| 摘要 |
An electrical resistance heater element has a metal tube containing an electrical resistance coil that is electrically insulated from the metal tube by magnesium oxide powder, the coil being bonded to a conductor pin that protrudes from an open end of the tube. The powder is sealed against moisture by placing at least the open end of the tube within a chamber and immersing the open end within liquid silicone. A gas is pumped into the chamber to pressurize the silicone sufficiently to cause some of it to encroach into the powder through the open end of the tube. The heater element is installed within a heat exchanger with the silicone remaining uncured.
|
