Sintered plate and preparation method thereof

Abstract

The invention discloses a sintered plate and a preparation method thereof, the sintered plate comprises a filter element, the filter element comprises a macroporous layer, a mesoporous layer and a microporous layer which are sequentially stacked, the average pore diameter of the macroporous layer is larger than that of the mesoporous layer, and the average pore diameter of the mesoporous layer is larger than that of the microporous layer. According to the technical scheme, the filter element of the sintered plate adopts the macroporous layer, the mesoporous layer and the microporous layer which are connected in series in three stages to sequentially intercept particles with different particle sizes in air flow, graded interception of the particles is achieved, the intercepted particles can be collected and classified, and therefore the yield of a crushing system and the utilization rate of materials can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of dust removal, and in particular to a sintered plate and a preparation method thereof. Background Art

[0002] Sintered plate, scientifically known as "plastic sintered plate", is a device used for filtering and dust removal, which can be used repeatedly when filtering gas. The processing and manufacturing process of sintered plate is to use high molecular weight polyethylene as the main substrate, add a variety of polymer compound powders and mix them into a mold, and then sinter to form a porous structure substrate. The current sintered plate's filtering effect on materials needs to be improved. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the present application proposes a sintered plate.

[0004] To achieve the above-mentioned purpose, the present application discloses a sintered plate, which includes a filter element, and the filter element includes a macroporous layer, a mesoporous layer and a microporous layer stacked in sequence, the average pore size of the macroporous layer is larger than the average pore size of the mesoporous layer, and the average pore size of the mesoporous layer is larger than the average pore size of the microporous layer.

[0005] In some embodiments of the present application, the average pore size of the macroporous layer is equal to Da of the normally distributed particles, the average pore size of the mesoporous layer is equal to Db of the normally distributed particles, and the average pore size of the microporous layer is equal to Dc of the normally distributed particles;

[0006] Da is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching a%, Db is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching b%, and Dc is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching c%.

[0007] In some embodiments of the present application, 30≤ab≤60, 30≤bc≤60, a, b, c are natural numbers ranging from 0 to 100, respectively, and c is not 0.

[0008] In some embodiments of the present application, a is a natural number from 90 to 100, b is a natural number from 40 to 60, and c is a natural number from 0 to 20.

[0009] In some embodiments of the present application, the normally distributed particles are lithium hydroxide powder with a D50 of 2.5 μm to 20 μm.

[0010] In some embodiments of the present application, the average pore size of the macroporous layer is 80 μm to 120 μm, the average pore size of the mesoporous layer is 7 μm to 17 μm, and the average pore size of the microporous layer is 0 μm to 1.4 μm and is not 0 μm.

[0011] In some embodiments of the present application, the filter element further includes a first accommodating cavity disposed between the macroporous layer and the mesoporous layer, and a second accommodating cavity disposed between the mesoporous layer and the microporous layer.

[0012] In some embodiments of the present application, the first accommodating chamber is adapted to be in communication with a negative pressure device;

[0013] And / or, the second accommodating chamber is suitable for communicating with a negative pressure device;

[0014] And / or, the macroporous layer is suitable for connection with a backflush device;

[0015] and / or, the mesoporous layer is suitable for connection with a backflush device;

[0016] And / or, the microporous layer is suitable for connecting to a backflushing device.

[0017] In some embodiments of the present application, the filter element further comprises a separation layer;

[0018] The isolation layer is disposed on two opposite sides of the macroporous layer, and / or the isolation layer is disposed on two opposite sides of the mesoporous layer, and / or the isolation layer is disposed on two opposite sides of the microporous layer.

[0019] In some embodiments of the present application, the material of the isolation layer is polytetrafluoroethylene.

[0020] In some embodiments of the present application, the filter element further comprises a water-removing and carbon-removing layer, and the water-removing and carbon-removing layer is in a cross-grid structure;

[0021] The water-removing and carbon-removing layer is disposed on a side of the macroporous layer away from the mesoporous layer, and / or the water-removing and carbon-removing layer is disposed on a side of the microporous layer away from the mesoporous layer.

[0022] In some embodiments of the present application, the material of the water and carbon removal layer is at least one of zeolite and molecular sieve.

[0023] In some embodiments of the present application, a separation layer and a water and carbon removal layer are sequentially provided on the side of the macroporous layer facing away from the mesoporous layer;

[0024] And / or, a separation layer and a water and carbon removal layer are sequentially provided on a side of the microporous layer away from the mesoporous layer.

[0025] In some embodiments of the present application, the sintered plate further includes a protective shell, which wraps the air inlet side of the filter element, and the protective shell is provided with a plurality of flow holes.

[0026] In some embodiments of the present application, the aperture of the flow hole is R1, the average aperture of the macroporous layer is Ra, and 0 μm is satisfied. <R1-Ra≤10μm;

[0027] And / or, the flow holes are arranged in an array;

[0028] And / or, the protective shell also wraps the air outlet side of the filter element.

[0029] In some embodiments of the present application, the material of the macroporous layer, the mesoporous layer and the microporous layer is at least one of polyethylene, polytetrafluoroethylene and polyphenylene sulfide.

[0030] The second aspect of the present application discloses a method for preparing a sintered plate, the method comprising the following steps:

[0031] The first raw material is sintered at a first temperature for a time h1 to form a macroporous layer, sintered at a first temperature for a time h2 to form a mesoporous layer, and sintered at a first temperature for a time h3 to form a microporous layer, where h1<h2<h3.

[0032] In some embodiments of the present application, a second raw material is disposed on the surface of the first raw material and sintered together, so that the second raw material forms a separation layer.

[0033] In some embodiments of the present application, a third raw material is placed on the surface of the second raw material and heated by microwaves, so that the third raw material forms a water-removing and carbon-removing layer.

[0034] The filter element of the sintered plate of the technical solution of the present application adopts a three-stage series-connected macroporous layer, a mesoporous layer and a microporous layer to intercept particles of different particle sizes in the airflow in turn, thereby realizing graded interception of particles. The intercepted particles can be collected and classified for processing, which is beneficial to improving the yield of the crushing system and the utilization rate of materials.

[0035] Other advantages of the present application will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other designs can be obtained based on the structures shown in these drawings without paying any creative work.

[0037] Figure 1 Schematic diagram of a sintered plate in some embodiments;

[0038] Figure 2 Schematic diagram of sintered plates in other embodiments;

[0039] Figure 3Schematic diagram of water and carbon removal layer in some embodiments;

[0040] Figure 4 Schematic diagram of a protective shell in some embodiments;

[0041] Figure 5 A schematic diagram of a sintered plate installed in a separator in some embodiments;

[0042] Figure 6 is a pore distribution curve diagram of a macroporous layer, a mesoporous layer and a microporous layer in some embodiments;

[0043] Figure 7 The following is a particle size distribution curve of materials in some embodiments (the horizontal axis in the figure is the particle size classification (μm), and the vertical axis is the volume density (%)).

[0044] Description of Figure Numbers:

[0045] Sintering plate 10 , separator 20 , inlet 21 , outlet 22 , discharge port 23 , filter element 100 , macroporous layer 110 , mesoporous layer 120 , microporous layer 130 , water and carbon removal layer 150 , first accommodating chamber 161 , second accommodating chamber 162 , protective shell 200 , flow hole 210 .

[0046] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0049] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0051] The first aspect of the present application discloses a sintered plate 10, combined with Figure 1 As shown, the sintered plate 10 includes a filter element 100, and the filter element 100 includes a macroporous layer 110, a mesoporous layer 120 and a microporous layer 130. The macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 are stacked in sequence, and the average pore size of the macroporous layer 110 is larger than the average pore size of the mesoporous layer 120, and the average pore size of the mesoporous layer 120 is larger than the average pore size of the microporous layer 130.

[0052] In the related art, a sintering plate can be arranged in a crushing system to filter the airflow to collect particles of corresponding particle sizes. For example, the bulk material is crushed into powder (a collection of particles) and then transported to the separator 20 by airflow transmission. The sintering plate is arranged in the separator 20, and the airflow needs to pass through the sintering plate. When the airflow passes through the sintering plate 10, the particles of corresponding particle sizes in the airflow are intercepted by the sintering plate. However, since the crushed powder in the bulk material is composed of particles of different particle sizes, the current filtering effect of the sintering plate needs to be improved. For this reason, the present application proposes improvements to this.

[0053] In this embodiment, the sintered plate 10 includes a filter element 100, and the filter element 100 includes a macroporous layer 110, a mesoporous layer 120 and a microporous layer 130. The materials of the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 can refer to the relevant technology. For example, the material of the macroporous layer 110 is at least one of polyethylene, polytetrafluoroethylene and polyphenylene sulfide, the mesoporous layer 120 is at least one of polyethylene, polytetrafluoroethylene and polyphenylene sulfide, and the microporous layer 130 is at least one of polyethylene, polytetrafluoroethylene and polyphenylene sulfide. The macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 form a porous structure, and the average pore size of the macroporous layer 110 is greater than the average pore size of the mesoporous layer 120, and the average pore size of the mesoporous layer 120 is greater than the average pore size of the microporous layer 130.

[0054] The macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 are stacked in sequence, and are stacked in sequence along the flow direction of the airflow. The stacking means stacking layers, and the two adjacent layers can be in direct contact or indirect contact, and can also be arranged alternately to form cavities (hereinafter referred to as the first accommodating cavity 161 and the second accommodating cavity 162). When the airflow passes through the sintering plate 10, the airflow passes through the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 in sequence. Since the average pore sizes of the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 are different, particles of different particle sizes in the airflow can be intercepted by the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 in a graded manner. The graded interception can intercept in sequence for different particle sizes, reduce the burden of single-stage interception, reduce the omission of particles, and effectively improve the yield. Since particles of different particle sizes have different application scenarios, through graded interception, particles of each level can be classified and processed, and the application is more targeted, which is conducive to improving the utilization rate of materials.

[0055] Combination Figure 6 and Figure 7 As shown, in some embodiments, the average pore size of the macroporous layer 110 is equal to Da of the normally distributed particles, the average pore size of the mesoporous layer 120 is equal to Db of the normally distributed particles, and the average pore size of the microporous layer 130 is equal to Dc of the normally distributed particles, Da is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching a%, Db is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching b%, and Dc is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching c%.

[0056] Specifically, Da, Db and Dc can be taken from any normally distributed particles (normally distributed particles are particles whose particle size distribution has normal distribution characteristics), and are taken from the same normally distributed particles. Da is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching a%, that is, the percentage of particles smaller than this particle size in all particles is a%. Db is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching b%, that is, the percentage of particles smaller than this particle size in all particles is b%. Dc is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching c%, that is, the percentage of particles smaller than this particle size in all particles is c%.

[0057] Since the average pore size of the macroporous layer 110 is larger than the average pore size of the mesoporous layer 120 , and the average pore size of the mesoporous layer 120 is greater than the average pore size of the microporous layer 130 , a>b>c.

[0058] For example, D90 is the particle size corresponding to when the cumulative particle distribution percentage of the normally distributed particles reaches 90%, that is, the percentage of particles smaller than this particle size accounts for 90% of all particles. D60 is the particle size corresponding to when the cumulative particle distribution percentage of the normally distributed particles reaches 60%, that is, the percentage of particles smaller than this particle size accounts for 60% of all particles. D20 is the particle size corresponding to when the cumulative particle distribution percentage of the normally distributed particles reaches 20%, that is, the percentage of particles smaller than this particle size accounts for 20% of all particles.

[0059] The average pore size of the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 can be measured according to the BET method. The BET method is based on the equilibrium adsorption of small molecules by pores. The pore size distribution is obtained by analyzing the amount of gas adsorbed by pores of different pore sizes during the adsorption process. Low-temperature physical adsorption (such as nitrogen adsorption) is used during the test. In simple terms, the material sample is first pretreated, and the moisture and other impurities adsorbed on the surface are removed by heating, and then cooled to a low temperature; then, the sample is placed in a device containing an adsorbed gas, and the gas will enter and fill the pores of the material; the molecules of the adsorbed gas will interact with the surface of the material, and the adsorption process will occur through surface tension; the pore structure and specific surface area information of the material can be evaluated based on the adsorption isotherm. For detailed BET method, please refer to the relevant technology.

[0060] It can be understood that the material is crushed into powder, which is a collection of particles, and the particle size distribution of the particles has a normal distribution characteristic, such as Figure 7 To this end, in this embodiment, the average pore sizes of the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 correspond to different particle sizes of normally distributed particles, so that more targeted graded interception is achieved for particles of different particle sizes, thereby achieving a better filtering effect and being more conducive to obtaining particles of the desired particle size.

[0061] In some embodiments, the conditions 30≤ab≤60, 30≤bc≤60 are met, a, b, c are natural numbers of 0 to 100, and c is not 0. It can be understood that when the particle size distribution of the particles follows a normal distribution, the particle sizes of most particles will be concentrated near the median (D50), and the number of particles away from the median gradually decreases. In this embodiment, by meeting the above conditions, the macroporous layer 110 intercepts the largest particles, the mesoporous layer 120 intercepts the most particles, and the microporous layer 130 intercepts the smallest particles, further improving the effect of graded interception. For example, a is a natural number of 90 to 100, b is a natural number of 40 to 60, and c is a natural number of 0 to 20. A can be 90, 92, 95, 98 or 100, b can be 40, 45, 50, 55 or 60, and c can be 1, 5, 10, 15 or 20. After a large number of experiments by the inventor, through such a setting, the graded interception effect of particles at each level is better and the utilization rate of the material is higher.

[0062] In some embodiments, the normally distributed particles are lithium hydroxide powders with a D50 of 2.5 μm to 20 μm. In this embodiment, the material is lithium hydroxide, which is crushed into powder and passes through the sintering plate 10 in the form of airflow. Most of the lithium hydroxide powders meeting this particle size can be intercepted and collected by the mesoporous layer 120. The lithium hydroxide of this particle size can react more fully with the precursor as a lithium source, so that the prepared positive electrode material has better performance (such as the positive electrode material in the lithium battery industry).

[0063] Optionally, combined Figure 6 As shown, the average pore size of the macroporous layer 110 is 80 μm to 120 μm, the average pore size of the mesoporous layer 120 is 7 μm to 17 μm, and the average pore size of the microporous layer 130 is 0 μm to 1.4 μm and is not 0 μm. After a lot of experiments by the inventors, by optimizing the average pore size of the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130, it is more suitable for lithium hydroxide powder, covers the D0 / D50 / D100 value of lithium hydroxide powder, and realizes graded interception and filtration of the largest particles, the most particles and the smallest particles.

[0064] Combination Figure 2As shown, in some embodiments, the filter element 100 further includes a first accommodating chamber 161 and a second accommodating chamber 162, wherein the first accommodating chamber 161 is disposed between the macroporous layer 110 and the mesoporous layer 120, and the second accommodating chamber 162 is disposed between the mesoporous layer 120 and the microporous layer 130. The first accommodating chamber 161 is provided to provide an accommodating space for particles intercepted by the mesoporous layer 120, and the second accommodating chamber 162 is provided to provide an accommodating space for particles intercepted by the microporous layer 130. In this way, the first accommodating chamber 161 can be connected to the negative pressure device, and the second accommodating chamber 162 can also be connected to the negative pressure device, and the particles intercepted by the mesoporous layer 120 and the particles intercepted by the microporous layer 130 can be sucked and collected by drawing negative pressure through the negative pressure device.

[0065] Combination Figure 5For explanation, the sintering plate 10 is vertically installed inside the separator 20. After the airflow enters from the inlet 21 of the separator 20, it passes through the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 in a relatively vertical manner in sequence, and is finally discharged from the outlet 22. The material intercepted by the macroporous layer 110 can directly fall and be discharged through the discharge port 23 of the separator 20. The material intercepted by the mesoporous layer 120 is in the first accommodating chamber 161, and the material intercepted by the microporous layer 130 is in the second accommodating chamber 162. The negative pressure device can collect particles of corresponding particle sizes by sucking the first accommodating chamber 161 and the second accommodating chamber 162. Among them, taking lithium hydroxide crushed by air flow mill as an example, the average particle size of the material collected in the first accommodating chamber 161 is between the average pore size of the macroporous layer 110 and the average pore size of the mesoporous layer 120, based on the average pore size of the macroporous layer 110 being equal to Da of lithium hydroxide particles with normal distribution, the average pore size of the mesoporous layer 120 being equal to Db of lithium hydroxide particles with normal distribution, and the average pore size of the microporous layer 130 being equal to Dc of lithium hydroxide particles with normal distribution, therefore, especially when 30≤ab≤60, 30≤bc≤60, a, b, c are natural numbers of 0 to 100 respectively, and c is not 0, the material collected in the first accommodating chamber 161 is suitable for being directly mixed with the qualified material discharged from the discharge port 23 of the separator 20 in specific production, thereby improving the separation efficiency of the separator 20, and the second accommodating chamber 16 2. The average particle size of the material collected in the mesoporous layer 120 is between the average pore size of the microporous layer 130. The particles of the material collected in this part are relatively small. However, in the field of positive electrode materials, the smaller the lithium hydroxide particles as the lithium source, the lower the amount of filling in the sagger in the subsequent sintering process (the amount of filling is proportional to the production capacity of the positive electrode material). On the other hand, the smaller the average particle size of the lithium source, the more uniform the mixing with other materials, such as precursors, during the sintering process, and the better the crystallinity of the sintered positive electrode material. Therefore, the material collected in the second accommodating chamber 162 can be mixed with a large-particle lithium source in a certain process ratio, thereby taking into account the amount of filling in the sagger and the electrical properties of the positive electrode material. The present application classifies and utilizes the dust collected material discharged from the separator 20, which can greatly reduce the production cost of the positive electrode material while ensuring product quality.

[0066] It is understandable that a portion of the particles will adhere to the surface of the macroporous layer 110, the surface of the mesoporous layer 120 and the surface of the microporous layer 130, so the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 can be connected to the backblowing device, and the backblowing device can realize pulse backblowing to make the particles fall off. For example, it is possible to directly backblow from the air outlet side of the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 toward the air inlet side, or the backblowing device can backblow toward the inside of the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130, so that the particles can be separated from the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130. After backblowing, the particles of the macroporous layer 110 can fall directly and be discharged through the discharge port 23 of the separator 20, and the particles of the mesoporous layer 120 are in the first accommodating chamber 161 after backblowing, and the particles of the microporous layer 130 are in the second accommodating chamber 162 after backblowing, so that they can be sucked and collected by the negative pressure device.

[0067] The macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 can be mounted on a non-metallic frame and fixed, so that a first accommodating cavity 161 is formed between the macroporous layer 110 and the mesoporous layer 120, and a second accommodating cavity 162 is formed between the mesoporous layer 120 and the microporous layer 130. Of course, other methods can also be used to achieve the fixation between the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 to form the first accommodating cavity 161 and the second accommodating cavity 162. For example, the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 are fixed to each other by bonding their edges with an adhesive material, and the adhesive material can be at least one of polypropylene, polyethylene, polytetrafluoroethylene, polyphenylene sulfide, polyetheretherketone, and polyimide.

[0068] In some embodiments, the filter element 100 further includes an isolating layer (not shown in the figure), and the isolating layers are provided on opposite sides of the macroporous layer 110, that is, the air inlet side and the air outlet side of the macroporous layer 110 are both provided with isolating layers. The isolating layer can make the surface of the macroporous layer 110 smoother, less likely to adhere to particles, and particles are more likely to detach from the macroporous layer 110, thereby reducing the number of cleaning times of the macroporous layer 110, and at the same time can play a role of coating and protecting the macroporous layer 110, thereby extending the service life of the macroporous layer 110. Similarly, isolating layers can also be provided on opposite sides of the mesoporous layer 120, and isolating layers can also be provided on opposite sides of the microporous layer 130.

[0069] The material of the isolation layer can be polytetrafluoroethylene, which has the properties of acid resistance, alkali resistance, and oxidation resistance, so that the sintered plate 10 has anti-stickiness and can adapt to a variety of chemical environments. Of course, the material of the isolation layer can also be other materials, which are not listed here one by one.

[0070] Combination Figure 1 and Figure 3As shown, in some embodiments, the filter element 100 also includes a water-removing and carbon-removing layer 150, and the water-removing and carbon-removing layer 150 is in a cross-grid structure. The water-removing and carbon-removing layer 150 is arranged on the side of the macroporous layer 110 away from the mesoporous layer 120. The cross-grid structure can form a mesh to avoid completely covering the pores of the macroporous layer 110, leaving a channel for airflow to pass through. The water-removing and carbon-removing layer 150 can absorb water and carbon dioxide in the airflow. When filtering lithium hydroxide, lithium hydroxide is hygroscopic and easily reacts with water and carbon dioxide to deteriorate. For this reason, in this embodiment, the water-removing and carbon-removing layer 150 is arranged on the side of the macroporous layer 110 away from the mesoporous layer 120, that is, the water-removing and carbon-removing layer 150 is arranged on the air inlet side of the macroporous layer 110. The water-removing and carbon-removing layer 150 can absorb water and carbon dioxide in the airflow, effectively avoiding the deterioration of lithium hydroxide.

[0071] Of course, a water removal and carbon removal layer 150 may be provided on the side of the microporous layer 130 away from the mesoporous layer 120, that is, a water removal and carbon removal layer 150 may be provided on the air outlet side of the microporous layer 130, so as to further reduce the moisture and carbon dioxide content in the airflow, which is beneficial to the reuse of the airflow.

[0072] The material of the water removal and carbon removal layer 150 is at least one of zeolite and molecular sieve. For example, the material of the water removal and carbon removal layer 150 is molecular sieve, which is a kind of aluminosilicate compound with cubic lattice, mainly composed of silicon and aluminum connected by oxygen bridges to form an open skeleton structure, and there are many pores with uniform pore size and neatly arranged holes with large internal surface area in the structure. The pore size of the molecular sieve can be controlled by different processing techniques, and can effectively realize the adsorption of water vapor, carbon dioxide and other gases, and effectively remove water vapor and carbon dioxide in the airflow. In addition, the inventors found that the molecular sieve or zeolite has weak adsorption on lithium hydroxide particles, and the use of molecular sieve or zeolite to form a water removal and carbon removal layer is particularly suitable for filtering lithium hydroxide.

[0073] When the macroporous layer 110 is provided with both the alienation layer and the dewatering and carbon removal layer 150, the alienation layer and the dewatering and carbon removal layer 150 are sequentially arranged on the side of the macroporous layer 110 facing away from the mesoporous layer 120 (the air inlet side), that is, along the direction away from the mesoporous layer 120, the alienation layer and the dewatering and carbon removal layer 150 are sequentially arranged on the air inlet side of the macroporous layer 110. In this way, the airflow first flows through the dewatering and carbon removal layer 150, then flows through the alienation layer, and finally flows through the macroporous layer 110. The dewatering and carbon removal layer 150 is a cross-grid structure, which can form a mesh to avoid completely covering the pores of the macroporous layer 110, leaving a channel for the airflow to pass through. It is also because the dewatering and carbon removal layer 150 is a cross-grid structure that the alienation layer can be strengthened in structure, effectively inhibiting the damage of the alienation layer under the impact of particles and extending the service life.

[0074] Similarly, when the microporous layer 130 is provided with both a separation layer and a water and carbon removal layer 150, the separation layer and the water and carbon removal layer 150 are sequentially provided on the side of the microporous layer 130 facing away from the mesoporous layer 120 (the air outlet side), that is, along the direction away from the mesoporous layer 120, the separation layer and the water and carbon removal layer 150 are sequentially provided on the air outlet side of the microporous layer 130.

[0075] Combined Figure 1 and Figure 4 As shown, in some embodiments, the sintered plate 10 further includes a protective shell 200. The protective shell 200 wraps the air inlet side of the filter element 100. The protective shell 200 is provided with a plurality of flow-through holes 210. The term "plurality" means two or more. The flow-through holes 210 can be arranged in an array. In this way, the air flow can pass through the protective shell 200 more evenly and then flow through the filter element 100. The protective shell 200 can be made of materials such as stainless steel and ceramics that do not contain magnetic metals. Some of the particles in the air flow hit the protective shell 200 and then change direction and continue to pass through the flow-through holes 210. The setting of the protective shell 200 can protect the filter element 100 and prevent the filter element 100 from being damaged by the particles flowing at high speed. In particular, it can protect the water and carbon removal layer 150 and the separation layer, and improve the service life of the sintered plate 10.

[0076] In some embodiments, the aperture of the flow-through hole 210 is R1, and the average aperture of the macroporous layer 110 is Ra, satisfying 0μm < R1 - Ra ≤ 10μm. The protective shell 200 can intercept particles larger than the average aperture of the macroporous layer 110, which can not only meet the protective effect of the protective shell 200 on the filter element 100, but also ensure the passage of the air flow (particles).

[0077] Of course, the protective shell 200 can also wrap the air outlet side of the filter element 100. By including the air outlet side of the filter element 100 in the protective shell 200, the air outlet side of the filter element 100 can also be protected. For example, there are two protective shells 200, and the two protective shells clamp the filter element 100 to form protection for the opposite sides (the air inlet side and the air outlet side) of the filter element 100.

[0078] The second aspect of the present application discloses a method for preparing a sintered plate 10, including the following steps:

[0079] S1: Take the first raw material and sinter it at the first temperature for a sintering time h1 to form the macroporous layer 110, sinter it at the first temperature for a sintering time h2 to form the mesoporous layer 120, and sinter it at the first temperature for a sintering time h3 to form the microporous layer 130, where h1 < h2 < h3.

[0080] Specifically, a first raw material with a particle size of 20 to 100 mesh is selected for standby use. The material of the first raw material can be at least one of polyethylene, polytetrafluoroethylene, and polyphenylene sulfide. The first raw material is added to a first mold, a second mold, and a third mold respectively. Each mold is filled densely. At this time, the first raw material particles in each mold are squeezed and piled on each other. The first mold, the second mold, and the third mold with the first raw material added are placed in a heating device for sintering. The sintering time of the first mold (time h1), the sintering time of the second mold (time h2), and the sintering time of the third mold (time h3) satisfy h1<h2<h3. During the sintering process, the first raw material in each mold begins to melt and expand due to heat. The first raw materials are squeezed and adhered to each other in the space limited by the mold, and the gap part without adhesion forms a tiny through-aperture. This embodiment changes the flowability between the first raw material particles by controlling the holding time (sintering time, h1<h2<h3) so that the void portion meets the requirements, thereby forming different pore size distributions. That is, when the holding time is short, the flowability of the first raw material particles is poor, and the void portion cannot be fully expanded, so the formed pore size is larger; as the holding time increases, the flowability of the first raw material particles gradually improves, and the void portion can be fully expanded, so the formed pore size gradually decreases; when the holding time is too long, the first raw material particles may flow excessively, resulting in the merging or disappearance of the void portion, so the formed pore size continues to decrease, thereby obtaining sintered bodies with different pore size distributions (macroporous layer 110, mesoporous layer 120, microporous layer 130).

[0081] Optionally, the sintering temperature (first temperature) is controlled to be 100°C to 300°C, the sintering time h1 is controlled to be 20min to 40min, the sintering time h2 is controlled to be 40min to 60min, and the sintering time h3 is controlled to be 60min to 90min, which is particularly suitable for the sintering of polyethylene materials to form different average pore sizes. The first raw material can be ultra-high molecular weight polyethylene with an average molecular weight of 2 million to 10 million, so that the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 obtained have higher structural strength.

[0082] The method for preparing the sintered plate 10 further includes the following steps:

[0083] S2: The macroporous layer 110 and the mesoporous layer 120 , as well as the mesoporous layer 120 and the microporous layer 130 are connected and fixed by sintering at a second temperature for a time h4, where h4≤h1.

[0084] Specifically, the macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 are placed in a layered mold, an adhesive material is injected into the layered mold, and the layered mold is placed in a heating device for sintering. The adhesive material can be at least one of polypropylene, polyethylene, polytetrafluoroethylene, polyphenylene sulfide, polyetheretherketone, and polyimide. After sintering, the macroporous layer 110 and the edge of the mesoporous layer 120 can be connected and fixed, and the edge of the mesoporous layer 120 and the microporous layer 130 can be connected and fixed to form a first accommodating cavity 161 and a second accommodating cavity 162.

[0085] Optionally, the second temperature is 80° C. to 180° C. to minimize the impact on the pores already formed in the macroporous layer 110 , the mesoporous layer 120 , and the microporous layer 130 .

[0086] The method for preparing the sintered plate 10 further includes the following steps:

[0087] In step S1 , a second raw material is placed on the surface of a first raw material and sintered together, so that the second raw material forms a separation layer.

[0088] Specifically, the second raw material can be polytetrafluoroethylene. Before adding the first raw material, a layer of polytetrafluoroethylene is first laid in the first mold, the second mold and the third mold. After adding the second raw material, another layer of polytetrafluoroethylene is laid. In this way, when each mold to which the first raw material and the second raw material are added is sintered, the first raw material and the second raw material are sintered together. During the sintering process, the second raw material will extend to the inside of the pores of the macroporous layer 110, the mesoporous layer 120, and the microporous layer 130 to form a coating effect, so that the isolation layer is fixed on the opposite sides of the macroporous layer 110, the opposite sides of the mesoporous layer 120, and the opposite sides of the microporous layer 130. By sintering the first raw material and the second raw material together, the processing steps can be reduced and the process can be saved.

[0089] The method for preparing the sintered plate 10 further includes the following steps:

[0090] Before step S2 , a third raw material is placed on the surface of the second raw material and heated by microwaves, so that the third raw material forms a water-removing and carbon-removing layer 150 .

[0091] Specifically, the second raw material can be selected as at least one of zeolite and molecular sieve. Taking molecular sieve as an example, the molecular sieve is sprayed in a cross shape on the surface of the isolation layer on the macroporous layer 110, and on the surface of the isolation layer on the microporous layer 130. Then, both are subjected to microwave heating. In this way, the molecular sieve is fixed on the surface of the isolation layer to form a water-removing and carbon-removing layer. The conditions are easy to control and the preparation process is simple.

[0092] Optionally, microwave heating is controlled to 360k-370k (temperature unit in the International System of Units, with absolute zero (-273.15 degrees Celsius) as zero point, symbol K), and the heating time is 18min to 22min, so that the formed water removal and carbon removal layer 150 has higher separation performance and shorter synthesis time.

[0093] Example 1

[0094] The sintered plate 10 includes a protective shell 200 and a filter element 100. The filter element 100 includes a water-removing and carbon-removing layer 150, a macroporous layer 110, a mesoporous layer 120, a microporous layer 130 and a water-removing and carbon-removing layer 150 arranged along the airflow direction. The macroporous layer 110, the mesoporous layer 120 and the microporous layer 130 are made of polyethylene with an average molecular weight of 2 million to 10 million. The first temperature is 230° C., h1 is 20 minutes, h2 is 40 minutes, h3 is 60 minutes, and the combination Figure 6 Shown and Figure 7 As shown, the average pore size of the macroporous layer 110 is 100 μm, the average pore size of the mesoporous layer 120 is 12 μm, and the average pore size of the microporous layer 130 is 0.4 μm, so that the interception effect for particles larger than 0.2 μm is higher.

[0095] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made based on the concept of the present application and the contents of the present application description and drawings, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A sintered plate (10), characterized in that: The sintered plate (10) comprises a filter element (100), wherein the filter element (100) comprises a macroporous layer (110), a mesoporous layer (120) and a microporous layer (130) which are stacked in sequence, wherein the average pore size of the macroporous layer (110) is greater than the average pore size of the mesoporous layer (120), and the average pore size of the mesoporous layer (120) is greater than the average pore size of the microporous layer (130).

2. The sintered plate (10) according to claim 1, characterized in that The average pore size of the macroporous layer (110) is equal to Da of the normally distributed particles, the average pore size of the mesoporous layer (120) is equal to Db of the normally distributed particles, and the average pore size of the microporous layer (130) is equal to Dc of the normally distributed particles; Da is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching a%, Db is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching b%, and Dc is the particle size corresponding to the cumulative particle distribution percentage in the normally distributed particles reaching c%.

3. The sintered plate (10) according to claim 2, characterized in that: 30≤ab≤60, 30≤bc≤60, a, b, c are natural numbers from 0 to 100, and c is not 0; And / or, the normally distributed particles are lithium hydroxide powder with a D50 of 2.5 μm to 20 μm.

4. The sintered plate (10) according to claim 3, characterized in that a is a natural number from 90 to 100, b is a natural number from 40 to 60, and c is a natural number from 0 to 20.

5. The sintered plate (10) according to claim 3, characterized in that The average pore size of the macroporous layer (110) is 80 μm to 120 μm, the average pore size of the mesoporous layer (120) is 7 μm to 17 μm, and the average pore size of the microporous layer (130) is 0 μm to 1.4 μm and is not 0 μm.

6. The sintered plate (10) according to claim 1, characterized in that The filter element (100) further comprises a first accommodating cavity (161) arranged between the macroporous layer (110) and the mesoporous layer (120), and a second accommodating cavity (162) arranged between the mesoporous layer (120) and the microporous layer (130).

7. The sintered plate (10) according to claim 6, characterized in that The first accommodating chamber (161) is suitable for being in communication with a negative pressure device; And / or, the second accommodating chamber (162) is suitable for communicating with a negative pressure device; And / or, the macroporous layer (110) is suitable for connection with a backflush device; And / or, the mesoporous layer (120) is suitable for connection with a backflush device; And / or, the microporous layer (130) is suitable for connecting to a backflush device.

8. The sintered plate (10) according to claim 1, characterized in that The filter element (100) further comprises a separation layer; The isolation layer is disposed on two opposite sides of the macroporous layer (110), and / or the isolation layer is disposed on two opposite sides of the mesoporous layer (120), and / or the isolation layer is disposed on two opposite sides of the microporous layer (130).

9. The sintered plate (10) according to claim 1, characterized in that: The filter element (100) further comprises a water-removing and carbon-removing layer (150), wherein the water-removing and carbon-removing layer (150) is in a cross-grid structure; The water-removing and carbon-removing layer (150) is provided on the side of the macroporous layer (110) facing away from the mesoporous layer (120), and / or the water-removing and carbon-removing layer (150) is provided on the side of the microporous layer (130) facing away from the mesoporous layer (120).

10. The sintered plate (10) according to claim 1, characterized in that A separation layer and a water and carbon removal layer (150) are sequentially provided on a side of the macroporous layer (110) facing away from the mesoporous layer (120); And / or, a separation layer and a water and carbon removal layer (150) are sequentially provided on a side of the microporous layer (130) facing away from the mesoporous layer (120).

11. The sintered plate (10) according to claim 1, characterized in that The sintered plate (10) further comprises a protective shell (200), wherein the protective shell (200) wraps the air inlet side of the filter element (100), and the protective shell (200) is provided with a plurality of flow holes (210).

12. The sintered plate (10) according to claim 11, characterized in that The aperture of the flow hole (210) is R1, and the average aperture of the macroporous layer (110) is Ra, satisfying 0 μm <R1-Ra≤10μm; And / or, the flow holes (210) are arranged in an array; And / or, the protective shell (200) also wraps the air outlet side of the filter element (100).

13. A method for preparing a sintered plate (10), characterized in that: The steps include: A first raw material is sintered at a first temperature for a time h1 to form a macroporous layer (110), a first temperature for a time h2 to form a mesoporous layer (120), and a first temperature for a time h3 to form a microporous layer (130), where h1<h2<h3.

14. The method for preparing a sintered plate (10) according to claim 13, characterized in that: A second raw material is placed on the surface of the first raw material and sintered together, so that the second raw material forms a separation layer.

15. The method for preparing a sintered plate (10) according to claim 14, characterized in that: A third raw material is placed on the surface of the second raw material and heated by microwaves, so that the third raw material forms a water and carbon removal layer (150).

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