PTC electric heater and temperature automatic control cabinet
The materials used in PTC electric heaters are generally required to have large resistivity, small resistance temperature coefficient, small deformation at high temperatures, and not easy to embrittle. Common are iron-aluminum alloy, nickel-chromium alloy and other non-metallic materials, such as silicon carbide, molybdenum disilicide.
According to the different materials, the working temperature of the PTC electric heater heating element can reach 1000-1500 °C, while the working temperature of the non-metal heating element can reach 1500~1700 °C. The latter is easy to install and can be replaced in the hot blast furnace, but it needs to be regulated in its operation, and the service life is shorter than that of alloy thermal energy elements, generally used in high-temperature furnaces, where the temperature exceeds the allowable working temperature of the metal material heating element and some special occasions.
The thermal effect formed by the induced current (eddy current) induced by the conductor in the alternating electromagnetic field causes the conductor to heat itself. Induction heating adopts AC power supply with frequency of 50~60 kHz, medium frequency (60~10000 Hz) and high frequency (more than 10000 Hz), which can meet different heating process requirements. Industrial frequency power supplies are AC power supplies commonly used in industry, and most use 50Hz industrial frequency power supplies. When the power frequency power supply is used for induction heating, the applied voltage must be adjustable. The high-voltage power supply (6~10 kV) can be used to supply power, can also be powered by heating equipment, and can also be powered by heating equipment in the 380-volt low-voltage grid.
