Crushing reclaimed sand lumps in foundries - using air streams to remove dust before crushed sand is sieved

摘要

The sand is fed into a vibrating hopper fitted with double walls, and each sloping inner wall (a) is perforated so the sand travels through the holes as fine particles and through at least one cross-current of air functioning as a sieve, and removing dust from the sand. The air streams are pref. horizontal, and their force is adjusted to remove dust particles up to a predetermined size. In the pref. crusher, the dust-free sand then falls onto a sieve removing grains above a desired size, whereas the remainder of the sand falls through the sieve into a collection duct. Suction fans are pref. used to create the cross-currents or air.