CORROSION RESISTANT MATERIALS FOR SO2 SCRUBBERS.

Exposing some segments of the scrubber to extremely corrosive concentrations can be avoided through proper engineering. One method is to design the scrubber with two loops so that large portions of hardware are in contact with only low chloride levels. This can be done by designing only the final loop as a closed loop which receives effluent from the low-chloride open loops. By restricting the need for highly corrosion-resistant materials to the closed-loop area and using less expensive materials where concentrations are lower, capital cost is minimal. The materials choices available, in order of increasing cost, are: carbon steel, carbon steel lined with some protective coating, rubber and plastics, alloys ranging from relatively inexpensive Type 304 stainless steel to the very expensive Hastelloys.