Apparatus for removing dust particles from an air stream

Apparatus for removing dust particles from an air stream, particularly for the ventilation of mines, said apparatus including a centrifugal separator having an air inlet end and an air outlet end and having blade wheel sections driven via a common shaft to rotate at an approximately constant speed within a stationary housing, said blade wheel sections having blades extending in axial planes connected with their radially outer ends to co-rotating peripheral walls, the distance of which walls from the axis of rotation of the blade wheel sections increasing in the direction from the inlet end to the outlet end of the centrifugal separator, at least one of said blade wheel sections having blades radially extending approximately in axial planes, and those portions of said peripheral walls which are spaced the largest distance from the axis having passage openings opening toward the housing surrounding the blade wheel sections, a blower connected to the outlet end of said centrifugal separator for moving the air stream through the centrifugal separator, and a means which precedes the centrifugal separator in the direction of flow of the air for spraying water into the air stream entering the centrifugal separator, characterized in that said blade wheel sections are preceded at the air inlet end of the centrifugal separator by at least one blade wheel section in which those generatrices of the surface of its blades which are equidistant from the axis are inclined at an angle of incidence from lines extending in axial planes parallel to the axis, in a direction which is opposite to the direction in which the resultant vector of the axial air entry velocity vector and the mean peripheral velocity vector of the blades of said preceding blade wheel section is inclined with respect to an axial plane extending through the axis of the centrifugal separator.