Fume Control in L-D Plants

Complex and expensive fume control systems are required in L-D plants due to the cyclic operation and heavy fume emission from the furnace. Evolution of gas and fume from the furnace varies greatly throughout the blowing period, and the blowing period is less than 50% of each cycle. Gas volume in the hood is influenced by oxygen blowing rate, and area of opening between furnace and hood. The principal components of a system are: hood, ductwork, gas cooling equipment, collectors, fans, instrumentation, and dust or sludge handling equipment. Several optional designs are available and should be evaluated in selecting a system. These include: open or closed hoods, dry or wet collectors, steaming or cold water hoods, and dust disposal or usage. The cost of the fume control system normally represents about 14-19% of the total cost of an L-D shop. Operational and maintenance costs are also major factors for evaluation in fume control system design.