Centrifugal fan is a widely used equipment for ventilation, dust removal, and cooling in factories, mines, tunnels, cooling towers, vehicles, ships, and buildings. Its main components include impeller, casing, inlet box, pilot, diffuser, etc.
impeller
The impeller is the core component of a centrifugal fan, and its size and shape have a significant impact on the performance of the fan. The impeller is usually composed of a front disc, a rear disc (middle disc), blades, and a shaft disc. According to the different outlet angles of the blades, the impeller of a centrifugal fan can be divided into three types: forward, radial, and backward. The shaft disc is a circular disk on the fan shaft, which plays a role in preventing gas leakage and providing some insulation.
Shell
The casing consists of a snail shell, an air inlet, and a snail tongue. The function of the snail shell is to collect the gas coming out of the impeller and guide it to the air outlet, discharging the gas into the pipeline or atmosphere. The air inlet, also known as the collector, can ensure that the airflow inside the impeller inlet is uniform, thereby reducing airflow loss. The snail tongue plays a crucial role in airflow diversion, with most of the airflow flowing towards the outlet of the fan and a small portion flowing back into the volute through the gap between the snail tongue and impeller.
Inlet air box
The air inlet box is generally only used in large or double suction centrifugal fans, which can reduce the flow loss caused by uneven airflow entering the impeller.
Preamble
The pilot is mainly used in the inlet or inlet duct of large centrifugal fans that require performance adjustment, and there are two types: axial and radial.
Diffuser
The diffuser is usually installed at the outlet of the fan casing to reduce the outlet flow velocity and convert some dynamic pressure into static pressure. There are two forms of diffusers: circular cross-section and square cross-section.
The main components of a centrifugal fan include the impeller, casing, inlet box, pilot, and diffuser. Each component has its specific function and role, working together to ensure the normal operation and efficient operation of the centrifugal fan.
