Gravity sludge thickener is a kind of central drive continuous or intermittent thickening and clarification equipment. Sludge thickener is mainly used in water treatment system of blast furnace, continuous casting, hot rolling and waterworks in metallurgical industry, or for concentration or purification of all solid slurry in coal, chemical industry, building materials, water source and sewage treatment industry. It can also be used for concentrate and dewatering of concentrate and tailings slurry in wet beneficiation.