Le spietratrici a peso specifico modelli QSX 56, 85, 100 vengono usate soprattutto nelle industrie The specific weight stone removers models QSX 56, 85, 100 are mainly used in the cereal transformation industries to eliminate impurities which are the same size as the grains but have a higher specific weight e.g. stones. The stone-remover divides the grains from the stones of the same size on the basis of their different specific weights and thanks to the upward airflow which passes through the spaces between the grains.

The stones and other foreign bodies of the same size as the grains remain underneath in contact with the base plate which moves with an alternating movement and are carried to a point where they are collected.

The grains are blown upwards by the suction and are thus separated from the stones.