Method and fixture for improving insulation heat-conducting property of electric heating tube

Abstract

The invention belongs to the manufacturing technology of electric heating devices and relates to a method and a tool part for improving the insulating heat conductive performance of electric heating tubes. The method of the invention includes the following steps: in the machining process of the electric heating tubes, as to semi-finished products of bent electric heating tubes which are filled with powder insulating media, pressure is exercised to each U-shaped bent passage in the direction which is vertical to a distribution plane of central line of the bent passage to flatten the bent passage so as to change the sectional area of the bent passage and increase the compactness of the insulating media in the tubes. By changing the shapes and sizes of the sections of the bent passages of the electric heating tubes in a flattening way, the technology can cause more porous powder insulating media in the shell of the part to be compacted so as to improve the insulating heat conductive performance.

Description

technical field [0001] The invention belongs to the manufacturing technology of an electric heating device, and relates to a method and tooling for improving the insulation and heat conduction performance of an electric heating tube. Background technique [0002] Ordinary electric heating tubes usually include a tubular casing, a heating wire passing through the casing, and a powdery insulating heat-conducting medium (usually magnesium oxide powder) filled between the heating wire and the inner wall of the casing. In order to meet the requirements of use, electric heating tubes are often bent into "U-shaped", "W-shaped" and other shapes. In this way, in each U-shaped bending section of the electric heating tube, the shell material at the curved outer diameter of the electric heating tube is stretched, resulting in the elongation of the linear dimension of this part of the shell material and the expansion of the actual cross-section, thereby making the The density of magnesi...

AI Technical Summary

Problems solved by technology

In this way, in each U-shaped bending section of the electric heating tube, the shell material at the curved outer diameter of the electric heating tube is stretched, which causes the linear dimension of this part of the shell material to elongate, and the actual cross-section expands, thereby making the The density of magnesium oxide powder filled in this part of the shell decreases

The main function of magnesium oxide powder is to fix the heating wire in the center of the tubular shell and to insulate and conduct heat between the heating wire and the shell, and the density of magnesium oxide powder in the bending part of the electric heating tube will reduce this part. The insulation and heat conduction ability of the whole electric heating tube is reduced, which is also an important reason for the early damage of the electric heating tube.

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