The multi-stage centrifugal fan is formed by a motor driving a centrifugal fan, where the centrifugal fan is composed of several impellers in series as the main body, and the supporting bearings are set at both ends of the impeller group, and the temperature is lowered by natural cooling. However, if the pressure in the multistage centrifugal fan exceeds 200 KPa, the forced lubrication system must be used to maintain a stable working state.
From the structural point of view, the core of multi-stage centrifugal fan is the impeller group. The angle of impeller blade is the key to the formation of wind pressure. Therefore, a reasonable angle must be adopted to locate the blade, and its width and radian should be designed according to the size of flow. When installing, the impeller with a slightly wider width is usually installed at the intake end, while the narrow impeller is installed at the outlet end. This combination can ensure the stability of the air pressure.
In order to ensure the smooth operation of multi-stage centrifugal fans, it is necessary to maintain the balance through the balance plate, so as to delay the service life of fan bearings, which is a good operating condition for fans. In addition, chassis, tuyere, sealing system and muffler are also indispensable components of multi-stage centrifugal fan.
The shell of multi-stage centrifugal fan is manufactured by sand-turning parts or welding parts according to the requirements, and is designed as a whole small segment, then superimposed by many segments, so that the shell has a very high strength. The inlet and outlet of multi-stage centrifugal fan are basically made of national standard circular flange, which fully meets the actual application requirements.
The combined seal is used between each stage impeller of multi-stage centrifugal fan and the extension end of the shaft. The seal has the outstanding advantages of good sealing performance, compact structure, simple and quick replacement, etc. The muffler is the standard of the multi-stage centrifugal fan, which is set at the front end of the inlet, outlet and exhaust devices respectively to effectively reduce the noise of the inlet and outlet ducts.