So now, it needs to place more and more; but excessive centrifugal fan air flow problems arise in the course of the Central Standing Committee. In this paper, the problem for centrifugal fans explaining to do. Centrifugal exhaust fan is an ideal product for ventilation. Since the centrifugal fan is to rely on the input of mechanical energy. But due to the low gas flow rate, increase the gas pressure side to send a gas driven fluid machinery; centrifugal fan and turbine compressor works basically the same. Little change in pressure, generally do not need to consider changes in the specific volume of gas that the gas as an incompressible fluid disposal. So centrifugal fan flow newly installed will be too big, big or too small fan occur after a new installation began formal operation, or use of the process too, can eliminate one of the following methods: * change the fan speed to regulate the flow. * An adjustment of the door opening and closing leveling flow. * Change the pipe network to regulate the flow resistance coefficient. * A higher or lower pressure exchange regulating flow fan. Vortex fan, whirlpool fan, vortex pump www.mingxintm.com