According to the different ways of electric energy conversion, electric heating is usually divided into resistance heating, induction heating, arc heating, electron beam heating, infrared heating and medium heating.

Resistance heating coil

The Joule effect of electric current is used to transform electric energy into heat energy to heat objects. It is usually divided into direct resistance heating and indirect resistance heating. The former power supply voltage is directly applied to the heated object. When the current flows past, the manufacturer of cast aluminium heating coil electrically heated ironing machine of the heated object itself.

It's feverish. The object that can be heated by direct resistance must be a conductor, but with high resistivity. Because heat is generated by the heated object itself, it belongs to internal heating and has high thermal efficiency. Indirect resistance heating needs to be made of special alloy or non-metallic materials. The heating element generates heat energy, which is transmitted to the heated object through radiation, convection and conduction. Because the heated object and the heating element are divided into two parts, the types of heated objects are generally unrestricted and easy to operate.

The materials used in indirect resistance heating heating heating elements generally require high resistivity, low resistance temperature coefficient, small deformation at high temperature and not easy to embrittle. Commonly used are iron-aluminum alloy, nickel-chromium alloy and other metal materials, silicon carbide, molybdenum disilicide and other non-metallic materials. The maximum working temperature of metal heating element can reach 1000-1500 C according to the material type, and that of non-metal heating element can reach 1500-1700 C. The latter is easy to install and can be replaced by heating furnace, but it needs pressure regulating device when it works, and its life is shorter than that of alloy heating element. It is generally used in high temperature furnace, places where the temperature exceeds the maximum allowable working temperature of metal heating element and some special occasions.