Can the outlet air pressure of a centrifugal fan exceed the rated value?
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As the title suggests, the blower motor has a power of 900 kW and a wind pressure of 11,900 Pa. By keeping the inlet damper fully open and reducing the outlet damper, can the wind pressure at the blower’s outlet be increased to 14,000 Pa?
The pressure can be achieved, but does it meet the allowable operating conditions of the unit? As mentioned above, it is necessary to examine the unit’s operation curve in order to make a definitive assessment!
Blowers are divided into positive-displacement and centrifugal types. Theoreticalmente, it is achievable for positive-displacement types if the motor does not trip due to overcurrent protection. Centrifugal types are not suitable, as extremely high pressures can cause surge; in other words, when the pressure exceeds the centrifugal force generated by rotation, the gas under pressure will flow back toward the fan outlet along the impeller’s flow channels, resulting in repeated fluctuations. It can be said that neither form of fan can achieve this. It’s impossible for the design margin to be this large. For reference only.