METHOD AND APPARATUS FOR CONDITIONING SLUDGE BEFORE DRYING Russian patent published in 2012 - IPC C02F11/14 C02F11/12 C02F11/18 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of conditioning liquid sludge formed when treating waste water. The method of conditioning liquid sludge, in accordance with which sludge is subjected to a mechanical dehydration step followed by a heat drying step, wherein iron (III) chloride and/or unslaked or slaked lime is injected into the sludge between the dehydration and drying steps and/or at the input of the drying step, wherein the lime is injected in form of powder such that a coating is formed on the sludge cake without excess mixing so as to prevent thixotropy in order to reduce sludge binding during the drying step and evaporation capacity. The apparatus for conditioning liquid sludge has, between the mechanical dehydration apparatus (1) and the heat drying apparatus (3) and/or the input of the heat drying apparatus (4), an apparatus (4) for injecting iron (III) chloride and/or apparatus (8, 9) for injecting unslaked and slaked lime on top of the sludge, wherein lime is injected in form of powder so as to form a coating on the sludge cake without excess mixing so as to prevent any thixotropy.

EFFECT: invention enables to reduce evaporation capacity of sludge coming into a drying apparatus and avoid increase in viscosity of the sludge.