Duct Type Electric Heater
Duct type electric heaters are mainly used for air heating in ducts, and are available in three specifications: low temperature, medium temperature, and high temperature. Structurally, they share the common feature of using steel plates to support the electric heating tubes to reduce vibration. The junction boxes are equipped with over-temperature control devices. In terms of control, in addition to over-temperature protection, an interlock device is installed between the fan and the duct type electric heater to ensure that the heater starts only after the fan starts. A differential pressure device is added before and after the heater to prevent fan failure. The gas pressure heated by the duct type electric heater should generally not exceed 0.3 Kg/cm2. If it is necessary to exceed the above pressure, a circulating electric heater can be selected. The maximum heating temperature for low-temperature type heaters is not exceeding 160°C; for medium-temperature type, not exceeding 260°C; and for high-temperature type, not exceeding 500°C.
Features of the Heater
Through the air supply system, the gas entering the duct type electric heater is formed into high-temperature, high-pressure gas and discharged. The produced hot air is dry, free of moisture, static-free, non-conductive, non-combustible, non-explosive, free of electrochemical corrosion, pollution-free, safe, and reliable. It is widely applied in aerospace, weapon industry, chemical industry, power station air conveying chute gasification wind heating, electrostatic precipitator ash hopper gasification wind and ash silo gasification wind heating, and other aspects.
High-temperature resistance wires are evenly distributed inside the high-temperature resistant stainless steel seamless tube, and the gaps are densely filled with crystalline magnesium oxide powder with good thermal conductivity and insulation performance. This structure is not only advanced and highly efficient in heat, but also uniform in heating. When current passes through the high-temperature resistance wire, 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 type electric heaters are used in industrial ducts, air conditioning ducts, and various industries to heat air through air convection, increasing the temperature of the output air. They are generally inserted horizontally into the duct opening. According to the working temperature of the duct, they are divided into low temperature, medium temperature, and high temperature; according to the wind speed in the duct, they are divided into low wind speed, medium wind speed, and high wind speed.
