Corrosion-resistant coatings for refractory lining anchors in aggressive high temperature environments

A large number of technical incineration processes uses refractory linings to protect the construction materials of their furnace chambers against high temperature. Metallic anchors are used to attach these linings to the metallic furnace walls. At this point, technical problems arise due to the permeability of the refractory materials to gasses as well as liquid condensates especially at joints or through material immanent porosity. Corrosive media from he combustion chamber can cause severe corrosion damage when getting in contact with the metallic anchors. Critical corrodents are primarily high chlorine containing compounds, other halogens, alkalies and volatile metal salts which condensate in lower temperature areas and infiltrate the refractory lining.

The present investigations are funded by he German Federal Ministry for Economics and Technology (BMWi) via AiF (German Federation of Industrial Research Associations) under contract no. 16078 N, which is gratefully acknowledged. Damage caused by anchor failure is extremely cost intensive. Detached and broken chunks of lining can fall down onto other parts of the furnace to cause severe secondary damage. Beyond that, repair entails high costs because of the necessary shutdown of the affected combustion lines. Refractory lining anchors on a metal construction therefore demand special attention on the choice of materials and the way of construction to prevent future damage and to grant long operation times. The presented project aims at developing corrosion resistant coatings (diffusion coatings, nickel plating and combined procedures) on the anchors, thereby providing an effective, yet still competitive solution for the problem.

Das IGF-Vorhaben Nr. 16078 N der Forschungsvereinigung DECHEMA e.V., Theodor-Heuss-Allee 25, 60486 Frankfurt am Main wurde über die AiF im Rahmen des Programms zur Förderung der industriellen Gemeinschaftsforschung (IGF) vom Bundesministerium für Wirtschaft und Energie aufgrund eines Beschlusses des Deutschen Bundestages gefördert.