Fluidized bed liquid phase coating device and powder coating system comprising same

Abstract

The utility model provides a fluidized bed liquid phase coating device and a powder coating system comprising the same. The fluidized bed liquid phase coating device comprises a shell, a coating material feeding mechanism and a powder feeding mechanism, wherein a discharge port of the coating material feeding mechanism is arranged at the downstream of a discharge port of the powder feeding mechanism along the powder flowing direction; the fluidized bed liquid phase coating device further comprises an air inlet device, and the air inlet device is used for enabling the to-be-coated powder material flowing out of the powder feeding mechanism to flow in the direction of the coating material feeding mechanism. Powder enters the shell from the powder feeding mechanism, the discharging port is arranged close to the central axis of the shell, so that the powder is conveniently dispersed from the center of the shell to the periphery of the shell, a liquid-phase coating agent is atomized in the liquid-phase feeding mechanism, the self-adhesion condition of the liquid-phase coating agent during coating is avoided, the liquid-phase coating agent enters the inner cavity of the shell from the peripheral side of the shell, and the liquid-phase coating agent can be uniformly dispersed in the inner cavity of the shell. Therefore, the powder material can be uniformly coated, and the problems of poor coating effect and low productivity of the generated negative electrode material are avoided.

Description

Technical Field

[0001] The utility model relates to a fluidized bed liquid phase coating device and a powder coating system comprising the same. Background Art

[0002] With the rise of new energy, lithium-ion batteries are widely used due to their advantages of high energy density, high safety, low cost and no memory effect. However, the negative electrode material graphite of lithium batteries has poor compatibility with the electrolyte, poor cycle stability, poor rate performance and other problems, which cannot meet the use requirements of large power batteries and digital batteries.

[0003] The current mainstream solid-phase coating technology is to add solid-phase coating asphalt to the coating kettle to coat the surface of graphite, which can effectively improve the cycle performance and rate performance. However, the current coating technology has the problem of uneven solid-phase coating and insufficient coating degree, which leads to abnormal self-adhesion of asphalt. Liquid-phase coating technology mainly uses a liquid-phase fusion machine to add a liquid-phase coating agent to coat the surface of graphite, which can effectively improve the uneven coating situation. However, the existing technology often uses a spraying method to spray the liquid-phase coating agent on the surface of graphite, etc. The liquid-phase coating agent still has self-adhesion during coating, resulting in poor coating effect and low production capacity of the generated negative electrode material. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the defects of the liquid phase coating technology in the prior art, that is, the liquid phase coating agent still has self-adhesion during coating, resulting in poor coating effect and low production capacity of the generated negative electrode material, and to provide a fluidized bed liquid phase coating device and a powder coating system comprising the same.

[0005] The utility model solves the above technical problems through the following technical solutions:

[0006] The utility model provides a fluidized bed liquid phase coating device, which comprises a shell, a coating material feeding mechanism, and a powder feeding mechanism. The coating material feeding mechanism is used to introduce liquid-phase coating material into the shell, and the powder feeding mechanism is used to introduce powder material to be coated into the shell. The discharge port of the coating material feeding mechanism is arranged downstream of the discharge port of the powder feeding mechanism along the powder flow direction.

[0007] The axis of the discharge port of the powder feeding mechanism is arranged close to the central axis of the shell and is parallel to the central axis of the shell;

[0008] The coating material feeding mechanism has a plurality of discharge ports arranged along the circumference of the shell, each of which is equipped with an atomizing nozzle and the opening of the atomizing nozzle faces the central axis of the shell;

[0009] The fluidized bed liquid phase coating device also includes an air inlet device, which is arranged on a side of the discharge port away from the coating material feeding mechanism, and is used to make the powder material to be coated flowing out of the powder feeding mechanism flow toward the coating material feeding mechanism.

[0010] In this scheme, the powder enters the shell from the powder feeding mechanism, and the discharge port is arranged close to the central axis of the shell, so as to facilitate the dispersion of the powder from the center of the shell to the surrounding of the shell. The liquid coating agent is atomized in the liquid feeding mechanism, and the liquid coating agent then enters the inner cavity of the shell from the peripheral side of the shell, so that the powder material can be evenly coated, avoiding the formation of large clumps of the coating agent itself, thereby avoiding poor coating effect of the generated material.

[0011] Preferably, the coating material feeding mechanism comprises an annular feeder, and the annular feeder is arranged along the circumference of the shell.

[0012] In this solution, the above-mentioned structure is adopted so that the liquid coating material sprayed from the annular feeder can be released from the inner edge of the shell to the center of the shell, so that the powder flowing upward from the edge of the shell can also contact the liquid coating material, so that the powder can be fully coated.

[0013] Preferably, the plurality of atomizing nozzles are evenly spaced apart along the circumference of the annular feeder.

[0014] In this solution, the above structure is adopted so that the liquid coating material sprayed from the atomizing nozzle can cover the entire cross-sectional area in the shell, so that the powder and the coating material are fully in contact, and finally a higher quality finished product can be formed.

[0015] Preferably, the coating material feeding mechanism is provided with a first heating mechanism, and the first heating mechanism is used to heat the liquid-phase coating material in the coating material feeding mechanism.

[0016] In this solution, a first heating mechanism is provided to heat the coating material before atomization, thereby ensuring that the liquid coating material has good fluidity during transportation and preventing the coating material from self-adhesion.

[0017] Preferably, the air inlet device comprises an annular air guide pipe, a long air inlet pipe and a short air inlet pipe, and the outer diameter of the annular air guide pipe is smaller than the inner diameter of the shell;

[0018] The long air inlet tube is connected to the annular air duct, the long air inlet tube is in a "cross" shape, and the inner cavity of the long air inlet tube is connected to the inner cavity of the annular air duct;

[0019] The long air inlet tube is sealed and connected with a plurality of the short air inlet tubes. The long air inlet tube is provided with an air inlet. The short air inlet tube is provided with a plurality of air inlet nozzles. The air inlet is connected with an external air source.

[0020] In this solution, multiple short air inlet tubes are arranged on the long air inlet tube so that the short air inlet tubes can cover the entire cross-section of the shell, and the gas sprayed from the air inlet nozzle can fill the entire cross-section of the shell, thereby facilitating the powder to be evenly blown toward the liquid coating mechanism.

[0021] Preferably, a second heating structure is further provided on the shell, and the second heating structure is arranged downstream of the coating material feeding mechanism along the powder flow direction.

[0022] In this solution, the above structure is adopted, and after the liquid phase coating process is completed, the second heating structure heats the coating agent on the powder surface, so that the coating agent can be fixed on the surface of the crystal core particles to complete the solidification of the finished negative electrode material particles.

[0023] Preferably, the air inlet device, the material outlet and the coating material feeding mechanism are arranged upward in sequence along the height direction of the shell.

[0024] Preferably, the air outlet of the air inlet device is arranged toward the inner bottom surface of the shell, and the discharge port of the powder feeding mechanism is arranged toward the air inlet device.

[0025] In this solution, the above-mentioned structure is adopted so that the inert gas flowing out of the air outlet is more uniform and smooth after rebounding through the inner bottom surface of the shell. The upward flowing inert gas forms convection with the powder flowing out of the powder feeding mechanism, which can make the negative electrode material powder more evenly dispersed and improve the uniformity of the particles before coating.

[0026] The utility model also provides a powder coating system, which comprises the fluidized bed liquid phase coating device as described above.

[0027] Preferably, the powder coating system further comprises a separator, the shell is provided with a material outlet, and the inlet of the separator is connected with the material outlet of the shell through a pipeline;

[0028] The powder coating system also includes a heat exchanger, the separator is provided with a gas outlet and a solid outlet, the tube-side inlet of the heat exchanger is connected to the gas outlet of the separator through a pipeline, and the tube-side outlet of the heat exchanger is connected to a buffer tank through a pipeline; the shell-side inlet of the heat exchanger is connected to an external inert gas source, and the shell-side outlet of the heat exchanger is connected to the inlet of the air inlet device.

[0029] In this scheme, the product coated by the fluidized bed liquid phase is separated into gas and solid by a separator, and the inert gas separated by the separator can be recovered by heat exchanger and recycled to the bottom of the shell for reuse. Specifically, the tube side of the heat exchanger is high-temperature tail gas, and the shell side is fresh nitrogen. The high-temperature tail gas of the tube side is used to preheat the fresh nitrogen of the shell side, and the high-temperature tail gas is cooled at the same time. Part of it is mixed with the supplementary fresh nitrogen and then enters the annular air inlet distribution device at the bottom of the device to complete the closed-loop cycle.

[0030] The positive and progressive effects of the utility model are that the powder enters the shell from the powder feeding mechanism, and the discharge port is arranged close to the central axis of the shell, so that the powder is dispersed from the center of the shell to the surrounding of the shell, and the liquid-phase coating agent is atomized in the liquid-phase feeding mechanism to avoid self-adhesion of the liquid-phase coating agent during coating. The liquid-phase coating agent enters the inner cavity of the shell from the peripheral side of the shell, so that the powder material can be evenly coated, thereby avoiding the poor coating effect and low production capacity of the generated negative electrode material. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of the powder coating system of the present utility model.

[0032] Figure 2 It is a front view of the air inlet device of the utility model.

[0033] Figure 3 It is a top view of the air inlet device of the utility model.

[0034] Figure 4 It is a structural schematic diagram of the coating material feeding mechanism of the utility model.

[0035] Description of reference numerals:

[0036] Shell 1

[0037] Coating material feeding mechanism 2

[0038] Powder feeding mechanism 3

[0039] Discharge port 31

[0040] Air inlet device 4

[0041] Annular air duct 41

[0042] Air inlet pipe 42

[0043] Air inlet short pipe 43

[0044] Ring feeder 5

[0045] Second heating mechanism 6

[0046] Separator 7

[0047] Heat exchanger 8

[0048] Buffer tank 9 DETAILED DESCRIPTION

[0049] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0050] like Figure 1-4 As shown, this embodiment provides a fluidized bed liquid phase coating device, which includes a shell 1, a coating material feeding mechanism 2, and a powder feeding mechanism 3. The coating material feeding mechanism 2 is used to introduce liquid phase coating material into the shell 1, and the powder feeding mechanism 3 is used to introduce powder material to be coated into the shell 1. The discharge port of the coating material feeding mechanism 2 is arranged downstream of the discharge port of the powder feeding mechanism 3 along the powder flow direction.

[0051] The axis of the discharge port of the powder feeding mechanism 3 is arranged close to the central axis of the shell 1 and is parallel to the central axis of the shell 1 .

[0052] The coating material feeding mechanism 2 is provided with a plurality of discharge ports along the circumference of the shell 1 , and an atomizing nozzle is installed on each discharge port, and the opening of the atomizing nozzle faces the central axis of the shell 1 .

[0053] The fluidized bed liquid phase coating device also includes an air inlet device 4, which is arranged on the side of the discharge port 31 of the powder feeding mechanism 3 away from the coating material feeding mechanism 2, and is used to make the powder material to be coated flowing out of the powder feeding mechanism 3 flow toward the coating material feeding mechanism 2.

[0054] The powder enters the shell 1 from the discharge port of the powder feeding mechanism 3. The discharge port is arranged close to the central axis of the shell 1, so that the powder is dispersed from the center of the shell 1 to the surrounding of the shell 1. After the air inlet device 4 is started, the powder is blown in the direction of the coating material feeding mechanism 2. The liquid-phase coating agent is atomized in the liquid-phase feeding mechanism, and the liquid-phase coating agent then enters the inner cavity of the shell 1 from the peripheral side of the shell 1, so that the powder material can be evenly coated to avoid the coating agent itself from agglomerating in large clumps, thereby avoiding the poor coating effect of the generated material. Specifically, the powder can be powders such as artificial graphite precursors, natural graphite, and hard carbon materials. The liquid-phase coating agent can be a liquid-phase coating agent such as a rubber plasticizer, a conductive agent, and graphene.

[0055] The coating material feeding mechanism 2 includes an annular feeder 5, which is arranged along the circumference of the shell 1. The liquid coating material sprayed from the annular feeder 5 can be released from the inner edge of the shell 1 to the center of the shell 1, so that the powder flowing upward from the edge of the shell 1 can also contact the liquid coating material, so that the powder can be fully coated.

[0056] A plurality of atomizing nozzles are evenly spaced along the circumference of the annular feeder 5, and the liquid coating material sprayed from the atomizing nozzles can cover the entire cross-sectional area of ​​the housing 1, so that the powder is fully in contact with the coating material, and finally a high-quality finished product can be formed. In this embodiment, four atomizing nozzles are specifically arranged on the annular feeder 5; in other embodiments, other numbers of atomizing nozzles can also be arranged to increase the distribution density of the liquid coating material.

[0057] The coating material feeding mechanism 2 is provided with a first heating mechanism, which is used to heat the liquid coating material in the coating material feeding mechanism 2. By arranging the first heating mechanism to heat the coating material before atomization, it is ensured that the liquid coating material has good fluidity during transportation and prevents the coating material from self-adhesion.

[0058] In this embodiment, specifically, the gas introduced into the air inlet device 4 is nitrogen, which provides a driving force for the flow of the negative electrode material powder introduced into the shell 1. The air inlet device 4 includes an annular air duct 41, a long air inlet tube 42 and a short air inlet tube 43. The outer diameter of the annular air duct 41 is smaller than the inner diameter of the shell 1. The long air inlet tube 42 is connected to the annular air duct 41. The long air inlet tube 42 is in a "cross" shape and the inner cavity of the long air inlet tube 42 is connected to the inner cavity of the annular air duct 41. The long air inlet tube 42 is sealed and connected with a plurality of short air inlet tubes 43. The long air inlet tube 42 is provided with an air inlet, and the short air inlet tube 43 is provided with a plurality of air inlet nozzles. The air inlet is connected to an external air source.

[0059] The temperature of the device is controlled by the amount of air intake. A large amount of air intake corresponds to a relatively low temperature in the housing 1. The external air source enters from the air inlet of the long air intake tube 42, and the gas is transported to various parts of the long air intake tube 42 through the annular air guide tube 41, so that the gas can flow out from the short air intake tube 43 on the long air intake tube 42.

[0060] By arranging a plurality of short air inlet tubes 43 on the long air inlet tube 42, the short air inlet tubes 43 can cover the entire cross section of the shell 1, so that the gas ejected from the air inlet nozzle can fill the entire cross section of the shell 1, thereby facilitating the powder to be evenly blown to the liquid coating mechanism. In other embodiments, the long air inlet tube 42 can also be in other structural forms, such as a ring shape.

[0061] The shell 1 is also provided with a second heating structure, which is arranged downstream of the coating material feeding mechanism 2 along the powder flow direction. In this embodiment, specifically, the second heating mechanism 6 is a heating resistance wire attached to the outer wall of the shell 1, and is serpentinely wound around the outer wall of the shell 1. After the liquid phase coating process is completed, the coating agent on the surface of the powder is heated, so that the coating agent can be fixed on the surface of the crystal core particles, and the solidification of the finished negative electrode material particles is completed.

[0062] In this embodiment, the air inlet device 4, the discharge port 31 and the coating material feeding mechanism 2 are arranged upward in sequence along the height direction of the shell 1. The negative electrode material powder overcomes the gravity and flows upward under the blowing of the air inlet device 4, so that the falling powder forms convection with the incoming inert gas, avoiding the powder from flowing downward too fast and easily clustering together, thereby increasing the dispersion of the powder.

[0063] In this embodiment, the air outlet of the air inlet device 4 is arranged toward the inner bottom surface of the housing 1, and the discharge port of the powder feeding mechanism 3 is arranged toward the air inlet device 4. Figure 1 As shown, the discharge port 31 of the powder feeding mechanism 3 is set downward, and the external air source enters from the bottom of the shell 1, and communicates with the annular air inlet distribution device. There are multiple small and short air inlet short tubes 43 arranged in an array on the air inlet device 4, which can make the nitrogen at the bottom evenly distributed, drive the air flow without dead corners and stagnation areas, and suspend the negative electrode material powder fed into the shell 1 in the fluidized bed dispersion area and coating area to form a fluidized bed effect of the entire device, so that the material distribution in the entire device is more uniform, thereby further improving the coating uniformity. In this embodiment, all the air inlet nozzles are set obliquely downward at 45°. The inert gas flowing out of the air outlet is more uniform and gentle after rebounding from the inner bottom surface of the shell 1. The upward flowing inert gas forms convection with the powder flowing out of the powder feeding mechanism 3, which can make the negative electrode material powder more evenly dispersed and improve the uniformity of the particles before coating.

[0064] In other embodiments, the air outlet of the air inlet device 4 is arranged toward the powder feeding mechanism 3, and the outlet 31 of the powder feeding mechanism is arranged downward. The powder flowing downward is directly blown upward by the air inlet device 4 to the area where the coating material feeding mechanism 2 is located, and is mixed with the liquid coating material.

[0065] This embodiment also provides a powder coating system, which includes the fluidized bed liquid phase coating device as described above, the discharge port of the fluidized bed liquid phase coating device is at the top of the shell 1, and the coated material and exhaust gas both flow out from the top outlet.

[0066] The powder coating system further includes a separator 7, a material outlet is provided on the shell 1, and the inlet of the separator 7 is connected to the material outlet of the shell 1 through a pipeline. The powder coating system further includes a heat exchanger 8, a gas outlet and a solid outlet are provided on the separator 7, the tube side inlet of the heat exchanger 8 is connected to the gas outlet of the separator 7 through a pipeline, and the tube side outlet of the heat exchanger 8 is connected to a buffer tank 9 through a pipeline. The shell side inlet of the heat exchanger 8 is connected to an external inert gas source, and the shell side outlet of the heat exchanger 8 is connected to the inlet of the air inlet device 4.

[0067] The product coated by the fluidized bed liquid phase is separated into gas and solid by the separator 7, and the inert gas separated by the separator 7 can be recovered by heat exchanger 8, and then circulated back to the bottom of the shell 1 for repeated use. Specifically, the tube side of the heat exchanger 8 is high-temperature tail gas, and the shell side is fresh nitrogen. The high-temperature tail gas of the tube side is used to preheat the fresh nitrogen of the shell side, and the high-temperature tail gas is cooled at the same time. A part of it is mixed with the supplementary fresh nitrogen and then enters the annular air inlet distribution device at the bottom of the device to complete the closed-loop circulation.

[0068] In this embodiment, if Figure 1 As shown, the separator 7 is specifically divided into a first separator and a second separator. The first separator is provided with a gas outlet and a solid outlet. The second separator is connected to the gas outlet of the first separator through a pipeline. By setting up two separators, the gas product can be separated for the second time. The first separator separates the coated precursor material from the nitrogen for gas-solid separation. The second separator is a pulse dust collector with a dust removal box. The second separator is arranged after the first separator, and can capture all the powder particles that are not completely separated and drop them to the discharge port of the second separator.

[0069] The utility model is not limited to the above-mentioned embodiments. Any changes in shape or structure are within the protection scope of the utility model. The protection scope of the utility model is defined by the attached claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the utility model, but these changes and modifications are within the protection scope of the utility model.

Claims

1. A fluidized bed liquid phase coating device, comprising a shell, a coating material feeding mechanism, and a powder feeding mechanism, wherein the coating material feeding mechanism is used to introduce liquid phase coating material into the shell, and the powder feeding mechanism is used to introduce powder material to be coated into the shell, characterized in that: The discharge port of the coating material feeding mechanism is arranged downstream of the discharge port of the powder feeding mechanism along the powder flow direction; The axis of the discharge port of the powder feeding mechanism is arranged close to the central axis of the shell and is parallel to the central axis of the shell; The coating material feeding mechanism has a plurality of discharge ports arranged along the circumference of the shell, each of which is equipped with an atomizing nozzle and the opening of the atomizing nozzle faces the central axis of the shell; The fluidized bed liquid phase coating device also includes an air inlet device, which is arranged on a side of the discharge port of the powder feeding mechanism away from the coating material feeding mechanism, and is used to make the powder material to be coated flowing out of the powder feeding mechanism flow toward the coating material feeding mechanism.

2. The fluidized bed liquid phase coating device according to claim 1, characterized in that: The coating material feeding mechanism comprises an annular feeder, and the annular feeder is arranged along the circumference of the shell.

3. The fluidized bed liquid phase coating device according to claim 2, characterized in that: The plurality of atomizing nozzles are evenly spaced along the circumference of the annular feeder.

4. The fluidized bed liquid phase coating device according to claim 1, characterized in that: The coating material feeding mechanism is provided with a first heating mechanism, and the first heating mechanism is used to heat the liquid coating material in the coating material feeding mechanism.

5. The fluidized bed liquid phase coating device according to claim 1, characterized in that: The air inlet device comprises an annular air guide pipe, a long air inlet pipe and a short air inlet pipe, and the outer diameter of the annular air guide pipe is smaller than the inner diameter of the shell; The long air inlet tube is connected to the annular air duct, the long air inlet tube is in a "cross" shape, and the inner cavity of the long air inlet tube is connected to the inner cavity of the annular air duct; The long air inlet tube is sealed and connected with a plurality of the short air inlet tubes. The long air inlet tube is provided with an air inlet. The short air inlet tube is provided with a plurality of air inlet nozzles. The air inlet is connected with an external air source.

6. The fluidized bed liquid phase coating device according to claim 1, characterized in that: The shell is also provided with a second heating structure, and the second heating structure is arranged downstream of the coating material feeding mechanism along the powder flow direction.

7. The fluidized bed liquid phase coating device according to any one of claims 1 to 6, characterized in that: The air inlet device, the material outlet and the coating material feeding mechanism are arranged upward in sequence along the height direction of the shell.

8. The fluidized bed liquid phase coating device according to claim 7, characterized in that: The air outlet of the air inlet device is arranged toward the inner bottom surface of the shell, and the discharge port of the powder feeding mechanism is arranged toward the air inlet device.

9. A powder coating system, characterized in that: The powder coating system comprises a fluidized bed liquid phase coating device as described in any one of claims 1-8.

10. The powder coating system according to claim 9, characterized in that: The powder coating system further comprises a separator, the shell is provided with a material outlet, and the inlet of the separator is connected with the material outlet of the shell through a pipeline; The powder coating system also includes a heat exchanger, the separator is provided with a gas outlet and a solid outlet, the tube-side inlet of the heat exchanger is connected to the gas outlet of the separator through a pipeline, and the tube-side outlet of the heat exchanger is connected to a buffer tank through a pipeline; the shell-side inlet of the heat exchanger is connected to an external inert gas source, and the shell-side outlet of the heat exchanger is connected to the inlet of the air inlet device.

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