Electric melting furnace heater

Abstract

To provide an electric melting furnace heater using a cylindrical heating element, which has higher heat insulation and can more efficiently conduct heat to a molten metal.SOLUTION: An electric melting furnace heater 100 of the present invention comprises: a cylindrical heating element 10 with a spiral shape; and a protective pipe 20 for storing and protecting the cylindrical heating element 10. The heater comprises: a glass wool 40 or a glass sleeve 50 inserted into a space between the cylindrical heating element 10 and the protective pipe 20 in a length range of 1 / 4 or more to the whole length of the protective pipe 20 at least on an electrode side; and a glass sleeve 50 inserted inside the cylindrical heating element in a length range of 1 / 4 or more to the whole length of the protective pipe at least on the electrode side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heater for an electric melting furnace, and more particularly to a heat insulating structure for a heater for an electric melting furnace used with a cylindrical heating element. [Background technology]

[0002] Conventionally, heaters used in electric melting furnaces for aluminum, etc. (hereinafter referred to as "electric melting furnace heaters") have been electric melting furnace heaters using a cylindrical heating element made of silicon carbide, etc. As shown in Fig. 3, the electric melting furnace heater mainly consists of a cylindrical heating element 210 made of silicon carbide, a protective tube 220, and a thermocouple 230 (Patent Document 1).

[0003] However, the conventional electric melting furnace heater 200 had a problem in that heat was easily transferred between the cylindrical heating element 210 and the protective tube 220 and through the inside 250 of the cylindrical heating element 210 toward the upper electrode, causing heat from the heater to escape to the outside, resulting in poor efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-257056 A Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, the present invention has been made in consideration of these problems, and has an object to provide a heater for an electric melting furnace that is used in conjunction with a cylindrical heating element and has higher insulation properties and can transfer heat to the molten metal more efficiently. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention employs the following means.

[0007] The heater for an electric melting furnace according to the present invention is A cylindrical heating element having a spiral shape; a protective tube that houses and protects the cylindrical heating element; Equipped with glass wool or a glass sleeve inserted between the cylindrical heating element and the protective tube over a length range of at least 1 / 4 of the entire length of the protective tube from the electrode side; a glass sleeve inserted inside the cylindrical heating element from the electrode side over a length of at least 1 / 4 of the entire length of the protective tube; The present invention is characterized by comprising:

[0008] In the electric melting furnace heater according to the present invention, insulating materials such as glass wool or a glass sleeve are inserted between the cylindrical heating element and the protective tube and inside the cylindrical heating element, respectively, so that the heat generated by the spiral-shaped part at the tip is reduced from radiating from the electrode side to the outside, and the heat can be efficiently transferred to the molten metal. In addition, by using a glass sleeve on the inside of the cylindrical heating element, which becomes hotter, the heat is also prevented from radiating from the space inside the cylindrical heating element to the outside. Therefore, it has higher insulating properties than conventional heaters and can transfer heat to the molten metal more effectively.

[0009] In addition, in the electric melting furnace heater according to the present invention, the electric melting furnace heater may be embedded in the wall of the electric melting furnace, and the glass wool and the glass sleeve may be inserted into the entire thickness of the wall. When disposed on the wall of the electric melting furnace, by arranging the glass wool or the glass sleeve so that it is present in a thickness greater than that of the wall, it is possible to reduce heat radiation to the wall and more effectively transfer heat to the molten metal.

[0010] Furthermore, in the heater for an electric melting furnace according to the present invention, the glass sleeve may be inserted in a portion other than the spiral-shaped portion. Since the spiral-shaped portion is the portion that becomes the hottest, by avoiding this portion, deterioration of the glass wool and the glass sleeve can be reduced.

[0011] Furthermore, in the heater for an electric melting furnace according to the present invention, the glass sleeve inserted into the inside of the cylindrical heating element may be unraveled into a twisted yarn state. By using such a glass sleeve, the glass sleeve can be inserted more uniformly and more densely than when the glass sleeve is inserted as it is, and therefore a higher heat insulating effect can be achieved.

[0012] Furthermore, in the heater for an electric melting furnace according to the present invention, the molten metal side end of either or both of the glass wool and the glass sleeve may be covered with a hemisulant insulator. By adopting such a configuration, it is possible to prevent the heated gas from directly contacting the glass wool or the glass sleeve, thereby improving the durability of the glass wool or the glass sleeve in addition to providing excellent heat insulation.

[0013] Furthermore, in the heater for an electric melting furnace according to the present invention, the cylindrical heating element may be a cylindrical silicon carbide heating element that is capable of withstanding high temperatures and can generate heat efficiently.

[0014] Furthermore, in the electric melting furnace heater according to the present invention, a thermocouple may be provided in the carbonized glass sleeve. By providing a thermocouple in the glass sleeve, the durability of the thermocouple can be improved. Effect of the Invention

[0015] According to the electric melting furnace heater of the present invention, a glass sleeve and glass wool insulation material are inserted, so that the heat generated by the spiral-shaped portion at the tip is reduced from being dissipated from the electrode side to the outside of the melting furnace, and heat can be efficiently transferred to the molten metal. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram of an electric melting furnace heater according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a state in which an electric melting furnace heater according to an embodiment is attached to a wall surface of a melting furnace. [Diagram 3] FIG. 3 is a schematic diagram of a conventional heater for an electric melting furnace. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of an electric melting furnace heater according to the present invention will be described in detail with reference to the drawings. Note that the embodiments and drawings described below are intended to exemplify a part of the embodiment of the present invention, and are not intended to be used for the purpose of limiting the present invention to these configurations. In addition, the same or similar reference numerals are used to designate corresponding components in each drawing.

[0018] A schematic side view of an electric melting furnace heater 100 according to this embodiment is shown in Fig. 1. As shown in Fig. 1, the electric melting furnace heater 100 mainly comprises a cylindrical heating element 10, a protective tube 20 that houses the cylindrical heating element 10, a thermocouple 30 disposed within the cylindrical heating element 10, and glass wool 40 or a glass sleeve 50 inserted within the protective tube 20.

[0019] As shown in FIG. 1, the cylindrical heating element 10 is wound in a spiral shape from the middle part to the tip, has a cylindrical shape as a whole, and generates heat by using electrical resistance heating. The spiral shape provides a large surface area and can obtain uniform heat distribution, which has the effect of realizing efficient heating. In addition, the spiral shape allows the electrodes to be concentrated on one side (the wall side when installed in a melting furnace). As a material, silicon carbide, which is a ceramic material with very high heat resistance and electrical properties, is preferably used. Since silicon carbide can withstand high temperatures, the cylindrical heating element 10 made of spiral-shaped silicon carbide is suitable for use in the high-temperature environment of a heat treatment furnace.

[0020] The protective tube 20 protects the cylindrical heating element 10 placed in the molten metal, and is formed so as to surround the cylindrical heating element 10. As the material for the protective tube 20, a ceramic protective tube is preferably used, which has the property of withstanding high temperatures, is chemically stable, and has a high function of protecting the cylindrical heating element 10 from corrosion and oxidation in the melting furnace 200.

[0021] The thermocouple 30 is a type of sensor used to measure temperature, and its configuration is not particularly limited, and any known thermocouple can be used. The thermocouple 30 is disposed in a glass sleeve inserted into the cylindrical heating element 10.

[0022] The glass wool 40 or the glass sleeve 50 is disposed in the protective tube 20 to reduce the heat radiation of the cylindrical heating element 10 to the outside. The glass wool 40 or the glass sleeve 50 is inserted into the protective tube 20 between the cylindrical heating element 10 and the protective tube 20, in a range of at least 1 / 4 of the length of the protective tube 20 from the electrode side of the protective tube 20. The glass wool 40 and the glass sleeve 50 have high heat resistance and high insulation properties, so that they can reduce the transfer of heat between the cylindrical heating element 10 at the tip side and the protective tube 20. In addition, the glass sleeve 50 is inserted inside the cylindrical heating element 10, in a range of at least 1 / 4 of the length of the protective tube 20 from the electrode side. The reason why the glass sleeve 50 is used inside the cylindrical heating element 10 is that this is the part exposed to the highest temperature in the protective tube 20, and if glass wool is used, there is a possibility that the temperature may reach the melting temperature and deterioration will be accelerated. The glass sleeve 50 generally has the ability to withstand use in high-temperature environments of several hundred degrees or more, and has high thermal insulation properties, so it can operate stably in high-temperature environments. In this way, by placing the glass wool 40 or the glass sleeve 50 between the cylindrical heating element 10 and the protective tube 20, and the glass sleeve 50 inside the cylindrical heating element 10, the high-temperature gas heated by the cylindrical heating element 10 at the tip side is insulated by the glass wool 40 or the glass sleeve 50, so that the transfer of heat to the electrode side and the loss of heat to the outside are reduced, and heat can be transferred efficiently to the molten metal.

[0023] 2, when the electric melting furnace heater 100 is installed on the wall surface 210 of the melting furnace 200, the glass wool 40 and the glass sleeve 50 are preferably inserted in a range corresponding to the thickness α of the wall surface. By providing the glass wool 40 and the glass sleeve 50 in this range, the temperature of the protective tube 20 in this range can be prevented from becoming high, improving the durability of the wall surface 210. In addition, the radiation of heat to the wall surface 210 can be reduced, and heat can be transferred to the molten metal more effectively.

[0024] Furthermore, the glass wool 40 and the glass sleeve 50 may be characterized in that the glass sleeve is inserted in a portion other than the spiral-shaped portion, because the spiral-shaped portion becomes extremely hot, and there is a possibility that the glass wool 40 and the glass sleeve 50 cannot withstand the heat.

[0025] In addition, it is preferable to use the glass sleeve 50 in an unraveled state to the state of the twisted threads used to knit or weave the glass sleeve 50. By using the glass sleeve in an unraveled state, it is possible to insert the glass sleeve more uniformly and to achieve a stable heat insulating effect.

[0026] Furthermore, a cover 60 made of a hemisulant insulator, which is an insulating plate made of a mixture of cement, glass fiber, aramid fiber, etc., may be provided on the end face on the tip side (molten metal side) of the glass wool 40 or the glass sleeve 50. By adopting such a configuration, it is possible to prevent the heated gas from directly contacting the glass wool or the glass sleeve, thereby improving the insulating properties. In addition, it is possible to improve the durability of the glass wool or the glass sleeve. [Industrial Applicability]

[0027] As shown in the above-described embodiment, the present invention can be industrially used as a heater for a melting furnace. [Explanation of symbols]

[0028] 10...Cylindrical heating element 20...Protection tube 30…Thermocouple 40…Glass wool 50…Glass sleeve 60…Lid 100...Heater for electric melting furnace 200…melting furnace 210…Wall

Claims

1. A cylindrical heating element having a spiral shape; a protective tube that houses and protects the cylindrical heating element; Equipped with a glass wool or glass sleeve inserted between the cylindrical heating element and the protective tube at least on the electrode side over a length of at least ¼ of the entire length of the protective tube; a glass sleeve inserted inside the cylindrical heating element at least on the electrode side over a length of at least ¼ of the entire length of the protective tube; A heater for an electric melting furnace comprising:

2. 2. The heater for an electric melting furnace according to claim 1, wherein the heater for an electric melting furnace is embedded in a wall of the electric melting furnace, and the glass wool and the glass sleeve are inserted into the entire wall portion.

3. 3. The heater for an electric melting furnace according to claim 1, wherein the glass sleeve is inserted in a portion other than the spiral-shaped portion.

4. 3. The heater for an electric melting furnace according to claim 1, wherein the glass sleeve inserted into the cylindrical heating element is unraveled into a twisted yarn state.

5. 3. A heater for an electric melting furnace according to claim 1, wherein the molten metal side end of either or both of said glass wool and said glass sleeve is covered with a hemisulative insulator.

6. 3. The heater for an electric melting furnace according to claim 1, wherein the cylindrical heating element is a silicon carbide cylindrical heating element.

7. 3. The heater for an electric melting furnace according to claim 1, wherein a thermocouple is provided inside the glass sleeve.

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