Abstract: Suspension device for electric resistor elements (5) in furnaces. A rod element (4) is horizontally arranged and is supported by consoles (2,3) at a distance from the furnace walls (1). The resistor element (5) is suspended on the rod element (4) and forms dense winding coils hanging freely from the rod element substantially in a flattened helical configuration.

Abstract: A coil assembly is formed by an elastic metal wire helical extension spring coil having convolutions resiliently urged towards each other and held apart by spacers pinched between the convolutions and held there by the spring-back of the convolutions. The spacers can interspace the coil convolutions and be made to extend radially inwardly and outwardly beyond the inside and outside of the coil, so as to radially space the coil from a coil center and the inside of a tubular casing enclosing the coil. In this way a tubular radiant heater can be made by using electric resistance wire to form the coil and making the spacers from refractory insulating material.

Abstract: A porcupine wire coil of electric resistance wire is positioned in a tube having an electrically insulating inside in which the peaks or looped ends of the coil convolutions are embedded so as to hold the coil convolutions spaced from each other. When the coil is energized, fluid flowed through the tube can be heated.