Machine for salvaging waste concrete material

In a machine for separating and salvaging cement, fine and coarse sand and aggregate from wet concrete material and water having an inclined frame, a classifying drum mounted for axial rotation above and parallel with said inclined frame and means for rotating said classifying drum;

• the improvement comprising forming said classifying drum with a first section adjacent its lower end incorporating an unbroken cylindrical wall, a second section adjacent thereto incorporating a fine sand screen cylindrical wall, a third section adjacent said second section incorporating a coarse sand screen cylindrical wall and a fourth section adjacent thereto incorporating an unbroken cylindrical wall with an open end, a spiral conveyor in said classifying drum attached to and extending continuously throughout said classifying drum, a receiving hopper and a well on said frame at the lower end thereof and adjacent the lower end of said classifying drum for receiving said wet concrete material and water, said hopper communicating with said well, a rotary elevator attached to the first section of said classifying drum for rotation therewith and partially disposed within said well and valve means comprising a movable apertured disc controlling communication between said hopper and said well, a discharge chute positioned through a central opening in said rotary elevator and extending into said first section of said classifying drum and arranged to receive said concrete material and water delivered thereto by said rotary elevator from said well and deliver said concrete material and water into said first section of said classifying drum, a receiving trough disposed under the screen cylindrical walls of said classifying drum for receiving water, cement and coarse and fine sand passing therethrough, openings in said receiving trough and a conveyor positioned on said frame and parallel therewith and beneath said openings in said trough for moving sand from beneath said receiving trough, a settling tank and a sump positioned beneath said conveyor for receiving said water, cement and fine sand therefrom and a water supply system arranged for communication with a water source, a spray bar in communication with said water supply system and positioned exteriorly of said fine sand screen cylindrical wall of said classifying drum for directing water thereagainst, said water supply system extended to and communicating with said well and said receiving hopper and arranged for directing wash water against said rotary elevator.