Insulating material and application thereof in calcium carbide furnace

Abstract

The invention discloses an insulating material and application thereof in a calcium carbide furnace, the insulating material is obtained by mixing and stirring corundum castable, 925 grade cement, a water reducing agent and water, the mass ratio of the corundum castable, the 925 grade cement and the water reducing agent is 45: 4: 1, the mass ratio of the water is 18%, then the insulating material is poured between a furnace cover and a water-cooled jacket, and the insulating material is cooled by the water-cooled jacket. The integrated insulating layer is formed between the furnace cover and the water-cooled jacket, so that the insulating layer has good insulativity and strength, the service life of the insulating layer is prolonged, the insulating layer is not easy to crack and shift, the sealing performance is better, and the problem of burnout between the furnace cover and the water-cooled jacket is solved; furnace shutdown maintenance caused by damage or water leakage of a water-cooled jacket and a furnace cover equipment insulating layer is avoided or reduced, the equipment operation rate is improved, the furnace gas quality can be improved, the furnace gas temperature and the on-site carbon monoxide concentration can be reduced, and environment safety is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of refractory materials for calcium carbide furnaces, and more specifically, to an insulating material applied to calcium carbide furnaces. Background Art

[0002] Insulation between the furnace cover and the water-cooled jacket of the calcium carbide furnace is achieved by adding an insulating material to ensure that there is no current passing between the furnace cover and the water-cooled jacket, reduce power loss, and ensure the safe production of the calcium carbide furnace. The current common furnace type in the calcium carbide industry is the closed calcium carbide furnace. During the production process, the electrode current is high, and it is easy for the accessories on the furnace cover to cause sparking and burning. In the industry, refractory bricks, mica material insulating plates, and fiberglass wool are used to achieve insulation between the furnace cover and the water-cooled jacket.

[0003] However, in actual use, using refractory bricks, mica material insulating plates, and fiberglass wool has inevitable defects: (1) The furnace cover is in a high-temperature state for a long time, and the mica material insulating plate has insufficient fire resistance. Once the insulation layer ages, it will powderize, causing sparking and damage to the accessories, with a high failure rate and potential safety hazards; (2) Due to the high temperature of the furnace cover of the calcium carbide furnace, each important accessory is cooled by the method of sandwich water circulation, so water leakage is inevitable. Once the mica material comes into contact with water, it will powderize and become scrapped, and the fiberglass wool will shrink when it comes into contact with water, resulting in voids between the accessories or sparking and damage to the furnace cover and the water-cooled jacket; (3) The refractory bricks have an independent and fragile structure. Once the insulating plate is damaged and the fiberglass wool shrinks, etc., when the furnace pressure of the electric furnace fluctuates, the refractory bricks are prone to displacement, falling, and fragmentation, resulting in conductive sparking between the furnace cover and the water-cooled jacket and damage to the furnace cover seal. Summary of the Invention

[0004] In view of the above, the present invention provides an insulating material and its application in a calcium carbide furnace to solve the problem of sparking between the furnace cover and the water-cooled jacket.

[0005] The present invention provides an insulating material, which is obtained by mixing and stirring corundum castable, 925-grade cement, water reducer, and water. The mass ratio of corundum castable, 925-grade cement, and water reducer is 45:4:1, and the mass of water is 18% of the total raw material mass.

[0006] The content of Al2O3 in the corundum castable is ≥85%.

[0007] Among them, the corundum castable has good high-temperature resistance. The corundum castable with an Al2O3 content of ≥85% has better high-temperature resistance. Adding 925-grade cement can improve the strength of the material. At the same time, since the insulating material is cast in a high-temperature environment, an appropriate amount of water reducer is added to make it quickly shaped. The obtained insulating material has the advantages of strong high-temperature resistance, high strength, easy shaping, good insulation performance, and good sealing performance.

[0008] An insulating material of the present invention is also applied to an electric calcium carbide furnace and is poured into the electric calcium carbide furnace by the following method:

[0009] (1) Remove the water-cooled jacket, separate the water-cooled jacket from the furnace cover, retain an appropriate spacing, and then clean the insulating areas of the water-cooled jacket and the furnace cover. There should be no conductive debris.

[0010] (2) Use cold-rolled carbon steel plates to make a mold for the insulating material, spot-weld it to the outer ring of the water-cooled jacket to make the position of the water-cooled jacket at the center, and ensure that the distances between the water-cooled jacket and the furnace cover are the same all around.

[0011] (3) Mix and stir evenly corundum castable, 925-grade cement, water reducing agent with a mass ratio of 45∶4∶1 and water with a mass proportion of 18% to obtain the insulating material, and then pour the insulating material between the water-cooled jacket and the mold. During the pouring process, it must be stirred evenly, and mechanical stirring is used to make the material uniform and compacted.

[0012] (4) After pouring, let it stand for 24 hours, and then use a 180h heating curve for ignition and heating baking, and remove the mold and the water-cooled jacket fixing parts; the heating process during baking is a slow and gradual heating, without large fluctuations, such as sudden heating or sudden cooling, etc., to prevent the material from cracking due to uneven heating.

[0013] Among them, when the water-cooled jacket is separated from the furnace cover, the retained spacing is 100 - 110 mm.

[0014] Advantages of the present invention:

[0015] (1) Pour the insulating material between the furnace cover and the water-cooled jacket to form an integral insulating layer between the furnace cover and the water-cooled jacket, which has good insulation and strength, is not easy to crack, and will not powder, solving the problem of sparking between the furnace cover and the water-cooled jacket, and avoiding or reducing furnace shutdown for maintenance caused by damage or leakage of the insulating layer of the water-cooled jacket and furnace cover equipment, improving the equipment operation rate.

[0016] (2) The present invention forms an integral insulating layer between the furnace cover and the water-cooled jacket, increasing the service life of the insulating layer, not easy to crack and shift, having good sealing performance, being able to improve the quality of furnace gas and reduce the temperature of furnace gas, as well as reduce the concentration of carbon monoxide on site, ensuring environmental safety, and solving the problems of easy damage of the insulating layer formed by combining refractory bricks, mica material insulating boards, and fiberglass cotton, resulting in poor sealing of the furnace cover, furnace gas overflow, and air mixing into the furnace. Description of the Drawings

[0017] Figure 1 It is a 180h heating curve graph. Specific Embodiments

[0018] Embodiments of the present application will be described in more detail below. The present application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided to more thoroughly and completely understand the present application. It should be understood that the embodiments of the present application are only for exemplary purposes and are not used to limit the protection scope of the present application.

[0019] Embodiments of the present invention are as follows:

[0020] 1. Insulating material: 45 kg of corundum castable with an Al2O3 content of ≥85%, 4 kg of 925-grade cement, 1 kg of water reducing agent, and 18% of the total raw material mass of water are mixed and stirred evenly to obtain the insulating material.

[0021] 2. It is cast into the calcium carbide furnace by the following method:

[0022] (1) Remove the water-cooled jacket, separate the water-cooled jacket from the furnace cover, lift the water-cooled jacket as a whole 100 mm away from the furnace cover, and then clean the insulating areas of the water-cooled jacket and the furnace cover. There should be no conductive debris such as iron filings and metal wires.

[0023] (2) Use a Q235 carbon steel cold-rolled plate with a thickness of 3 mm and a width of 130 mm to make a mold for the insulating material, and spot-weld it to the outer ring of the water-cooled jacket. The mold closely adheres to the outer ring of the water-cooled jacket to prevent the insulating material from flowing out or being lost during vibration ramming. The spot-welding or support fixing points do not damage the structures of the furnace cover and the water-cooled jacket, and keep the water-cooled jacket in the center, with the same distance between the water-cooled jacket and the furnace cover around to avoid uneven pouring of the insulating material.

[0024] (3) Pour the insulating material between the water-cooled jacket and the fixed mold. After the mold is filled, tap the outside of the mold, the water-cooled jacket, and the furnace cover to make the castable fully fill the mold without any gaps. At the same time, use a vibrating rod during the pouring process to make the material uniform and compact, prevent cavities and segregation, and prevent carbon monoxide in the furnace from overflowing, causing combustion or poisoning of personnel.

[0025] (4) Use a 180h heating curve for ignition and heating baking to ensure that the insulating material expands uniformly when heated, avoid stress cracking, and ensure the insulation and strength of the poured insulating material. After pouring, let it stand for 24 hours, and then remove the mold and the fixing parts of the water-cooled jacket.

[0026] Table 1: Implementation conditions of the embodiment and the performance of the material and the calcium carbide furnace after pouring the insulating material

[0027]

[0028] Table 1 shows the implementation conditions of the embodiments of the present invention and the performance of the insulating layer of the calcium carbide furnace after pouring the insulating material. It can be seen that the heat resistance performance and strength performance of the insulating layer of the calcium carbide furnace poured with the insulating material of the present invention can better meet the actual requirements, and it has a long service life. It is proved that the insulating material of the present invention is poured between the furnace cover and the water-cooled jacket, forming an integral insulating layer between the furnace cover and the water-cooled jacket, which has good insulation, heat resistance and strength, is not easy to crack and powder, and improves the service life of the insulating layer and the operation rate of the calcium carbide furnace.

[0029] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in this application can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An insulating material, characterized in that: The insulating material is obtained by mixing and stirring corundum casting material, 925 grade cement, water reducing agent and water, wherein the mass ratio of corundum casting material, 925 grade cement and water reducing agent is 45:4:1, and the mass of water is 18% of the total raw material mass.

2. An insulating material according to claim 1, characterized in that: The Al2O3 content in the corundum casting material is ≥85%.

3. An insulating material according to any one of claims 1 to 2, characterized in that: The insulating material is used in a calcium carbide furnace.

4. The use of an insulating material in a calcium carbide furnace according to claim 3, characterized in that: Pour into the calcium carbide furnace in the following way: (1) Remove the water cooling jacket, separate the water cooling jacket from the furnace cover, keep a suitable distance, and then clean the insulation area of ​​the water cooling jacket and the furnace cover. No conductive debris should be present; (2) Use carbon steel cold-rolled plate to make the mold of the insulating material, and spot weld it to the outer ring of the water cooling jacket so that the water cooling jacket is located in the center and the distance between the water cooling jacket and the furnace cover is consistent; (3) mixing and stirring a corundum casting material, 925 grade cement, a water reducing agent and 18% water by weight in a mass ratio of 45:4:1 to obtain an insulating material, and then pouring the insulating material between the water cooling jacket and the mold. During the pouring process, mechanical stirring is used to make the material uniform and compacted; (4) After pouring, let it stand for 24 hours, then use the 180-hour heating curve to ignite and heat it, and remove the mold and water-cooling jacket fixings.

5. The use of an insulating material in a calcium carbide furnace according to claim 4, characterized in that: The water cooling jacket is separated from the furnace cover, and the reserved spacing is 100-110 mm.

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