What effect will the electric cartridge heater have when the closure is not sealed?
After understanding the structure of the electric cartridge heater, the characteristics of the electric cartridge heater, the role of the filling in the electric cartridge heater, the quartz sand of the filling of the electric cartridge heater, and the magnesium oxide of the filling of the electric cartridge heater, let's take a look at how the electric cartridge heater is What about closure sealing?
In the structure of the electric cartridge heater, a dense powder-like filler is filled between the spiral heating wire and the metal tube shell. The filler has good thermal conductivity and insulation performance when it is dry and compact. But they all have different degrees of hygroscopicity. The filler exposed at both ends of the cartridge heater will greatly reduce its electrical insulation performance once it absorbs moisture. When the end of the cartridge heater is not sealed, the moisture absorption of the filler has a great influence on the insulation performance of the electric cartridge heater.
On the other hand, when magnesium oxide absorbs moisture, a part of magnesium oxide (especially the part with poor or imperfect crystalline state) will undergo hydration. The hydrated magnesium oxide will increase its molecular size and agglomerate. For the electric cartridge heater, the nozzle absorbs the most moisture, so the agglomeration is also serious. Once the nozzle is agglomerated, the moisture absorbed by the filler deeper from the nozzle is more difficult to discharge, so that the electric cartridge heater cannot restore the insulation when it is energized and heats itself, and even the water in the cartridge heater is heated and vaporized and expanded. The wall of the false cartridge heater is protruding and bursting.
The insulation decreases when wet, and the molecular size increases after hydration affects the recovery of the insulation resistance of the cartridge heater. For these two points, the electric cartridge heater needs to be sealed at the closure.
