The composition of grit chamber contents usually features an organic content of 50 to 80%. Conventional sand washers can only partially dewater the material from grit chambers. However, the high organic content and lack of dry matter are associated with unpleasant odours, high weight and consequently high disposal costs. The ABZ sand washer almost completely washes out the organic content from the grit chamber contents. This leads to a reduction in mass of up to 80% and, in the case of landfill disposal, to cost savings of up to 90%.
This process is also used in industry for separating recyclable materials from waste. Separate discharging of the different fractions facilitates their further processing, recycling or disposal. This allows recyclables to be fed back into the production process and waste materials to be disposed of separately and cost-effectively.
The ABZ sand washer is loaded with the heavy matter/water mixture. The deposited sediment mix is conveyed by an auger directly into the connected wash reactor. The lighter constituents are scrubbed out by the rotating agitator and simultaneous perfusion of the sediment with washing water and/or air, flushed out over an overflow barrier and fed into the subsequent process. The washed heavy matter sediments, collects on the reactor floor and is discharged with a low-wear auger in cyclical operation. Since a defined residual amount of washed sediment remains in the agitator vessel, this acts as a separating layer, thereby preventing contaminated material from being discharged smoothly. Sediment level and discharge rate are adjustable and can be adapted to suit the respective conditions.