Dip-type heater

Abstract

Provided is a dip-type heater, which can avoid it completely that the outer circumference edge of a spiral heating element is pushed by the inner wall of a protecting tube, thereby to prevent the disconnection resulting from the contact between adjoining heating elements. The dip-type heater has a band-shaped metallic heating element (8), one edge portion of which is inserted into and held in a spiral groove (7) thereby to form a spiral heating portion (9). A cylinder supporting member (11), which has a diameter smaller than the internal diameter of a bottomed protecting tube (2) of ceramics and larger than the outer circumference diameter of the spiral heating portion (9) and which is fitted in the hollow portion in an insulating cylinder (6), is arranged at each of the openings of the leading end and the trailing end of the insulating cylinder (6).

Description

technical field [0001] The present invention relates to an immersion heater used in, for example, heating equipment for molten metal such as an aluminum holding furnace, and more specifically, to an immersion heater including a metal heating element such as a Fe—Cr—Al alloy or the like. Background technique [0002] Conventionally, as an immersion heater for heating molten metal such as molten aluminum, there is a heater using a metal heating element. For example, Patent Document 1 discloses an immersion heater comprising: an insulating cylinder suspended within a bottomed cylindrical ceramic protective tube (immersion tube); A linear heating element (heating part) with a circular cross-section arranged in a spiral groove formed on the outer periphery of this insulating cylinder; One end of each is respectively connected to the linear heating element, and the other end passes through the insulating cover. [0003] Patent Document 1: Japanese Publication No. 5-21275 [000...

AI Technical Summary

Problems solved by technology

[0005] That is, when the eccentricity of the protective tube and the cylindrical body occurs, the outer peripheral edge of the helically wound strip-shaped heating element will be pressed by the inner wall of the protective tube. Poor contact between adjacent heating elements

In particular, in the way of horizontal immersion, since the rear end of the immersion heater is supported on the side wall of the furnace, the horizontal one-side support is adopted, so the heating part also becomes a horizontal one-side support in the same way, and the cylindrical body Since the heating element bends downward due to its own weight, the outer peripheral edge of the spiral heating element (furnace bottom side) is easily pressed by the inner wall of the protective tube, and the above-mentioned problems are more likely to occur.

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