First to understand what is the electric heating tube:
The electric heating tube belongs to a metal tubular electric heating element, and its structure is very simple. The spiral electric heating wire is located in the center of the tube, and the electric heating wire and the metal sheath tube are closely filled with a dense insulating and heat-conductive filling material, and the nozzle has a sealing mouth. The material is sealed and the tube end is led out by a conductive extraction rod for wiring.
It can be known from the above analysis that the metal shell of the heating tube and the electrothermal alloy wire are magnesium oxide powder which is filled with good thermal conductivity. Therefore, the electrothermal alloy wire is charged. If the insulating magnesium oxide powder is not filled in the middle, the surface of the electric heating tube is sure to be charged.
Therefore, the surface of the electric heating tube is not charged, and the main reason is that the tube is filled with an insulating filler, which is generally a high-purity magnesium oxide powder.