The air electric heater consists of two parts: the heater body and the control cabinet.
1.1 The electric heater body is composed of multiple tubular electric heating elements, a shell, a protective cover, a base, and other components. The heating element is a tubular electric heating element made of high-temperature resistance alloy wire, with a stainless steel tube as the protective sleeve and crystalline magnesium oxide as the filler, formed through a compression process. It features good mechanical strength, high thermal efficiency, wear resistance, and corrosion resistance. A guide baffle is installed inside the shell to ensure uniform heating of the air during flow.
1.2 The working principle of the control cabinet is to form a measurement, regulation, and control loop using an intelligent digital temperature controller, a high-power thyristor, and a thermal resistor. The thermal resistor converts the outlet temperature of the heater into a milliampere signal, which is sent to the intelligent digital temperature controller for amplification and comparison, and then the corresponding temperature value is displayed. When the displayed value is higher than the set value, the thyristor does not conduct. When the displayed value is lower than the set value, the intelligent digital temperature controller triggers the thyristor to conduct. When the displayed value is close to the set value (i.e., near the set value), the intelligent digital temperature controller changes according to the P, I, D law, so that the control cabinet has good control accuracy and regulation performance. The intelligent digital temperature controller automatically changes the number of trigger pulses of the thyristor based on the milliampere signal from the thermal resistor, that is, controls the conduction angle of the thyristor per unit time, adjusts the voltage, controls the heating power of the heating element, ensures energy saving and constant temperature, avoids current impact, and extends service life. When the equipment is suddenly shut down and then restarted, the control cabinet can automatically adjust smoothly.
1.3 When the electric heating elements are set in groups, the control cabinet can also adopt group control. The control part consists of digital circuits, trigger circuits, and other components. It automatically engages at low temperatures, alarms at high temperatures, and automatically cuts off power to achieve uniform temperature control.
