ENAMEL POWDER AND ENAMEL SLURRY FOR PRODUCING AN ENAMEL COATING ON A METALLIC SUBSTRATE, METHOD FOR MANUFACTURING AN ENAMEL SLURRY AND USE OF THE ENAMEL COATING FOR HEAT EXCHANGERS

摘要

The invention concerns the enameling of aluminium-containing metallic objects that may be exposed to high thermal and mechanical loads. A preferred field of application of the invention is the coating of heat exchangers for the heating of liquids, in particular water, so that by an enameling the heat exchanger at least in portions thereof is protected from hot flame gases and condensing as well as condensed fluids. This is achieved with an enamel powder for the manufacture of an enamel slurry for producing an enamel coating on a metallic aluminium- containing substrate, which enamel powder is a mixture of an enamel frit and up to 15 % of a powder-form oxidic light metal compound and up to 20 % of a high-grade steel powder and with an enamel slurry containing such enamel powder and a special liquid such that the resulting enamel coating is resistant to high thermal and mechanical loads.