Whenever process-parameters or given combustible material or the construction of the vessel/boiler are limiting the possibilities to combat corrosion and/or abrasion, covering the heat-exchanger-surfaces with appropiate materials very often is the only possibility to protect and significally extent the lifetime of these elements.
Besides the application-technique, choosing the correct coating-materials is a driving factors to success.
As surface's stess-profiles are very different and determined by a huge number of different parameters, there is no „universal" solution for all parts and types of incinerators/boilers. Different solutions and coating-materials are necessary to ensure long-term protection.
This is why Häuser & Co GmbH develops and otimizes since 1995 coating-alloys to meet the different requirements caused by temperature, corrosion, abrasion, or erosion.
For waste-incinerators with Cl-induced corrosion, Ni-base-alloys with content of different refractory-metals. On vaporizing surfaces, alloys with added portions of Cr or Mo have proven to protect. On superheater-surfaces, addition of Tungsten-carbides is benificial to improve corrosion and abrasion resistance.
At biomass-incinerators, specially wood or cellulosic biofuels represent a higher stress-level and emaciation-rates to the heat-exchanger-elements because of the higher dust-freights in the flue-gas-stream and the higher temperature-levels (compared to waste-incinerators), or if CFB or SFB-installations. Coatings with Ni-base-alloys enriched with Tungsten-carbides have proven to be very good protectors in these surroundings. Due to maintaining their hardness even at high working-temeratures and in combination with their corrosion-stability, they perform superiour to most of the Inconel- or Hastelloy-alloys.
In black-/lignine coal, chemical or metallurgical works, as well Fe- or Cobalt-base alloys and different ceramics are used when protection against mechanical emaciation under high temperature environment of up to 1.000°C is requested.