Thickening has usually been accomplished with separate equipment, prior to the development of the 3-belt approach.
Click here to enlarge imageThe thickening operation is accomplished by the system’s “third” belt, which operates independent of the dewatering functions. This allows sludge with extremely low solids content to be processed through the thickening stage at accelerated rates, while sludge with higher solids content can be processed at the slower rates they require. This minute-by-minute adaptability is especially appropriate for the highly variable sludge inflow typically seen at Enviroganics.
After the sludge is thickened through the action of the third belt, it moves directly into the gravity dewatering zone of the dewatering section of the system. From there, it proceeds into an adjustable wedge dewatering zone, which gradually increases the pressure on the sludge. Subsequently, the sludge is processed into two additional zones to achieve maximum solids content in the dry cake - regardless of the properties of the incoming sludge.
Because of the high throughputs available with this multi-belt approach, Enviroganics was able to achieve its process goals with a single unit instead of the two units previously required.
Beneficial Results
Enviroganics is virtually a non-stop operation and has ongoing commitments to provide contract dewatering. This meant that the entire installation of the new thickening and dewatering system had to occur within a single four-day window. Though not an easy task, the installation was completed on schedule, and the improvement in dewatering capabilities was realized immediately.