■Introduction According to the principle of screw sludge dewatering machine, we developed a new type of sludge thickening equipment-screw sludge thickener as the demand of market. Screw sludge thickener inherits advantages of screw sludge dewatering machine, like: automatic continuous operation, low energy consumption, high efficiency, running stable and excellent properties, directly concentrate the sludge in secondary sedimentation tank. This equipment can be used instead of concentrated tank, reduces the area as well as the civil engineering construction cost, and effectively reduce stench and phosphorus release of sludge concentration pool. This equipment can be used as pretreatment of sludge dewatering and depth dewatering equipment. ■Principle Screw sludge thickener sets mixing flocculation device, concentrated subject, integrating liquid trough, flushing device, electric cabinet, it can realize high efficient continuous, unmanned operation. Sludge and flocculant form alum flower in mixing device, gravity flow into concentrated body. Screw sludge thickener mainly have screw axis, fixed ring and moving ring. The sludge moves with the rotation of screw shaft, dewaters gradually with pressure of cubage cavity and discharge mud cake, the dewatered water flow into sump from the gap of rings. The rotation of screw shaft drives the rings, so forming a continuous washing and avoid congestion. ■Application (1) Suitable for the municipal sewage, oil refining, brewing tanning, printing and dyeing, papermaking, coal dressing, biochemical, pharmaceutical, steel pickling, chemical industry, sugar, food processing and slaughter (2) Worked as depth sludge dewatering pretreatment equipment, ancillary equipment for the ultrahigh pressure press, membrane filter press (3) Replace sludge thickener pool, worked as the pretreatment equipment