Optimum roll cooling during hot and cold rolling operations on steel or aluminum blooms, billets and slabs is necessary in order to avoid fire cracks on the rolls. Firecracks are often formed when the heat extraction from the rolls is not adequate or is un-uniform in nature. Due to temperature differences within the rolls and the consequent formation thermal stresses, firecracks are often formed. The rolls then have to be removed and machined in order resume rolling operations. This reduces the life of the rolls besides being a time-consuming and costly exercise.

This can be avoided by effective heat extraction at the exit location where the rolled product loses contact with the rolls. The maximum heat generation and temperature increase due to friction between the rolls and the rolled products happen at this point and it requires the most effective and uniform heat removal.

Traditionally, spraying systems without air atomization have been used for roll cooling. BNG’s spray nozzles use our patented air atomized dual-atomization-technology (DAT) that enables more effective and more uniform heat extraction through the use of lesser coolant. The liquid layer than often forms on the roll surface prevents the subsequent coolant droplets from reaching the roll surface. However, the air in air-atomized nozzles blows the liquid layer away and the smaller coolant droplet sizes and therefore greater cumulative surface area enable more effective heat extraction from the roll surface.