Patent attributes
A mixed flow fan wheel has a convex hub, an axially-spaced away concave annular shroud, and a plurality of angularly distributed blades extending between and interconnecting the hub and shroud, all which cooperatively define a plurality of inter-blade flow channels. Each has a pressure surface and spaced suction surface extending not only between spaced inlet and discharge edges but also, crosswise thereto, spaced hub-side and shroud-side edges. Each discharge edge is convex relative a center of geometry of the blade therefor. Each inter-blade flow channel originates in a generally rectangular shape between flanking inlet edges and terminates in another generally rectangular shape between flanking discharge edges, with a procession of gradations of generally rectangular shapes forming a progressive transition therebetween. Moreover, each inter-blade flow channel twists or corkscrews from inlet thereof to the discharge.