Principle of Electromagnetic Heater:
An electromagnetic heater is a device that converts electrical energy into heat by utilizing the principle of electromagnetic induction. The electromagnetic controller converts 220V/380V, 50/60Hz AC power into DC power through a rectifying circuit, then transforms the DC power into a high-frequency current of 10-40kHz via a control circuit. As the current flows through the coil, it generates a varying alternating magnetic field. When the alternating magnetic flux lines within the field pass through ferromagnetic materials (such as iron, cobalt, and nickel), numerous tiny eddy currents are induced within the metal, causing the metal to heat up rapidly, thereby achieving the purpose of heating the metal material.
Variable-frequency drives are the core components of high-frequency electromagnetic heaters, utilizing the on-off action of power semiconductor devices to convert AC power sources to another frequency of electrical energy control devices. The variable-frequency drives currently in use mainly adopt AC-DC-AC conversion, first converting the AC power source to DC through a rectifier, and then converting the DC power to AC power with controllable frequency and voltage for the motor. The circuit of the variable-frequency drive generally consists of four parts: rectification, intermediate DC link, inversion, and control. The rectification part is a three-phase bridge uncontrolled rectifier, the inversion part is a IGBT three-phase bridge inverter with PWM output, and the intermediate DC link is for filtering, DC energy storage, and reactive power buffering.
Electromagnetic heating advantages:
Energy-saving, precise temperature control, long lifespan, improved working environment, safe and reliable, utilizes internal heat heating method, the molecules inside the heating body directly感应 magnetic energy to generate heat, with extremely fast heat-up, average preheating time is reduced by over 60% compared to other heating methods, and the thermal efficiency reaches above 97%. Energy-saving by 30% to 70% under the same conditions. The electromagnetic heating coil section employs a ring-shaped cable structure, with the cable itself not generating heat, resulting in minimal thermal resistance and low thermal inertia. The outer wall temperature of the heating body is consistent, with real-time and accurate temperature control, 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 safe for human touch, enhancing the working environment of the production site and significantly boosting the enthusiasm of production workers, while reducing ventilation and cooling costs in the factory area during summer. The electromagnetic coil has good insulation properties, eliminating the need for direct contact with the outer wall of the heating body, making the heating process safer.
