The invention discloses a twisted
diffusion cylinder and an axial-flow fan applying the same. The twisted
diffusion cylinder comprises a cylinder body, wherein through ventilation holes are formed in the cylinder body in the axis direction, the two ends, in the axis direction, of the cylinder body are an air inlet end and an air outlet end, and from the air inlet end to the air outlet end in the axis direction, the sectional area of the inner wall surface of the cylinder body is gradually increased in a manner of being vertical to the axis, and the cylinder body is arranged in a mode of being twisted along a coaxial
spiral line. The axial-flow fan comprises a wind wheel and the cylinder body, wherein the spiral direction of the
spiral line is opposite to the rotating direction of the wind wheel. The twisted
diffusion cylinder and the axial-flow fan applying the same have the following beneficial effects: on the premise of not changing the original size and installation matching sizes, reverse secondary flow is generated when
airflow passes through the cylinder body to weaken eddy and disturb a boundary layer on the inner wall surface, the rectification effect is enhanced, tangential
airflow flowing is reduced, the flowing speed of the axial
airflow is increased, the effects of pressurization, efficiency increasing,
noise reduction and resistance reduction are further achieved on the basis of an original diffusion cylinder, and through experimental calculation, the efficiency is increased by 2% or above, and the
noise is reduced by 2 dB (A) or above.