Abstract: Fibers and lint floating around a spinning machine are aspirated into a system comprising a plurality of filter boxes, each filter box being divided by a screen into a lower raw-air compartment and an upper clean-air compartment, the latter containing a blower serving to circulate incoming air from the screen to a normally open discharge duct. The raw-air compartment has a permanently open intake duct for the aspirated air and is further provided with a normally closed suction duct communicating with a central exhauster common to a group of such filter boxes. From time to time, or when a sensor detects an excessive pressure in the raw-air compartment due to accumulation of solids on the entrance side of the filter screen, the suction duct is opened and the discharge duct is closed whereby the solids are enabled to drop off the screen for removal by the exhauster to a central receptacle.