Duct electric heater is mainly used for heating air in ducts. It is available in three types: low temperature, medium temperature, and high temperature. Structurally, they all use steel plates to support the electric heating tubes to reduce vibration, and the junction box is equipped with an over-temperature control device. In terms of control, in addition to over-temperature protection, an interlock device is installed between the fan and the duct electric heater to ensure that the heater starts only after the fan starts. A differential pressure device is installed before and after the heater to prevent fan failure. The gas pressure heated by the duct electric heater should generally not exceed 0.3 Kg/cm². If it needs to exceed this pressure, a circulating electric heater can be used. The maximum heating temperature for low-temperature heaters is 160°C; for medium-temperature, 260°C; and for high-temperature, 500°C.
Features of the Heater
Through the air supply system, the gas entering the duct electric heater forms high-temperature and high-pressure gas that is discharged. The generated hot air is dry, free of moisture, static electricity, non-conductive, non-combustible, non-explosive, non-electrochemical corrosive, pollution-free, safe, and reliable. It is widely used in aerospace, weaponry, chemical industry, power station air conveying chute aeration heating, electrostatic precipitator hopper aeration heating, and ash silo aeration heating.
High-temperature resistance wires are evenly distributed inside a high-temperature resistant stainless steel seamless tube, and the gaps are densely filled with crystalline magnesium oxide powder, which has good thermal conductivity and insulation properties. This structure is not only advanced and highly efficient but also provides uniform heating. When current passes through the high-temperature resistance wires, the generated heat diffuses through the crystalline magnesium oxide powder to the surface of the metal tube, and then transfers to the heated object or air, achieving the purpose of heating.
Duct electric heaters are used in industrial ducts, air conditioning ducts, and various industries to heat air and increase the output air temperature. They are generally inserted horizontally into the duct. According to the duct working temperature, they are classified as low, medium, and high temperature; according to the air velocity in the duct, they are classified as low, medium, and high wind speed.
