Arrangement for cleaning a sealing ring on a shaft

Abstract From the Canadian patent

A rotatable shaft extends from the interior of a receptacle through a wall thereof forming a closed chamber surrounding the shaft; and a first sealing ring surrounding the shaft is operable to prevent flow into the chamber from the receptacle interior but to allow flow in the opposite direction, a second sealing ring surrounding the shaft to prevent flow from the chamber in the axial direction away from the receptacle interior. Valve means are operable selectively to connect the chamber to either a cleaning liquid supply source or a draining passage or to disconnect the chamber simultaneously from both said source and passage.