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 pass through ferromagnetic materials (such as iron, cobalt, and nickel), countless tiny eddy currents are induced within the metal, causing the metal to heat up rapidly, thereby achieving the purpose of heating the metal material.
Inverters are the core components of high-frequency electromagnetic heaters, functioning as control devices that convert power frequency AC power into another frequency of electrical energy by utilizing the on-off action of power semiconductor devices. The inverters currently in use mainly adopt AC-DC-AC conversion, first converting the power frequency AC power into DC power through a rectifier, and then converting the DC power into AC power with controllable frequency and voltage to supply the motor. The circuit of the inverter typically consists of four parts: rectification, intermediate DC link, 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 waveform output, and the intermediate DC link is for filtering, DC energy storage, and buffering reactive power.
Electromagnetic heating advantages:
Energy-saving, precise temperature control, long lifespan, improved working environment, safe and reliable. Utilizes internal heat heating method, where the molecules within the heating body directly sense magnetic energy to generate heat, resulting in extremely fast heat-up. The average preheating time is reduced by over 60% compared to other heating methods, with a thermal efficiency of over 97%. It saves energy by 30% to 70% under the same conditions. The electromagnetic heating coil section is designed with a ring-shaped cable structure, which itself does not produce 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 during summer. The electromagnetic coil has excellent insulation properties, eliminating the need for direct contact with the outer wall of the heating body, ensuring safer heating.
