Electric heating tube moisture-proof magnesia powder and proportioning method

Abstract

The invention discloses electric heating tube moisture-proof magnesia powder and a proportioning method. The electric heating tube moisture-proof magnesia powder is prepared by fully mixing silicon powder, molten silicon and magnesia powder, wherein the silicon powder accounts for 0.2%-0.5% of the weight of the mixture, and the molten silicon accounts for 0.2%-0.6% of the weight of the mixture. The evenly mixed mixture is filled into a metal external tube of an electric heating tube to manufacture the electric heating tube. The manufactured electric heating tube is subjected to silicon removing process treatment, a gas is exhausted before the complete sealing is carried out, the required baking temperature of the silicon removing process ranges from 400 to 600 DEG C, and the baking time ranges from 1 to 4 hours. The electric heating tube moisture-proof magnesia powder and the proportioning method have the beneficial effects that: since the usage requirements cannot be satisfied by using the traditional technology simply, the optimal proportion of the silicon powder, the molten silicon and the magnesia powder is determined through experiments, the concerted reaction is generated, and the moisture-proof performance can be improved maximally; and the silicon removing process is adopted to ensure that the gas is exhausted before the complete sealing is carried out, thereby improving the insulation performance, prolonging the service life and preventing pipe explosion.

Description

technical field [0001] The invention relates to the technical field of electrical insulating materials, and mainly relates to an electric heating tube moisture-proof magnesium oxide powder and a proportioning method thereof. Background technique [0002] At present, the insulating material used for the electric heating tube is magnesium oxide powder, which is filled between the metal shell and the electric heating wire to play the role of insulation and heat conduction. Ordinary magnesium oxide powder will generate magnesium hydroxide after contacting with moisture in the air, thus losing its insulating effect and causing the risk of leakage and short circuit. There are currently three solutions to this problem: [0003] Method 1: Seal the nozzle of the electric heating tube with a sealing material to isolate the magnesium oxide powder of the electric heating tube from the air, and prevent the moisture in the air from contacting with the magnesium oxide powder to lose the i...

AI Technical Summary

Problems solved by technology

The reason is that silicon powder and silicon water are organic substances with multiple boiling points. They gasify at high temperature and produce a large amount of gas. Since the two ends of the electric heating tube are sealed, the gas cannot be removed, and the generated gas will accumulate in the inner cavity of the electric heating tube, which reduces the insulation of the electric heating tube. performance

The gas accumulates in the electric heating tube, the pressure increases, and the gas expands further at high temperature, causing local stress concentration and reducing the service life of the electric heating tube

When the metal outer tube is a soft aluminum tube, it will directly cause the tube to explode

Images