Design of the Inlet Vanes

In conventional tangential inlet cyclones the swirl velocity near the wall is determined by the entrance duct velocity Cj , and an entrance constriction coefficient. In swirl tubes, it is mostly determined by the velocity exiting the 

Only sporadic work has been done to optimise the shape of the vanes for maximal swirl generation with minimal pressure drop. Simple vanes are 2-D , which are only bent in one direction, while 3-D vanes are also twisted so that a line drawn in the plane perpendicular to the cyclone axis along the surface of the vane will always cut the swirl tube axis. 

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