A foam ceramic filter plate and its preparation method

Abstract

The application discloses a kind of foam ceramic filter plate and its preparation method, comprising the following steps: preparation first ceramic modified slurry;By first ceramic modified slurry to foam ceramic precursor is handled once, and preliminary modified foam ceramic precursor is obtained;Preparation second ceramic modified slurry;By second ceramic modified slurry to preliminary modified foam ceramic precursor is handled twice, and after modification ceramic matrix is obtained;The modified ceramic body is dried, sintered, and the foam ceramic filter plate is obtained;Realize the pore ridge of the internal pore of the prepared foam ceramic material and the pore ridge of surface, and the degree of high ceramic of surface, the internal and surface strength of material is high simultaneously, the porosity of internal pore does not reduce, and the opening rate of pore does not reduce.

Description

Technical Field

[0001] This invention relates to the field of foam ceramics technology, specifically to a foam ceramic filter plate and its preparation method. Background Technology

[0002] Foam ceramics are porous materials with high-temperature resistance. Their pore sizes range from nanometers to micrometers, with porosity between 20% and 95%, and an operating temperature range from room temperature to 1600℃. Foam ceramics are generally divided into two categories: open-cell (mesh) ceramic materials and closed-cell ceramic materials. In closed-cell ceramic materials, the internal pores are separated by a continuous ceramic matrix, and the pore surfaces are solid walls. In open-cell (mesh) ceramic materials, the pores are bonded to ceramic solids, and the internal pores are interconnected. Open-cell (mesh) ceramics are mainly used in filtration applications.

[0003] Traditional methods for preparing open-cell ceramic foam materials primarily involve ceramicizing the internal pore edges of the sponge to achieve high porosity through-holes and increase the material's strength. However, traditional open-cell ceramic materials suffer from the following problems: while the ceramicization strength of the internal pore edges is high, the surface pore edges cannot be effectively ceramicized. If the surface pore edges are highly ceramicized and their strength is increased, the porosity of the internal through-holes will significantly decrease.

[0004] Therefore, how to achieve a high degree of ceramicization of the internal pores and surface pores of open-cell ceramic foam materials, as well as high internal and surface strength, while ensuring that the internal porosity does not decrease has become a technical challenge in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a foam ceramic filter plate and its preparation method, which achieves high ceramicization degree of the internal pore edges and surface pore edges of the prepared foam ceramic material, high internal and surface strength of the material, while maintaining the porosity of the internal pores and the open porosity of the pores.

[0006] According to one aspect of the present invention, a method for preparing a foam ceramic filter plate is provided, comprising the following steps:

[0007] Preparation of the first ceramic-modified slurry;

[0008] The foam ceramic precursor is processed by a first ceramic modification slurry to obtain a primary modified foam ceramic precursor.

[0009] Preparation of a second ceramic-modified slurry;

[0010] The primary modified foam ceramic precursor is subjected to secondary treatment using a second ceramic modification slurry to obtain a modified ceramic matrix.

[0011] The modified ceramic blank is dried and sintered to obtain the foam ceramic filter plate;

[0012] The bulk density of the foam ceramic filter plate is ≤0.42 g / cm³. 3 The compressive strength is ≥3MPa, and the porosity is ≥86%; preferably, the bulk density of the foam ceramic filter plate is ≤0.38g / cm³. 3 Compressive strength ≥ 3.5 MPa, porosity ≥ 90%.

[0013] The advantages of this invention over the prior art lie in the fact that it prepares a first ceramic modification slurry and a second ceramic modification slurry, and performs two treatments on the foam ceramic precursor. The first treatment of the foam ceramic precursor allows the ceramic substrate to adhere to the internal pores and edges, thus achieving ceramicization of the internal pores and edges of the foam ceramic and making the internal pores through-holes. The second treatment of the foam ceramic precursor allows the ceramic substrate to adhere to the pores and edges on the surface of the foam ceramic precursor, thus achieving ceramicization of the surface pores and edges while maintaining the internal pores as through-holes, and keeping the porosity unchanged. Ultimately, this results in a foam ceramic filter plate with low bulk density, high compressive strength, and high porosity.

[0014] Furthermore, the specific process of the first ceramic modification slurry treating the foam ceramic precursor is as follows:

[0015] The foamed ceramic precursor is immersed in the first ceramic modification slurry;

[0016] After soaking, the foam ceramic precursor is filtered to remove the first ceramic modification slurry from the pores of the foam ceramic precursor.

[0017] The beneficial effect of adopting the above technical solution is that by immersing the foam ceramic precursor in the first ceramic modification slurry, the first ceramic modification slurry is fully attached to the internal pores and edges of the ceramic precursor.

[0018] By filtering the soaked ceramic foam precursor to remove excess first ceramic modification slurry, the first ceramic modification slurry is uniformly attached to the pores of the foam ceramic precursor, while avoiding clogging of the pores by the first ceramic modification slurry. This results in uniform ceramicization of the internal pores of the final foam ceramic, with the pores being through-holes and open pores. However, the drawback is that the first ceramic modification slurry attached to the pores of the foam ceramic precursor is removed during the filtration process, resulting in the first ceramic modification slurry not being attached to the pores of the foam ceramic precursor after the first treatment.

[0019] Furthermore, the first ceramic modification slurry includes α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, and solvent.

[0020] The mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, and solvent is (85-95):(5-10):(1.6-2.0):(19-24):(1.5-2.5):(20-30); the solvent is water.

[0021] The beneficial effect of adopting the above technical solution is that the first ceramic modified slurry, which includes silica sol, enables ceramic powder to adhere to the pore edges. The above mass ratio enables the first ceramic modified slurry to have a high solid content, which is beneficial for the ceramic powder to adhere to the pore edges.

[0022] Furthermore, the first ceramic-modified slurry also includes acrylate monomers and initiators;

[0023] The mass ratio of silica sol, acrylate monomer, and initiator is (1.5-2.5):(1.0-2.0):(0.006-0.01); wherein the soaking temperature is controlled at 20-40℃; and the pressure filtration temperature is controlled at 65-85℃.

[0024] The beneficial effect of adopting the above technical solution is that, since the first ceramic modified slurry also includes acrylate monomers and initiators, the first ceramic modified slurry has good fluidity when soaking the ceramic precursor and increases viscosity during pressure filtration. This is conducive to the uniform adhesion of the first ceramic modified slurry to the pores and edges inside the ceramic precursor without clogging the through holes. At the same time, the acrylate adhering to the surface of the pores and edges volatilizes away during the subsequent sintering process, without affecting the porosity of the foam ceramic and achieving through holes and open pores inside.

[0025] Furthermore, the specific process of the first ceramic modification slurry treating the foam ceramic precursor is as follows:

[0026] The foamed ceramic precursor is immersed in the first ceramic modification slurry;

[0027] After soaking, the foam ceramic precursor is filtered to remove the first ceramic modification slurry from the pores of the foam ceramic precursor.

[0028] The soaking temperature is controlled at 20-40℃; the pressure filtration temperature is controlled at 65-85℃.

[0029] The beneficial effect of adopting the above technical solution is that by immersing the foam ceramic precursor in the first ceramic modification slurry, the first ceramic modification slurry is fully attached to the internal pores and edges of the ceramic precursor.

[0030] By filtering the soaked ceramic foam precursor to remove excess first ceramic modification slurry, the first ceramic modification slurry is uniformly attached to the pores of the foam ceramic precursor, while avoiding clogging of the pores by the first ceramic modification slurry. This results in uniform ceramicization of the internal pores of the final foam ceramic, with the pores being through-holes and open-pores. However, the drawback is that the first ceramic modification slurry attached to the pores of the foam ceramic precursor is removed during the filtration process, resulting in no first ceramic modification slurry attached to the pores of the foam ceramic precursor after the first treatment.

[0031] By immersing the foamed ceramic precursor in a first ceramic modification slurry at 20-40℃, the viscosity of the first ceramic modification slurry does not increase during the immersion process.

[0032] Furthermore, the second ceramic modification slurry includes α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, dispersant, and solvent;

[0033] The mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, dispersant, and solvent is (85-95):(5-10):(1.6-2.0):(19-24):

[0034] (0.5-1):(1-1.5):(35-45).

[0035] The dispersant includes one or more of water glass, sodium tripolyphosphate, and xanthodextrin.

[0036] The beneficial effect of adopting the above technical solution is that, by using the second ceramic modification slurry, which includes silica sol, dispersant, and one or more of water glass, sodium tripolyphosphate, and dextrin, the second ceramic modification slurry has good fluidity and the ceramic powder is uniformly attached to the internal pores of the foam ceramic.

[0037] By adjusting the proportions of each material in the second ceramic-modified slurry, a relatively low solid content is achieved. Therefore, even if a small amount of the second ceramic-modified slurry enters the interior of the primary modified foam ceramic precursor, it is beneficial to ensure that the second ceramic-modified slurry does not remain inside the primary modified foam ceramic precursor.

[0038] Furthermore, the specific process for secondary treatment of the primary modified foam ceramic precursor is as follows:

[0039] A second ceramic modification slurry is sprayed onto one surface of the primary modified foam ceramic precursor;

[0040] Then, the primary modified foam ceramic precursor is flipped over, and a second ceramic modification slurry is sprayed onto the other side of the primary modified foam ceramic precursor to obtain the modified ceramic matrix.

[0041] Both the spraying and flipping are performed while the primary modified foam ceramic precursor is in motion.

[0042] The beneficial effect of adopting the previous technical solution is that the second ceramic modification slurry is attached to the pores and edges of both surfaces of the primary modified foam ceramic precursor.

[0043] Furthermore, during the movement of the primary modified foam ceramic precursor, a second ceramic modification slurry is sprayed onto one surface of the primary modified foam ceramic precursor.

[0044] Then the primary modified foam ceramic precursor is flipped during the movement;

[0045] After flipping, a second ceramic modification slurry is sprayed onto one surface of the primary modified foam ceramic precursor during the movement process.

[0046] The beneficial effect of adopting the above technical solution is that by spraying the second ceramic modified slurry on the primary modified foam ceramic precursor while it is in motion, it is beneficial to avoid the phenomenon of splashing when the second ceramic modified slurry is dispersed on the surface of the primary modified foam ceramic precursor. This helps to avoid the problem that the liquid material of the second ceramic modified slurry, due to its low solid content and good fluidity, does not easily adhere to the surface of the primary modified foam ceramic precursor when it falls on it. At the same time, it is beneficial to improve production efficiency by conveying the material during the spraying process.

[0047] Furthermore, the spraying of each surface includes at least two sprayings. During each spraying process, the outlet pressure of the second ceramic modified slurry is Q, the outlet flow rate of the second ceramic modified slurry is W, the distance from the outlet of the second ceramic modified slurry to the surface to be sprayed of the primary modified foam ceramic precursor is X, the angle between the outlet direction of the second ceramic modified slurry and the movement direction of the primary modified foam ceramic precursor is θ, and the horizontal movement speed of the primary modified foam ceramic precursor is V.

[0048] X = δv·sin|α|+Q, where δ is the flow velocity control coefficient;

[0049] W = πr 2 (2Q / ρ) 1 / 2 ;

[0050] r is the inner radius of the outlet pipe of the second ceramic modified slurry;

[0051] ρ is the density of the second ceramic-modified slurry;

[0052] 0.5MPa≤Q≤2.5MPa, 1m / min≤V≤5m / min or 1MPa≤Q≤2.5MPa, 3m / min≤V≤5m / min;

[0053] Preferably, the two sprayings are intermittent sprayings; that is, the primary modified foam ceramic precursor is sprayed with the second ceramic modification slurry on one surface of the primary modified foam ceramic precursor in an intermittent manner during the movement process; and the primary modified foam ceramic precursor is sprayed at least twice on one surface.

[0054] Preferably, the second ceramic modified slurry enters the outlet pipe by gravity and is dispersed in the outlet pipe under the action of pressure Q onto the surface of the primary modified foam ceramic precursor to be sprayed.

[0055] The beneficial effect of adopting the above technical solution is that by adjusting the included angle α of the movement direction of the primary modified foam ceramic precursor, it can be effectively achieved that the second ceramic modified slurry will not splash or penetrate into the foam ceramic when it is dispersed onto the surface to be sprayed of the primary modified foam ceramic precursor.

[0056] By controlling the outlet flow rate W of the second ceramic modified slurry, the outlet pressure Q of the second ceramic modified slurry, and the horizontal movement speed v of the primary modified foam ceramic precursor, and by adjusting the distance X between the outlet of the second ceramic modified slurry and the surface to be sprayed of the primary modified foam ceramic precursor, the second ceramic modified slurry will not enter the interior of the foam ceramic.

[0057] Adjusting the relationship between W and ρ further helps to avoid the problem of uneven spraying;

[0058] By using 0.5MPa≤Q≤2.5MPa; 1m / min≤V≤5m / min, it is beneficial to achieve production capacity, while ensuring uniform spraying and preventing the slurry from entering the interior of the foam ceramic.

[0059] The second ceramic-modified slurry enters the outlet pipe by gravity and is dispersed onto the surface of the primary modified foam ceramic precursor to be sprayed under the action of pressure Q. This avoids the problem of excessive and uncontrollable longitudinal force caused by the material being directly pumped out under pressure. It achieves that after being sprayed out under pressure Q, the slurry is output laterally and the longitudinal output force is small, and the disadvantages caused by this can be buffered by the distance X. At the same time, the material can be dispersed and atomized at the outlet due to the large lateral pressure.

[0060] Furthermore, the primary modified foam ceramic precursor is heat-treated, and then the primary modified foam ceramic precursor is subjected to secondary treatment to obtain the modified ceramic matrix.

[0061] The heat treatment process is as follows: sequentially undergoing a first-stage heating, a second-stage heating, and a third-stage heating; the first-stage heating temperature is 65-85℃, and the heating time is 0.5-1h; the second-stage heating temperature is 85-95℃, and the heating time is 1.5-2.5h; the third-stage heating temperature is 135-145℃, and the heating time is 1.5-2.5h; preferably, 1MPa≤Q≤2.5MPa; 3m / min≤V≤5m / min.

[0062] The beneficial effect of adopting the above technical solution is that by heat-treating the primary modified foam ceramic precursor and then performing a secondary treatment, the strength of the primary modified foam ceramic precursor is increased, the viscosity of its internal pores is reduced, and it has hydrophobic properties. This allows the primary modified foam ceramic precursor to withstand higher pressure during the secondary treatment and prevents the second ceramic modification slurry that occasionally enters the foam ceramic from remaining inside the foam ceramic. Ultimately, this improves the spraying efficiency while preventing the second ceramic modification slurry from remaining inside the foam ceramic.

[0063] Furthermore, the specific process for drying the modified ceramic green body is as follows: the temperature is raised from room temperature to 100°C within 200 minutes, then raised from 100°C to 140°C within 50 minutes, and held at 140°C for 4 hours.

[0064] The sintering process after drying is as follows: the temperature is raised from room temperature to 400℃ within 400 minutes, held at 400℃ for 60 minutes, raised from 400℃ to 600℃ within 150 minutes, held at 600℃ for 120 minutes, raised from 600℃ to 1250℃ within 200 minutes, and held at 1250℃ for 4 hours.

[0065] The beneficial effect of adopting the above technical solution is that the segmented sintering facilitates ceramization and avoids the rapid concentrated volatilization of volatiles with different molecular weights, which could lead to deformation or damage of the finished product.

[0066] According to another aspect of the present invention, a foam ceramic filter plate is provided, prepared according to the method for preparing the foam ceramic filter plate; the bulk density of the foam ceramic filter plate is ≤0.42 g / cm³. 3 The compressive strength is ≥3MPa, and the porosity is ≥86%; preferably, the bulk density of the foam ceramic filter plate is ≤0.38g / cm³. 3 Compressive strength ≥ 3.5 MPa, porosity ≥ 90%.

[0067] The advantages of this invention over the prior art lie in the fact that it treats the foam ceramic precursor twice by preparing a first ceramic modification slurry and a second ceramic modification slurry. The first treatment of the foam ceramic precursor allows for the attachment of a ceramic substrate to the internal pores and edges, thus achieving ceramicization of the internal pores and edges and ensuring that the internal pores are through-holes. The second treatment of the foam ceramic precursor allows for the attachment of a ceramic substrate to the surface pores and edges, achieving ceramicization of the surface pores and edges while maintaining the internal pores as through-holes, and keeping the porosity unchanged. Ultimately, this results in a foam ceramic filter plate with low bulk density, high compressive strength, and high porosity.

[0068] A foam ceramic filter board preparation device adapted to the foam filter board preparation method includes: an soaking device, a filter press device, and a spraying device; the soaking device includes a first container; the soaking device is located upstream of the filter press device, and the spraying device is located downstream of the filter press device; the spraying device includes a first conveying mechanism, a second conveying mechanism, a tilting mechanism, and a plurality of spraying mechanisms; the first conveying mechanism is connected to the second conveying mechanism through the tilting mechanism; a portion of the plurality of spraying mechanisms is located above the first conveying mechanism, and the remaining spraying mechanisms are located above the second conveying mechanism;

[0069] The injection mechanism is connected to the storage tank of the second ceramic modified slurry; the injection mechanism is connected to the gas source through a gas pipeline.

[0070] The first ceramic-modified slurry is used to soak the foam ceramic precursor through an immersion device. The foam ceramic precursor is the raw material for preparing the foam ceramic filter plate.

[0071] The soaked foam ceramic precursor is conveyed to the filter press mechanism through the first conveying mechanism; the soaked foam ceramic precursor passes through the filter press mechanism to filter out the excess first ceramic modification slurry in the soaked foam ceramic precursor.

[0072] Then, the filtered foam ceramic precursor enters the first conveying mechanism. During transportation in the first conveying mechanism, a second ceramic modification slurry is sprayed onto one surface of the filtered foam ceramic precursor. Then, it enters the turning mechanism to turn the foam ceramic precursor 180 degrees and then enters the second conveying mechanism. During transportation in the second conveying mechanism, the second ceramic modification slurry is sprayed onto the other surface of the filtered foam ceramic precursor. This achieves the spraying of the second ceramic modification slurry onto both surfaces of the foam ceramic precursor.

[0073] The injection mechanism is connected to the storage tank of the second ceramic modified slurry to provide slurry to the injection mechanism. The injection mechanism is connected to the air source and the air supply pipeline to provide power for the movement of the slurry after it leaves the injection mechanism.

[0074] The soaking device includes a material storage mechanism, and the filter press includes a third conveying mechanism and a filter press mechanism that cooperates with the third conveying mechanism; the third conveying mechanism includes a third conveying mesh belt; the filter press mechanism includes a plurality of first conveying rollers and a plurality of second conveying rollers arranged opposite to the first conveying rollers;

[0075] The first conveying roller is rotatably connected to the first support frame at both ends, and the second conveying roller is rotatably connected to the second support frame at both ends;

[0076] The first support frame and the second support frame are connected by a telescopic device; the second conveying roller is connected to the power unit.

[0077] The soaked foam ceramic precursor is transported between the first conveyor roller and the second conveyor roller via the third conveyor mechanism, which includes a third conveyor mesh belt, and then conveyed to the first conveyor mechanism.

[0078] The filter press mechanism includes several first conveying rollers and several second conveying rollers arranged opposite to the first conveying rollers. At the same time, the foam ceramic precursor is conveyed on the second conveying rollers, and the first conveying rollers filter the foam ceramic precursor. The pressed slurry flows into the container below through the gap between the second conveying rollers.

[0079] The first support frame and the second support frame are connected by a telescopic device to raise or lower the first conveying roller for filtration.

[0080] The spraying mechanism is connected to the storage tank and is also connected to the air source through an air supply pipeline; the spraying mechanism includes a feed pipe, an air inlet pipe, and a discharge pipe; the axis of the air inlet pipe and the axis of the discharge pipe are on a straight line; the angle between the axis of the feed pipe and the axis of the feed pipe is greater than 40-60°.

[0081] The slurry changes its discharge direction after turning at the bend in the feed pipe, avoiding the phenomenon of the slurry entering the foam ceramic precursor in a straight line or splashing due to gravity. By controlling the angle between the axis of the feed pipe and the axis of the discharge pipe to be greater than 40-60°, the slurry is atomized at the discharge port, and the horizontal speed is controllable. At the same time, it avoids the problem of eddy currents or retention of slurry in the pipeline, thereby avoiding problems such as increased slurry viscosity and pipeline blockage during long-term use.

[0082] The first conveying mechanism includes a first conveying support and a first conveyor belt.

[0083] The first conveyor belt is connected to the first conveyor support via a first rotating shaft; the second conveying mechanism includes a second conveyor support and a second conveyor belt, the second conveyor belt being connected to the second conveyor support via a second rotating shaft.

[0084] Two sets of spraying mechanisms are provided above the first conveyor belt; two sets of spraying mechanisms are provided above the second conveyor belt;

[0085] The vertical distance X between the discharge port of the spraying mechanism above the first conveyor belt and the first conveyor belt is;

[0086] The outlet pressure of the spraying mechanism is Q, and the material flow rate of the outlet of the spraying mechanism of the storage tank is W; the angle between the liquid discharge direction of the outlet of the spraying mechanism and the movement direction of the second conveyor belt is α; the horizontal movement speed of the first conveyor belt is V.

[0087] X = δV·sin|α|+Q, where δ is the flow rate control coefficient;

[0088] W = πr 2 (2Q / ρ) 1 / 2 ;

[0089] r is the inner radius of the outlet of the injection mechanism;

[0090] ρ is the density of the material stored in the storage tank; that is, the density of the second ceramic-modified slurry.

[0091] 0.5MPa≤Q≤2.5MPa; 1m / min≤V≤5m / min; the two sets of injection mechanisms are the first set of injection mechanisms and the second set of injection mechanisms;

[0092] The first group of injection mechanisms is closer to the filter press mechanism, and the second group of injection mechanisms is farther away from the filter press mechanism;

[0093] The angle α between the liquid discharge direction of the first group of spraying mechanisms and the movement direction of the second conveyor belt is greater than or equal to 90°; the angle α between the liquid discharge direction of the second group of spraying mechanisms and the movement direction of the second conveyor belt is less than or equal to 90°.

[0094] The liquid outlet direction of the first group of spraying mechanisms forms an angle α greater than or equal to 90° with the movement direction of the second conveyor belt; the liquid outlet direction of the second group of spraying mechanisms forms an angle α less than or equal to 90° with the movement direction of the second conveyor belt. This achieves that the horizontal direction of the liquid outlet direction of the first group of spraying mechanisms is opposite to the movement direction of the second conveyor belt, and the horizontal direction of the liquid outlet direction of the second group of spraying mechanisms is the same as the movement direction of the second conveyor belt. Thus, the horizontal directions of the liquid outlets of the first group of spraying mechanisms and the second group of spraying mechanisms that the foam ceramic precursor passes through are opposite, ultimately achieving uniform slurry adhering to the surface of the foam ceramic precursor.

[0095] The surface temperature of the first conveyor belt is 20-40℃; the first conveyor roller and / or the second conveyor roller are equipped with a heating device, which achieves a surface temperature of 65-85℃ for the first conveyor roller and / or the second conveyor roller.

[0096] The above-mentioned process enables the first and second conveying rollers to extrude excess slurry from the soaked foam ceramic precursor while simultaneously heating the foam ceramic precursor. This increases the viscosity of the slurry remaining on the pores inside the foam ceramic precursor, thereby enhancing its adhesion properties.

[0097] The air inlet pipe is connected to the air source through the air delivery pipeline, and the feed pipe is connected directly or through the liquid delivery pipeline to the liquid outlet of the storage tank. The material in the storage tank enters the liquid inlet pipe by gravity.

[0098] The second ceramic-modified slurry enters the outlet pipe by gravity and is dispersed onto the surface of the primary modified foam ceramic precursor to be sprayed under the action of pressure Q. This avoids the problem of excessive and uncontrollable longitudinal force caused by the material being directly pumped out under pressure. It achieves that after being sprayed out under pressure Q, the slurry is output laterally and the longitudinal output force is small, and the disadvantages caused by this can be buffered by the distance X. At the same time, the material can be dispersed and atomized at the outlet due to the large lateral pressure.

[0099] The flipping mechanism includes a first turntable, a second turntable, and a fourth conveying mechanism; the fourth conveying mechanism includes a fourth conveying bracket and a fourth conveying mesh belt, and the fourth conveying mesh belt is connected to the fourth conveying bracket via a third rotating shaft.

[0100] The first turntable and the second turntable are located on both sides of the fourth conveyor belt, and the first turntable and the second turntable are arranged opposite to each other. The first turntable and the second turntable are rotatably connected to the fourth conveyor support through the fourth rotating shaft.

[0101] The first turntable is provided with a plurality of first grooves, and the second turntable is provided with a plurality of second grooves corresponding to the positions of the first grooves; that is, the oppositely arranged first grooves and second grooves are arranged parallel to each other.

[0102] The system includes a conveyor support and a third conveyor belt, which is connected to the third conveyor support via a second rotating shaft; the first turntable and the second turntable rotate synchronously.

[0103] The above scheme achieves a receiving space formed by a first groove on the first turntable and a second groove on the second turntable. The receiving space can overlap with the fourth conveyor belt, so that the foam ceramic precursor conveyed on the fourth conveyor belt enters the receiving space. At the same time, the foam ceramic precursor rotates in the receiving space with the rotation of the first and second turntables. After being rotated, the foam ceramic precursor falls onto the fourth conveyor belt and is then conveyed by the fourth conveyor belt to the third conveying mechanism.

[0104] The liquid storage tank includes a first liquid storage tank and a second liquid storage tank. The first liquid storage tank is fixed above the first conveyor belt by a first fixed bracket, and the second liquid storage tank is fixed above the second conveyor belt by a second fixed bracket.

[0105] The end of the feed pipe of the spraying mechanism away from the outlet pipe is connected to the bottom of the storage tank.

[0106] The first liquid storage tank and the second liquid storage tank are respectively equipped with a first stirring mechanism and a second stirring mechanism.

[0107] The storage of the second ceramic-modified slurry into the foam ceramic precursor is achieved by a short distance. Most importantly, the experimental second ceramic-modified slurry enters the spraying mechanism by gravity with stable power and flow rate. This avoids the problems of inconsistent slurry flow rate and longitudinal power caused by long delivery pipelines and inconsistent pipeline directions during continuous spraying. This avoids uneven adhesion of the slurry sprayed onto the foam ceramic precursor and problems of splashing or entering the interior of the foam precursor.

[0108] The fourth conveying bracket of the fourth conveying mechanism is equipped with a positioning sensor. The positioning sensor controls the rotation of the fourth rotating shaft through the positioning control system. When the positioning sensor detects that an object has passed through, it sends a signal to the positioning control system. The positioning control system then controls the rotation of the fourth rotating shaft to make the plane formed by a set of first and second grooves coincide with the plane of the fourth conveyor belt.

[0109] When the foam ceramic precursor, after being coated with a surface slurry, reaches the front of the first and second turntables via the fourth conveyor mechanism, a plane formed by a set of first and second grooves coincides with the plane of the fourth conveyor belt. This allows the foam ceramic precursor to enter the aforementioned plane and rotate with the first and second turntables to flip over. When the flipped foam ceramic precursor coincides with the plane of the fourth conveyor belt, it is conveyed to the third conveyor mechanism via the fourth conveyor belt for coating of the other side. Detailed Implementation

[0110] To better understand the technical solution of the present invention, the present invention will be further described below with reference to specific embodiments.

[0111] Example 1:

[0112] In one aspect of this embodiment, a method for preparing a foam ceramic filter plate is provided, comprising the following steps: preparing a first ceramic-modified slurry;

[0113] The first ceramic modification slurry includes α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, and solvent;

[0114] The mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, and solvent is 90:7.5:1.8:22:2:25; the solvent is water.

[0115] The foam ceramic precursor is processed by a first ceramic modification slurry to obtain a primary modified foam ceramic precursor.

[0116] The specific process of the first ceramic modification slurry for treating the foam ceramic precursor is as follows: the foam ceramic precursor is soaked in the first ceramic modification slurry; after soaking, the foam ceramic precursor is filtered to remove the first ceramic modification slurry from the pores of the foam ceramic precursor.

[0117] A second ceramic-modified slurry is prepared; the second ceramic-modified slurry comprises α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, dispersant, and solvent; the solvent is water;

[0118] The mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, dispersant, and solvent is 90:7.5:1.8:23:0.7:1.2:40; the dispersant includes water glass and sodium tripolyphosphate.

[0119] The primary modified foam ceramic precursor is subjected to secondary treatment by a second ceramic modification slurry to obtain a modified ceramic matrix; the specific process of secondary treatment of the primary modified foam ceramic precursor is as follows: the primary modified foam ceramic precursor is coated with a second ceramic modification slurry on one surface.

[0120] Then, the primary modified foam ceramic precursor is flipped over, and a second ceramic modification slurry is sprayed onto the other side of the primary modified foam ceramic precursor to obtain the modified ceramic matrix.

[0121] Both the spraying and flipping are performed while the primary modified foam ceramic precursor is in motion.

[0122] During the movement of the primary modified foam ceramic precursor, a second ceramic modification slurry is sprayed onto one surface of the primary modified foam ceramic precursor; then the primary modified foam ceramic precursor is flipped during the movement; after flipping, the second ceramic modification slurry is sprayed onto one surface of the primary modified foam ceramic precursor during the movement.

[0123] Each surface is coated twice. During each coating process, the outlet pressure of the second ceramic modified slurry is Q, the outlet flow rate of the second ceramic modified slurry is W, the distance from the outlet of the second ceramic modified slurry to the surface to be coated of the primary modified foam ceramic precursor is X, the angle between the outlet direction of the second ceramic modified slurry and the movement direction of the primary modified foam ceramic precursor is α, and the horizontal movement speed of the primary modified foam ceramic precursor is V.

[0124] X = δV·sin|α|+Q, where δ is the flow rate control coefficient;

[0125] W = πr 2 (2Q / ρ) 1 / 2 ;

[0126] r is the inner radius of the outlet pipe of the second ceramic modified slurry;

[0127] ρ is the density of the second ceramic-modified slurry;

[0128] Q = 0.9 MPa, V = 2 m / min;

[0129] The two spraying processes are intermittent; that is, during the movement of the primary modified foam ceramic precursor, the second ceramic modification slurry is sprayed intermittently onto one surface of the primary modified foam ceramic precursor; the primary modified foam ceramic precursor is sprayed twice on one surface; during the first spraying of each surface, the angle between the outlet direction of the second ceramic modification slurry and the movement direction of the primary modified foam ceramic precursor is greater than or equal to 90°; the angle between the outlet direction of the second ceramic modification slurry and the movement direction of the primary modified foam ceramic precursor is less than or equal to 90°.

[0130] The second ceramic modified slurry enters the outlet pipe by gravity and is dispersed in the outlet pipe under the action of pressure Q onto the surface of the primary modified foam ceramic precursor to be sprayed.

[0131] The modified ceramic blank is dried and sintered to obtain the foam ceramic filter plate;

[0132] The specific process for drying the modified ceramic green body is as follows: the temperature is raised from room temperature to 100°C within 200 minutes, then raised from 100°C to 140°C within 50 minutes, and held at 140°C for 4 hours.

[0133] The sintering process after drying is as follows: the temperature is raised from room temperature to 400℃ within 400 minutes, held at 400℃ for 60 minutes, raised from 400℃ to 600℃ within 150 minutes, held at 600℃ for 120 minutes, raised from 600℃ to 1250℃ within 200 minutes, and held at 1250℃ for 4 hours.

[0134] Another aspect of this embodiment provides a foam ceramic filter plate, prepared according to the method described above; the foam ceramic filter plate has a bulk density of 0.41 g / cm³. 3 It has a compressive strength of 3.5 MPa and a porosity of 89%.

[0135] A foam ceramic filter board preparation device adapted to the foam filter board preparation method includes: an soaking device, a filter press device, and a spraying device; the soaking device includes a first container; the soaking device is located upstream of the filter press device, and the spraying device is located downstream of the filter press device; the spraying device includes a first conveying mechanism, a second conveying mechanism, a tilting mechanism, and a plurality of spraying mechanisms; the first conveying mechanism is connected to the second conveying mechanism through the tilting mechanism; a portion of the plurality of spraying mechanisms is located above the first conveying mechanism, and the remaining spraying mechanisms are located above the second conveying mechanism;

[0136] The injection mechanism is connected to the storage tank of the second ceramic modified slurry; the injection mechanism is connected to the gas source through a gas pipeline.

[0137] The first ceramic-modified slurry is used to soak the foam ceramic precursor through an immersion device. The foam ceramic precursor is the raw material for preparing the foam ceramic filter plate.

[0138] The soaked foam ceramic precursor is conveyed to the filter press mechanism through the first conveying mechanism; the soaked foam ceramic precursor passes through the filter press mechanism to filter out the excess first ceramic modification slurry in the soaked foam ceramic precursor.

[0139] Then, the filtered foam ceramic precursor enters the first conveying mechanism. During transportation in the first conveying mechanism, a second ceramic modification slurry is sprayed onto one surface of the filtered foam ceramic precursor. Then, it enters the turning mechanism to turn the foam ceramic precursor 180 degrees and then enters the second conveying mechanism. During transportation in the second conveying mechanism, the second ceramic modification slurry is sprayed onto the other surface of the filtered foam ceramic precursor. This achieves the spraying of the second ceramic modification slurry onto both surfaces of the foam ceramic precursor.

[0140] The injection mechanism is connected to the storage tank of the second ceramic modified slurry to provide slurry to the injection mechanism. The injection mechanism is connected to the air source and the air supply pipeline to provide power for the movement of the slurry after it leaves the injection mechanism.

[0141] The soaking device includes a material storage mechanism, and the filter press includes a third conveying mechanism and a filter press mechanism that cooperates with the third conveying mechanism; the third conveying mechanism includes a third conveying mesh belt; the filter press mechanism includes a plurality of first conveying rollers and a plurality of second conveying rollers arranged opposite to the first conveying rollers;

[0142] The first conveying roller is rotatably connected to the first support frame at both ends, and the second conveying roller is rotatably connected to the second support frame at both ends;

[0143] The first support frame and the second support frame are connected by a telescopic device; the second conveying roller is connected to the power unit.

[0144] The soaked foam ceramic precursor is transported between the first conveyor roller and the second conveyor roller via the third conveyor mechanism, which includes a third conveyor mesh belt, and then conveyed to the first conveyor mechanism.

[0145] The filter press mechanism includes several first conveying rollers and several second conveying rollers arranged opposite to the first conveying rollers. At the same time, the foam ceramic precursor is conveyed on the second conveying rollers, and the first conveying rollers filter the foam ceramic precursor. The pressed slurry flows into the container below through the gap between the second conveying rollers.

[0146] The first support frame and the second support frame are connected by a telescopic device to raise or lower the first conveying roller for filtration.

[0147] The spraying mechanism is connected to the storage tank and is also connected to the air source through an air supply pipeline; the spraying mechanism includes a feed pipe, an air inlet pipe, and a discharge pipe; the axis of the air inlet pipe and the axis of the discharge pipe are on a straight line; the angle between the axis of the feed pipe and the axis of the feed pipe is greater than 40-60°.

[0148] The first conveying mechanism includes a first conveying support and a first conveyor belt.

[0149] The first conveyor belt is connected to the first conveyor support via a first rotating shaft; the second conveying mechanism includes a second conveyor support and a second conveyor belt, the second conveyor belt being connected to the second conveyor support via a second rotating shaft.

[0150] Two sets of spraying mechanisms are provided above the first conveyor belt; two sets of spraying mechanisms are provided above the second conveyor belt;

[0151] The two sets of spraying mechanisms are a first set of spraying mechanisms and a second set of spraying mechanisms; the vertical distance between the discharge port of the spraying mechanism above the first conveyor belt and the first conveyor belt is X;

[0152] The outlet pressure of the spraying mechanism is Q, and the material flow rate of the outlet of the spraying mechanism of the storage tank is W; the angle between the liquid discharge direction of the outlet of the spraying mechanism and the movement direction of the second conveyor belt is α; the horizontal movement speed of the first conveyor belt is V.

[0153] X = δV·sin|α|+Q, where δ is the flow rate control coefficient;

[0154] W = πr 2 (2Q / ρ) 1 / 2 ;

[0155] r is the inner radius of the outlet of the injection mechanism;

[0156] ρ is the density of the material stored in the storage tank; that is, the density of the second ceramic-modified slurry.

[0157] The first group of injection mechanisms is closer to the filter press mechanism, and the second group of injection mechanisms is farther away from the filter press mechanism;

[0158] The angle α between the liquid discharge direction of the first group of spraying mechanisms and the movement direction of the second conveyor belt is greater than or equal to 90°; the angle α between the liquid discharge direction of the second group of spraying mechanisms and the movement direction of the second conveyor belt is less than or equal to 90°.

[0159] The flipping mechanism includes a first turntable, a second turntable, and a fourth conveying mechanism; the fourth conveying mechanism includes a fourth conveying bracket and a fourth conveying mesh belt, and the fourth conveying mesh belt is connected to the fourth conveying bracket via a third rotating shaft.

[0160] The first turntable and the second turntable are located on both sides of the fourth conveyor belt, and the first turntable and the second turntable are arranged opposite to each other. The first turntable and the second turntable are rotatably connected to the fourth conveyor support through the fourth rotating shaft.

[0161] The first turntable is provided with a plurality of first grooves, and the second turntable is provided with a plurality of second grooves corresponding to the positions of the first grooves; that is, the oppositely arranged first grooves and second grooves are arranged parallel to each other.

[0162] The third conveyor belt is connected to the third conveyor support via the second rotating shaft; the first turntable and the second turntable rotate synchronously.

[0163] The above scheme achieves a receiving space formed by a first groove on the first turntable and a second groove on the second turntable. The receiving space can overlap with the fourth conveyor belt, so that the foam ceramic precursor conveyed on the fourth conveyor belt enters the receiving space. At the same time, the foam ceramic precursor rotates in the receiving space with the rotation of the first and second turntables. After being rotated, the foam ceramic precursor falls onto the fourth conveyor belt and is then conveyed by the fourth conveyor belt to the third conveying mechanism.

[0164] The liquid storage tank includes a first liquid storage tank and a second liquid storage tank. The first liquid storage tank is fixed above the first conveyor belt by a first fixed bracket, and the second liquid storage tank is fixed above the second conveyor belt by a second fixed bracket.

[0165] The end of the feed pipe of the spraying mechanism away from the outlet pipe is connected to the bottom of the storage tank.

[0166] The first liquid storage tank and the second liquid storage tank are respectively equipped with a first stirring mechanism and a second stirring mechanism.

[0167] The fourth conveying bracket of the fourth conveying mechanism is equipped with a positioning sensor. The positioning sensor controls the rotation of the fourth rotating shaft through the positioning control system. When the positioning sensor detects that an object has passed through, it sends a signal to the positioning control system. The positioning control system then controls the rotation of the fourth rotating shaft to make the plane formed by a set of first and second grooves coincide with the plane of the fourth conveyor belt.

[0168] When the foam ceramic precursor, after being coated with a surface slurry, reaches the front of the first and second turntables via the fourth conveyor mechanism, a plane formed by a set of first and second grooves coincides with the plane of the fourth conveyor belt. This allows the foam ceramic precursor to enter the aforementioned plane and rotate with the first and second turntables to flip over. When the flipped foam ceramic precursor coincides with the plane of the fourth conveyor belt, it is conveyed to the third conveyor mechanism via the fourth conveyor belt for coating of the other side.

[0169] Example 2:

[0170] The contents that are the same as in Example 1 will not be repeated here; the different aspects of this embodiment compared to Example 1 are as follows:

[0171] One aspect of this embodiment provides a method for preparing a foam ceramic filter plate, wherein the mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, and solvent is 92:8:1.8:22:2.3:28.

[0172] The first ceramic-modified slurry also includes acrylate monomers and initiators; the mass ratio of the silica sol, acrylate monomers, and initiators is 2:1.5:0.008.

[0173] The mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, dispersant, and solvent is 92:8:1.8:22:0.8:1.2:40; the dispersant includes water glass and dextrin.

[0174] Q = 1.8 MPa, v = 3.5 m / min;

[0175] The soaking temperature is controlled at 30℃; the pressure filtration temperature is controlled at 75℃.

[0176] The surface temperature of the first conveyor belt is 30°C; the first and second conveyor rollers are equipped with heating devices, which enable the surface temperature of the first and second conveyor rollers to be 75°C.

[0177] Another aspect of this embodiment provides a foam ceramic filter plate, which is prepared according to the method described above; the foam ceramic filter plate has a bulk density of 0.36, a compressive strength of 4.3 MPa, and a porosity of 91%.

[0178] Example 3:

[0179] The contents that are the same as in Example 2 will not be repeated here; the differences between this embodiment and Example 2 are as follows:

[0180] One aspect of this embodiment provides a method for preparing a foam ceramic filter plate, wherein the mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, and solvent is 88:6:1.7:20:1.7:22.

[0181] The mass ratio of the silica sol, acrylate monomer, and initiator is 1.7:1.2:0.007.

[0182] The mass ratio of α-alumina, feldspar powder, magnesium aluminum spinel powder, aluminum dihydrogen phosphate, silica sol, dispersant, and solvent is 88:6:1.7:20:0.7:1.1:38; the dispersant includes water glass, sodium tripolyphosphate, and xanthodextrin.

[0183] Q = 2.2 MPa, v = 4.5 m / min.

[0184] The soaking temperature is controlled at 32℃; the pressure filtration temperature is controlled at 80℃.

[0185] The surface temperature of the first conveyor belt is 32°C; the first and second conveyor rollers are equipped with heating devices, which enable the surface temperature of the first and second conveyor rollers to be 80°C.

[0186] Another aspect of this embodiment provides a foam ceramic filter plate, prepared according to the method described above; the foam ceramic filter plate has a bulk density of 0.33 g / cm³. 3 It has a compressive strength of 4.4 MPa and a porosity of 92%.

[0187] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, the above-described features have similar functions to (but are not limited to) those disclosed in this application.

Claims

1. A method of making a foamed ceramic filter plate, characterized by, The method comprises the following steps: preparing a first ceramic modification slurry; the first ceramic modification slurry comprises α-alumina, feldspar powder, magnesium aluminate spinel powder, aluminum dihydrogen phosphate, silica sol, and a solvent; the mass ratio of the α-alumina, feldspar powder, magnesium aluminate spinel powder, aluminum dihydrogen phosphate, silica sol, and the solvent is (85-95):(5-10):(1.6-2.0):(19-24):(1.5-2.5):(20-30); the solvent is water; performing one-time treatment on the foam ceramic precursor by using the first ceramic modification slurry to obtain a primary modified foam ceramic precursor; the specific treatment process of the one-time treatment of the first ceramic modification slurry on the foam ceramic precursor is as follows: immersing the foam ceramic precursor in the first ceramic modification slurry; after immersion, the foam ceramic precursor is subjected to pressure filtration to remove the first ceramic modification slurry in the pores of the foam ceramic precursor; preparing a second ceramic modification slurry; the second ceramic modification slurry comprises α-alumina, feldspar powder, magnesium aluminate spinel powder, aluminum dihydrogen phosphate, silica sol, a dispersant, and a solvent; the mass ratio of the α-alumina, feldspar powder, magnesium aluminate spinel powder, aluminum dihydrogen phosphate, silica sol, dispersant, and solvent is (85-95):(5-10):(1.6-2.0):(19-24):(0.5-1):(1-1.5):(35-45); the dispersant comprises one or more of water glass, sodium tripolyphosphate, and yellow dextrin; performing two-time treatment on the primary modified foam ceramic precursor by using the second ceramic modification slurry to obtain a modified ceramic matrix; the specific process of the two-time treatment of the primary modified foam ceramic precursor is as follows: spraying the second ceramic modification slurry on one surface of the primary modified foam ceramic precursor; then, the primary modified foam ceramic precursor is turned over, and the second ceramic modification slurry is sprayed on the other surface of the primary modified foam ceramic precursor to obtain the modified ceramic matrix; the spraying and turning over are both performed while the primary modified foam ceramic precursor is kept in a moving state; the spraying on each surface comprises at least two times of spraying; in each spraying process, the outlet pressure of the second ceramic modification slurry is Q, the outlet flow rate of the second ceramic modification slurry is W, the distance from the outlet of the second ceramic modification slurry to the surface to be sprayed of the primary modified foam ceramic precursor is X, the included angle between the outlet direction of the second ceramic modification slurry and the moving direction of the primary modified foam ceramic precursor is α, and the horizontal moving speed of the primary modified foam ceramic precursor is V; X = δV•sin|α|+Q, α≥90°, and δ is a flow rate control coefficient; W = πr 2 (2Q / ρ) 1 / 2 ; r is the inner radius of the outlet pipe of the second ceramic modification slurry; ρ is the density of the second ceramic modification slurry; 0.5MPa≤Q≤2.5Mpa, 1m / min≤V≤5m / min or 1MPa≤Q≤2.5Mpa, 3m / min≤V≤5m / min; drying and sintering the modified ceramic matrix to obtain the foam ceramic filter plate.

2. The method of claim 1, wherein the ceramic foam filter is prepared by the steps of: the first ceramic modification slurry further comprises an acrylate monomer and an initiator; The mass ratio of the silica sol, the acrylate monomer and the initiator is (1.5-2.5):(1.0-2.0):(0.006-0.01); The temperature is controlled at 20-40 DEG C during soaking and 65-85 DEG C during pressure filtration.

3. The method of claim 1, wherein the ceramic foam filter is prepared by the steps of: The primary modified foam ceramic precursor is heat treated and then subjected to secondary treatment to obtain a modified ceramic matrix. The heat treatment process comprises one-stage heating, two-stage heating and three-stage heating in sequence; the one-stage heating temperature is 65-85 DEG C and the heating time is 0.5-1 h; the two-stage heating temperature is 85-95 DEG C and the heating time is 1.5-2.5; and the three-stage heating temperature is 135-145 DEG C and the heating time is 1.5-2.

5.

4. The method of claim 1, wherein the ceramic foam filter is prepared by the steps of: The specific drying process of the modified ceramic matrix is as follows: the temperature is raised from room temperature to 100 DEG C in 200 min, then raised from 100 DEG C to 140 DEG C in 50 min, and kept at 140 DEG C for 4 h; The sintering process after drying is as follows: the temperature is raised from room temperature to 400 DEG C in 400 min, kept at 400 DEG C for 60 min, raised from 400 DEG C to 600 DEG C in 150 min, kept at 600 DEG C for 120 min, raised from 600 DEG C to 1250 DEG C in 200 min, and kept at 1250 DEG C for 4 h.

5. A foamed ceramic filter plate characterized in that, The foam ceramic filter plate is prepared according to the preparation method of any one of claims 1-4.