Abstract: An apparatus which serves to clean air containing fine dust and also larger particles, such as fibrous material, thread ends, etc., which are produced in an industrial environment, especially a textile plant. In order to conduct a two-stage cleaning process without the necessity of dimensioning two filtering stages for the full air flow, there is provided a vortex chamber into which the unclean air is admitted tangentially or in some manner which produces a rotary flow with centrifugal force components which act on the larger particles in the air stream. The vortex chamber includes a rotating filter drum, the interior of which may preferably be provided with suction, causing air to flow from the vortex chamber through the filter, depositing thereon the fine dust carried by the incoming air.

Abstract: A double twisting machine is equipped with air flow control devices which create preferred conditions in the vicinity of each twisting station and, particularly, in the immediate vicinity of the twisting mechanism and the thread balloons. Pre-conditioned air, adjusted for temperature and humidity, is delivered through a nozzle located above each twisting spindle and is directed generally to the location of the thread guide loop. The protective container for the bobbin has a lower opening which permits the air flowing into the container from the top to emerge below where an exhaust conduit carries it away. A coaxial shroud surrounds the protective container and forms an annular air passage through which conditioned air may flow in both directions.