Method and apparatus for enhanced settling and collection of settled material

Abstract

Apparatus and methods provide individual blades driven by drives configured to reduce a tendency of sludge to be moved in an undesired return direction. Drive configurations apply “pull” and “pull” forces that only pull on tensile structures, avoiding a need in actual commercial practice for use of extra structural drive members having high resistance to both tension and compressive forces exerted parallel to a sludge movement direction. Each of two separate tensile structures carries one blade, or a separate set of blades, with blade(s) of one structure adjacent to, and alternating with, blade(s) of the other structure. Embodiments move sludge from a corner of a basin and across a floor of the basin. The reduced tendency of sludge movement in the return direction results from moving one tensile structure and blade(s) in the sludge movement direction as the other tensile structure and adjacent opposed blade(s) move in the return direction.

1 . A method of moving material along a floor of a basin, comprising the operations of:
 defining a first space for a portion of the material, the first space having a first volume and being adjacent to the floor; and   reducing the first volume of the first space by moving a first pusher and a second pusher into the first volume relative to each other to push a first spillover volume of the portion of the material out of the reduced first volume past the second pusher in a first direction.   
     
     
         2 . A method as recited in  claim 1 , wherein the first spillover volume pushed past the second pusher enters a second space having a second volume, the method comprising the operation of:
 reducing the second volume of the second space by moving the second pusher in the first direction and by moving in a second direction opposite to the first direction a third, the movements being into the second volume with the second and third pushers moving relative to each other to push a second spillover volume of the material in the first direction and out of the second volume past the third pusher.   
     
     
         3 . A method as recited in  claim 1 , wherein the operations of reducing the first and second volumes are repeated alternately so that the first volume is reduced simultaneously with an enlarging of the second volume and the second volume is reduced simultaneously with an enlarging of the first volume. 
     
     
         4 . A method as recited in  claim 2 , wherein:
 according to a length of the floor of the basin across which the material is to be moved, defining a plurality of the first and second volumes by providing a plurality of the pushers comprising spaced ones of the first and second and third pushers and fourth and fifth and more spaced pushers as necessary to define the volumes extending across the length of the floor across which the material is to be moved;   the reducing of the first volume between the first and second pushers and reducing of a similar first volume between the third and fourth pushers occurs alternately with the reducing of the second volume between the second and third pushers and reducing of a similar second volume between the fourth and fifth pushers; and   the alternating reducing of the first and second volumes is effective to push successive spillover volumes over the second pusher and over the third pusher and over the fourth pusher and over the remaining provided pushers until the material is across the length of the floor across which the material is to be moved.   
     
     
         5 . A method as recited in  claim 1 , wherein:
 the moving of the material along the floor of the basin comprises moving the material away from a corner of the basin, the corner being defined by intersecting walls;   the operation of defining the first space comprises defining the first space with the first volume adjacent to the walls; and   the operation of reducing the first volume of the first space comprises an operation of pulling on sections of an endless cable that extends around spaced pulleys, the reducing of the first volume being by pulling on a first of the sections that is secured to the second pusher to move the first section and the second pusher toward the walls, the reducing of the first volume being further by an operation of the first section pulling on a second of the sections that is secured to the first pusher to move the second section and the first pusher away from the walls to reduce the first volume and push the first spillover volume of the material out of the reduced first volume past the second pusher in the first direction and to a location away from the corner.