The dewatering of sludges using a tubular filter press

✍ Scribed by K. Treffry-Goatley; M.I. Buchan; G.E. Rencken; W.J. Vortman; C.A. Buckley

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 485 KB
• Volume: 67
• Category: Article
• ISSN: 0011-9164
• DOI: 10.1016/0011-9164(87)90263-3

✦ Synopsis

SUNNARY

A tubular filter press process using fabric tubes has been developed to dewater the sludge resulting from the clarification of raw water.

A prototype plant, designed to dewater the sludge resulting from the treatment of 30 Ml/day of surface water, has been constructed by a water authority.

The slurry is fed under pressure into an array of porous tubes, the liquid in the slurry filters through the tube walls while the slurry solids are deposited as a thin layer on the internal walls of the tubes.

The cake is dislodged periodically from the tube walls and transported hydraulically out of the tubes where it is drained and conveyed to a collection hopper.

The raw dam water associated with the prototype unit is clarified using a polyelectrolyte/bentonite mixture.

The resultant sludge has a mean solids concentration of 23 g/l.

The prototype tubular filter press has produced on average a cake with a solids concentration of 32% mass/mass and a filtrate with a suspended solids of 57 mg/l.

The process operates with minimum supervision and no chemical addition.

The solids dewatering capacity for a feed solids concentration of 23 g/l and operating at a pressure of 400 kPa is 1.5 kg dry solids/m2h.

The performance of the unit can be described using standard filtration theory modified for a circular filtration surface.

The performance to date indicates that this process compares favourably with other commercially available sludge dewatering methods.