what is centrifugal fan， how to select correct specification

What is a centrifugal fan

What should be paid attention to in the selection of centrifugal fans

A centrifugal fan is a fluid machine that relies on input. Centrifugal fans are widely used in ventilation, dust removal and cooling of charging piles, factories, mines, tunnels, cooling towers, robots, purifiers, vehicles, ships and buildings; ventilation and cooling in air conditioning equipment and household appliances, centrifugal The fan can be made into two types: right-handed and left-handed. Viewed from the side of the motor, the impeller rotates clockwise, called a right-handed fan, and counterclockwise, called a left-handed fan. The working principle of a centrifugal fan is roughly the same as that of a compressor. According to the principle of kinetic energy conversion, the pressure of the gas is increased and the gas is transported. The high-speed rotating impeller is used to accelerate the discharge of the gas, and then decelerate and change the flow direction to convert the kinetic energy into pressure. Handle as an incompressible fluid.

1 . The main control parameters of the centrifugal fan are air volume, total pressure, efficiency, specific sound pressure level, speed and motor power.

2 . Centrifugal fans are divided into three pressure levels: high pressure p>3000Pa, medium pressure 1000≤3000pa, and low pressure p<1000pa. When selecting, different types of centrifugal fans should be selected according to the physical, chemical properties and uses of the gas being transported.

3 . When selecting a centrifugal fan, the leakage loss of the piping system, the calculation error, and the actual air volume of the centrifugal fan should be considered. For the negative deviation of wind pressure, the air volume is generally 1.05~1.1, and the safety factor of wind pressure is 1.1~1.15. However, it is not appropriate to use an excessive safety factor to prevent the centrifugal fan from operating efficiently for a long time.

4 . Pay attention to the matching relationship between the resistance characteristics of the pipe network and the characteristics of the centrifugal fan. In order to make the centrifugal fan run stably, the centrifugal fan should be used to work near its highest efficiency point. 80%). The efficiency of the fan selected in the design condition should not be lower than 90% of the maximum efficiency of the fan.

5 . When a variable frequency centrifugal fan is used, the total pressure loss calculated by the system should be taken as the rated wind pressure, but the fan motor power should be added 15~20% to the calculated value

6 . When the operating conditions of the fan (such as gas temperature, atmospheric pressure, etc.) are inconsistent with the sample conditions of the fan, the performance of the fan should be corrected.

7.  When choosing a centrifugal fan, you should compare them carefully, and give priority to products with higher efficiency, smaller machine size, light weight and wide adjustment range.

8 . When choosing a centrifugal fan, not only the one-time investment issue, but also the long-term economical operation effect should be considered.

9 . When multiple fans are running in parallel or in series, centrifugal fans of the same type should be selected.