Classification of electric heaters

Electric heaters refer to electrical appliances that use electric energy to achieve a heating effect. They are distinguished by the types of heating methods and can be divided into three categories:

1. Electromagnetic heating

Electromagnetic heating is to generate an alternating magnetic field through the components of the electronic circuit board. When an iron-containing container is placed on it, the surface of the container cuts the alternating magnetic field lines and produces an alternating current (that is, eddy current) on the metal part of the bottom of the container. The iron atoms at the bottom of the container move randomly at high speeds, and the atoms collide and rub against each other to generate heat energy. So as to play the effect of heating objects [1]. Because the iron container heats itself, all heat conversion rates are extremely high, reaching 95%. Induction cookers and induction cookers all adopt electromagnetic heating technology.

2. Infrared heating

The heat transfer form of infrared is radiation heat transfer, which transfers energy by electromagnetic waves. When the far-infrared rays irradiate the heated object, part of the rays are reflected back, and part of the rays are penetrated. When the emitted far-infrared wavelength is the same as the absorption wavelength of the heated object, the heated object absorbs the far-infrared. At this time, the molecules and atoms inside the object "resonate"-produce strong vibration and rotation, and vibration and rotation cause The temperature of the object rises to achieve the purpose of heating [2].

3. Resistance heating

A heating method that uses electric current to emit heat through an electric heating element to heat the blank. Common resistance wire heating, ceramic heaters, resistance coil heating, and quartz tube heating are all resistance heating in principle.

Compared

1. The heating of the resistance heater is primitive, so the thermal efficiency is also poor, usually the thermal efficiency is only about 70%, and a large amount of heat energy is dissipated into the air.

2. The infrared heating method is better than the resistance, but still a lot of heat is dissipated into the air, but it is not the infrared itself that dissipates into the air, but the heated object dissipates the heat into the air.

3. When the Feiru electromagnetic heater is working, there is a thermal insulation layer to wrap the heated object, and then the magnetic field directly heats the object itself through the thermal insulation layer, so the thermal efficiency is high and almost no thermal energy is lost, and its thermal efficiency exceeds 95%. Moreover, because the Feiru electromagnetic heater heats the object itself, there is no heat transfer loss. The overall energy saving is about 30%-70% resistance heating under the same conditions. The infrared heater cannot be compared with electromagnetic heating in detail because of its heating characteristics. , But calculated from the emitted temperature, under the same conditions, electromagnetic heating should save more than 20% of energy than infrared heating.