Ceramic filter plate preparation process and application of ceramic filter plate

Abstract

The invention provides a ceramic filter plate preparation process and application of a ceramic filter plate. The preparation process of the ceramic filter plate comprises the following steps: a ceramic filter tube preparation step S1: putting cellulose powder and glycerol liquid into a reaction kettle, injecting water, uniformly stirring, adding silicon nitride powder and diatomite powder, and mixing to form a ceramic material; s2, extruding the ceramic material to form a pipe body with a wave structure by adopting an extrusion process, and then drying, sintering and cooling; c1, diatomite and a dispersing agent are mixed and dispersed through ultrasonic treatment, nano-silica and water glass are added, and stirring is performed to form a coating; c2, coating the surface of the ceramic filter tube with the coating, baking to form a film layer, and calcining to improve the compactness and thermal shock resistance of the film coating; the preparation method of the ceramic filter plate comprises the following steps: adhering the tail end socket to the tail end of the ceramic filter tube, inserting the ceramic filter tube into the positioning hole of the head sheath for adhesion, curing, and sealing in the head sheath.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of manufacturing and processing of refractory materials, and in particular to a ceramic filter plate preparation process and application of the ceramic filter plate. BACKGROUND

[0002] In the field of dust removal, separation and purification, filter elements are the core components for dust control and medium separation, and are of great significance to environmental purification and industrial production efficiency improvement. Currently, the widely used filter elements in the industry are mainly high polymer filter plates and high polymer filter cylinders, both of which are prepared by sintering process, and the raw materials are generally selected from organic polymer materials, including three common types of ultrahigh molecular polyethylene, polyphenyl ether and polytetrafluoroethylene.

[0003] However, in actual working condition applications, such high polymer filter elements have the following defects: On the one hand, if ultrahigh molecular polyethylene is used as raw material, although the cost of raw materials can be effectively controlled, it has certain economic advantage, but the material itself has poor high temperature resistance, which cannot adapt to the filtering scene in high temperature environment, greatly limiting its application range; on the other hand, if polyphenyl ether or polytetrafluoroethylene is selected, although it can be used stably at a temperature of about 200 DEG C, it can meet the high temperature resistance demand of part of the low temperature working condition, but the cost of raw materials of the two is too high, which makes the user hesitate in the actual popularization and application process due to economic problems, and it is difficult to realize large-scale popularization and application.

[0004] In order to solve the technical short board of high polymer filter material not resistant to high temperature, ceramic filter material is used to replace high polymer filter element in the industry, for example, a plurality of parallel ceramic cyclone subassemblies are used as core dust removal components, or ceramic filter cylinders are used as core dust capture components; but the existing ceramic filter element has the structural defect of extremely small single filter area, in order to meet the dust removal efficiency requirement in actual production, the number of ceramic filter elements needs to be increased to realize the superposition of filter area, which directly leads to the doubling of the volume of the whole dust removal equipment and the significant increase of equipment investment cost, and the economic disadvantage is prominent. SUMMARY

[0005] Therefore, the present application aims to solve the problem of providing a ceramic filter plate preparation process and application of the ceramic filter plate.

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is: A ceramic filter plate preparation process and application of the ceramic filter plate; The ceramic filter plate preparation process comprises: Ceramic filter tube preparation step S1: Put the cellulose powder and glycerol liquid into the reaction kettle, stir uniformly, then add the silicon nitride powder and diatomite powder for mixing, to form a ceramic material with plasticity; S2: Use the extrusion process to make the ceramic material form a wave structure pipe body after extruding through a tubular mold, and then go through the drying, sintering and cooling processes to obtain a ceramic filter pipe; Film processing step C1: Mix the diatomite with the dispersing agent, uniformly disperse by ultrasonic treatment, then add the nano silicon dioxide and water glass, and stir to form a coating; C2: Apply the coating to the surface of the ceramic filter pipe, bake to form a film layer, and then calcine to improve the density and thermal shock resistance of the film coating; Ceramic filter plate preparation step After the tail head is bonded to the tail end of the ceramic filter pipe, the ceramic filter pipe is inserted into the positioning hole of the head sheath for bonding, and after solidification, the seal is loaded in the head sheath.

[0007] In the ceramic filter pipe preparation step, the mass ratio of cellulose powder, glycerol liquid, silicon nitride powder and diatomite powder is 7%, 5%, 80% and 8%, and the mass of water is 15% of the total mass of the four materials; The mixing temperature is 65℃; The stirring paddle speed is 60r / min, and the stirring time is 240min.

[0008] In the drying process, step-by-step staged temperature rising drying is carried out by a drying box with an infrared radiation source, which is divided into the following stages: First stage: use medium wave infrared with a wavelength of 2-5μm, heating temperature is 80-100℃, heating time is 1h; Second stage: use long wave infrared with a wavelength of 5-15μm, heating temperature is 100-150℃, heating time is 2h; Third stage: use long wave infrared with a wavelength of 5-15μm, heating temperature is 150-180℃, heating time is 2h.

[0009] Put the pipe body in a nitrogen atmosphere to form a silicon nitride compound, and the sintering time and temperature are divided into the following stages in turn: Low temperature stage of sintering process: from room temperature to 600℃, with a heating rate of 50-100℃ / h; Medium temperature stage of sintering process: from 600℃ to 1200℃, with a heating rate of 100-200℃ / h; High temperature stage of sintering process: from 1200℃ to 1450℃, with a heating rate of 50-100℃ / h.

[0010] In the cooling process, the time and temperature are divided into the following stages in sequence: The holding stage of the cooling process: the temperature is maintained at 1450 DEG C, and the time lasts for 1-4h; The cooling stage of the cooling process: the temperature is decreased from 1450 DEG C to 1200 DEG C at a rate of 50-100 DEG C / h; The medium temperature stage of the cooling process: the temperature is decreased from 1200 DEG C to room temperature at a rate of 100-200 DEG C / h.

[0011] Before the film processing step, the nano-silica and diatomite are pretreated respectively; The pretreatment of the nano-silica comprises: using a silane coupling agent to modify the surface of the nano-silica, and then dispersing by ultrasonic, the ultrasonic power is 200W, and the dispersion time is 20min; The pretreatment of the diatomite comprises: using hydrochloric acid with a concentration of 5%-10% to acid treat the diatomite, and then calcining the diatomite at a high temperature, the calcining temperature is 600-800 DEG C, and the calcining time is 1-2 hours.

[0012] In the film processing step, the mass ratio of the nano-silica, diatomite, water glass and dispersant is 25%:35%:25%:15%.

[0013] In the high-temperature calcining process of the film layer, the calcining temperature is divided into two stages; The first stage calcining: the temperature is increased from room temperature to 600 DEG C at a rate of 50-100 DEG C / h; The second stage calcining: the temperature is increased from 600 DEG C to 1000 DEG C at a rate of 100-200 DEG C / h, after 1h of holding, the temperature is decreased from 1000 DEG C to 600 DEG C at a rate of 50-100 DEG C / h, and the temperature is decreased from 600 DEG C to room temperature at a rate of 100-200 DEG C / h.

[0014] The application of the ceramic filter plate, which is manufactured by the ceramic filter plate preparation process, is applied to the high-temperature-resistant dust collector.

[0015] The head sheath end of the ceramic filter plate is connected with the clean room flower plate through a three-dimensional flexible sealing strip, and a compressed air delivery nozzle connected with a pulse electromagnetic valve is arranged above the double exhaust gas holes of the head sheath end of the ceramic filter plate.

[0016] The application has the advantages and positive effects that: The process is because the ceramic filter tube adopts the wave structure design, not only increases the filtering area, and the wave surface is a continuous curved surface, the curvature is uniform change, no corner structure is convenient for dust cleaning, at the same time, the ceramic filter plate made by the process can withstand 500 DEG C high temperature environment, meet the space small, high filtration efficiency and precision, good thermal shock resistance use demand, provide more options for the upgrading iteration of ceramic filter plate. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, together with the embodiments of the application, to explain the application, and do not constitute a limitation on the application.

[0018] In the drawings: Figure 1 is the internal microstructure of the ceramic filter tube; Figure 2 is the internal microstructure diagram of the ceramic filter tube at the first visual angle; Figure 3 is the internal microstructure diagram of the ceramic filter tube at the second visual angle; Figure 4 is the internal microstructure diagram of the ceramic filter tube at the third visual angle; Figure 5 is the internal microstructure diagram of the ceramic filter tube at the fourth visual angle; Figure 6 is the particle size distribution diagram of the ceramic filter tube; Figure 7 is the overall structure diagram of the ceramic filter plate with multiple wave shapes; Figure 8 is the overall structure diagram of the ceramic filter plate with single wave shape; Figure 9 is the overall structure diagram of the ceramic filter tube; Figure 10 is the overall structure diagram of the tail head; Figure 11 is the overall structure diagram of the head sheath; Figure 12 is the dust removal efficiency test diagram of the ceramic filter plate; In the figure: 1, head sheath; 2, ceramic filter tube; 3, tail head. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0020] It should be understood that when a component is referred to as being "on" another component, it can be directly on the other component or intervening components can also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components can also be present. When a component is referred to as being "disposed" on another component, it can be directly disposed on the other component or intervening components can also be present. The terms "vertical", "horizontal", "left", "right", and similar terms as used herein are for purposes of description only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0022] Referring to Figures 1-6 The application provides a ceramic filter plate preparation process and application of the ceramic filter plate; the ceramic filter plate preparation process comprises a ceramic filter tube preparation step, a film coating processing step and a ceramic filter plate preparation step. The ceramic filter tube preparation step comprises: S1: cellulose powder and glycerol liquid are put into a reaction kettle, stirred uniformly after water injection, and then silicon nitride powder and diatomite powder are added for mixing, to form a ceramic material with plasticity, facilitating subsequent extrusion processing; The mass ratio of cellulose powder, glycerol liquid, silicon nitride powder and diatomite powder is 7%, 5%, 80% and 8%, and the mass of water is 15% of the total mass of the four materials; The mixing temperature is 65°C; The stirring paddle rotates at a speed of 60 r / min, and the stirring time is 240 min.

[0023] S2: an extrusion process is adopted, in this embodiment, a double-screw extruder is used to make the ceramic material form a wave-structured tube body after extrusion through a tubular die, and then the ceramic filter tube is prepared through the processes of drying, sintering and cooling.

[0024] In the drying process, the drying box with an infrared radiation source is used for gradual and phased temperature rising drying, which is divided into the following phases: The first stage: using middle wave infrared, wavelength is 2-5 μm, heating temperature is 80-100℃, heating time is 1h; the purpose is to evaporate the surface free water slowly, because the radiation energy of this wave band matches the vibration energy level of water molecules in the material higher, and the inherent vibration frequency of water molecules corresponds to the infrared absorption peak mainly concentrated in 2.7 μm, therefore, this wave band just covers the strong absorption area of water molecules, which can realize the surface evaporation; The second stage: using long wave infrared, wavelength is 5-15 μm, heating temperature is 100-150℃, heating time is 2h; the energy is absorbed on the surface of the pipe blank, and then gradually transmitted to the inside through heat conduction from the surface layer, so as to accelerate the internal water diffusion; The third stage: using long wave infrared, wavelength is 5-15 μm, heating temperature is 150-180℃, heating time is 2h, and then the residual bound water is removed.

[0025] After the drying process is completed, sintering is carried out, in the sintering process, the sintering process adopts reaction sintering method, the pipe body is placed in nitrogen atmosphere, so as to generate silicon nitride compound, and the sintering time and temperature are divided into the following stages in turn: The low temperature stage of the sintering process: from room temperature to 600℃, the temperature is raised at a rate of 50-100℃ / h, so as to remove the organic binder in the blank; The medium temperature stage of the sintering process: from 600℃ to 1200℃, the temperature is raised at a rate of 100-200℃ / h; The high temperature stage of the sintering process: from 1200℃ to 1450℃, the temperature is raised at a rate of 50-100℃ / h, compared with the previous two temperature stages, the temperature rising rate is slowed down, so as to avoid the internal stress of the blank due to thermal shock.

[0026] In the cooling process, the cooling time and temperature are divided into the following stages in turn: The holding stage of the cooling process: the temperature is maintained at 1450℃ for 1-4h, so as to make the liquid phase diffuse fully and control the uniform growth of silicon nitride grains; The cooling stage of the cooling process: from 1450℃ to 1200℃, the temperature is lowered at a rate of 50-100℃ / h, so as to make the liquid phase solidify gradually, avoid the internal stress concentration caused by rapid cooling, and even avoid the problem of cracking; The medium temperature stage of the cooling process: from 1200℃ to room temperature, the temperature is lowered at a rate of 100-200℃ / h; after the cooling process is completed, the ceramic filter pipe is taken out and subjected to film coating processing.

[0027] Before the film coating processing step, the nano silicon dioxide and diatomite are pretreated respectively; The pretreatment of nano-silica includes: using a silane coupling agent to modify the surface of the nano-silica, thereby improving the dispersibility in the inorganic binder, and then dispersing by ultrasonic waves with a power of 200 W for 20 min to ensure uniform distribution of the nano-particles; The pretreatment of diatomite includes: acid treatment of the diatomite with hydrochloric acid with a concentration of 5%-10% to improve the purity of the diatomite, and then high-temperature calcination of the diatomite at a temperature of 600-800℃ for 1-2 hours to enhance the compatibility with the binder.

[0028] The film coating process includes: C1: mixing the diatomite with a dispersant, uniformly dispersing by ultrasonic treatment, adding nano-silica and water glass, and stirring to form a coating, the mass ratio of nano-silica, diatomite, water glass and dispersant being 25%:35%:25%:15%; The components of water glass, nano-silica and diatomite are mainly siloxane bonds, and the surface of the diatomite can be pretreated by a silane coupling agent to enhance the chemical bonding between the three, forming a composite structure of "nano-particle filling - diatomite skeleton - water glass bonding"; and the properties of the materials and the synergistic advantages are also fully considered when the film coating materials are mixed; The core role of nano-silica is that the nano-particles can fill the micro-pores of the coating to form a continuous and dense film structure, and the interface bonding force between the nano-particles and the matrix is strong, which can enhance the hardness, wear resistance and impact resistance of the coating; The core role of diatomite is that its micro-porous structure can endow the coating with air permeability and moisture absorption, and at the same time provide a dispersion carrier for nano-silica, the porous structure can also load functional substances such as catalysts to endow the coating with additional functions such as self-cleaning, and the low density of diatomite can reduce the overall weight of the coating, and the raw materials are both natural and economical; water glass is used as a film-forming binder, and a dispersant is used to improve the compatibility of nano-particles and diatomite; Water glass is used as a film-forming binder, and a dispersant is used to improve the compatibility of nano-particles and diatomite.

[0029] C2: applying the coating to the surface of the ceramic filter tube, baking at a high temperature of 250℃ to form a film layer, and then calcining to improve the denseness and thermal shock resistance of the film coating; In the high-temperature calcination process of the film layer, the calcination temperature is divided into two stages; First-stage calcination: heating from room temperature to 600℃ at a rate of 50-100℃ / h; Second stage calcination: from 600℃ to 1000℃, temperature rising at 100-200℃ / h; holding for 1h, then from 1000℃ to 600℃, temperature falling at 50-100℃ / h; from 600℃ to room temperature, temperature falling at 100-200℃ / h; After the high-temperature calcination process of the film layer is completed, the ceramic filter tube film coating processing step is completed, and the internal microstructure of the ceramic filter tube can be seen in Figures 1 to 5 , and the particle size distribution of the ceramic filter tube can be seen in Figure 6 .

[0030] The ceramic filter plate preparation step includes: After the tail end cap 3 is bonded to the tail end of the ceramic filter tube 2, the ceramic filter tube is inserted into the positioning hole of the head sheath 1 for bonding, and after solidification is completed, a seal is loaded in the head sheath.

[0031] Referring to Figures 7-11 , the head sheath 1 and the tail end cap 3 are both molded from aluminum alloy or aluminum-magnesium alloy, and process holes are provided at both ends of the sheath, process grooves are left around the head sheath 1, and a single row or multiple rows of through holes are provided in the center of the head sheath 1. The process holes are an up-and-down through structure, which plays a role of bolt fastening when the ceramic filter plate is installed, and the process grooves are used for inlaying a seal, which plays a role of sealing the upper and lower parts when connected. After the tail end cap 3 is bonded to the tail end of the ceramic filter tube, the ceramic filter tube 2 is inserted into the positioning hole of the head sheath 1 for bonding, and after solidification is completed, a seal is loaded in the head sheath 1. The positioning hole is a single row or multiple rows of cross arrangement, which can form a single / multiple wave shape of tubular waves and arranged waves. The wave surface is a continuous curved surface with uniform curvature change. Since there are no corners, it is convenient for complete dust cleaning. The bonding agent is an organic ultrahigh-temperature silicone adhesive.

[0032] Referring to Figure 12 , through experimental testing, the ceramic filter plate made by this preparation process can withstand a high-temperature environment of 500℃. Since the ceramic filter tube adopts a wave structure design, the filtration area is increased, and the wave surface is a continuous curved surface with uniform curvature change. The structure without corners is convenient for dust cleaning, meets the requirements of small space occupation, high filtration efficiency and precision, and high-temperature resistance.

[0033] In the experimental test, the test method adopts: ANSI / ASHRAE Standard 52.2-2017 Section 10 to determine the particle size efficiency; the sample description is: sintered filter; the sample processing is: tested as is, without static electricity elimination; the sample size: 564*767*80mm; the effective filtration area: 2.2m2; the 100% test flow: 132 m3 / h; the face wind speed: 1m / min; the final pressure drop: 2000Pa; the pollutant (efficiency): KCI; the pollutant (loading): ASHRAE ash; the minimum efficiency report value (MERV) of the sample: MERV13@2000Pa, 1m / min, and the test results are detailed in Figure 12 .

[0034] The application of the ceramic filter plate manufactured by the ceramic filter plate manufacturing process is applied to the high-temperature-resistant dust collector.

[0035] The head sheath end of the ceramic filter plate is connected to the clean room flower plate through a three-dimensional flexible sealing strip, and a compressed air delivery nozzle connected to a pulse electromagnetic valve is arranged above the double exhaust gas holes of the head sheath end of the ceramic filter plate.

[0036] After the dust-containing gas enters the high-temperature-resistant dust collector, the dust is captured by the ceramic filter plate, and the gas is discharged through the micropores on the wave surface of the ceramic filter plate, thereby realizing dust control or medium separation. When the filtration resistance gradually increases, compressed air is delivered to the compressed air delivery nozzle through the pulse electromagnetic valve, and then sprayed into the tubular channel of the ceramic filter plate, so that the gas in the inner cavity of the ceramic filter plate expands and contracts sharply, causing impact vibration to perform dust removal work, and the dust on the ceramic filter plate is shaken off and falls, thereby realizing dust removal. Since the wave surface is a continuous curved surface with uniform curvature change without edges and corners, the problem of dust hiding in the ceramic filter plate is avoided.

[0037] The embodiments of the application are described in detail above, but the content described is only the preferred embodiments of the application and cannot be considered as limiting the scope of the implementation of the application. Any equivalent changes and improvements made within the scope of the application should still be included in the scope of the patent.

Claims

1. A process for preparing a ceramic filter plate, characterized in that, include: Ceramic filter tube preparation steps S1: After mixing cellulose powder and glycerol liquid in a reaction vessel with water, add silicon nitride powder and diatomaceous earth powder and knead to form a plastic ceramic material. S2: The ceramic filter tube is made by extrusion process, which makes the ceramic material form a corrugated tube after being extruded through a tubular die, and then the tube is processed by drying, sintering and cooling processes. Coating process steps C1: Diatomaceous earth is mixed with a dispersant, and after being ultrasonically treated to achieve uniform dispersion, nano-silica and water glass are added and stirred to form a coating. C2: The coating is applied to the surface of the ceramic filter tube, baked to form a film layer, and then calcined to improve the density and thermal shock resistance of the film coating. Ceramic filter plate preparation steps After bonding the tail end cap to the end of the ceramic filter tube, insert the ceramic filter tube into the positioning hole of the head cover for bonding. After curing, install a seal in the head cover.

2. The ceramic filter plate preparation process according to claim 1, characterized in that, In the preparation steps of the ceramic filter tube, the mass ratios of cellulose powder, glycerol liquid, silicon nitride powder, and diatomaceous earth powder are 7%, 5%, 80%, and 8%, respectively, and the mass of water added is 15% of the total mass ratio of the four materials. The mixing temperature is 65℃; The stirring paddle rotates at 60 r / min, and the stirring time is 240 min.

3. The ceramic filter plate preparation process according to claim 1, characterized in that, The drying process involves gradual, staged heating and drying in a drying oven equipped with an infrared radiation source, divided into the following stages: First stage: Using mid-wave infrared with a wavelength of 2-5μm, a heating temperature of 80-100℃, and a heating time of 1 hour; The second stage: long-wave infrared radiation with a wavelength of 5-15μm is used, the heating temperature is 100-150℃, and the heating time is 2h. The third stage: long-wave infrared radiation with a wavelength of 5-15μm is used, the heating temperature is 150-180℃, and the heating time is 2h.

4. The ceramic filter plate preparation process according to claim 1, characterized in that, In the sintering process, the tube is placed in a nitrogen atmosphere to generate silicon nitride compounds. The sintering time and temperature are divided into the following stages: Low-temperature section of sintering process: The temperature is raised from room temperature to 600℃ at a rate of 50-100℃ / h; In the intermediate temperature section of the sintering process, the temperature is increased from 600℃ to 1200℃ at a rate of 100-200℃ / h. High-temperature section of sintering process: The temperature is increased from 1200℃ to 1450℃ at a rate of 50-100℃ / h.

5. The ceramic filter plate preparation process according to claim 1, characterized in that, In the cooling process, the cooling time and temperature are divided into the following stages: Cooling process heat preservation section: The temperature is maintained at 1450℃ for 1-4 hours; Cooling process: The temperature is reduced from 1450℃ to 1200℃ at a rate of 50-100℃ / h. In the cooling process, the temperature range is from 1200℃ to room temperature, with a cooling rate of 100-200℃ / h.

6. The ceramic filter plate preparation process according to claim 1, characterized in that, Before the coating process, nano-silica and diatomaceous earth are pretreated respectively. The pretreatment of nano-silica includes: surface modification of nano-silica using a silane coupling agent, followed by ultrasonic dispersion with an ultrasonic power of 200W and a dispersion time of 20min. The pretreatment of diatomaceous earth includes: acid treatment with 5%-10% hydrochloric acid, followed by high-temperature calcination at 600-800℃ for 1-2 hours.

7. The ceramic filter plate preparation process according to claim 1, characterized in that, In the coating process, the mass ratio of nano-silica, diatomaceous earth, water glass, and dispersant is 25%:35%:25%:15%.

8. The ceramic filter plate preparation process according to claim 1, characterized in that, In the high-temperature calcination process of the film layer, the calcination temperature is divided into two stages; First stage of calcination: The temperature is raised from room temperature to 600℃ at a rate of 50-100℃ / h; Second stage of calcination: The temperature is increased from 600℃ to 1000℃ at a rate of 100-200℃ / h; after holding at this temperature for 1 hour, the temperature is decreased from 1000℃ to 600℃ at a rate of 50-100℃ / h; and then decreased from 600℃ to room temperature at a rate of 100-200℃ / h.

9. Application of ceramic filter plates, wherein the ceramic filter plates are manufactured using the ceramic filter plate preparation process described in any one of claims 1-8, characterized in that, The ceramic filter plate is used in a high-temperature dust collector.

10. The application of the ceramic filter plate according to claim 9, characterized in that, The head sheath of the ceramic filter plate is connected to the cleanroom tube sheet via a three-dimensional flexible sealing strip. Above the double exhaust holes at the head sheath of the ceramic filter plate, there is a compressed air delivery nozzle connected to a pulse solenoid valve.

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