Interpretation Of Centrifugal Blower Surge

There are two prerequisites for the centrifugal blower system surge:

Firstly, the centrifugal blower flow is very small, the difference between the inlet airflow angle β1 and the blade inlet installation angle β1A is larger, that is, the angle of impact τ=β1A-β1 is significantly increased. The more rapid the efficiency is, the more it is impossible to output the airflow; the second is the influence of the pipeline. If the resistance coefficient of the pipe network is large, the performance curve of the pipe network is easily intersected with the ventilation performance curve at the lower left part, and the surge occurs in the surge zone. Vibration. The pipe network has a small resistance, or the pipe is relatively short and it is not easy to generate surge.

In general, high-pressure small-flow centrifugal blowers are more prone to surge than low-pressure large-flow centrifugal blowers. If measured by test methods, the product can be determined by the analogy method to determine its surge limit. The centrifugal blower with a pressure rise of 500~1000pa, the surge flow is generally 50% of the design flow.

Surge is very harmful to the centrifugal blower. When the surge occurs, the noise is intensified due to the pulse of the airflow and the periodic oscillation. The centrifugal blower not only greatly increases the blade stress of the impeller, but also has a great impact on the impeller weld and the connecting rivet, and also makes The axial force of the main shaft and the bearing, the bearing and the bearing housing are greatly increased, which directly jeopardizes the impeller, the main shaft, the bearing, the bearing housing and the foundation.