ABSTRACT
Belt filter presses avoid the sludge pick-up problem occasionally experienced with rotary vacuum filters.
The sludge is gravity thickened, chemically conditioned with polymer and then pressure dewatered in the filter press to increase the solids content of either digested or undigested sludge.
The influent mixture of sludge and polymer is fed to the moving porous belt on the filter press. Dewatering occurs as the sludge moves through a series of rollers which squeeze the sludge to the belt or squeeze the sludge between two belts.
The cake is discharged from the belt by a scraper mechanism and the water is returned to the plant for treatment.
