Direct Firing Furnace honoured Grand Prix at Fives’ Innovation Awards

Fives Innovation Award

Fives has developed a new flameless Direct Firing Furnace (DFF) for continuous annealing or galvanizing lines, which will enable the production of new generation steels (Gen3 AHSS) for the automotive industry.

Direct Firing Furnace from Fives

It is a breakthrough innovation responding to the constraints associated with the production of Gen3 AHSS, the new steel grades needed to manufacture lightweight vehicles with reduced emissions. The new concept received the Grand Prix at Fives’ Innovation Award in Paris on September 24, 2020. Fives’ Innovation Award is an annual event, held by the group, to support innovative ideas and solutions among its employees. 

In strip processing lines, the furnace is a key technology for achieving the final product properties– but if preheating temperature in DFF is not homogenous, those properties can be compromised. The innovative DFF uses new S-shaped tunnel geometry combined with flameless combustion to achieve homogeneous heating in all the sections of the furnace by using a new generation of lateral burners. The result is a homogeneous temperature of +/-10°C along the whole width of the strip at the exit of the furnace. 

“We conducted CFD modelling to optimize the furnace design – in particular the waste flue gas passage between the active and recuperative zones – and define the design of the burners. By running a series of tests, we were able to come up with a totally new burner concept that achieves a flameless combustion mode. The final DFF concept was validated by CFD modelling on a complete furnace,” explains Sébastien Lemaire, R&D Engineer at Fives Stein, a Fives’ subsidiary in France.

“This technological solution offers steelmakers many different advantages,” highlights Camille Moukarzel, Business Development Manager at Fives Stein. “Reduced operational costs, thanks to the 600°C preheated air flameless side burners; simplified control; minimized maintenance and, more importantly, a dramatic reduction of NOx and CO2 emissions.”