ROTATING SCREEN AND DRIVE UNIT

摘要

A liquid filtering apparatus for use in, for example, storm water overflows of sewage systems. A cylindrical liquid permeable screen is supported in a housing so as to obstruct the passage of solids of greater than a predetermined size from an inlet of the housing to an outlet of the housing. The screen is rotable about a horizontal axis and its interior is drained by the outlet from the housing. The exterior of the body is at least partially submerged by the liquid to be filtered, and the body supports internal vanes arranged such that it is driven in rotation by the filtered liquid. The interior of the body is partitioned by the vanes into a series of sections arranged relative to the outlet such that for any given rotational position of the body liquid is retained in at least one of the submerged sections as a result of one or more of the vanes preventing liquid flowing from that section to the outlet. The weight of liquid retained by the vanes applies a torque to the body to cause it to rotate.