Dust collection efficiency is a measure of the basic performance parameters, which indicates precipitator dust airflow capacity, which with the filter running and are subject to the nature of the dust, filter type, resistance, dust layer thickness, filtration velocity and clearance method of ash and many other factors. With dust particle removal efficiency has a direct relationship and useful classification efficiency represents a particle size (or size range) the collection efficiency, it is also one of the indicators evaluated precipitator performance. Since foundry dust precipitator for various particle sizes have a high collection efficiency, so under normal circumstances less used classification efficiency evaluation baghouse performance. Engineering design in the dust, is mentioned more baghouse outlet emission concentration is. It has been suggested by the following equation predicted baghouse dust outlet concentration.