The fan for the furnace is a machine that depends on the input mechanical energy to increase the gas pressure and send gas simultaneously. It is a kind of driven fluid machinery. Centrifugal fans are widely used in factories, mines, tunnels, cooling towers, vehicles, ships and buildings for ventilation, dust removal and cooling; Ventilation and inducement of boilers and industrial furnaces; Cooling and ventilation in air conditioning equipment and household electrical equipment; Drying and selection of grains; Wind tunnel aeration and propulsion of wind sources and hovercraft.

According to the principle of converting kinetic energy into potential energy, the furnace fan uses a high-speed rotating impeller to accelerate the gas, and then decelerates and changes the flow direction to convert kinetic energy into potential energy (pressure). In a single-stage centrifugal fan, the gas enters the impeller from the axial direction, changes radial as the gas flows through the impeller, and then enters the diffuser. In the diffuser, the gas changes the direction of flow and the increase in the section area of the pipe slows down the gas flow, which converts kinetic energy into pressure energy. The pressure mainly occurs in the impeller, followed by the diffuser process. In a multistage centrifugal fan, a reflow is used to make the air flow into the next blade to produce a higher pressure.