The adjustable static blade axial flow fan allows for the regulation of wind pressure and air volume by adjusting the inlet guide blades during operation. The fan structure is relatively simple, with a lower rotational speed compared to a moving blade adjustable axial flow fan, and its design and performance fall between that of a moving blade adjustable axial flow fan and a centrifugal fan.
The adjustable static blade axial flow fan allows for the regulation of wind pressure and air volume by adjusting the inlet guide blades during operation. The fan structure is relatively simple, with a lower rotational speed compared to a moving blade adjustable axial flow fan, and its design and performance fall between that of a moving blade adjustable axial flow fan and a centrifugal fan. By utilizing the inlet guide vanes to alter the incoming air conditions to the impeller, the static blade adjustable axial flow fan can improve its performance. In certain ranges, reverse direction adjustment to achieve negative pre-swirl can also enhance the fan's performance.
The efficiency curve of the static blade adjustable axial flow fan is nearly circular, and its high-efficiency operation zone is between that of the moving blade adjustable axial flow fan and the centrifugal fan. The fan achieves high efficiency at TB point and BMCR conditions. For boiler units with basic load and suitable peak regulation, its electrical consumption is comparable to that of the moving blade adjustable fan. However, when the unit often operates at low loads, the efficiency of the fan declines more significantly compared to the moving blade adjustable axial flow fan. Due to the characteristics of the fan, the efficiency of a small static blade adjustable fan will not exceed 86.5%.
The rotor's outer edge of the static blade adjustable fan has a lower linear velocity, which provides better adaptability to dust content at the inlet compared to the moving blade adjustable fan. When the dust content is below 400mg/Nm³, the blade life can exceed 20,000 hours. The fan has a simpler structure and fewer parts that require maintenance. The rear guide vanes are the main wear parts, and they are usually designed to be removable for easy replacement. Additionally, after 1–2 major overhauls, the impeller blades can be replaced 3–4 times on the original hub, further extending the impeller's lifespan.
The static blade adjustable fan uses rolling bearings with grease lubrication, and the bearing housing is equipped with forced ventilation cooling. The electric adjustment mechanism, compared to the oil station lubrication and hydraulic adjustment of moving blade adjustable fans, results in lower operating and maintenance costs.
