Rotary rake structure for a settling tank

摘要

A rotary rake structure for use in a settling tank comprises a torque transmitting member and a pair of rake arms. The torque transmitting member is mounted in the tank for rotation about a vertical axis. Each rake arm comprises one or more upper chords and one or more lower chords, the two rake arms being symmetrically disposed on opposite sides of the vertical axis of rotation along a transverse axis generally perpendicular to the axis of rotation. The upper and lower chords of each rake arm are fixedly positioned with respect to each other by truss members. The upper chords of both rake arms are attached to the torque transmitting member so as to permit pivotal motion of each rake arm in a plane containing the transverse axis and the vertical axis of rotation. Scraping devices depend from the lower chords for raking sediment at the bottom of the tank when the rake arms are rotated by the torque transmitting member. The end of each lower chord adjacent the axis of rotation terminates in a flange. The flanged end of each lower chord of one rake arm is spaced apart from the flanged end of a corresponding lower chord of the other rake arm by shim means in order to maintain each rake arm at a desired orientation with respect to the bottom of the tank.