Continuous Steel Annealing and Galvanizing
Continuous steel annealing and galvanizing lines are downstream finishing processes found in most steel mills.
After casting, steel is formed into thin sheets and rolled into a coil. The sheet is then thermally processed in a furnace containing between 125 and 400 radiant tubes.
The indirect heat provided by the radiant tubes maintains critical furnace atmosphere and provides uniform temperatures, ensure proper steel annealing prior to shipment or coating with zinc or other alloys.
The annealing furnace consumes a significant amount of energy and generates carbon and nitrogen oxide emissions.
Steel galvanizing lines are similar to continuous annealing and galvanizing lines, though these are typically standalone lines solely focused producing galvanized steel.
Coiled steel is received from steel mills before the sheet is thermally processed in a furnace containing radiant tubes. This furnace is typically horizontal and contains between 25 and 150 radiant tubes.
In each of these cases, radiant tubes’ energy usage, emissions and thermal performance can be improved through the use of high surface area heat exchangers such as HeatCor™, radiant tube inserts such as SpyroCor™, and low emission devices such as NOxBuster®.