Immersion heating element with a thermally-conductive polymeric coating disposed over a resistance wire

摘要

Electrical resistance heating elements (100) are provided which are useful in heating fluid mediums, such as air and water. The heating elements include an element body (100) having a supporting surface (10) and a resistance wire (14) wound onto the supporting surface (10) which is connected to a pair of terminal end portions (16 and 12). Disposed over the resistance wire (14), and over most of the supporting surface (10), is a polymeric coating (30) which hermetically encapsulates and electrically insulates the resistance wire (14) from the fluids to be heated. This thermally-conductive polymer coating (30) has a thermal conductivity value of at least about 0.5 W/mK. Improved properties are provided by ceramic powder, aluminum oxide and magnesium oxide, and glass fiber additives.