FURNACE RUN LENGTH EXTENSION BY FOULING CONTROL

摘要

The invention relates to a method for cleaning the surface of an alloy comprising a base metal and an alloying metal, comprising the steps of: (a) pigging said alloy surface; and thereafter (b) passivating said alloy by contacting said surface with a gas comprising steam for a time and at a temperature sufficient to form at least on mixed oxide layer on said alloy wherein said mixed metal oxide contains an average alloying metal content of from equal to the alloying metal content in said alloy up to 100% alloying metal. The method is particularly applicable in increasing the run length in a refinery process conducted in a unit having alloy surfaces susceptible to fouling.