What are the reasons for uneven heating of single-head electric heating tubes?

What are the causes of uneven heating in single-ended electric heating tubes?

1. Uneven hardness of the resistance wire used in the electric heating tube.

Uneven hardness of the resistance wire material causes uneven pitch after winding. This often occurs during the recovery process of the drawn heating wire. Uneven tension during the winding of the spiral heating wire can also affect pitch unevenness.

2. Improper design of the resistance wire in the electric heating tube.

Typically, the heating wire in the electric heating tube is spiral-shaped, i.e., spring-like. When the ratio of the core diameter D to the heating wire diameter D is greater than 8, sagging may occur when powder is added, indicating a difference in the density of the heating wire.

3. Improper operation of the electric heating tube process.

When adding powder, the exposed rod does not meet the requirements. When the powder is too short, the powder is twisted, causing the powder to be pulled out and the tube to be pulled out. When the rod is too long, the powder vibrates, causing the rod to be compressed. This can cause the heating wire to be too thin in some places or too dense in others, or even short-circuit the heating wire and coil. Improper operation of the shrink tubing process can also affect the uniformity of the heating wire distribution.

4. Defective heating tube filling equipment

For example, unstable amplitude of the dosing device, uneven guide rod lifting speed, and rapid and slow powder leakage. Even if all other parameters are normal, the magnesium oxide powder may be too dense.