Controlled sludge composting system - which mixes sludge and composting agent and distributes the mixt. in composting silos

摘要

Sludge from first storage device and composting agent from a second storage means are fed in controlled ratio to a mixing device the output of which is fed to the top of a first silo where it is spread by a distributor conveyor in even layers over the entire area to fill the first silo with the mixt. A first horizontal screw conveyor is mounted at each end on rack and pinion conveyors to traverse and remove the bottom most layer of processed material from the first silo. The removed material is fed by a conveyor to a second silo where again it is distributed in even layers over the entire area, with a screw conveyor mounted on rack and pinions at each end to remove the bottom most layer of processed material from the second silo for delivery via a further conveyor to a discharge point for bulk distribution or bagging. Pref. sludge is mixed with a carbonaceous composting agent and air is forced through both silos to promote composting action. Raw sewage sludge is made safe for disposal or agricultural use without producing disagreeable odours.