Playpit sand cleaning by disinfective heating

摘要

The soiled sand is transported by first path (28) from pickup point to a heater as a rotary tubular oven (20) and from here passes along a parallel second transport path (16) to discharge point. The heat emanating from the sand leaving the oven is transferred in part at least to the sand coming in along the first path (28) so as to preheat this sand ahead of the oven. Both paths carry equal volume and the sand is freed from mechanical impurities before travelling path (28) and/or before entering the oven (20). The two paths run parallel and are thermally coupled to one another. The levels of the transport path gradients can differ so the two paths lie higher than the oven at their upper ends but lower than the oven at the bottom end. Sand is carried up in the first path (28) but downwards in the oven. The unit is placed on an undercarriage (4) in the form of a trailer or having its own drive and transport and heater facilities can be powered by an emergency power unit.