Abstract: A duct fan (1) has a centrifugal fan with a motor (10) and a centrifugal impeller (11). A housing has an intake shell (2) on an intake side, that defines an intake portion (52), and accommodates the centrifugal impeller (11). The housing also has an exhaust shell (3) on an exhaust side that defines an exhaust portion (53). A bowl-shaped motor mount (5) is arranged in the exhaust shell (3). A continuous flow channel (20) to the exhaust portion (53) is formed between the motor mount (5) and the exhaust shell (3). A flow (S) generated by the centrifugal impeller (11), during operation, is guided by the flow channel (20).

Abstract: The invention relates to a drum rotor wheel for a fan having bulges to accommodate balancing weights. A drum rotor wheel according to the invention has several blades that are curved forward. The blades have a leading edge and a trailing edge. A top disc and a bottom disc are provided on the drum rotor wheel. At least one blade of the drum rotor wheel has a bulge on its leading edge. This bulge minimizes the area of flow separation, as a result of which the magnitude of the flow separation is likewise minimized. In other words, due to the bulge, the efficiency of the drum rotor wheel is increased.

Abstract: The invention relates to a drum rotor wheel for a fan having bulges to accommodate balancing weights. A drum rotor wheel according to the invention has several blades that are curved forward. The blades have a leading edge and a trailing edge. A top disc and a bottom disc are provided on the drum rotor wheel. At least one blade of the drum rotor wheel has a bulge on its leading edge. This bulge minimizes the area of flow separation, as a result of which the magnitude of the flow separation is likewise minimized. In other words, due to the bulge, the efficiency of the drum rotor wheel is increased.