Sludgless: Screw-Press

SLUDGLESS represents innovation in design and provides an economic solution for either sludge thickening or dewatering at small to medium water, waste water and industrial effluent treatment works in addition to certain larger applications. Low outlay cost, running cost and maintenance costs were fundamental to design objectives and this has culminated with the development of a highly cost-effective process. Sludge export or transportation costs can therefore be significantly reduced with consequential further savings on operational and energy costs. Sludge thickening up to 15% DS or, sludge dewatering up to 25% DS are attainable. Systems can operate automatically or manually – either continuous, or intermittently for batch processing. Various manufacturers’ flocculants may be used and the system can be supplied with or without preparation plant to suit requirements.

Operation

SLUDGLESS consists of static circular drums with internal screw conveyor. The drums are fabricated in stainless steel using various size special wedge-wire screen profiles with large surface to obtain optimum liquor drainage characteristics. Flocculated sludge enters the inlet chamber into the drum zone where it conveys by spiral movement and is gradually compacted. Liquor continuously drains through the drum wedge-wire screen and gravitates to the filtrate outlet where it can be discharged or returned for treatment. The sludge retained in the drum is subjected to continuous movement and progressive compaction applying the desired effect of releasing more liquor to drain – flocculated sludgeis treated gently and flocculent utilization kept low. Spray nozzles provide intermittent wash to the screen sections,however with inlet sludge solids content ≥ 1.5% DS, washing will not be necessary and water consumption is negated.

Eventually the solids will pass into the discharge section and to the outlet where it can be collected into a container or conveyed for eventual disposal.

Advantages

• Simple mechanized operation
• No rotating synthetic filter cloth requiring periodic care
• Low speed operation – low energy input
• High solids capture
• Low shear – excellent recovery of all sludge types
• Easy operation and maintenance
• High reliability and long asset life
• Non-clogging even with fibrous materials
• Compact, low space requirement

Dewatered Sludge

Sludgless Specifications