Water-free anti-explosion induction coil for induction furnace

Abstract

A waterless explosion-proof induction coil for an induction furnace comprises an induction coil body and an insulating refractory castable, the induction coil body is formed by winding a nano Al2O3 dispersion strengthened copper rectangular solid core bar, and the insulating refractory castable comprises the following main components: 82-90wt% of white corundum aggregate, 6-10wt% of CA90 cement and 4-8wt% of an aluminum dihydrogen phosphate solution. The induction coil body has the advantages of no softening at the temperature of 930 DEG C, no deformation, no water, explosion prevention, high high-temperature conductivity and the like, and the refractory castable has the characteristics of high temperature resistance of 1750 DEG C and heat insulation, so that the induction coil body melting phenomenon caused by direct contact between the induction coil body and metal liquid under high-temperature work can be avoided, and the induction coil has high-temperature resistance and explosion prevention performance.

Description

Technical Field

[0001] This invention relates to the field of induction melting technology, and in particular to a waterless explosion-proof induction coil for an induction furnace. Background Technology

[0002] Induction furnaces are widely used in industry as a means of metal heating and smelting. However, with the expanding applications of induction furnaces, the previously overlooked issue of high-temperature explosion protection has gradually become a significant obstacle to their development. Induction coils typically use hollow copper tubes circulated with water. Under special circumstances, such as during the smelting stage, furnace leaks frequently occur. The leakage of high-temperature molten metal can wash away and burn the induction coil. Direct contact between the high-temperature molten metal and water inevitably leads to explosions, sometimes resulting in injuries or fatalities. Therefore, ensuring the explosion-proof and high-temperature resistant properties of the induction coil is a crucial prerequisite for ensuring the stable operation of the induction furnace. The induction coil is the core component of the induction furnace. Alternating current is used to create a magnetic field on the coil to heat the metal. The requirements are even more stringent in the heating and smelting of special metals, where the operating temperature of the induction coil may exceed 1000℃. At this temperature, circulating water through the induction coil is extremely dangerous. Therefore, the industry urgently needs an induction coil that can withstand high temperatures without water, along with a high-temperature resistant insulation process. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention discloses a waterless explosion-proof induction coil for induction furnaces.

[0004] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: An anhydrous explosion-proof induction coil for an induction furnace is characterized by comprising an induction coil body and an insulating refractory castable. The induction coil body is made by winding a nano-Al2O3 dispersed reinforced copper rectangular solid rod on a steel roller jig. The main components of the insulating refractory castable are: 82-90 wt% white corundum aggregate, 6-10 wt% CA90 cement, and 4-8 wt% aluminum dihydrogen phosphate solution.

[0005] Preferably, the construction method of the induction coil is as follows: (1) The induction coil body is made by winding a rectangular solid copper rod reinforced with nano-Al2O3 dispersion on a steel roller jig with a 10mm turn gap; (2) Mix white corundum aggregate, CA90 cement and aluminum dihydrogen phosphate according to the proportion, add 5-8wt% water to the mixed raw materials, stir for 0.5-1 hour, and after mixing evenly, obtain insulating refractory castable; (3) Place the induction coil body in an oven at 400-450℃ for 1-2 hours to relieve stress; (4) Place the stress-relieved induction coil body into a barrel-shaped steel plate mold, fill it with insulating refractory castable, vibrate for 20-30 minutes, let it stand for 3-5 hours, and then demold. (5) After demolding, place in an oven at 90-110℃ for 8-10 hours; (6) Increase the temperature to 550℃, keep it at a constant temperature for 10-12 hours, and then let it cool naturally to obtain the product.

[0006] Preferably, the nano-Al2O3 dispersion-reinforced copper rectangular solid rod has the following composition: 0.3 wt% nano-Al2O3 and 99.7 wt% copper.

[0007] Preferably, the cross-section of the barrelled steel plate is annular.

[0008] Preferably, in step (4), when the induction coil body is placed in the barrel-shaped steel plate mold, the gap between the outer side and inner wall of the induction coil body and the inner wall of the mold is 10-15mm.

[0009] By employing the technical solution described above, the present invention has the following beneficial effects: This invention discloses a waterless explosion-proof induction coil for induction furnaces and its preparation method. The induction coil body is fixed within a mold, and a refractory insulating material is injected into the mold. This refractory insulating material wraps around the inner and outer sides of the induction coil, forming a refractory insulating layer on both sides of the coil body. This encapsulates the induction coil body within the refractory insulating castable, which possesses high-temperature resistance up to 1750℃ and heat insulation properties. This prevents the induction coil body from directly contacting molten metal at temperatures exceeding 1000℃ during high-temperature operation, thus avoiding melting. The coil exhibits high-temperature resistance and explosion-proof performance. This nano-Al2O3 dispersion-reinforced copper induction coil body exhibits advantages such as no softening or deformation in a 600-degree environment, waterless explosion-proof properties, and high high-temperature conductivity, ensuring safe production. Detailed Implementation Example 1

[0010] Insulating refractory castable: 85wt% white corundum aggregate, 8wt% CA90 cement, 7wt% aluminum dihydrogen phosphate solution; Induction coil body nano-Al2O3 dispersed reinforced copper rectangular solid rod material: 0.3wt% nano-Al2O3, 99.7wt% copper.

[0011] (1) Mix white corundum aggregate, CA90 cement and aluminum dihydrogen phosphate solution according to the ratio, add 6wt% water of the mixed raw materials, stir for 0.5-1 hour, and after mixing evenly, obtain insulating refractory castable; (2) The induction coil body, which is made by winding a rectangular solid copper rod reinforced with nano-Al2O3 dispersion on a steel roller jig with a 10mm turn gap, is placed in an oven at 400-450℃ for 1h to relieve stress. (3) Place the stress-relieved induction coil body into a barrel-shaped steel plate mold, fill it with insulating refractory castable, vibrate for 20 minutes, let it stand for 3 hours, and then demold. (4) After demolding, place in an oven at 90-110℃ for 8 hours; (5) Increase the temperature to 550℃, keep it at a constant temperature for 10 hours, and then let it cool naturally to obtain the product. Example 2

[0012] Insulating refractory castable: 82wt% white corundum aggregate, 10wt% CA90 cement, 8wt% aluminum dihydrogen phosphate solution; Induction coil body nano-Al2O3 dispersed reinforced copper rectangular solid rod material: 0.3wt% nano-Al2O3, 99.7wt% copper.

[0013] (1) Mix white corundum aggregate, CA90 cement and aluminum dihydrogen phosphate solution according to the ratio, add 5wt% water to the mixed raw materials, stir for 0.5-1 hour, and after mixing evenly, obtain insulating refractory castable; (2) The induction coil body, which is made by winding a rectangular solid copper rod reinforced with nano-Al2O3 dispersion on a steel roller jig with a 10mm turn gap, is placed in an oven at 400-450℃ for 1.5h to relieve stress; (3) Place the stress-relieved induction coil body into a barrel-shaped steel plate mold, fill it with insulating refractory castable, vibrate for 25 minutes, let it stand for 4 hours, and then demold. (4) After demolding, place in an oven at 90-110℃ for 9 hours; (5) Increase the temperature to 550℃, keep it at a constant temperature for 11 hours, and then let it cool naturally to obtain the product. Example 3

[0014] Insulating refractory castable: 90wt% white fused alumina aggregate, 6wt% CA90 cement, 4wt% aluminum dihydrogen phosphate solution; Induction coil body nano-Al2O3 dispersed reinforced copper rectangular solid rod material: 0.3wt% nano-Al2O3, 99.7wt% copper.

[0015] (1) Mix white corundum aggregate, CA90 cement and aluminum dihydrogen phosphate solution according to the ratio, add 5-8wt% water to the mixed raw materials, stir for 0.5-1 hour, and after mixing evenly, obtain insulating refractory castable; (2) The induction coil body, which is made by winding a rectangular solid copper rod reinforced with nano-Al2O3 dispersion on a steel roller jig with a 10mm turn gap, is placed in an oven at 400-450℃ for 2 hours to relieve stress. (3) Place the stress-relieved induction coil body into a barrel-shaped steel plate mold, fill it with insulating refractory castable, vibrate for 30 minutes, let it stand for 5 hours, and then demold. (4) After demolding, place in an oven at 90-110℃ for 10 hours; (5) Increase the temperature to 550℃, keep it at a constant temperature for 12 hours, and then let it cool naturally to obtain the product.

[0016] Comparative Example 1 The existing medium-frequency furnace uses a hollow water-passing copper tube induction coil, and the castable material is a commonly used refractory mortar.

[0017] Table 1 Comparison of Induction Coil Body Performance

[0018] According to Table 1, compared with Comparative Example 1, Example 1 not only has better high-temperature conductivity, but also has a particularly obvious advantage of being waterless and non-explosive in terms of high-temperature resistance and resistance to molten steel erosion. When working for a long time at 300-400℃, its conductivity and explosion-proof properties are superior to those of traditional copper tube induction coils.

[0019] Table 2 Comparison of performance of induction coils after casting

[0020] As can be seen from Table 2, Examples 1-3 have better overall performance and higher safety under extreme conditions compared to Comparative Example 1 in high-temperature environments.

[0021] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all changes falling within the meaning and scope of the equivalents of the claims be included within the invention.

Claims

1. A waterless explosion-proof induction coil for an induction furnace, characterized in that: It includes an induction coil body and an insulating refractory castable. The induction coil body is made of nano-Al2O3 dispersed reinforced copper rectangular solid rods wound together. The main components of the insulating refractory castable are: white corundum aggregate 82-90wt%, CA90 cement 6-10wt%, and aluminum dihydrogen phosphate solution 4-8wt%.

2. The waterless explosion-proof induction coil for an induction furnace as described in claim 1, characterized in that: The construction method for the induction coil is as follows: (1) The induction coil body is made of a rectangular solid copper rod reinforced with nano-Al2O3 dispersion, wound on a steel roller jig with a 10mm turn gap; (2) Mix white corundum aggregate, CA90 cement and aluminum dihydrogen phosphate according to the proportion, add 5-8wt% water to the mixed raw materials, stir for 0.5-1 hour, and after mixing evenly, obtain insulating refractory castable; (3) Place the induction coil body in an oven at 400-450℃ for 1-2 hours to relieve stress; (4) Place the stress-relieved induction coil body into a barrel-shaped steel plate mold, fill it with insulating refractory castable, vibrate for 20-30 minutes, let it stand for 3-5 hours, and then demold. (5) After demolding, place in an oven at 90-110℃ for 8-10 hours; (6) Increase the temperature to 550℃, keep it at a constant temperature for 10-12 hours, and then let it cool naturally to obtain the product.

3. The waterless explosion-proof induction coil for an induction furnace as described in claim 1, characterized in that: The nano-Al2O3 dispersion-reinforced copper rectangular solid rod is composed of 0.3 wt% nano-Al2O3 and 99.7 wt% copper.

4. The waterless explosion-proof induction coil for an induction furnace as described in claim 2, characterized in that: The cross-section of the barrel-shaped steel plate is annular.

5. The waterless explosion-proof induction coil for an induction furnace as described in claim 2, characterized in that: In step (4), when the induction coil body is placed in the barrel-shaped steel plate mold, the gap between the outer side and inner wall of the induction coil body and the inner wall of the mold is 10-15mm.

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