A bucket loader pushes recyclables onto in-feed conveyors to move the recyclables into the waste sorting system. A horizontal conveyor is typically placed below grade so that recyclables can be slid onto the conveyor. For dual steam MRFs, separate in-feed conveyors are dedicated to commingled containers and fiber. In single stream MRFs, both containers and fibers are pushed onto the same in-feed conveyor. The horizontal conveyor connects to an incline conveyor that runs at a slightly faster speed to spread out the material.
Materials should be fed into the waste sorting system at a consistent flow rate. Metering or leveling drum feeders are often used to accomplish this. A consistent material feed rate prevents surges, allows for more efficient manual sorting in the presort area, and maximizes the efficiency of automated equipment encountered later in the processing line.
The in-feed conveyor typically delivers material to a presort conveyor line where large contaminants, bulky recyclables, and items that could damage downstream sorting equipment or pose a threat to personnel are removed. Recyclables that might be removed at this stage include corrugated cardboard, telephone directories, or large stacks of paper. Sorters stand at work stations alongside a horizontal conveyor belt and inspect material as it passes by. Contaminants or bulky recyclables are dropped through chutes into roll-off containers or waste storage bunkers below the sorting system. Some MRFs have a top conveyor at this stage where telephone directories or large stacks of paper are placed and conveyed for final cleanup and baling.
