Patent attributes
A fan has an air conveying conduit (16) and a fan wheel (22) arranged therein, which wheel is rotatable about a central axis (25) and is formed with a central hub (20; 120) having an outer periphery (27) on which fan blades (26) are mounted. These extend with their radially outer rims (40) as far as a surface (17) that is substantially coaxial with the central axis (25) and delimits the air conveying conduit (16) externally. The blades (26) have a profile similar to an airfoil profile. A flow element (42) is provided along the radial outer edge (40) of a fan blade and serves as an obstacle to a compensating flow proceeding around that radial outer edge (40) from the delivery side to the intake side, and likewise has, in cross section, an airfoil profile.