FEED SCREW FOR SEDIMENTATION OR TREATMENT SYSTEMS

摘要

The invention concerns a feed screw in the form of a self-supporting, axleless helix whose surface extends essentially radially, the feed screw being used in sedimentation or treatment systems for clearing suspensions in paper making processes. The invention is characterized by a second helix whose surface, or generatrix, deviates preferably between 0.degree. and 20.degree. from the direction of the central axis and extends in the feed direction. The second helix may deviate between 0.degree. and maximally 40.degree. and have a length - per lead - between 20% and 40% of the lead of the helices.