The target of the countercurrent sifter is the reduction of the dust content in chemically bonded foundry sand. Sand attrition units remove the organic binder surface at means by friction from the sand grain.
This organic „binder dust“ must be removed as proper as possible to keep the L.O.I of the reclaimed sand low. The sand/dust mixture passes trough a two-layer low channel. The upper layer leads to an adjustable deflection plate. In the lower layer, a controlled airflow is forced trough the flow channel. The light particles are reflected by the deflection plate in a different angle, compared to the sand particles. Due to this, the light organic dust is carried out by the air flow while the sand is passing to the next sifter stage.