How to avoid salt deposition and corrosion on metal surface in distillation columns

Prevention of corrosion in equipment used in hydrocarbon refining and processing is and has been the subject of much attention . A specific problem area is the overhead equipment and piping associated with distillation columns in certain processing units. particular attention to process vapor condensing equipment is necessary. carbon steels are predominantly used as materials of construction for shch equipment.while it is possible to fabricate hydrocarbon processing equipment from metals which are less prone to corrosive attack, such as stainless steel and other high alloys , the cost of such equipment is sufficiently high that it is seldom used . instead of higher metallurgy prevention and protection measures are applied to carbon steel equipment. particularly susceptible to excessive corrosion is the air cooled heat exchangers used to cool and condense overhead vapors from the columns. initial cooling of overhead vapors is often accomplished by heat exchnage with feed stock or another hydrocarbon stream which required heating. further cooling and condensation is normally accomplished in a heat exchanger of the type in which liquid flows through a plurality of tubes over which atmospheric air is passed through air -cooled heat exchangers .