BELT FILTER PRESS – FACT OR FICTION ?
McLoughlin P W.
Ashbrook Simon Hartley
(free)
Over the last 10 years improvements in mechanical biosolids dewatering have been limited to incremental changes within a proven design. Belt presses have reviewed roller configurations and belt tension, centrifuges have focused upon differential speeds and beach angle, whilst filter frame presses still rely on cycle time and filtration pressure to achieve the desired performance.
In parallel, we have seen developments from the chemical suppliers with changes in flocculant structure and the method of application being the major reason for process improvements.
External to mechanical dewatering machines we have seen the advancement of hydrolysis and other high temperature and/or pressure systems that as a by product of cell lysis have enabled the release of previously entrapped water molecules. These processes often result in a biosolids structure that is more amenable to dewater albeit with a major capital cost impact.
However, the future is about to change. The adoption of electro kinetic geosynthetics (EKG) technology [1] to the dewatering of biosolids (and other materials) will allow the belt filter press to enter a new phase, achieving levels of performance previously thought impossible by conventional mechanical dewatering techniques
KEY WORDS Belt Filter Press, Dewatering, Sewage Sludge, Electro Kinetic Geosynthetics.
