Argon oxygen decarburization furnace is known as AOD furnace in India. In this system a water cooled or a normal top draft suction hood is provided at the top of furnace vessel to extract the fumes generated by the furnace at the time of melting, this hood further goes to the gas cooler or heat exchanger or to the spark arrestor to eliminate the excess heat or sparks from the fumes. Then the fumes which are cooled down goes to pulse jet bag filter or bag house or air pollution control system where SPM or dust or fumes get filtered and then clean air travels thru the centrifugal fan and to atmosphere thru stack or chimney. The outlet emission after these systems can be achieved as low as 2 mg/nm3 depending on the pollution control norms at the location.