Anti-surge impeller of axial-flow fan

The utility model discloses an anti-surge impeller of an axial-flow fan. Existing anti-surge measures of subway and tunnel fans are achieved generally by arranging anti-surge rings on the inner wall of a casing corresponding to the top of an impeller, the anti-surge rings can effectively prevent stalls and surges of a fan during rapid air blast capacity reduction, but the ant-surge structure is complex and the fan production process is complicated. The anti-surge impeller of the axial-flow fan is characterized in that two sides of every blade both contract inwards, the setting angle of every blade is 40-50 degrees, the radius of curvature rho of every blade is 22-28; with an axial-flow fan impeller with a diameter of 100mm serving as a benchmark, the ratio of chord length of the outermost end of the blade to the height of the blade is (0.15-0.20) : 1, and the chord length of the innermost end of the blade to the height of the blade is (0.45-0.06) : 1. The anti-surge impeller of the axial-flow fan is reasonable in structural design, needs no anti-surge rings arrangement and enables the fan to avoid surges when the fan deviates from a normal working condition or is in an emergency state.