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Passavant Filter Drum Concentrator Roefilt

The Roefilt filter drum concentrator is the constructive and processtechnical further development of drum screens, as used in our belt filter presses according to the Passavant-Roediger system. As mechanical sludge thickening constitutes a link with the subsequent treatment steps, particularly stringent requirements have to be met by the technical design, performance readiness operational reliability and flexibility of plants.

Roefilt makes five standardized types available which can be sued for thin sludge and statically prethickened sludge of throughputs of up to 120 m2/h, duly adapted to the various requirements and meting continuously changing needs. It follows that optimum results can be attained at high throughput performance, whilst achieving a maximum possible degree of thickening at minimal return load and lowest operational cost, in continuous operation.

Roefilt is the cost-effective alternative to static thickener, centrifuges and flotation pants.

Unique Selling Point

  • Cost – effective alternative to static thickeners, centrifuges and flotation plants
  • Optimum adaptation to changing types of sludge, properties and operational conditions
  • With double drum plants separate drum drives possible
  • Hydraulic relief of digestion chambers thank to high degrees of thickening in the case of thin sludge
  • Reduction of the sludge volume to a fraction of the original quantity of sludge
  • Low running costs thanks to low energy and flocculent consumption
  • Short term amortization thanks to low capital investment cost


A sludge specific polyelectrolyte solution is prepared in a semi or fully automatic Roedos flocculent dosage unit and added to the sludge inlet pipe as a function of quantity. Floc formation takes place in the subsequent flocculation reactor with plate agitator mechanism at gentle reaction intensity. The sludge flows via a central pipe, without turbulence or mechanical tress, into the thickening drum whose revolutions are adjustable and which is covered by a polyester filter fabric.

The water drained during flocculation is discharged already in the inlet zone, which results in the formation of a sludge roller whose own weight accelerates drainage further due to the constant fulling effect. The clean filtrate is collected in a tank below the drum and returned as spray water to the filter cloth cleaning. A worm gear weir extending in the flow direction takes the increasing thickening sludge roller through the drum under constant filter discharge. On the discharge side, the thick sludge drops into the chute shoes level is monitored of a sludge conveyor pump and thus reaches the next treatment stage.

Locations and Contact


Aqseptence Group Co. Ltd., Hangzhou

Sales and Manufacturing Location
8 Chengye Road,
Binjiang District Hangzhou
Zhejiang Province, 310053

Tel: +86 0571 86698098

Fax: +86 0571 86698066



Aqseptence Group (India) Private Limited, Ahmedabad

Sales and Manufacturing Location
E-540, GIDC, Sanand-II Industrial Estate,
Village: Bol, Tak: Sanand,
Gujarat 382170, Ahmedabad

Tel: +91 2717 618000



Aqseptence Group FZCO, Dubai

Sales Location
East Side 5EA, 7th floor, 722
P.O. Box 371082
Dubai Airport Free Zone
United Arab Emirates
United Arab Emirates

Tel: +971 42278456


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