For the hot dip galvanizing of round, square and rectangular tubes, KÖRNER provides standard and customised designs that enable throughputs of 4 to 20 t/h. The systems vary in terms of automation, and come as semi or fully automatic.
Hot dip galvanizing requires that tubes have clean metallic surfaces. This can be achieved by the batch-wise immersion of bundles of tubes in a chemical pre-treatment.
Each tube is then passed through galvanizing on the basis of a pre-set cycle. It first passes through the drying device, it is then immersed in the zinc bath and after a certain immersion time, pulled from the bath either by the operator or by a tube lifting machine, and fed to the tilted extendable track. Once on this track, the tube passes through a tubular die that blows off any excess zinc with compressed air and immediately polishes the tube’s outer surface.
Afterwards, the tube reaches the blow-out station. There the excess zinc is removed from the inside of the tube and the inner surface is immediately polished. The removed zinc or sucked-out zinc dust are separated.
After passing through blow-out, the tubes go into a temperate water bath, are cooled down and passed to the downstream equipment.