Heat treatment for the production of electrical tubular heating elements

Tubular heating elements are electrical heating elements which consist of a thin resistance wire built as a fine spiral, which is placed central in a protection tube made of metal. The tube is filled with a insulating compound. This basic principal configuration was already patented in USA in 1859. More than half a century passed until this idea could be used comercially. The following explains the manufacturing of tubular heating elements. Furthermore, the report is comparing annealing systems with innovative heat treatment systems which are used to produce the tubular heating elements.