphate powder; S5. Cooling the heat transfer oil, closing the stop valve C (510), and opening the stop valve B (58), the oil in the oil inlet pipeline (52) changes its flow direction, enters the heat transfer oil cooler (59) from the bypass pipeline (57) for cooling, and then is sent to the heat transfer oil chamber B (211) and the heat transfer oil chamber A (13) through the oil inlet pipeline (52); S6. Discharging the material, turning off the servo motor (331) and the right-angle reducer (332), and positioning the discharge port (16) downward, and opening the butterfly valve to discharge the dried lithium iron phosphate powder.

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