U-shaped electric heating tube typical structure (common structure) generally consists of 5 parts: insulator, sealing material, lead-out rod, filler, heating wire, metal sheath tube, and terminal.
The spiral heating wire and lead-out rod are located in the center of the metal sheath tube. Its manufacturing process is to thread the spiral heating wire into a seamless steel tube, copper tube, or aluminum tube, and uniformly fill the gaps with an insulating and thermally conductive oxide medium, such as crystalline magnesium oxide powder (or aluminum oxide or clean quartz sand), using a multi-tube filling machine. Then, the tube diameter is reduced using a tube shrinking machine to compact the oxide medium (density reaches above 3.3g/cm³), ensuring that the heating wire is isolated from air and the center position does not shift and touch the tube wall. In this way, the heat generation per unit area can be increased by more than ten times. The service life can also be correspondingly increased to more than 10 years. Compared with electric heating elements of the same large heat output, tubular electric heating tubes can save 5% of heating material, and the thermal efficiency can reach over 90%.
Therefore, from the structure of the U-shaped electric heating tube, the metal tubular electric heating tube is currently a widely used, simple in structure, reliable in performance, and long in service life sealed electric heating element. It can be successfully applied in industry and household appliances, and its use is becoming more and more widespread. It is hoped that more users will have a clear understanding of the structural principles of electric heating tubes.
