Abstract: The invention relates to a coupling between a centrifugal fan and the suction inlet thereof, comprising a suction inlet (1) defining an opening (2) for the passage of a flow of fluid under suction and a rotatably mounted centrifugal suctioning fan (3). A closure coupling is formed around the opening (2), between said centrifugal fan (3) and the suction inlet (1), by means of fitting together flanges (7) of the centrifugal fan (3) and flanges (8) of the suction inlet (1), which flanges define therebetween a labyrinthine passage that obstructs the ingress of an air disturbing flow through the coupling.

Abstract: A sound-proofed helicocentrifugal fan includes a helicocentrifugal propeller associated with a motor, housed in a casing formed by a central piece and respective end pieces, which pieces are perforated with holes distributed over the entire surface except for the area around the propeller. A sound-absorbing blanket surrounds the casing, and an outer casing is disposed around the entire assembly.

Abstract: The invention relates to a sound-proofed helicocentrifugal fan comprising a helicocentrifugal propeller (6) associated with a motor (5), housed in a casing formed by a central piece (1) and respective end pieces (2 and 3), which pieces are perforated with holes distributed over the entire surface except for the area around the propeller (6), a sound-absorbing blanket (8) being incorporated on said casing and an outer casing (7) being incorporated around the entire assembly.