JP7437097B1 - Heater for electric melting furnace - Google Patents

Abstract

An object of the present invention is to provide a heater for an electric melting furnace that is used with a cylindrical heating element, has higher heat insulation properties, and is capable of more efficiently transmitting heat to molten metal. A heater 100 for an electric melting furnace according to the present invention includes a cylindrical heating element 10 having a spiral shape and a protective tube 20 for accommodating and protecting the cylindrical heating element 10. and a glass wool 40 or a glass sleeve 50 inserted at least on the electrode side between the protection tube 20 and a length of 1/4 or more of the entire length of the protection tube 20, and at least It is characterized in that it includes a glass sleeve 50 inserted on the electrode side over a length range of 1/4 or more of the entire length of the protection tube. [Selection diagram] Figure 1

Description

The present invention relates to a heater for an electric melting furnace, and particularly to a heat insulating structure of a heater for an electric melting furnace used with a cylindrical heating element.

Conventionally, heaters for electric melting furnaces that use cylindrical heating elements made of silicon carbide, etc., have been used as heaters for electric melting furnaces for materials such as aluminum (hereinafter referred to as "heaters for electric melting furnaces"). There is. As shown in FIG. 3, the electric melting furnace heater mainly includes a cylindrical heating element 210 made of silicon carbide, a protective tube 220, and a thermocouple 230 (Patent Document 1).

However, in the conventional electric melting furnace heater 200, heat is easily transferred upward toward the electrode between the cylindrical heating element 210 and the protective tube 220 and through the inside 250 of the cylindrical heating element 210, and the heat of the heater is transferred to the outside. There was a problem that the efficiency was low as the staff ran away from the office.

Japanese Patent Application Publication No. 2001-257056

Therefore, the present invention has been made based on these problems, and uses electric melting that has higher heat insulation properties and can transfer heat to the molten metal more efficiently in the heater used with the cylindrical heating element. The purpose is to provide a furnace heater.

In order to achieve the above-mentioned object, the present invention takes the following measures.

The electric melting furnace heater according to the present invention includes:
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 protection tube, both from the electrode side to a length of at least 1/4 or more of the entire length of the protection tube;
a glass sleeve inserted into the cylindrical heating element from the electrode side to a length of at least 1/4 or more of the entire length of the protective tube;
It is characterized by having the following.

In the electric melting furnace heater according to the present invention, a heat insulating material such as glass wool or a glass sleeve is inserted between the cylindrical heating element and the protective tube and inside the cylindrical heating element, so that the spiral at the tip Heat generated by the shaped portion is prevented from being radiated to the outside from the electrode side, and the heat can be efficiently transferred to the molten metal. Furthermore, by using a glass sleeve inside the cylindrical heating element, which becomes even hotter, heat is prevented from being radiated to the outside from the space inside the cylindrical heating element. Therefore, compared to the conventional method, it has higher heat insulation properties and can transfer heat to the molten metal more effectively.

Furthermore, in the electric melting furnace heater according to the present invention, the electric melting furnace heater is embedded in the wall surface of the electric melting furnace, and the glass wool and the glass sleeve are inserted into the entire thickness of the wall surface. It may also be characterized by the fact that When placed on the wall of an electric melting furnace, by arranging the glass wool or glass sleeve so that it is thicker than the thickness of the wall, the radiation of heat to the wall can be reduced, making it even more effective. Heat can be effectively transferred to the molten metal.

Furthermore, in the electric melting furnace heater according to the present invention, the glass sleeve may be inserted into a portion other than the spiral-shaped portion. Since the spiral-shaped portion is the portion that receives the highest temperature, deterioration of the glass wool and the glass sleeve can be reduced by arranging it while avoiding this portion.

Furthermore, in the electric melting furnace heater according to the present invention, the glass sleeve inserted into the cylindrical heating element may be unraveled into a twisted yarn state. By employing such a glass sleeve, compared to the case where the glass sleeve is inserted as is, it can be inserted more densely and uniformly, so that a higher heat insulation effect can be exhibited.

Furthermore, in the electric melting furnace heater according to the present invention, the molten metal side end of either or both of the glass wool or the glass sleeve may be covered with a hemisal insulator. good. By adopting such a configuration, it is possible to prevent heated gas from coming into direct contact with the glass wool or glass sleeve, which not only provides excellent heat insulation properties but also improves the durability of the glass wool or glass sleeve. I can do it.

Furthermore, in the heater for an electric melting furnace according to the present invention, the cylindrical heating element may be a heating element made of cylindrical silicon carbide. Silicon Carbide Cylindrical Heating Element Silicon Carbide Cylindrical Heating Element has the ability to withstand high temperatures and can generate heat efficiently.

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

According to the electric melting furnace heater according to the present invention, since the glass sleeve and the glass wool insulation material are inserted, the heat generated by the spiral-shaped portion at the tip is radiated from the electrode side to the outside of the melting furnace. heat can be efficiently transferred to the molten metal.

FIG. 1 is a schematic diagram of a heater for an electric melting furnace according to an embodiment. FIG. 2 is a schematic diagram showing a state in which the electric melting furnace heater according to the embodiment is attached to the wall surface of the melting furnace. FIG. 3 is a schematic diagram of a conventional electric melting furnace heater.

EMBODIMENT OF THE INVENTION Hereinafter, embodiments of the heater for electric melting furnaces according to the present invention will be described in detail with reference to the drawings. Note that the embodiments and drawings described below illustrate some of the embodiments of the present invention, and are not used for the purpose of limiting the configuration to these. In addition, corresponding components in each figure are given the same or similar symbols.

A schematic side view of a heater 100 for an electric melting furnace according to this embodiment is shown in FIG. The electric melting furnace heater 100, as shown in FIG. The protective tube 20 includes a glass wool 40 or a glass sleeve 50 inserted into the protective tube 20.

As shown in FIG. 1, the cylindrical heating element 10 is spirally wound from the midsection toward the tip, and has a cylindrical shape as a whole, and generates heat using electrical resistance heating. It is something that generates. The spiral shape has the effect of providing a large surface area and achieving uniform heat distribution, thereby achieving efficient heating. Further, by forming the spiral shape, the electrodes can be concentrated on one side (the wall side when installed in the melting furnace). Preferably, the material used is silicon carbide, which is a ceramic material with very high heat resistance and electrical properties. Since silicon carbide can withstand high temperatures, the spiral-shaped cylindrical heating element 10 made of silicon carbide is suitable for use in the high-temperature environment of a heat treatment furnace.

The protective tube 20 protects the cylindrical heating element 10 placed in the molten metal, and is formed to surround the cylindrical heating element 10 . As the material for the protection tube 20, it is recommended to use a ceramic protection tube that has properties that can withstand 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. good.

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. This thermocouple 30 is arranged within a glass sleeve inserted into the cylindrical heating element 10.

The glass wool 40 or the glass sleeve 50 is disposed within the protective tube 20 to reduce the heat radiated from the cylindrical heating element 10 to the outside. The glass wool 40 or the glass sleeve 50 is placed between the cylindrical heating element 10 and the protection tube 20 within the protection tube 20, and extends at least 1/4 of the length of the protection tube 20 from the electrode side of the protection tube 20. inserted into the range. Since the glass wool 40 and the glass sleeve 50 have high heat resistance and high heat insulation properties, they can reduce heat transfer between the cylindrical heating element 10 on the tip side and the protective tube 20. Further, a glass sleeve 50 is inserted inside the cylindrical heating element 10 and within a range of at least 1/4 of the length of the protective tube 20 from the electrode side. The use of the glass sleeve 50 inside the cylindrical heating element 10 is the part of the protective tube 20 that is exposed to the highest temperature, and if glass wool is used, it may reach the melting temperature. This is because deterioration becomes faster. The glass sleeve 50 generally has the ability to withstand use in a high-temperature environment of several hundred degrees or higher, and has high heat insulation properties, so it can operate stably in a high-temperature environment. In this way, by installing the glass wool 40 or the glass sleeve 50 between the cylindrical heating element 10 and the protection tube 20 and the glass sleeve 50 inside the cylindrical heating element 10, the cylindrical heating element 10 on the tip side The heated gas is insulated by the glass wool 40 or the glass sleeve 50, and the heat is transferred to the electrode side, reducing the possibility of heat escaping to the outside, and efficiently transferring heat to the molten metal.

Further, as shown in FIG. 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 inserted into an area corresponding to the thickness α of the wall surface. It is preferable. By providing the glass wool 40 and the glass sleeve 50 in this range, it is possible to reduce the temperature of the protection tube 20 in this range from becoming high, and the durability of the wall surface 210 is improved. Further, the radiation of heat to the wall surface 210 can be reduced, and heat can be more effectively transmitted to the molten metal.

Furthermore, the glass wool 40 and the glass sleeve 50 may be characterized in that the glass sleeve is inserted into a portion other than the spiral-shaped portion. This is because the spiral shaped portion reaches a very high temperature, so the glass wool 40 and the glass sleeve 50 may not be able to withstand the heat.

Further, the glass sleeve 50 is preferably made by loosening the glass sleeve 50 into a knitted or woven thread. By unraveling it before use, it can be inserted more evenly and a stable heat insulating effect can be achieved.

Furthermore, a lid 60 may be provided on the end face of the glass wool 40 or the glass sleeve 50 on the tip side (molten metal side) using a hemisal insulator, which is a heat insulating board made of a mixture of cement, glass fiber, aramid fiber, or the like. By employing such a configuration, it is possible to prevent heated gas from coming into direct contact with the glass wool or the glass sleeve, thereby improving the heat insulation properties. Furthermore, the durability of the glass wool or glass sleeve can be improved.

As shown in the embodiments described above, it can be used industrially as a heater for a melting furnace.

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 surface

Claims (6)

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 protection tube at least on the electrode side over a length of 1/4 or more of the entire length of the protection tube;
a glass sleeve inserted into the inside of the cylindrical heating element at least on the electrode side over a length of 1/4 or more of the entire length of the protective tube;
Equipped with
A heater for an electric melting furnace, wherein the glass sleeve inserted inside the cylindrical heating element is loosened into a twisted thread state. 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 protection tube at least on the electrode side over a length of 1/4 or more of the entire length of the protection tube;
a glass sleeve inserted into the inside of the cylindrical heating element at least on the electrode side over a length of 1/4 or more of the entire length of the protective tube;
Equipped with
A heater for an electric melting furnace, characterized in that a molten metal side end of the glass wool or glass sleeve inserted between the cylindrical heating element and the protective tube is covered with a hemisal insulator. The electric melting furnace heater is embedded in the wall of the electric melting furnace, and the glass wool and glass sleeve inserted between the cylindrical heating element and the protective tube are inserted throughout the wall. The heater for an electric melting furnace according to claim 1 or 2, characterized in that: The heater for an electric melting furnace according to claim 1 or 2, wherein the glass sleeve inserted inside the cylindrical heating element is inserted in a part other than a spiral-shaped part. The heater for an electric melting furnace according to claim 1 or 2, wherein the cylindrical heating element is a silicon carbide cylindrical heating element. The heater for an electric melting furnace according to claim 1 or 2, wherein a thermocouple is provided within the glass sleeve.

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