In the process of selecting centrifugal fan, it is necessary to determine the flow rate, pressure and density of gas, which is the three essential factors in the selection process of centrifugal fan.
Density of centrifugal fan
If the density of centrifugal fan is not given, the density of working gas should be calculated or converted according to the working conditions of the fan, such as altitude, local atmospheric pressure, working temperature and standard density of gas.
Pressure of centrifugal fan
According to the given or calculated working condition density, the working pressure of centrifugal fan is converted to the pressure in the standard state of the fan. If the fan takes the intake box or muffler, the pressure loss should be taken into account and can be calculated or estimated.
Flow rate of centrifugal fan
If the system requires the mass flow rate of gas in centrifugal fan, it is necessary to convert the mass flow rate of gas into the volume flow rate in the standard state of the fan. If the system requires the volume flow rate of the gas, the volume flow rate under the standard state of the fan is the same as the volume flow rate under the working condition.
The model of centrifugal fan determines its performance curve, which can be divided into dimensionless curve and dimensionless curve. The dimensionality curve is the basis for judging whether it meets the field requirements, while the dimensionless curve is the basis for describing the characteristics of the fan, and the dimensionless curve represents the particularity and universality. Generally available dimensionless parameters are flow coefficient, pressure coefficient, internal efficiency, specific revolution. One of the flow coefficient and pressure coefficient can be used as the basis for calculating the fan number, the specific speed is the basis for selecting the fan model, and the internal efficiency is the basis for judging whether the model is an efficient fan or not.www.jnblower.com