Abstract: A central vacuum or air cleaning system handling fibrous materials such as spilled cotton waste in a cotton gin or lint in a textile mill, chaff in grain handling and/or wood dust and dirt in lumber industries and other air contaminating industrial processes. Dirt and lint laden air is drawn into a bin structure with a drum filter or condenser at the top that rotates through an area in operational contact with doffer rolls that remove drum filter deposited lint and dirt to fall down a still chamber provided with an internal plate or baffle extending downwardly from the tower doffer roll a substantial distance approximating one-half the vertical length of the bin. This eliminates pressure differential across the critical area of the doffer rolls that is encountered with filter drum and doffer roll structure delivering deposited lint and dirt waste directly to the exterior.