Hot-dip galvanizing installation for steel strip

A hot-dip galvanizing installation for continuously moving rolled steel strip, the installation comprising:

• a coating tank and a preparation device configured for continuously circulating a molten metal mixture therebetween;
• said coating tank having a molten metal mixture inlet and being configured for immersing the strip in the molten metal mixture and depositing the molten metal mixture on the strip;
• said preparation device including a first zone having a fusion zone, a second zone having an outlet and a molten-metal-mixture transfer device linking said first and second zones;
• a local regulation device disposed in said first zone for lowering a temperature of the molten metal mixture if necessary as an aid to a required lowering of the temperature of the molten metal mixture being effected by selective dipping and removal of at least one metal ingot in said first zone;
• said preparation device lowering the temperature of the molten metal mixture to reduce an iron solubility threshold and keep the temperature of the molten metal mixture at a temperature to activate fusion of the at least one metal ingot providing an additional supply of the molten metal mixture in said fusion zone, in sufficient quantity to offset the molten metal mixture deposited on the strip;
• said preparation device imposing a sequential flow of the molten metal mixture from said coating tank, through said first zone fusing the metal ingot and causing dross to settle, through said transfer device and to said second zone receiving the molten metal mixture cleansed of dross and returned to circulation in said coating tank through a return-flow path of the cleansed molten metal mixture from said outlet to said inlet;
• and
• a thermal adjustment device disposed along a flow of the molten mixture providing a thermal loop between said outlet and said inlet in said return-flow path.