Set air control Set the wind's role is to get accelerated airflow, pressure loss in the case of guaranteed minimum intake velocity uniform, stable. Set the wind is good or bad a great impact on fan performance, and no set of wind turbines is compared to a set of well-designed wind turbine efficiency devices Ring can be increased by 10 - 15%. Set the wind is generally adopts arc. 3 body fairing and diversion For good smooth inlet conditions, the inlet guide vane of the impeller or the front air control means and adapted to set the fairing to Constitute axial fan inlet flow channels. Semi-spherical or dome shape is semi-elliptical, but also together with the rear deflector designed streamlined body, Figure 1-2? Shown. Figure 1-27 Schematic axial fan I an inlet chamber; 2 a shell; 3 a moving blade; 4 a wicket; 5 a rotor blade adjustment mechanism 6 a diffuser; 7 a deflector body; 8 a shaft; 9 a bearing; 10 a coupling 4 vanes Vane axial fan settings There are several situations: ① impeller front set only leading leaf; ② impeller vanes only after setting; ③ Front wheel is provided with guide vanes. Leading role is to make the leaves before the fan airflow into the deflected cited as the air from the axial rotation into, and most Negative rotation number (i.e., the opposite steering wheel) to make the impeller outlet axial flow direction of the airflow. After the guide vane axial fans in the most widely used. Axial gas into the impeller, the impeller effluent gas from the absolute speed Certain rotation, post and guide vane diffuser, the gas flow in the axial direction. 5. Diffusion tube Diffusion tube is the role of the rear vane air flow out of the pressure part of the further converted to static pressure to improve fan static pressure. Expand Loose tube structure shown in Figure 1-28. 6 Performance stabilizing device In recent years, a large axial fan unit on the installation of a stable performance, also known as KSE device (The device consists of the former Soviet Union 3 "K • Ivanov invention) shown in dotted lines in Figure 1-29. When operating at rated flow, KSE has no effect. If the flow rate decreases, a part or the entire outer edge of the impeller Import section stall will occur, resulting in a tangential flow (vortex), when the tangential flow is large, the flow starts reverse back. If there is no KSE device, impeller inlet section of the air more and more unstable; if with KSE device is reverse tapered back Shaped portion and in situ bypass stable, rotor imports no longer blocked. Due to reverse back into the bypass within the turning point, and then cascade Back through the annular groove and join the mainstream, thus ensuring stable operation of axial fan.