Abstract: Apparatus to remove dust, fibers, lint or other undesirable particles from air. Air ladened with dust, lint or other undesirable matter is drawn into a filtering housing to contact the surface of a rotatable screen-covered drum. The air passes through the drum while the particles remain on the drum surface. The air passes from a higher pressure area exterior of the drum into a lower pressure area within the center of the drum and is conveyed away. The particles are retained on the exterior surface of the drum which is covered by the fine mesh screen. The particles, which form a bat, are then separated from the rotating drum surface by being moved into contact with a smooth compressor roll cooperating with a flighted doffing to lift away the bat from the drum and drop it to a collection zone. Fixed rubber seals are located to contact the rotating edges of the drum.