Centrifugal fan selection needs attention 

 The correct selection of centrifugal fan is a very important link for manufacturers, because the correct selection is related to whether we can give full play to the maximum efficiency and produce the maximum work efficiency. The following Kunshan Sheng Tang ventilation equipment manufacturers for this A question to give you some reference guidance and advice. Centrifugal fan selection, first of all to determine the gas flow, pressure, density, which is the three elements of the centrifugal fan selection process. Flow rate: If the system requires the mass flow rate of gas, it needs to convert the mass flow rate of gas into the volume flow rate under the standard condition of the fan. If the system requires the volume flow of gas, the volume flow of the fan under standard condition The volume is the same as the volume flow under the working condition. Density: If the density is not set, it is necessary to calculate or convert the density of gas under working conditions according to the working environment of the fan, such as altitude, local atmospheric pressure, working temperature, and gas standard density. Pressure: According to the given or calculated working condition density, the working condition pressure is converted into the fan pressure under standard condition. If the fan has an intake box or muffler, it is necessary to consider the pressure loss, which can be calculated or estimated Losses are generally between 100 and 300Pa. The next is to find the specific revolution of the fan, because the specific revolution is an important step in the selection process of the centrifugal fan, is the main basis for judging the specific model of the fan. The performance will be converted to the standard state of the fan Parameters and speed are substituted into the calculation formula of specific revolutions. Different specific revolutions can be calculated according to different rotational speeds. First-order specific revolutions are the basis of single suction fan. Second order specific revolution is the basis of double suction fan. The model of centrifugal fan determines its performance curve, which can be divided into dimensionless curve and dimensionless curve. The dimensionless curve is the basis for determining whether the field requirements are met, while the dimensionless curve is the basis for describing the fan characteristics Data, dimensionality represents particularity, dimensionlessness represents universality. Generally available dimensionless parameters are flow coefficient, pressure coefficient, internal efficiency, specific revolutions. Flow coefficient, pressure coefficient one of them can be used The specific revolution is the basis for selecting the fan model, and the internal efficiency is the basis for judging whether the model is a high efficiency fan. According to the specific revolution obtained, the model of the fan is selected and whether the corresponding point is in the high efficiency zone. If it is in the high efficiency zone, the number of the fan is preliminarily calculated according to the corresponding flow coefficient or pressure coefficient. According to the known density, speed, model, and the rough calculation of the fan machine number round, using the point drawing function of the software, can express the fan's dimensional performance curve, and calibrate the fan's working point, can also be List the dimensional performance table and calibrate the position of the operating point. Further, the internal power of the fan can be calculated according to the actual performance. After the above three stages, the selection of centrifugal fan is basically over. When we buy, as long as we follow the above steps to choose to ensure that you can choose the right fan.