1.xHas sufficient insulation properties and electrical strength;
2.Has good thermal conductivity, that is, has a high thermal conductivity;
3.Having an expansion coefficient similar to that of the heating wire;
4.Having chemical inertness to the heating wire material;
5.Highly heat resistant;
6.Can withstand the rapid changes in temperature;
8.Has high mechanical properties;
9.The materials come from a wide range of sources and are inexpensive.
At the same time, it is very difficult to meet the above nine requirements, because a good good thermal conductor is a good electrical conductor at the same time, and its electrical insulation performance is high, and its thermal conductivity is very low. In general, the fillers commonly used in electric heating tubes are quartz sand, alumina and magnesia.
The filler used by our company is magnesium oxide, which is currently the best filling material.
Magnesium oxide uses different temperature-resistant magnesium oxide powders according to different working temperatures.
The selection of unused filling materials will directly affect the price and life of the electric heating tube. This is the reason for paying for a penny. Magnesium powders range from a few thousand tons to tens of thousands of tons, the main difference between which is insulation and temperature resistance.
From this point alone, it can be understood that for the same size of the tube, the shell material is the same, different manufacturers, the quotation will be a lot of error. Each factory location is also inconsistent.