The process starts in the screen that holds back solids only. The internal part of the screen is continuously cleaned by brushes fixed on the outside diameter of the flighting. As the water runs through the screen the shaftless spiral conveys the solids up towards the compaction module where the material is further de-watered. Depending to the material properties, screenings can be reduced by more than 50% of their original volume.
First, a powerful TASKMASTER grinder reduces the solids to small particles, loosens biological material and increases surface area. The reduced solids are ideally conditioned for further processing by the SPIRALIFT screw screen. As the solids are discharged from the grinder, the reduced particles are subject to the turbulent cleansing action of the channel flow. The particles are then captured on the SPIRALIFT’s fine screen basket. The spiral unit is energized on a timed cycle or when the upstream flow reaches a predetermined level. The brushes of the unit’s shaftless screw sweep the solids off the screen. They are then spray washed and transported up the shaftless spiral.