The integration and summary of the guide vanes and diffuser of the exhaust fan box

The integration and summary of the guide vanes and diffuser of the exhaust fan box

The main performance items of the exhaust air box are tested in the factory and the flow rate, air volume, pressure, shaft power and noise of the test conditions (inlet temperature, atmospheric pressure, speed, etc. during the test) Measured value converted to rated conditions designated temperature, gas density, intake pressure, speed, etc.) and achieved. Most of the boiler feed fan selection rear guide vane layout, rear guide vane will be the export of the impeller of the air flow movement into the axial movement, improve the power of the fan. Exhaust air box air flow through the rear guide vane kinetic energy is still large, at the highest power point when the total pressure of about 30%. Therefore, in order to improve the power of the fan, but also in the rear guide vane and then set the diffuser, and further some kinetic energy into pressure energy.

The type of diffuser is mainly the following:

  1. The diffuser is simply diametrically sized, and the inner core is a shortened cone, so that the flow area of the fluid can be added. This diffuser is easy to use and is suitable for applications where the diameter of the exhaust pipe is the same as the outside diameter of the fan.

  2. A diffuser with a dispersive outer cylinder and a converging mandrel is preferable because the dispersion area is large, so that it is suitable for the case where the diameter of the exhaust pipe is larger than the outside diameter of the blower.

  3. A diffuser with an equal diameter inner core and a dispersive outer cylinder. Its expansion effect is not as good as the above, but because it is simple layout technology, but also applies to the diameter of the exhaust pipe is greater than the fan diameter of the occasion.

  In normal daily life, we take the exhaust fan, the air flow through the diffuser due to the expansion of the flow area, there will be a certain loss of resistance, in order to reduce the resistance of the diffuser, in particular, to prevent the boundary layer The divergence angle of the diffuser can not be too big. In order to improve the function of the fan, improve the power of the fan. Some of the current large-scale exhaust fan chassis, the fairing and diffuser core made of a streamlined shape of the whole.

Shanghai up Pa Ventilation Equipment Co., Ltd