Pipe furnace heat-insulating material and its manufacturing method

Abstract

The application relates to a kind of pipe furnace heat-insulating materials and its manufacturing method, including heat-insulating material body, further including the silicon sol layer coated on the surface of the heat-insulating material body, the aluminum sol layer coated on the surface of the silicon sol layer.The silicon sol layer and the aluminum sol layer are attached to the surface of the heat-insulating material body after drying, which well solves the powder dropping of the original heat-insulating material, and has no adverse reaction to the heating wire in the pipe furnace, no volatilization in the sintering process, can be attached to the heat-insulating material body for a long time, and will not affect the sintered product.

Description

Technical Field

[0001] This invention relates to an insulation material for tubular furnaces and its manufacturing method. Background Technology

[0002] In existing technologies, tube furnaces are mainly used in industries such as metallurgy, glass, solar panels, and new energy, as well as for firing some high-precision products.

[0003] Many insulation materials currently used in tube furnaces are sintered by mixing active ingredients and binders. During use, the resulting plate materials are prone to breakage, scratches, and powdering, which affects the fired products. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a thermal insulation material for tubular furnaces.

[0005] To solve the aforementioned technical problems, the present invention adopts the following technical solution: a thermal insulation material for tube furnaces, comprising a thermal insulation material body, a silica sol layer coated on the surface of the thermal insulation material body, and an aluminum sol layer coated on the surface of the silica sol layer. After drying, the silica sol layer and the aluminum sol layer adhere to the surface of the thermal insulation material body, effectively solving the problem of powder shedding from the original thermal insulation material. Furthermore, they have no adverse reaction with the heating wires in the tube furnace, do not volatilize during sintering, and can adhere to the thermal insulation material body for a long time without affecting the fired products.

[0006] In some embodiments, the silica sol layer is formed by spraying a silica sol solution, wherein the silica sol content of the silica sol solution is 65-75%; the aluminum sol layer is formed by spraying an aluminum sol solution, wherein the aluminum sol content of the aluminum sol solution is 25-35%.

[0007] In some embodiments, the insulation material body is made into a single unit by sintering.

[0008] In some embodiments, the raw materials for making the thermal insulation material body are: 60-100 parts of aluminum silicate fiber, 10-50 parts of quartz fiber, 30-60 parts of high-purity alumina powder, 7-12 parts of boron trioxide fine powder, 5-20 parts of silica sol, and 1-5 parts of cationic starch.

[0009] In some embodiments, the density of the aluminosilicate fiber is 85~198 kg / m³, the total slag ball content is ≥0.212 mm and ≤55%, the permanent linear change upon heating is 1100℃*8hr and ≤3%, the density of the quartz fiber is 100~210 kg / m³, the long-term temperature resistance is above 1200℃, the silica content is ≥98%, the high-purity alumina powder has a mesh size of 500~1000 mesh, an Al₂O₃ content of ≥99.5%, a particle size of ≤20 μm, and a purity of ≥99%, and the silica sol has a Na₂O content of ≤0.5% and a pH value of 8~11.

[0010] The technical problem to be solved by the present invention is to provide a method for manufacturing insulation materials for tubular furnaces.

[0011] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: Step S1, placing the insulation material body on a workbench, and spraying a layer of silica sol solution onto the insulation material body using a spray gun, with a spray thickness of 30~70μm and a spraying speed of 5.4~6.4㎡ / h; Step S2, placing the insulation material body coated with a layer of silica sol solution into an oven for drying, with a drying temperature of 280~300℃ and a drying time of 2~2.5h; Step S3, after drying, placing it back on the workbench, and spraying another layer of aluminum sol solution using a spray gun, with a spray thickness of 30~70μm and a spraying speed of 5.4~6.4㎡ / h; Step S4, placing the insulation material coated with a layer of aluminum sol solution into an oven for drying, with a drying temperature of 280~300℃ and a drying time of 2~2.5h.

[0012] In some embodiments, during steps S1 and S3, the room temperature during spraying is 20°C to 25°C, and the relative humidity is 45% to 70%.

[0013] The scope of this invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.

[0014] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: The present invention provides a heat insulation material for tube furnaces and its manufacturing method. After the silica sol layer and alumina sol layer are dried, they will adhere to the surface of the heat insulation material body, which effectively solves the problem of powder shedding of the original heat insulation material. Moreover, it has no adverse reaction to the heating wire in the tube furnace, does not volatilize during the sintering process, and can adhere to the heat insulation material body for a long time without affecting the fired product. Attached Figure Description

[0015] Figure 1This is a schematic diagram of thermal insulation materials;

[0016] The components are: 1. Insulation material body; 2. Silica sol layer; 3. Alumina sol layer. Detailed Implementation

[0017] A thermal insulation material for tubular furnaces and its manufacturing method are disclosed. The thermal insulation material includes a thermal insulation material body 1, a silica sol layer 2 coated on the surface of the thermal insulation material body 1, and an aluminum sol layer 3 coated on the surface of the silica sol layer 2. In this embodiment, the silica sol layer 2 is formed by spraying a silica sol solution with a silica sol content of 70%, and the aluminum sol layer 3 is formed by spraying an aluminum sol solution with an aluminum sol content of 30%.

[0018] The specific manufacturing method is as follows: Step S1, place the insulation material body 1 on a workbench, and under the conditions of room temperature of 20℃~25℃ and relative humidity of 45%~70%, spray a layer of silica sol solution onto the insulation material body 1 using a spray gun. The spraying thickness is 30~70μm, and the spraying speed is 5.4㎡ / h; Step S2, place the insulation material body 1 coated with a layer of silica sol solution into an oven for drying. The drying temperature is 300℃, and the drying time is 2h; Step S3, ... After drying, the insulation material body 1 is placed on the workbench again. Under the conditions of room temperature of 20℃~25℃ and relative humidity of 45%~70%, an aluminum sol solution is sprayed onto the insulation material body 1 with a spray gun. The spray thickness is 30~70μm and the spraying speed is 5.4㎡ / h. In step S4, the insulation material with a layer of aluminum sol solution sprayed is placed in an oven to dry at a drying temperature of 300℃ for 2 hours. The insulation material for tube furnace is then completed.

[0019] There are many types of insulation materials in the existing technology, but most insulation materials have low hardness and strength, which makes them easy to break and scratch during installation and use.

[0020] In this embodiment, a thermal insulation material with high flexural strength and high hardness was specially developed. Details are as follows:

[0021] Based on the general sintering raw materials of thermal insulation material 1500LP, boron trioxide fine powder was added to form thermal insulation material 1500LP-B. The specific raw materials are: 80 parts of aluminum silicate fiber, 30 parts of quartz fiber, 50 parts of high-purity alumina powder, 15 parts of silica sol, 4 parts of cationic starch, and 10 parts of boron trioxide fine powder.

[0022] Among them, the density of aluminum silicate fiber is 85~198kg / m³, the total content of slag balls is ≥0.212mm and ≤55%, the permanent linear change after heating is 1100℃*8hr and ≤3%, the density of quartz fiber is 100~210kg / m³, the long-term temperature resistance is above 1200℃, the content of silicon dioxide is ≥98%, the mesh size of high-purity alumina powder is 500~1000 mesh, the content of AL2O3 is ≥99.5%, the particle size is ≤20um, the purity is ≥99%, and the Na2O content in silica sol is ≤0.5%, and the pH value is 8~11.

[0023] The fiber mixture is sintered through the following steps: aluminum silicate fiber and quartz fiber are crushed and mixed, silica sol is added and water is added to form a fiber mixture and mixed thoroughly. Boron trioxide fine powder and high-purity alumina powder are mixed thoroughly with water. At the same time, cationic starch is mixed with water to form a cationic starch aqueous solution and stirred thoroughly. The mixed boron trioxide fine powder and high-purity alumina powder mixture is added to the fiber mixture and mixed thoroughly. Then, the cationic starch aqueous solution is mixed into the fiber mixture to form agglomerates.

[0024] The agglomerates were vacuum adsorption molded to produce the thermal insulation material body 1 preform;

[0025] Dry the insulation material body 1 blank;

[0026] After the dried insulation material body 1 is sintered, the insulation material body 1 is obtained.

[0027] The insulation material body 1 is sintered in the following manner: heated from room temperature to 650°C for at least 2 hours; heated from 650°C to 960°C to 1300°C for at least 10 minutes; held at 960°C to 1300°C for at least 20 minutes; and cooled to obtain the insulation material body 1.

[0028] Sample Name 1500LP thermal insulation material (ordinary) 1500LP-B thermal insulation material Force at sample fracture 100 274 Sample width 32 32 Sample thickness 26 26 Sample length 100 100 Flexural strength 0.7 MPa 1.9Mpa According to the national standard GB / T 3002-2004, the experimental results show that the flexural strength of the 1500LP-B insulation material is 63% higher than that of the 1500LP insulation material.

[0029] This invention provides a thermal insulation material for tubular furnaces and its manufacturing method. The thermal insulation material body with added boron trioxide is not easily broken or scratched. After spraying a silica sol layer and an aluminum sol layer onto the thermal insulation material body, the problem of powder shedding of the original thermal insulation material is effectively solved. It also has no adverse reaction with the heating wire in the tubular furnace, does not volatilize during the sintering process, and can adhere to the thermal insulation material body for a long time, which helps to ensure the quality of the processed and fired products.

[0030] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A thermal insulation material for tubular furnaces, comprising a thermal insulation material body (1), characterized in that: It also includes a silica sol layer (2) coated on the surface of the insulation material body (1) and an aluminum sol layer (3) coated on the surface of the silica sol layer (2); the insulation material body (1) is integrally sintered by the following steps: aluminum silicate fiber and quartz fiber are crushed and mixed, silica sol is added and water is added to form a fiber mixture and mixed thoroughly, boron trioxide fine powder and high-purity alumina powder are added to water and mixed thoroughly, cationic starch is added to water to form a cationic starch aqueous solution and stirred thoroughly, the mixed boron trioxide fine powder and high-purity alumina powder mixture is added to the fiber mixture and mixed thoroughly, and then the cationic starch aqueous solution is mixed into the fiber mixture to form an agglomerate; the agglomerate is vacuum adsorption molded to produce the insulation material body (1) preform; the insulation material body (1) preform is dried; and then the dried insulation material body 1 preform is sintered to obtain the integral insulation material body (1).

2. The insulation material for tubular furnaces according to claim 1, characterized in that: The silica sol layer (2) is formed by spraying a silica sol solution, and the silica sol content of the silica sol solution is 65-75%; the aluminum sol layer (3) is formed by spraying an aluminum sol solution, and the aluminum sol content of the aluminum sol solution is 25-35%.

3. The insulation material for tubular furnaces according to claim 2, characterized in that: The raw materials for the thermal insulation material body (1) are: 60-100 parts of aluminum silicate fiber, 10-50 parts of quartz fiber, 30-60 parts of high-purity alumina powder, 7-12 parts of boron trioxide fine powder, 5-20 parts of silica sol, and 1-5 parts of cationic starch.

4. The insulation material for tubular furnaces according to claim 3, characterized in that: The aluminosilicate fiber has a density of 85~198 kg / m³, a total slag ball content ≥0.212 mm and ≤55%, and a permanent linear change of ≤3% after heating at 1100℃*8hr. The quartz fiber has a density of 100~210 kg / m³, a long-term temperature resistance of over 1200℃, and a silica content ≥98%. The high-purity alumina powder has a mesh size of 500~1000 mesh, an Al2O3 content ≥99.5%, a particle size ≤20 μm, and a purity ≥99%. The silica sol has a Na2O content ≤0.5% and a pH value of 8~11.

5. A method for manufacturing insulation material for tubular furnaces according to any one of claims 1-4, characterized in that: Specifically, the process includes the following steps: Step S1, placing the insulation material body on a workbench and spraying a layer of silica sol solution onto the insulation material body using a spray gun, with a spray thickness of 30~70μm and a spraying speed of 5.4~6.4㎡ / h; Step S2, placing the insulation material body coated with a layer of silica sol solution into an oven for drying at a temperature of 280~300℃ for 2~2.5h; Step S3, after drying, placing it back on the workbench and spraying another layer of aluminum sol solution using a spray gun, with a spray thickness of 30~70μm and a spraying speed of 5.4~6.4㎡ / h; Step S4, placing the insulation material coated with a layer of aluminum sol solution into an oven for drying at a temperature of 280~300℃ for 2~2.5h.

6. The method for manufacturing insulation material for tubular furnaces according to claim 5, characterized in that: In steps S1 and S3, the room temperature during spraying is 20℃~25℃ and the relative humidity is 45%~70%.

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