Process and arrangement for the treatment of solid combustion residues

Abstract

The arrangement for treating combustion residues of a combustion installation comprises an ash discharger into which opens a fall shaft, into which the solid combustion residues fall from a furnace grate. The ash is conveyed from the ash discharger into the discharge shaft via a diagonally ascending push-out chute by a push-out ram whose operating rate is so adjusted that the ash is piled up in the fall shaft in a tower formation reaching above the liquid level. Fresh water or a chemical is introduced into the discharge shaft via an inlet. The ash discharger water present in the ash discharger and charged with fine particles is drained into a hermetically sealed settling tank via a draw-off duct. Ash discharger water, with which a chemical can be mixed via another line, is fed from the upper region of the settling tank by a pump via a return line to spray nozzles which are arranged in the upper region of the fall shaft. Ash discharger water which is enriched with solids particles is drawn off from the bottom of the settling tank via another pump which is arranged in an outlet line proceeding from the settling tank. This is effected at a rate such that solids particles having a diameter of up to 2 mm are carried away with the ash discharger water which is drawn off through the draw-off duct.