Coating of metals with liq. to prevent corrosion - by hot spraying with liq. contg. no solvents which cause environmental pollution

摘要

The liq. is e.g. a lacquer dissolved in water, or a viscous wax; and the spraying zone surrounding one or more spraying nozzles is heated to the working temp. of the liq. to prevent evapn. of that liq. before it reaches the workpiece. The heating of the spraying zone is pref. achieved via a stream of air heated electrically or electromagnetically. One pref. plant includes a heated tank from which the liq. is pumped through a filter to a spraying nozzle surrounded by a duct (a) fed with a stream of hot air from a blower. Duct (a) may also contain baffles in which electric resistance heater coils are located; and the baffles direct the hot air onto the workpiece. When organic solvents are used with the protective lacquers, high costs are involved in preventing environmental pollution. The invention eliminates such costs.