What are the common heating methods and characteristics of electric heaters?

- Jun 24, 2019-

The electric heater is used to heat the alloy heating wire by turning on the power source to cause the heating wire to generate high temperature. In actual production, there are many heating methods commonly used in electric heaters, including resistance heating, induction heating, arc heating, electron beam heating, infrared heating, medium heating, etc., each having unique characteristics. When the electric heater is heated by electrical resistance, it uses the Joule effect of the current to convert electrical energy into thermal energy to heat the object. Direct resistance heating has a high thermal efficiency because heat is generated in the object itself being heated. However, indirect resistance heating is generally not limited to the type of object to be heated, and is easy to handle. Induction heating of an electric heater requires that the conductor be in an alternating electromagnetic field, thereby creating a thermal effect formed by the induced current to heat the conductor itself. The premise of applying this heating method is that the object to be heated needs to be a conductor in order to uniformly heat the entire object and heat the surface layer. Arc heating is also a common heating method for electric heaters. In order to maintain the stability of the arc during arc heating, when the arc current crosses zero, the instantaneous value of the circuit voltage is greater than the arc voltage value. At the same time, in order to limit the short-circuit current, it is necessary to connect a resistor of a certain value in series in the power supply circuit. Under the action of the electric field, the surface of the object is bombarded by electrons moving at high speed, thereby heating the object into electron beam heating, and the electric heater is also heated, which not only can change the heating power conveniently and quickly, but also can freely change the heated part or free. Adjust the area of the electron beam bombardment part; increase the power density so that the material of the bombardment point evaporates in an instant.