When the fan is thawed, the flow of the fan is periodically repeated and varies over a wide range. Due to the large fluctuations in the flow of the air flow of the violent impact, so that the fan itself has a strong vibration, while the noise of the fan work intensified.Axial Fan Large capacity of the high pressure head fan generated when the great harm caused by the surge, may lead to damage to equipment and bearings, resulting in accidents, a direct impact on the safe operation of the boiler.
Prevention of axial fan surge measures:
1) Keep the fan working in a stable area. Therefore, the P-Q characteristic curve should be selected without a hump fan; if the performance curve of the fan has a hump, Axial Fan the fan should be kept in the stable area.
2) Recycling is used. So that part of the exhaust gas and then lead back to the fan inlet, do not make the fan flow is too small and in the unstable area of work.
3) Install the release valve. When the delivery flow is less than or close to the critical flow of surge, open the bleed valve, let go of some of the gas, Axial Fan reduce the pressure on the tube to avoid surge.
4) Use the appropriate adjustment method to change the flow of the fan itself. Such as the use of changing the speed, the blade installation angle and other methods to avoid the operating point of the fan into the surge zone.
5) When the two fans run in parallel, Axial Fan should try to adjust the output balance, to prevent excessive deviation.
The axial fan is operated according to the pulsation principle. Impeller upstream and downstream of the static pressure is almost equal. Axial Fan When the fluid passes through the impeller, the energy delivered to the fluid mainly refers to the useful energy in the form of kinetic energy downstream of the impeller. Axial Fan The flow of fluid from the impeller is a vortex that can be directly fed into the connected diffuser by the rear guide vanes downstream of the impeller, allowing most of the kinetic energy to be converted to the required hydrostatic energy.
The operating range of the axial fan is limited by the stall line. If this limit is exceeded, the airflow at the blade will inevitably be locally separated. Axial Fan When there is a certain amount of eddy current in the fan, it may produce 'surge', that is, the air flow cycle backwards.