Measures to prevent axial fan surge

  • Make the flow rate of the pump or fan constant greater than QK. If the required flow in the system is less than QK, a recirculation pipe or an automatic discharge valve can be installed to make the discharge flow of the fan always greater than QK.


  • If the pipeline performance curve does not pass through the origin of the coordinates, changing the fan speed may also obtain a stable operating condition. Through the parabola of the highest pressure point in the performance curve of the fan at various speeds, the performance curve of the fan is divided into two parts, the right side is the stable working area, and the left side is the unstable working area. When the pipeline performance curve passes the coordinate origin, change the speed There is no effect, so the operating points at each speed are similar operating points.


  • The axial flow fan adopts adjustable blade adjustment. When the flow required by the system decreases, the installation angle is reduced, the performance curve moves down, the critical point moves to the lower left, and the output flow decreases accordingly.


  • The most fundamental measure is to try to avoid using fans with hump-shaped performance curves, and use fans with performance curves that slope straight down.

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