Reclaiming hot foundry moulding sand - in fluidised bed fed with cooling water obtd. from wet dust extractor for fluidising air

摘要

The hot, used sand is fed over a perforated, vibrating conveyor, through which air is blown upwards via the perforations to form a fluidised bed of sand. Above the fluidised bed is a set of spraying nozzles feeding cooling water into the fluidised bed. The air is removed from above the bed and fed through a wet dust extn. system using water so that a suspension of dust in water is obtd. and this suspension is used as the cooling water in the spraying nozzles. The binding agents, viz. bentonite and carbon are partly removed from the fluidised bed by the cooling air, but are trapped in the dust extn. system and are returned to the sand in the cooling water, so the loss of such agents is minimal. Environmental pollution is reduced.