Principle of electromagnetic heater:
An electromagnetic heater is a device that converts electrical energy into heat using the principle of electromagnetic induction. The electromagnetic controller converts 220V/380V, 50/60Hz AC power into DC through a rectifying circuit, then through a control circuit, it converts the DC into a high-frequency current of 10-40kHz. As the current flows through the coil, it generates a varying alternating magnetic field. When the alternating magnetic lines in the field pass through ferromagnetic materials (such as iron, cobalt, nickel), numerous small eddy currents are produced within the metal, causing the metal to heat up rapidly by itself, thereby achieving the purpose of heating the metal.
Inverters are the core components of high-frequency electromagnetic heaters, functioning as control devices that convert power frequency AC sources into electrical energy of another frequency using the on-off action of power semiconductor devices. The inverters currently in use mainly operate in an AC-DC-AC mode, first converting the power frequency AC source into DC power through a rectifier, and then converting the DC power into AC power with adjustable frequency and voltage to supply the motor. The circuit of an inverter typically consists of four parts: rectification, intermediate DC section, inversion, and control. The rectification section is a three-phase bridge-type uncontrolled rectifier, the inversion section is an IGBT three-phase bridge inverter with PWM output, and the intermediate DC section is for filtering, DC energy storage, and buffering reactive power.
Electromagnetic heating advantages:
Energy-efficient, precise temperature control, long lifespan, improves working environment, safe and reliable. Utilizes internal heat heating method, the molecules within the heating body directly感应 magnetic energy to generate heat, resulting in a very quick heat-up time. The average preheating time is over 60% shorter than other heating methods, with a heat efficiency of over 97%. It saves 30% to 70% energy under the same conditions. The electromagnetic heating coil part uses a circular cable structure, the cable itself does not produce heat, has minimal heat resistance, and low thermal inertia, ensuring uniform wall temperature of the heating body. The temperature control is real-time and accurate, and can withstand temperatures above 500°C, with a lifespan of up to 10 years. The surface temperature of the equipment can be improved to a level where it is touchable by the human body, enhancing the working environment in the production area and significantly boosting the enthusiasm of production workers, reducing ventilation and cooling costs in the factory area during summer. The electromagnetic coil has excellent insulation properties, eliminating the need for direct contact with the heating body's outer wall, making the heating process safer.
