•Notícia

One of the major problems faced by wire-manufacturing companies is the zinc-coating or galvanizing system. The steel from which the wire is made must be cooled from 900°C to 500°C in just a few seconds and a coating of zinc must be applied to protect it from rust.

The product exits at high speed from the large vat where it is submerged in molten zinc, thereby dragging with it a large amount of the zinc and preventing the end product from achieving the thinnest possible final gauge. Inefficient blowers are currently used to eliminate the excess zinc; they use a large amount of energy and waste a lot of zinc.

Professor Saturnino-Luis Virto of the School of Industrial and Aeronautical Engineering of Terrassa has designed a subsonic nozzle with a chamber that generates a nitrogen vortex. When the nitrogen reaches the nozzle chamber, it becomes a helicoidal vortex that surrounds the zinc along the wire. "In this way, the force of the nitrogen pulls off the excess zinc, achieving a very fine, high-quality wire", explains Virto. The nozzle has been patented by the company Automat Industrial, S.L.

Virto, though he is retired, continues to give vent to his innovative spirit and has also designed for the same Catalan company another subsonic nozzle that blows away the excess liquid and blows an intense current of gas or air onto the wire at an adjustable speed. The jet of air or gas acts on the surface of the wire and completely removes the coat of excess liquid.

Moreover, professor Virto has designed an equivalent system but with a supersonic nozzle, i.e., it projects jets of air or gas moving faster than the speed of sound onto the product as it comes out of the galvanization process. These innovations "have contributed to significantly reducing energy consumption in the process of manufacturing wire by means of a non-polluting technology", concluded the professor.