The selection of centrifugal fans is an important part of the fan, as the correctness of the selection is related to whether the centrifugal fan can achieve maximum efficiency and produce maximum working efficiency. How to make a reasonable selection for it? Below, the editor will answer this question and provide readers with some reference guidance and suggestions. The analysis is as follows.
The first stage of selection:
To select a centrifugal fan, the first step is to determine the gas flow rate, pressure, and density. These are the three elements of the centrifugal fan selection process, specifically:
Density is the most crucial first element in the selection process. If density is not given, the density of the working gas needs to be calculated or converted based on the operating environment of the fan, such as altitude, local atmospheric pressure, working temperature, and gas density.
Pressure is the second element in fan selection. Based on the given or calculated operating density, the operating pressure is converted into the pressure under the standard state of the fan. If a fan is equipped with an intake box or muffler, its pressure loss needs to be considered. After calculation or estimation, the estimated loss is generally between 100-300Pa.
Flow rate is the third element in the selection process. If the system requires a mass flow rate of gas, it is necessary to convert the gas mass flow rate to the volumetric flow rate under the standard state of the fan. If the system requires a volumetric flow rate of gas, the volumetric flow rate of the fan under standard conditions is the same as that under operating conditions.
The next step is to calculate the specific speed of the fan, as the calculation of the specific speed is an important step in the fan selection process and the main basis for determining the specific model of the fan. Substitute the performance parameters and speed converted to the standard state of the fan into the calculation formula for specific speed, and calculate different specific speeds based on different speeds. The first order specific speed is the basis for a single suction fan; The second order specific speed is the basis for the double suction fan.