Process and arrangement for the regeneration of foundry sand

Abstract

Used foundry sand which is predominantly in the form of lumps containing a binder for the sand particles is regenerated. In the course of the regeneration, the lumps are comminuted and, simultaneously therewith, an at least partial separation of the sand and the binder is effected. The simultaneous comminution and separation is effected by a dry, mechanical procedure during which the lumps are subjected to an abrasive or scouring action. This is accomplished by means of a pair of vibrating or rotating brush-like members provided with steel bristles. These members are located adjacent the bottom of a trough-shaped strainer which permits the passage of sand particles having a size less than a predetermined size. A cover is provided for the strainer and serves to cause rebounding of particles which impinge upon it. A feed hopper feeds the lumps of used foundry sand to the brush-like members and a bar overlying the gap between the latter prevents entry of the lumps into the gap. A housing surrounds the brush-like members and the feed hopper, and dust-like material is withdrawn from the housing by suction. A chute located beneath the strainer serves to convey sand particles which have passed through the latter from the housing.

Dependencies are inferred from the claim text.