REBOX® DFI (direct flame impingement) is for customers looking for rapid pre-heating, degreasing as well as pre-oxidation of steel strips in continuous galvanising and annealing lines.
One or several rows of REBOX® DFI burners are installed on each side of your strip; high intensity flames then impinge the surface of the strip, ensuring rapid heat transfer and degreasing.
Direct Flame Impingement oxyfuel is based on Linde’s vast experience in oxyfuel combustion and its application in steel heating processes. This expertise was adapted to continuous and large-scale use in reheating and annealing furnaces. With our DFI technology, where controlled oxyfuel flames are fired directly onto the moving metal, the heat transfer is drastically improved. Tests have verified the higher level with local heat flux for the DFI oxyfuel technology, reaching levels of 400 kW/m2 and even more.
Benefits of REBOX® DFI
- Up to 30% increase in productivity due to rapid pre-heating
- Surface pre-oxidation to promote wetting in subsequent process steps
- Effective degreasing of the strip surface
Would you like to have more information about REBOX® DFI?
Find out how ThyssenKrupp could increase their galvanizing capacity
Customer: ThyssenKrupp Steel (TKS), Finnentrop, Germany was searching for an easy-to-implement and effective solution in order to increase the galvanising capacity of an existing production line at the Finnentrop works. The galvanizing line at TKS Finnentrop (FBA 3) processes both hot and cold rolled strip with a width of 650–1550 mm and thicknesses of 0.3–3.25 mm for automotive, white goods and construction applications. The total furnace length is 130 m, where 67 m is air-fuel-fired. The highest strip speed is 180 m/min and the maximum output was limited to 82 tonnes/hour.
Challenge: TKS had identified that by increased strip heating, the line could reach 105 tonnes/h. It was also determined that the appropriate heating solution should free the strip surface from unwanted contaminants, such as emulsions, oils, grease and particles, which originate from the upstream strip production process. Another requirement was that the boosting unit should allow for strict control of the required surface properties needed for successful galvanising of the strip. With these specifications in mind, TKS met with Linde at the end of 2004 to discuss the possibilities of applying oxyfuel to its galvanising lines.
Find out how Linde could solve these challenges