Abstract: A stepping screen assembly bottom portion is located in a liquid waste stream containing solids. The assembly contains a grid structure containing dynamic and static bars horizontally spaced apart. An outer frame on one side of the grid structure contains a pair of hydraulic cylinders operating rods which move the dynamic grid structure outwardly, upwardly, backwardly and downwardly to cause the solids to be lifted from the liquid waste stream for deposit on a conveyor.

Abstract: A stepping screen assembly bottom portion is located in a liquid waste stream containing solids. The assembly contains a grid structure surrounded by an outer frame. The grid structure includes multiple parallel alternate static and dynamic bars horizontally spaced apart by spacers attached to the sides of the dynamic bars. Each bar has multiple vertically spaced apart shelves at a right angle to the vertical axis of the bar. The outer frame on each side of the grid structure contains a single and double stroke pneumatic cylinder connected to the dynamic bars. The single stroke cylinder causes the dynamic bars to move in a vertical plane and the double stroke pneumatic cylinder causes the dynamic bars to move in a horizontal plane.

Abstract: An endless screen lifts fecal matter and sewer influent debris from an influent channel. The endless screen is powered by an externally positioned air cylinder driving a pawl and rachet to move the screen in an elliptical path. A tank positioned below a top drop point for the screen receives the fecal matter and debris. A paddle mixer breaks up the fecal matter for return to the sewer channel and a conveyor picks up the debris and deposits it in a landfill receptacle.

Abstract: An apparatus is described which separates small solids from process waste water. A continuously rotating elongated drum screen having a large diameter interior flow channel removes the solids. The drum screen contains a continuous loop of closely spaced link members each having a foot at one end projecting towards the interior of the drum chambr. Pivot members are connected to the links and these pivot members are driven by lugs attached to an endless loop chain. The chain is driven by variable speed motors. A flushing system mounted on top of the drum screen washes solids into a hopper where liquid is returned to the drum inner chamber and solids are sent to solid waste disposal.

Abstract: A bar grid is formed with multiple vertical rods supporting multiple horizontal roll formed elements with a flange at a front edge of each element. The grid is mounted in a water effluent stream on each side of a solid filter screen or grinder and funnels solid material down to the compactor without buildup of solids on the grid screen.

Abstract: Three parallel hydraulically driven shafts are mounted on a pair of bearing plates attached to the side plates of a housing containing a comminution chamber for receipt of waste water effluent. The waste water effluent stream enters the comminution chamber transverse to the three shafts. Two shafts support a stack of spaced apart tooth cutters. Toothed cutters are positioned so that each level is in the same plane as a toothed cutter in the opposite shaft. The third shaft is positioned distal from the input of the waste water effluent and behind the first two shafts. The third shaft supports a stack of shearing cutters overlapping the toothed cutters. Each shearing cutter is on a plane with a spacer disk between each toothed cutter. Debris in the water effluent such as rag material is caught by the toothed cutters and shredded by the scissors action of the shearing cutter against the toothed cutters.

Abstract: An apparatus is described which separates small solids from process waste water. A continuously rotating elongated drum screen in a three foot diameter flow channel removes the solids. The solids are deposited by spray wash into a dewatering chamber. The screen components include row of closely spaced links and pivot members connected end-to-end to form a continuous loop mounted within a frame driven by a variable speed motor.

Abstract: An apparatus for continuously removing waste materials from a water stream. The apparatus includes a rotating screen assembly formed by a plurality of articulated "L"-shaped links that form separate, laterally spaced closed loops. The space between the loops of links defines the maximum size of material that can pass through the apparatus without being removed from the stream. The respective truncate portions of the "L"-shaped links facilitate the lifting of the debris from the stream. The screen assembly is rotated by motor-driven sprocket segments that are positioned at the discharge end of the apparatus. These segments substantially occupy the spaces between the links when the links travel past the segments, and the occupation of the spaces by the segments displaces the waste materials from the spaces and dislodges the materials from the links as well so that the materials may fall under the influence of gravity to a receptacle.