A slurry conveying system and a method for cleaning the same

Abstract

The present invention belongs to the technical field of conveying systems, and specifically relates to a slurry conveying system, comprising a mixer (1), a first diaphragm pump (2), a transfer tank (4), a second diaphragm pump (5), a three-way valve (6), a head tank (7), a screw pump (8) and a coating machine (9), wherein the mixer (1), the first diaphragm pump (2) and the transfer tank (4) are sequentially connected in series, the transfer tank (4) is connected to the head tank (7) through the second diaphragm pump (5), the three-way valve (6) is arranged on a pipeline between the second diaphragm pump (5) and the head tank (7), the three-way valve (6) is arranged close to the bottom of the head tank (7), the three-way valve (6) is an automatically controlled three-way valve, and the head tank (7), the screw pump (8) and the coating machine (9) form a loop. The system prevents the slurry from being stationary in the conveying pipeline, thereby avoiding adverse effects on the coating quality. In addition, the present invention also discloses a method for cleaning the above system, thereby avoiding the generation of coating bubbles.

Description

Technical Field

[0001] The invention belongs to the technical field of conveying systems, and in particular relates to a slurry conveying system and a method for cleaning the system. Background Art

[0002] In the production process of lithium battery pole pieces, the slurry used as the raw material needs to be transported over long distances in the conveying pipeline. After the transportation is completed, the conveying pipeline needs to be cleaned to prevent the residual slurry from solidifying and clogging the conveying pipeline, thereby affecting the next transportation of the slurry.

[0003] The lithium-ion battery slurry conveying system generally refers to the slurry conveying equipment from the stirring tank to the coating die head. The slurry conveying system of the prior art (such as Figure 1 The working mode of the coating machine (as shown in the figure) is: open the first ball valve 201' and the second ball valve 202', and the slurry is transported from the mixer 1' to the transfer tank 4' via the first diaphragm pump 2'; the slurry in the transfer tank 4' is transmitted to the inside of the head tank 7' via the second diaphragm pump 5'; the slurry in the head tank 7' forms a closed-loop circulation system through the screw pump 8' and the coater 9'. During coating, the reflux pipe 30' is closed, and the slurry in the head tank 7' is continuously transported to the coater 9', and when the coating stops, the reflux pipe 30' is opened, and the slurry is continuously circulated between the head tank 7' and the coater 9' to avoid slurry precipitation and the introduction of bubbles, which affect the quality of the subsequent coated electrodes. Since the volume of the machine head tank 7' is generally much smaller than the slurry transfer tank 4', the machine head tank 7' is equipped with a liquid level detection mechanism. When it is detected that the liquid level of the machine head tank 7' is lower than the set value, a control signal is output to control the second diaphragm pump 5' from the transfer tank 4' to the machine head tank 7' to start, and the slurry is transferred from the transfer tank 4' to the machine head tank 7'. When the liquid level of the machine head tank 7' reaches the upper limit, the second diaphragm pump 5' is closed. Such a slurry conveying system has the following shortcomings when working: 1. When the second diaphragm pump 5' is turned off, the slurry in the pipeline from the transfer tank 4' to the head tank 7' is in a static state, and the slurry is prone to precipitation, which easily produces defects such as bubbles and scratches during coating; 2. A return pipe 30' and a manually controlled three-way valve 6' are installed between the transfer tank 4' and the head tank 7', but the return pipe 30' is only enabled when the coating is stopped and is in a normally closed state during production, resulting in the deposition of slurry in the return pipe; 3. The manually controlled three-way valve 6' needs to be manually operated by workers when working, which has low work efficiency and high production costs;

[0004] At the same time, when the production line is not in production, the entire slurry conveying system needs to be cleaned. The cleaning method adopted by the prior art is to manually clean the mixer 1', transfer tank 4' and head tank 7', and disassemble and clean the filter 31', filter element 103' and coater 9', and circulate and flush the feed pipeline and the second diaphragm pump 5' with deionized water, and then assemble all components after cleaning. This cleaning method has disadvantages in industrial production: when the next production starts, the pipeline system is often dry and has poor wettability with the slurry, causing bubbles to be generated when the coating resumes production, reducing production efficiency, and the cleaning method needs to be optimized. Summary of the invention

[0005] One of the purposes of the present invention is to provide a slurry conveying system to address the deficiencies of the prior art. During the slurry conveying process, the system can prevent the slurry from standing still in the conveying pipeline and also avoid the adverse effects on the coating quality.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A slurry conveying system includes a mixer, a first diaphragm pump, a transfer tank, a second diaphragm pump, a three-way valve, a head tank, a screw pump and a coating machine, wherein the mixer, the first diaphragm pump and the transfer tank are connected in series in sequence, the transfer tank is connected to the head tank through the second diaphragm pump, the three-way valve is arranged on the pipeline between the second diaphragm pump and the head tank, the three-way valve is arranged close to the bottom of the head tank, the three-way valve is an automatically controlled three-way valve, and the head tank, the screw pump and the coating machine form a loop. Driven by the first diaphragm pump and the second diaphragm pump, the slurry flows in the pipeline, and then the slurry can flow directly to the coating system during production through the automatic control of the three-way valve, so that the slurry can be continuously circulated between the transfer tank, the three-way valve and the reflux pipeline when waiting for production, thereby avoiding the problem of precipitation and agglomeration of the slurry when it is stationary in the long conveying pipeline between the transfer tank and the head tank.

[0008] As an improvement of the slurry conveying system of the present invention, the three-way valve is an automatically controlled three-way ball valve. In the case of the present invention, the automatically controlled three-way ball valve can realize automatic control, thereby reducing labor costs and improving production efficiency.

[0009] As an improvement of the slurry conveying system described in the present invention, it also includes a filter and a filter element, wherein the filter includes a first filter and a second filter, the first filter is arranged between the first diaphragm pump and the transfer tank, and the second filter is arranged between the second diaphragm pump and the three-way valve; the filter element includes a first filter element and a second filter element, the first filter element is arranged between the second filter and the three-way valve, and the second filter element is arranged between the screw pump and the coating machine. Under the action of multiple filtration, free iron ions such as iron filings and impurities contained in the slurry are effectively filtered out, and product quality is improved.

[0010] As an improvement of the slurry delivery system of the present invention, it also includes a return pipe.

[0011] The flow pipe is connected to the transfer tank and the three-way valve. Since the return pipe is connected to the three-way valve and the transfer tank, the slurry circulates in the pipe to avoid the slurry from being stationary.

[0012] As an improvement of the slurry conveying system of the present invention, it also includes ball valves, which include a first ball valve, a second ball valve, a third ball valve, a fourth ball valve and a fifth ball valve, wherein the first ball valve is arranged between the mixer and the first diaphragm pump, the second ball valve is arranged between the first filter and the transfer tank, the third ball valve is arranged between the transfer tank and the second diaphragm pump, the fourth ball valve is arranged between the second filter and the first filter element, and the fifth ball valve is arranged on the return pipe close to the transfer tank. Due to the application of the above-mentioned multiple different ball valves, the slurry can be flexibly controlled during the flow of the pipeline.

[0013] As an improvement of the slurry conveying system of the present invention, the fourth ball valve includes an A ball valve connected in series with the second filter, and two B ball valves connected in series with the A ball valve. The use of series and parallel connection increases the control of the slurry in the pipeline.

[0014] As an improvement of the slurry conveying system of the present invention, the number of the agitator, the head tank, the screw pump and the coating machine are all two. Such a structural design realizes the dual-pipeline slurry transportation and improves the transportation efficiency.

[0015] The second purpose of the present invention is to provide a method for cleaning the slurry delivery system to avoid bubbles during coating and re-production in order to address the deficiencies of the prior art.

[0016] To achieve the above object, the present invention provides a method for cleaning a slurry conveying system, comprising the following steps:

[0017] S1. First, clean the mixer, pour deionized water into the mixer, and start the first diaphragm pump to clean the pipe part between the mixer and the transfer tank with the deionized water;

[0018] S2, first clean the transfer tank, pour deionized water into the transfer tank, then close the fifth ball valve, start the second diaphragm pump, and use the deionized water to clean the pipe part between the transfer tank and the head tank, and finally start the second diaphragm pump and open the fifth ball valve, so that the three-way valve is connected to the reflux pipe, so that the deionized water is circulated and flushed in the pipe loop formed by the transfer tank and the head tank;

[0019] S3, first clean the head tank so that deionized water enters the head tank, and then clean the pipeline between the head tank and the coating machine.

[0020] As an improvement of the slurry conveying system cleaning method of the present invention, the first filter needs to be removed for cleaning while executing step S1, and the first filter is installed after step S1 is completed; the second filter and the first filter element need to be removed for cleaning while executing step S2, and the second filter and the first filter element are installed after step S2 is completed. The first filter, the second filter and the first filter element can be fully cleaned by removing them for cleaning, and installing them back after the pipeline is cleaned can reduce the flushing resistance when the pipeline is cleaned with deionized water, thereby increasing the cleaning effect.

[0021] Compared with the prior art, after cleaning the system pipelines, deionized water is retained in the pipelines under the action of the ball valve, and then the deionized water is released when resuming production, so that the pipelines maintain wettability, which can avoid the problem of coating bubbles caused by poor wettability between the pipeline system and the slurry when resuming production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 It is a structural schematic diagram of the prior art;

[0024] Among them: 1'-mixer; 2'-first diaphragm pump; 201'-first ball valve; 202'-second ball valve; 30'-reflux pipe; 31'-filter; 4-transfer tank; 5'-second diaphragm pump; 6'-three-way valve; 7'-head tank; 8'-screw pump; 9'-coating machine; 103'-filter element.

[0025] Figure 2It is a structural schematic diagram of the present invention;

[0026] Among them: 1- mixer; 2- first diaphragm pump; 20- ball valve; 201- first ball valve; 202- second ball valve; 203- third ball valve; 204- fourth ball valve; 2041- A ball valve; 2042- B ball valve; 205- fifth ball valve; 30- reflux pipe; 31- first filter; 32- second filter; 4- transfer tank; 5- second diaphragm pump; 6- three-way valve; 7- head tank; 8- screw pump; 9- coater; 10- filter element; 101- first filter element; 102- second filter element. DETAILED DESCRIPTION

[0027] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect.

[0028] In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings, but this is not intended to limit the present invention.

[0031] Example 1

[0032] like Figure 2As shown, a slurry conveying system includes a mixer 1, a first diaphragm pump 2, a transfer tank 4, a second diaphragm pump 5, a three-way valve 6, a head tank 7, a screw pump 8 and a coater 9. The mixer 1, the first diaphragm pump 2 and the transfer tank 4 are connected in series in sequence. The transfer tank 4 is connected to the head tank 7 through the second diaphragm pump 5. The three-way valve 6 is arranged on the pipeline between the second diaphragm pump 5 and the head tank 7. The three-way valve 6 is arranged close to the bottom of the head tank 7. The three-way valve 6 is an automatically controlled three-way valve. The head tank 7, the screw pump 8 and the coater 9 form a loop.

[0033] Preferably, the three-way valve 6 is an automatically controlled three-way ball valve, which realizes automatic control through electrical connection, reduces manpower and improves work efficiency.

[0034] The present invention also includes a filter 3, a filter element 10, a reflux pipe 30, and a ball valve 20. The filter 3 includes a first filter 31 and a second filter 32. The first filter 31 is arranged between the first diaphragm pump 2 and the transfer tank 4, and the second filter 32 is arranged between the second diaphragm pump 5 and the three-way valve 6; the filter element 10 includes a first filter element 101 and a second filter element 102. The first filter element 101 is arranged between the second filter 32 and the three-way valve 6, and the second filter element 102 is arranged between the screw pump 8 and the coating machine 9, which can filter out free iron ions and impurities such as iron filings contained in the slurry, thereby improving the quality of the product; the reflux pipe 30 is connected to the transfer tank 4 and the three-way valve 6, so that the slurry can circulate in the pipe. Prevent standing still; the ball valve 20 includes a first ball valve 201, a second ball valve 202, a third ball valve 203, a fourth ball valve 204 and a fifth ball valve 205. The first ball valve 201 is arranged between the mixer 1 and the first diaphragm pump 2, the second ball valve 202 is arranged between the first filter 31 and the transfer tank 4, the third ball valve 203 is arranged between the transfer tank 4 and the second diaphragm pump 5, the fourth ball valve 204 is arranged between the second filter 32 and the first filter element 101, the fourth ball valve 204 includes an A ball valve 2041 connected in series with the second filter 32, and two B ball valves 2042 connected in series with the A ball valve 2041, and the fifth ball valve 205 is arranged on the return pipe 30 near the transfer tank 4. The arrangement of the ball valve facilitates the control of the slurry when it flows in the pipeline.

[0035] Preferably, the number of the mixer 1, the head tank 7, the screw pump 8 and the coater 9 are all two, so that dual-pipeline production is realized and production efficiency is improved.

[0036] The working principle of the present invention is: (1) the slurry is first stirred evenly in the mixer 1, and then transferred by the first diaphragm pump 2 to the transfer tank 4 not far from the mixer 1. The first filter 31 is connected in series in the transmission pipeline to filter the slurry. The first ball valve 201 and the second ball valve 202 connected in series in the pipeline can control the switch of the slurry transmission pipeline; (2) a transfer tank can supply either one coating machine or two coating machines. In this embodiment, a transfer tank 4 supplies two head tanks 7. The transfer tank 4 is far away from the coating machine 9, more than 10m. A third ball valve 203 and a fourth ball valve 204 are connected in series between the transfer tank 4 and the head tank 7 to control the discharge of the material. A second diaphragm pump 5 is connected in series between the third ball valve 203 and the fourth ball valve 204 to transfer the slurry from the transfer tank 4 to the head tank 7. A second filter 32 and a first filter element 101 are connected in series after the second diaphragm pump 5 to filter the slurry again. A three-way valve 6 is installed at the bottom of the head tank 7. The three-way valve 6 is controlled by an electromagnetic valve. The switch of the electromagnetic valve can be integrated into the coating control panel. The liquid level sensor of the head tank 7 is used to monitor the high and low closed-loop control of the liquid level of the three-way valve 6. More ball valves and filter elements can be installed in the feed pipeline from the transfer tank 4 to the head tank 7 to control the feed process. The other interface of the three-way valve 6 is connected to the return pipe 30, and the return pipe 30 is connected back to the transfer tank 4. In this way, a slurry circulation system independent of the head tank 7 is established between the transfer tank 4 and the coating machine 9. When the coating stops, or the liquid level of the head tank 7 is not at the lower limit, the three-way valve 6 is controlled, and the transfer tank 4 no longer supplies slurry to the head tank 7, but the return pipe is connected, and the slurry circulates in the circulation system to prevent the slurry from standing in the feed pipe, agglomerating and precipitating, and causing coating bubble defects; (3) The feed system from the head tank 7 to the coating machine 9 is normally provided by the coating machine suppliers on the market, and the working principles are well known to the personnel in this technical field, and will not be described here one by one.

[0037] Example 2

[0038] like Figure 2 As shown, a method for cleaning the slurry delivery system of Example 1 comprises the following steps:

[0039] S1, first clean the mixer 1, pour deionized water into the mixer 1, start the first diaphragm pump 2, so that the deionized water cleans the pipe part between the mixer 1 and the transfer tank 4;

[0040] S2, first clean the transfer tank 4, pour deionized water into the transfer tank 4, then close the fifth ball valve 205, start the second diaphragm pump 5, so that the deionized water cleans the pipe part between the transfer tank 4 and the head tank 7, and finally open the fifth ball valve 205, connect the three-way valve 6 to the reflux pipe 30, so that the deionized water circulates and flushes in the loop formed by the transfer tank 4 and the head tank 7;

[0041] S3, first clean the head tank 7 to allow deionized water to enter the head tank 7, and then clean the pipeline part between the head tank 7 and the coating machine 9.

[0042] It should also be noted that: while executing step S1, the first filter 31 needs to be removed for cleaning, and the first filter 31 can be installed after step S1 is completed; while executing step S2, the second filter 32 and the first filter element 101 need to be removed for cleaning, and the second filter 32 and the first filter element 101 can be installed after step S2 is completed. The first filter 31, the second filter 32 and the first filter element 101 can be removed for cleaning to fully clean them, and they can be installed again after the pipeline is cleaned to reduce the flushing resistance when the pipeline is cleaned with deionized water.

[0043] Example 3

[0044] like Figure 2 As shown, a method for cleaning the slurry delivery system of Example 1 comprises the following steps:

[0045] S1. Clean the part between the mixer 1 and the transfer tank 4. First, clean the mixer 1, then remove the first filter 31, clean it and put it aside. Then connect the pipeline, open the first ball valve 201 and the second ball valve 202, and then inject deionized water into the cleaned mixer 1. Then, turn on the first diaphragm pump 2. Driven by the first diaphragm pump 2, the deionized water flows from the mixer 1 into the transfer tank 4. This process can clean the feeding pipeline. Finally, install the cleaned first filter 31 back into the feeding system, fill the feeding pipeline with deionized water, and then close the first ball valve 201 and the second ball valve 202 to keep the deionized water in the pipeline. In this way, the cleaning of this part is completed. When resuming production, the deionized water in the pipeline can be discharged to directly transport the slurry;

[0046] S2. Clean the part between the transfer tank 4 and the head tank 7. First, disassemble and clean the second filter 32 and the first filter element 101, and put them aside after cleaning. Then clean the transfer tank 4 and connect the feed pipeline again. Then open the third ball valve 203, A ball valve 2041 and B ball valve 2042 in the circulation pipeline between the transfer tank 4 and the coating machine 9, and open the three-way valve 6 while closing the connection with the head tank 7 and opening the interface to the reflux pipeline 30 and the second diaphragm pump 5. Then, inject deionized water into the transfer tank 4 to circulate the deionized water in the circulation pipeline. When the circulation pipeline is cleaned, the deionized water can be discharged. Then, the cleaned second filter 32 and the first filter element 101 are reinstalled into the pipeline. Then, deionized water is injected into the transfer tank 4 again to fill the entire circulation pipeline with deionized water. Finally, close the third ball valve 203 and the fifth ball valve 205 to keep the deionized water in the circulation pipeline. When resuming production, the deionized water can be discharged to transport the slurry.

[0047] S3, cleaning the part between the head tank 7 and the coating machine 9. The equipment between this part, including the head tank 7, the screw pump 8, the second filter element 102, the coating machine 9 and the intermediate pipeline, can be disassembled and cleaned normally, and then reassembled. It should be emphasized here that the coating machine 9 must be blown dry after cleaning before being reassembled.

[0048] The above description shows and describes several preferred embodiments of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. Changes and variations made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for cleaning a slurry conveying system, characterized in that: The slurry conveying system comprises a mixer (1), a first diaphragm pump (2), a transfer tank (4), a second diaphragm pump (5), a three-way valve (6), a head tank (7), a screw pump (8) and a coating machine (9); the mixer (1), the first diaphragm pump (2) and the transfer tank (4) are sequentially connected in series; the transfer tank (4) is connected to the head tank (7) via the second diaphragm pump (5); the three-way valve (6) is arranged on a pipeline between the second diaphragm pump (5) and the head tank (7); the three-way valve (6) is arranged close to the bottom of the head tank (7); the three-way valve (6) is an automatically controlled three-way valve; the head tank (7), the screw pump (8) and the coating machine (9) form a loop; The three-way valve (6) is an automatically controlled three-way ball valve; it also includes a ball valve (20), and the ball valve (20) includes a first ball valve (201), a second ball valve (202), a third ball valve (203), a fourth ball valve (204) and a fifth ball valve (205); Cleaning the slurry delivery system comprises the following steps: S1, first cleaning the mixer (1), then pouring deionized water into the mixer (1), starting the first diaphragm pump (2), so that the deionized water cleans the pipe part between the mixer (1) and the transfer tank (4); S2, first cleaning the transfer tank (4), then pouring deionized water into the transfer tank (4), starting the second diaphragm pump (5) and opening the third ball valve (203), the fourth ball valve (204) and the fifth ball valve (205) and the three-way valve (6) to connect the return pipe (30), so that the deionized water circulates in the loop formed by the transfer tank (4), the return pipe (30) and the three-way valve (6), so that the deionized water cleans the pipe section between the transfer tank (4) and the head tank (7); S3, first clean the head tank (7) to allow deionized water to enter the head tank (7), and then clean the pipeline between the head tank (7) and the coating machine (9).

2. The method for cleaning a slurry delivery system according to claim 1, characterized in that: The invention also comprises a filter (3), wherein the filter (3) comprises a first filter (31) and a second filter (32), wherein the first filter (31) is arranged between the first diaphragm pump (2) and the transfer tank (4), and the second filter (32) is arranged between the second diaphragm pump (5) and the three-way valve (6).

3. The method for cleaning a slurry delivery system according to claim 2, characterized in that: It also includes a filter element (10), wherein the filter element (10) includes a first filter element (101) and a second filter element (102), wherein the first filter element (101) is arranged between the second filter (32) and the three-way valve (6), and the second filter element (102) is arranged between the screw pump (8) and the coater (9).

4. The method for cleaning a slurry conveying system according to claim 3, characterized in that: It also includes a return pipe (30), wherein the return pipe (30) is connected to the transfer tank (4) and the three-way valve (6).

5. The method for cleaning a slurry conveying system according to claim 4, characterized in that: The first ball valve (201) is arranged between the mixer (1) and the first diaphragm pump (2), the second ball valve (202) is arranged between the first filter (31) and the transfer tank (4), the third ball valve (203) is arranged between the transfer tank (4) and the second diaphragm pump (5), the fourth ball valve (204) is arranged between the second filter (32) and the first filter element (101), and the fifth ball valve (205) is arranged on the reflux pipe (30) close to the transfer tank (4).

6. The method for cleaning a slurry delivery system according to claim 5, characterized in that: The fourth ball valve (204) comprises an A ball valve (2041) connected in series with the second filter (32), and two B ball valves (2042) connected in series with the A ball valve (2041).

7. The method for cleaning a slurry delivery system according to claim 1, characterized in that: The number of the mixer (1), the head tank (7), the screw pump (8) and the coating machine (9) is two.

8. The method for cleaning a slurry delivery system according to claim 3, characterized in that: While executing step S1, the first filter (31) needs to be removed for cleaning, and the first filter (31) can be installed after step S1 is completed; while executing step S2, the second filter (32) and the first filter element (101) need to be removed for cleaning, and the second filter (32) and the first filter element (101) can be installed after step S2 is completed.

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