Screening equipment, system and screen damage monitoring method for battery negative electrode materials

Abstract

The present invention provides a screening device, system and screen damage monitoring method for battery negative electrode materials, and relates to the field of screening technology. The screening device includes a screening device body, which is formed with a accommodating cavity; a first screen is arranged in the accommodating cavity; a second screen is arranged in the accommodating cavity and is arranged at intervals from the first screen; the mesh number of the second screen is less than the mesh number of the first screen; the first screen and the second screen divide the accommodating cavity into a first inner cavity, a second inner cavity and a third inner cavity in sequence; a feed port; a second discharge port is arranged on one side of the screening device body and is connected to the second inner cavity; a third discharge port is arranged on the side of the screening device body away from the second discharge port and is connected to the third inner cavity. The screening system includes the above-mentioned screening device, material conveying equipment, weighing equipment, storage equipment and linkage control equipment. The present invention can stop the machine in time after the screen in the screening device is damaged, so as to ensure that the large particle material after the screen is damaged will not enter the subsequent process, thereby eliminating product quality risks.

Description

Technical Field

[0001] The present invention relates to the field of screening technology, and in particular to screening equipment, a system and a screen damage monitoring method for battery negative electrode materials. Background Art

[0002] In the process of manufacturing negative electrode materials for lithium-ion batteries, the screening process is an essential step in the finished product preparation process. Its purpose is to screen out large particles in the graphite powder after the previous process such as graphitization, coating carbonization, etc., to ensure that the graphite powder entering the subsequent process is D v max does not exceed the standard, D v max is the maximum particle size of the negative electrode material. Typically, the screening equipment is completed with a screen of a predetermined mesh size. In the actual screening process, the screen may be damaged after being used for a period of time; and the screening equipment is a sealed system. During the screening process, the graphite powder will generate a lot of dust. Therefore, even if there is an observation window, it is impossible to see the internal situation clearly, let alone judge whether the screen is damaged. At present, the industry usually replaces the screen in advance after the predetermined time or the predetermined amount of screened material is used to avoid the raw materials entering the subsequent process without screening after the screen is damaged, which ultimately affects the quality of the battery negative electrode material. Despite the method of early replacement, there is still a situation where the screen is damaged in advance, and the time of damage cannot be determined. In this way, the large particles of material from the time the screen is damaged to the time before the screen is found to be damaged have entered the subsequent process. Therefore, in the actual production process, large particles of foreign matter are often found in the product, which will cause significant losses to both the battery negative electrode material supplier and the end customer. Summary of the invention

[0003] In order to improve at least some of the above shortcomings or deficiencies, the embodiments of the present invention provide a screening device, a system and a screen damage monitoring method for battery negative electrode materials. By arranging screening equipment, weighing equipment and linkage control equipment, the damage of the screen in the screening equipment can be discovered in time during the production process of battery negative electrode materials, and the screening can be stopped in time to avoid unqualified materials from entering the subsequent processes, thereby realizing online monitoring of the qualification of the screened materials and avoiding reducing the quality of the battery negative electrode materials.

[0004] Specifically, on the one hand, an embodiment of the present invention provides a screening device for battery negative electrode materials, including a screening device body, which is formed with a accommodating cavity; a first screen, which is arranged in the accommodating cavity; a second screen, which is arranged in the accommodating cavity and is spaced apart from the first screen; wherein the mesh number of the second screen is less than the mesh number of the first screen; wherein the first screen and the second screen divide the accommodating cavity into a first inner cavity, a second inner cavity and a third inner cavity in sequence; a feed port, which is arranged at the top of the screening device body and is connected to the first inner cavity; a first discharge port, which is arranged on one side of the screening device body and is connected to the first inner cavity; a second discharge port, which is arranged on one side of the screening device body and is connected to the second inner cavity; and a third discharge port, which is arranged on a side of the screening device body away from the second discharge port and is connected to the third inner cavity.

[0005] In one embodiment, it includes a vibration isolation device and a power device, wherein the power device is located on the outer wall of the screening device, and the vibration isolation device is located at the bottom of the outer wall of the screening device.

[0006] Another embodiment of the present invention provides a screening system for battery negative electrode materials, comprising the above-mentioned screening equipment; a material conveying equipment, the outlet end of the material conveying equipment is connected to the feed port of the screening equipment; a weighing equipment, which is connected to the second discharge port of the screening equipment; a storage device, which is connected to the third discharge port of the screening equipment; and a linkage control device, which is respectively connected to the material conveying equipment, the screening equipment, the weighing equipment and the storage device.

[0007] In one embodiment, a switching valve is further included, and the number of the storage devices is multiple; one end of the switching valve is connected to the multiple storage devices respectively, and the other end of the switching valve is connected to the third discharge port.

[0008] In one embodiment, it also includes a buffer bin, which is respectively connected to the screening device and the storage device, and a sampling valve is provided at the outlet end of the buffer bin; the third discharge port is connected to the buffer bin; and a sampling reminder device is connected to the linkage control device; the sampling reminder device is used to prompt sampling of the material in the buffer bin.

[0009] In one embodiment, an alarm device is further included, and the alarm device is connected to the linkage control device.

[0010] In one embodiment, a coarse material barrel is further included, and the first discharge port of the screening device is connected to the coarse material barrel.

[0011] Another embodiment of the present invention provides a method for monitoring the damage of a mesh screen of a battery negative electrode material, which is applied to a screening system for the battery negative electrode material as described above, comprising: a material conveying device conveying material to a screening device; the screening device screens the material through a first screen to obtain material under the first screen; the screening device screens the material under the first screen through a second screen to obtain material under the second screen and material on the second screen; the screening device conveys the material under the second screen to a storage device through a third discharge port, so that the storage device conveys the material under the second screen to a next process device; the screening device passes the material on the second screen through a second discharge port The material is transported to the weighing device at the discharge port; the weighing device generates weight information according to the material on the second screen and sends it to the linkage control device; the linkage control device determines whether the weight information exceeds a preset threshold; if so, the linkage control device determines that the first screen is damaged, and generates first control information according to the weight information and sends it to the material conveying device, so that the material conveying device stops conveying materials to the screening device according to the first control information; the linkage control device generates second control information according to the weight information and sends it to the storage device, so that the storage device stops supplying materials to the next process according to the second control information.

[0012] In one embodiment, there are multiple storage devices, and the method also includes the linkage control device sending third control information to the switching valve according to the weight information, so that the switching valve switches the current storage device to a target storage device among the multiple storage devices according to the third control information, and the target storage device is other storage devices among the multiple storage devices except the current device.

[0013] In one embodiment, the method further includes the linkage control device acquiring preset time information, and sending fourth control information to the sampling reminder device according to the preset time information.

[0014] It can be seen from the above that the above technical features of the present invention can have one or more of the following beneficial effects: the screening equipment for battery negative electrode materials in the embodiment of the present invention is provided with a first sieve and a second sieve to screen the battery negative electrode materials in turn, and a first discharge port, a second discharge port and a third discharge port are provided to respectively convey the material on the first sieve, the material on the second sieve and the material under the second sieve, so as to facilitate the collection of the battery negative electrode materials that have passed through the sieve and have not passed through the sieve.

[0015] The screening system for negative electrode materials of the battery of the embodiment of the present invention cooperates with the screening equipment, the weighing equipment and the linkage control equipment so that the damage of the screen in the screening equipment can be timely discovered during the production process of the negative electrode materials of the battery, and the screening can be stopped in time to prevent unqualified materials from entering the subsequent processes, thereby realizing the online monitoring of the qualification of the screened materials and avoiding the reduction of the quality of the negative electrode materials of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 A schematic diagram of module connections of a screening system for battery negative electrode materials provided in an embodiment of the present invention.

[0018] Figure 2 A schematic structural diagram of a battery negative electrode material screening device provided in an embodiment of the present invention.

[0019] Figure 3 for Figure 1 Schematic diagram of the structure of the specific screening system.

[0020] Figure 4 Another structural schematic diagram of a battery negative electrode material screening system provided in an embodiment of the present invention.

[0021] Figure 5 A schematic diagram of another structure of a screening system for battery negative electrode materials provided in an embodiment of the present invention.

[0022] Figure 6 for Figure 3 A schematic diagram of the enlarged structure in the middle.

[0023] Figure 7 Another schematic diagram of module connection of a battery negative electrode material screening system provided in an embodiment of the present invention.

[0024] Reference numerals:

[0025] 1. Screening system; 10. Material conveying equipment; 20. Screening equipment; 201. Screening equipment body; 2011. Accommodating chamber; 2012. First inner chamber; 2013. Second inner chamber; 2014. Third inner chamber; 202. First screen; 203. Second screen; 204. First discharge port; 205. Second discharge port; 206. Third discharge port; 207. Feed port; 208. Vibration isolation equipment; 209. Power equipment; 30. Weighing equipment; 301. Electronic scale; 302. Sample tank; 40. Linkage control equipment; 50. Storage equipment; 60. Switching valve; 70. Buffer bin; 701. Sampling valve; 702. Sampling reminder equipment; 80. Coarse material barrel; 90. Preparation bin; 110. Alarm equipment. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] This embodiment provides a screening system for the screening process of manufacturing lithium-ion battery negative electrode materials. Lithium-ion battery negative electrode materials are powder materials, and their particle size distribution is one of the important factors affecting battery manufacturing process and battery performance. Generally, the particle size distribution of battery negative electrode materials should be controlled within an appropriate range, and the characteristic parameters mainly include D v 00, D v 01.D v 10. D v 50. D v 90 and D v 99,D v max. Where D v max controls the largest particle size in the battery negative electrode material powder, which is mainly controlled by the crushing and shaping process of the battery negative electrode material. However, it is inevitable that there will be a small amount exceeding D v Max control standard large particles escape; moreover, in the subsequent preparation process of battery negative electrode materials such as granulation, graphitization, coating carbonization, etc., some particles will agglomerate, fuse, grow, etc., resulting in the presence of more than D vThe large particles in the max control standard. If these large particles enter the terminal product, they will have a great negative impact on the battery process and battery performance: in pulping, the presence of large particles will cause the slurry screening screen to be blocked, which needs to be cleaned frequently, affecting production efficiency; in coating, the presence of large particles will cause scratches on the surface of the pole piece during the coating process, resulting in the pole piece being scrapped; in the rolling process, large particles that are not exposed in the previous process will produce bright spots in the rolling process, and the large particles will be over-pressurized, resulting in the pole piece being scrapped; in battery performance, large particles that are over-pressurized and not detected by the rolling process will cause insufficient battery capacity during the battery charging and discharging process, lithium precipitation will occur, and ultimately the battery life will be deteriorated. In severe cases, safety accidents such as combustion and explosion will occur.

[0028] like Figure 1 , Figure 2 and Figure 3 As shown, one embodiment of the present invention provides a screening system for battery negative electrode materials, the screening system comprising a screening device 20, a material conveying device 10, a weighing device 30, a storage device 50 and a linkage control device 40. The outlet end of the material conveying device 10 is connected to the feed port 207 of the screening device 20, the weighing device 30 is connected to the second discharge port 205 of the screening device 20, the storage device 50 is connected to the third discharge port 206 of the screening device 20, and the linkage control device 40 is connected to the material conveying device 10, the screening device 20, the weighing device 30 and the storage device 50 respectively.

[0029] Among them, Figure 2 As shown, the screening device 20 includes a screening device body 201, a first screen 202, a second screen 203, a feed port 207, a first discharge port 204, a second discharge port 205 and a third discharge port 206. The screening device body 201 is formed with a receiving cavity 2011; the first screen 202 is arranged in the receiving cavity 2011. The second screen 203 is arranged in the receiving cavity 2011 and is spaced apart from the first screen 202. The mesh number of the second screen 203 is less than the mesh number of the first screen 202, and the first screen 202 and the second screen 203 divide the receiving cavity 2011 into a first inner cavity 2012, a second inner cavity 2013 and a third inner cavity 2014 in sequence. The feed port 207 is arranged at the top of the screening device body 201 and is communicated with the first inner cavity 2012. The first discharge port 204 is disposed on one side of the screening device body 201 and communicates with the first inner cavity 2012. The second discharge port 205 is disposed on one side of the screening device body 201 and communicates with the second inner cavity 2013. The third discharge port 206 is disposed on one side of the screening device body 201 away from the second discharge port 205 and communicates with the third inner cavity 2014.

[0030] The mesh number of the second screen 203 is less than that of the first screen 202, that is, the mesh number of the first screen 202 is greater than that of the second screen 203, wherein the mesh number of the first screen 202 is, for example, 270 / 300 / 325 meshes, and the mesh number of the second screen 203 is, for example, 100 / 150 / 200 meshes, etc. The mesh number of the screen is, for example, the number of mesh holes on a length of 1 inch (25.4 mm) (or within a preset length range), and the mesh number of the screen is inversely proportional to the aperture of the screen, that is, the aperture on the first screen 202 is smaller than the aperture on the second screen 203.

[0031] The negative electrode material of the battery to be screened (i.e., the material) enters the screening device 20 through the feed port 207, and is screened through the first screen 202 and the second screen 203. Specifically, the material enters the screening device 20, and the material is screened through the first screen 202 to obtain the material on the first screen and the material under the first screen, and the material on the first screen is discharged through the first discharge port 204. The material on the first screen is the negative electrode material of the lithium battery that has not been screened by the first screen 202, and the material under the first screen is the negative electrode material of the lithium battery that has been screened by the first screen 202. Since the mesh number of the first screen 202 is greater than the mesh number of the second screen 203, when the first screen 202 is not damaged, the material under the first screen can be smoothly screened by the second screen 203, and flow out through the third discharge port 206 and transported to the storage device 50. When the first screen 202 is damaged, the screening function of the first screen 202 is lost. At this time, many materials larger than each mesh size of the first screen 202 will be directly discharged from the damaged first screen 202 to the second screen 203. These materials are unqualified materials. Then these unqualified materials are screened through the second screen 203 to obtain materials on the second screen and materials under the second screen. The materials on the second screen are discharged to the weighing device 30 through the second discharge port 205, and the materials under the second screen with unqualified materials are discharged to the storage device 50 through the third discharge port 206. The materials on the second screen are lithium battery negative electrode materials that have not passed through the second screen 203, and the materials under the second screen are lithium battery negative electrode materials that have successfully passed through the second screen 203. Among them, the storage device 50 is, for example, a tank with an inner cavity.

[0032] In one embodiment, Figure 2 and Figure 7As shown, the screening device 20 also includes a vibration isolation device 208 and a power device 209. The power device 209 is located on the outer wall of the screening device 20, and the vibration isolation device 208 is located at the bottom of the outer wall of the screening device 20; the power device 209 is used to control the working state of the screening device 20. Turn on the power device 209, so that the screening device 20 is in a working vibration state and can perform screening. The power device 209 drives the screening device body 201 to vibrate uniformly, thereby helping the materials entering the screening device body 201 to be evenly distributed on the first screen 202, thereby improving the screening efficiency. The vibration of the screening device 20 can effectively discharge the materials on the first screen from the first discharge port 204, effectively discharge the materials on the second screen from the second discharge port 205, and effectively discharge the materials under the second screen from the third discharge port 206. The vibration isolation device 208 can reduce the impact of the vibration generated by the screening device 20 during operation on the surrounding environment. The vibration isolation device 208 is, for example, a metal coil spring, a rubber spring, a composite spring, and an inflatable spring, etc., to achieve the effect of vibration isolation. The power device 209 is connected to the linkage control device 40 and is controlled by the linkage control device 40. The power device 209 is, for example, a motor in the prior art.

[0033] The screening system 1 in this embodiment can be used to monitor whether the first screen is damaged. The monitoring method is as follows (i.e., the working principle of the screening system 1):

[0034] During operation, the screening device 20 is started first, and then the material conveying device 10 is turned on. The material conveying device 10 conveys the material to the screening device 20, and the material is screened by passing through the first screen 202 and the second screen 203 in sequence. The material is divided into the material on the first screen and the material under the first screen through the first screen 202, and the unqualified material on the first screen is discharged through the first discharge port 204. Among them, the material on the first screen is the negative electrode material material of the lithium battery that has not been screened by the first screen 202, and the material under the first screen is the negative electrode material material of the lithium battery that has been screened by the first screen 202. The material on the first screen is screened on the second screen 203 to obtain the material on the second screen and the material under the second screen. The material on the second screen is the negative electrode material material of the lithium battery that has not been screened by the second screen 203, and the material under the second screen is the negative electrode material material of the lithium battery that has been screened by the second screen 203. The material on the second screen is transported to the weighing device 30 through the second discharge port 205, and the material under the second screen is transported to the storage device 50 through the third discharge port 206. The weighing device 30 generates weight information based on the material on the second screen and sends it to the linkage control device 40, which determines whether the weight information exceeds a preset threshold: if it does not exceed the preset threshold, it indicates that the first screen 202 is not damaged, and the system can work normally at this time; if it exceeds the preset threshold, it indicates that the first screen 202 is damaged, resulting in a large amount of material on the second screen remaining on the second screen 203, indicating that the material under the second screen transported to the storage device 50 also contains unqualified materials. At this time, the linkage control device 40 generates a first control information according to the weight information and sends it to the material conveying device 10, so that the material conveying device 10 stops conveying materials to the screening device 20 according to the first control information; generates a sixth control information and sends it to the power device 209, so that the power device 209 is turned off and the screening device 20 stops screening; generates a second control information to the storage device 50, so that the storage device 50 stops supplying materials to the next process. After the fault is repaired (the net is changed), the materials in the storage device 50 storing unqualified materials are re-screened. The first control information is, for example, information for controlling the material conveying device 10 to stop outputting materials, the sixth control information is, for example, information for controlling the power device 209 to turn off to stop the screening device 20 from working, and the second control information is, for example, information for controlling the storage device 50 to stop conveying materials to the next process.

[0035] The material conveying device 10 is, for example, a rotary feeder, and the material conveying device transports the material to the screening device 20 by rotating. The linkage control device 40 can control the material conveying speed by controlling the rotation speed of the material conveying device 10 to prevent the material conveying speed from being too slow to reduce the overall operating efficiency of the equipment, or when the material conveying speed is too fast, it exceeds the processing capacity of the screening device 20, causing the screening device 20 to be overloaded or the material to accumulate and clog on the screen, affecting the screening efficiency and equipment life. When the linkage control device 40 determines that the first screen 202 is damaged, the linkage control device 40 controls the material conveying device 10 to stop running to stop conveying materials to the screening device 20. After the fault is repaired (the screen is replaced), the material conveying device 10 is started to continue rotating to convey materials to the screening device 20.

[0036] Among them, the weight information is the weight value of the material on the second sieve obtained by the weighing device 30, the preset threshold is the preset value of the weight increase speed, and the increase speed is measured in seconds. For example, when the preset value of the weight increase speed is set to ≤100g / second, it is better to be ≤50g / second. For example, when the preset value of the weight increase speed is set to 100g / s, the weighing device 30 weighs once per second and feeds back the weight information to the linkage control device 40. When the linkage control device 40 detects that the increased weight of the material on the second sieve within a certain second reaches 100g / s, the linkage control device 40 performs subsequent work. The specific weight increase speed can be set according to the actual scene requirements, and is not specifically limited here.

[0037] Among them, a valve is provided on the storage device 50. When the storage device 50 receives the material under the second screen from the screening device 20, the storage device 50 collects the material. After the storage device 50 is full, the valve is opened to allow the material in the storage device 50 to enter the subsequent process. The valve can be controlled by a control module or manually controlled. The manual control method is, for example, to open a visual window on the storage device 50. The staff observes the material storage situation in the storage device 50 through the visual window. When the storage device 50 is full, the valve can be opened. The automatic control method is, for example, to connect the valve to the linkage control device 40, and use a timer to calculate the time required for the storage device 50 to be full when the screen in the screening device 20 is not damaged. The linkage control device 40 can set the time according to the value measured this time. After the set time is reached, the linkage control device 40 controls the valve to be opened. Change according to the actual scene, not limited to the above method.

[0038] Furthermore, the linkage control device 40 can record the running time of the screening device 20, and when the set time is reached, the control interface will prompt to replace the screen, and when the limit value is reached, the screening device 20 will be automatically prohibited from starting. After the operator replaces the screen, the operator will reset the timer of the linkage control device 40 that records the running time of the screening device 20 and restart the time. It should be noted that the limit value is the time required for the expected screen to break, and the set time is the time required for the screen to be about to break.

[0039] In addition, the screening system 1 may include a material preparation bin 90, which is used to hold the material processed in the previous process, that is, the graphite powder processed by graphitization, coating carbonization, etc. The outlet of the material preparation bin 90 is connected to the inlet of the material conveying device 10 to convey the material to the material conveying device 10.

[0040] like Figure 1 and Figure 4 As shown, in one embodiment, the screening system 1 further includes a switching valve 60, the number of storage devices 50 is multiple, the switching valve 60 is connected to the multiple storage devices 50 respectively, and the third discharge port 206 is connected to the switching valve 60. The switching valve 60 is used to switch the switching valve 60 to transport the material to another storage device 50 when one of the storage devices 50 is full. In addition, in the previous process, when the linkage control device 40 determines that the weight information exceeds the preset threshold, the linkage control device 40 sends the third control information to the switching valve 60, so that the switching valve 60 switches the current storage device to the target storage device among the multiple storage devices according to the third control information, that is, the switching valve 60 connects the third discharge port 206 with the target storage device according to the third control information. Among them, the current storage device is a storage device among the multiple storage devices that is currently receiving materials, and the target storage device is other storage devices among the multiple storage devices except the current storage device, and is also another storage device among the multiple storage devices except the current storage device. Since the screening system 1 is always running, the screening system 1 can always monitor and determine whether the first screen is damaged. When it is determined that the first screen is damaged, the switching valve 60 can switch the third discharge port 206 to be connected to the target storage device, and transport the materials in the storage device 50 previously loaded with unqualified materials to the preparation bin 90 for re-screening. The third control information is, for example, information for controlling the switching valve 60 to switch the third discharge port 206 on the screening device 20 to be connected to a storage device 50 among the multiple storage devices 50.

[0041] like Figure 1 , Figure 5 and Figure 7As shown, in one embodiment, the screening device 20 further includes a buffer bin 70 and a sampling reminder device 702. The buffer bin 70 is connected to the screening device 20 and the storage device 50 respectively, and a sampling valve 701 is provided at the outlet end of the buffer bin 70, and the third discharge port 206 is connected to the buffer bin 70; the sampling reminder device 702 is used to prompt the sampling of the material in the buffer bin 70, and the sampling reminder device 702 is connected to the linkage control device 40, and the sampling reminder device 702 can be an LED lamp or a buzzer. The linkage control device 40 presets the time information, and when the preset time is reached, the linkage control device 40 sends the fourth control information to the sampling reminder device 702 according to the preset time information. Assuming that the sampling reminder device 702 is an LED lamp, the sampling reminder device 702 lights up at this time. After the staff sees the light, they can close the sampling valve 701 of the buffer bin 70, take out the material from the buffer bin 70, that is, the material under the second screen, for inspection, and reset the sampling reminder device 702. If the material under the second sieve is found to be qualified, it indicates that the first sieve 202 is not damaged, that is, the material in the working storage device 50 is qualified. Otherwise, it indicates that the first sieve 202 is damaged, and the staff can control the material conveying device 10 to stop working through the linkage control device 40. Among them, the staff can test the material under the second sieve taken out through the inspection sieve, and the mesh number of the inspection sieve is equal to the mesh number of the first sieve 202. If there is no material residue in the inspection sieve after screening, the first sieve 202 is working normally. If there is material residue in the inspection sieve after screening, the first sieve 202 is damaged. In addition, the linkage control device 40 can set different sampling times, such as when the storage device 50 starts to load, when the storage device 50 is half loaded with materials, or when the storage device 50 is about to be full.

[0042] In one embodiment, Figure 3 and Figure 6 As shown, the screening system 1 also includes a coarse material barrel 80, and the first discharge port 204 is connected to the coarse material barrel 80. The coarse material barrel 80 promptly collects the material on the first screen that has not passed through the first screen 202, ensuring that the material passes through the screen evenly, improving the screening efficiency, reducing the wear of the screen, and avoiding the mixing of unqualified materials with newly conveyed materials, thereby maintaining the consistency of the product.

[0043] In one embodiment, Figure 7 As shown, the screening system 1 also includes an alarm device 110, and the alarm device 110 is connected to the linkage control device 40. The alarm device 110 can be an LED lamp or a buzzer. When the linkage control device 40 determines that the weight information exceeds a preset threshold value based on the weight information, that is, when the first screen 202 is damaged, the linkage control device 40 sends a fifth control information to the alarm device 110 to remind the staff to check and handle the fault. The fifth control information is, for example, information for controlling the alarm device 110 to issue an alarm.

[0044] In a preferred embodiment of this embodiment, if Figure 6 As shown, the weighing device 30 includes, for example, an electronic scale 301 and a sample tank 302. The sample tank 302 is disposed on the electronic scale 301, and is connected to the second discharge port 205. The sample tank 302 is used to receive the material on the second sieve. The electronic scale 301 is connected to the linkage control device 40. Specifically, the material on the second sieve remaining on the second sieve 203 enters the sample tank 302 through the second discharge port 205, and is weighed by the electronic scale 301 and the weight information is fed back to the linkage control device 40 in real time.

[0045] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0046] In addition, it can be understood that the aforementioned embodiments are only exemplary descriptions of the present invention. Under the premise that the technical features do not conflict, the structures do not contradict, and the purpose of the present invention is not violated, the technical solutions of the various embodiments can be arbitrarily combined and used in combination.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A screening device for battery negative electrode materials, characterized in that: include: The screening device body is formed with a receiving cavity; A first sieve, arranged in the accommodating cavity, for screening the material to be screened to obtain material on the first sieve and material under the first sieve, wherein the material on the first sieve is material that has not passed through the first sieve, and the material under the first sieve is material that has passed through the first sieve, and the material to be screened is a negative electrode material of a battery to be screened; a second screen, arranged in the accommodating cavity and spaced apart from the first screen; wherein the mesh number of the second screen is less than the mesh number of the first screen; wherein the first screen and the second screen divide the accommodating cavity into a first inner cavity, a second inner cavity and a third inner cavity in sequence; A feed inlet, which is arranged on the top of the screening device body and is communicated with the first inner cavity; A first discharge port, disposed on one side of the screening device body and connected to the first inner cavity; a second discharge port, disposed on one side of the screening device body and communicating with the second inner cavity; and a third discharge port, which is disposed on a side of the screening device body away from the second discharge port and is in communication with the third inner cavity; When the first screen is not damaged, the material under the first screen passes through the second screen and then flows out from the third discharge port, and the material on the first screen is discharged through the first discharge port; When the first screen loses its screening function due to damage, the material under the first screen is screened by the second screen to obtain material on the second screen and material under the second screen, and the material on the second screen is discharged through the second discharge port. The material under the second screen contains unqualified material that is discharged from the damaged first screen to the second screen and is larger than each mesh size of the first screen, and the material under the second screen is discharged through the third discharge port.

2. A screening device for battery negative electrode materials according to claim 1, characterized in that: It also includes a vibration isolation device and a power device. The power device is located on the outer wall of the screening device, and the vibration isolation device is located at the bottom of the outer wall of the screening device.

3. A screening system for battery negative electrode materials, characterized in that: include: The screening device according to any one of claims 1 to 2; A material conveying device, wherein the outlet end of the material conveying device is connected to the feed inlet of the screening device; A weighing device, connected to the second discharge port of the screening device; A plurality of storage devices, wherein the plurality of storage devices are in communication with a third discharge port of the screening device; A material preparation bin, the outlet of which is connected to the inlet of the material conveying device so as to convey materials to the material conveying device; A switching valve, one end of which is connected to the plurality of storage devices respectively, and the other end of which is connected to the third discharge port; as well as A linkage control device, respectively connected to the material conveying device, the screening device, the weighing device and the storage device; Wherein, the weighing device is used to generate weight information according to the material on the second screen and send it to the linkage control device, and the linkage control device is used to determine whether the weight information exceeds a preset threshold value, and determine that the first screen is damaged after exceeding the preset threshold value; The switching valve is used to switch the third discharge port to communicate with a non-current storage device among the multiple storage devices when the linkage control device determines that the first screen is damaged, and to transport the material in the storage device previously loaded with unqualified battery negative electrode materials to the preparation bin; The material preparation bin is used to store unqualified battery negative electrode materials, and to transport the unqualified battery negative electrode materials to the screening equipment for screening.

4. A screening system for battery negative electrode materials as claimed in claim 3, characterized in that: Also includes: A buffer bin, the buffer bin is connected to the screening device and the storage device respectively, and a sampling valve is provided at the outlet end of the buffer bin; The third discharge port is connected to the buffer bin; as well as A sampling reminder device is connected to the linkage control device; the sampling reminder device is used to remind the sampling of the material in the buffer bin.

5. A screening system for battery negative electrode materials as claimed in claim 3, characterized in that: It also includes an alarm device, which is connected to the linkage control device.

6. A screening system for battery negative electrode materials according to any one of claims 3 to 5, characterized in that: It also includes a coarse material barrel, and the first discharge port of the screening device is connected to the coarse material barrel.

7. A method for monitoring mesh damage of battery negative electrode materials, applied to the screening system of battery negative electrode materials as described in any one of claims 3 to 6, characterized in that: include: The material conveying equipment conveys the materials to the screening equipment; The screening device screens the material through a first screen to obtain material under the first screen; The screening device screens the material under the first screen through the second screen to obtain the material under the second screen and the material on the second screen when the first screen loses its screening function due to damage, and the material under the second screen contains unqualified materials that are discharged from the damaged first screen to the second screen and are larger than each mesh size of the first screen; The screening device transports the material under the second screen to the storage device through the third discharge port, so that the storage device transports the material under the second screen to the next process equipment; The screening device transports the material on the second screen to the weighing device through the second discharge port; the weighing device generates weight information according to the material on the second screen and sends it to the linkage control device; The linkage control device determines whether the weight information exceeds a preset threshold; If so, the linkage control device determines that the first screen is damaged, and generates first control information according to the weight information and sends it to the material conveying device, so that the material conveying device stops conveying materials to the screening device according to the first control information; The linkage control device generates second control information according to the weight information and sends it to the storage device, so that the storage device stops supplying materials to the next process equipment according to the second control information; The number of the storage devices is multiple, and the linkage control device sends third control information to the switching valve according to the weight information, so that the switching valve switches the current storage device to a target storage device among the multiple storage devices according to the third control information, and transports the materials in the current storage device containing unqualified materials to the material preparation bin; Wherein, the target storage device is other storage devices among the plurality of storage devices except the current device; The mesh number of the second sieve is smaller than the mesh number of the first sieve; The weight information is the weight of the material on the second sieve, and the preset threshold is a preset value of the weight increase speed of the material on the second sieve.

8. A method for monitoring mesh damage of a battery negative electrode material as claimed in claim 7, characterized in that: The method further comprises: The linkage control device obtains preset time information, and sends fourth control information to the sampling reminder device according to the preset time information.

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