SURFACE TREATMENT DEVICE AND PROCESS FOR A METAL PRODUCT LAYED IN A REACTIVE SOLUTION, PARTICULARLY FOR THE CHEMICAL CLEANING OR THE GALVANIZATION OF HOT ROLLED METAL SHEETS

摘要

Company known as: SOLLAC OF THE TECHNICAL CONTENT OF THE INVENTION Method and device for the surface treatment of a metallic product staying in a reactive solution in particular for the pickling or the galvanization of hot rolled sheets. According to this method le, high-frequency vibrations are printed on the sheet (1) while traveling in a tank filled with acid; the device comprises at least one pair of electromagnets (2, 3) arranged opposite one another on either side of the sheet (1), supplied by currents of the same frequency and each exercising on the sheet (1) a periodic attraction force, the forces exerted by each electromagnet (2, 3) being offset by .pi. / 2, so that the sheet (1) vibrates at a frequency twice that supply current. The vibratory power injected into the sheet is greater than the cavitation threshold of the reactive solution in the vicinity of the sheet, so that this cavitation as well as the vibrations imparted to the sheet crack the layer of scale and facilitate its attack by the acid, which considerably reduces the time required for pickling the sheet. Fig. 1