380v-200kw Air Heater Meltblown process requires a large amount of hot air. The compressed air output from the air compressor is dehumidified and filtered, then delivered to the air heater for heating, and finally sent to the meltblown die assembly. The air heater is a pressure vessel and must resist oxidation from high-temperature air, so the material must be stainless steel.
The heating element of the air heater is a stainless steel electric heating tube. Multiple baffles are arranged in the heater cavity to prolong the residence time of air in the heater cavity, thereby improving heat exchange efficiency. Appropriately increasing the number of heating tubes and raising the installed power of the air heater can shorten the heating-up time during production line startup. The meltblown process requires high temperature control accuracy for the drawing air heater, and the drawing air temperature must be stable within ±1°C.
Working Principle
A primary coil with many turns and a secondary coil with fewer turns are mounted on the same iron core. The input-to-output voltage ratio equals the turns ratio of the coils, while energy remains constant. Therefore, the secondary coil generates a large current under low voltage conditions. For induction heaters, the bearing is a short-circuited single-turn secondary coil, passing a large current under low AC voltage, thus generating significant heat. The heater itself and the magnetic yoke remain at normal temperature. Since this heating method induces current, the bearing becomes magnetized. It is important to demagnetize the bearing afterward to prevent it from attracting metal chips during operation. FAG induction heaters have an automatic demagnetization function.
It uses the eddy current generated by metal in an alternating magnetic field to heat itself, commonly used in metal heat treatment and other applications. The principle is that when thicker metal is placed in an alternating magnetic field, current is generated due to electromagnetic induction. For thicker metal, the current forms a spiral flow path inside, and the heat generated by the current is absorbed by the metal itself, causing rapid heating.
High-temperature resistance wires are evenly distributed inside a seamless stainless steel tube resistant to high temperatures, and the gaps are densely filled with crystalline magnesium oxide powder with good thermal conductivity and insulation properties. This structure is not only advanced with high thermal efficiency 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 metal tube surface, then transfers to the heated object or air, achieving the heating purpose.
The electric air heater is mainly used to heat the required air flow from the initial temperature to the desired air temperature, up to 850°C.
