Vacuum drive scraper device for drum filter

摘要

An arrangement for scraping the filtered solids build up from the surface of a drum filter (l6) is disclosed, in which a scraper (96) is mounted with an edge against the surface so that rotation of the drum (l6) will accomplish scraping of the surface. Clutching engagement with a rotary drive member (72) is produced by a predetermined extent of axial shifting of the drum (l6) against the resistance of a spring bias force. The drum (l6) is also arranged to be subjected to an axial pressure force developed by flow through the filter so that clutching engagement is automatically produced upon build-up of solids to a predetermined extent to cause a level of pressure force to be developed to produce a consequent axial shifting sufficient to produce clutching engagement and rotation of the drum (l6). A drag out conveyor (92) moving through the tank (l2) engages a rotary sprocket (72) which comprises the rotary drive member, and the scraper edge (96) and drum (l6) are positioned to directly deposit the scraped solids on the conveyor (92) to be removed from the tank (l2).