Interest of Alloy G-35® Heat Exchangers in Phos-acid Concentration Loops

HASTELLOY® G-35® alloy was developed to provide corrosion resistance to the most difficult phosphoric acid environments. Good corrosion behavior was found from testing in the laboratory and has been confirmed by industrial applications. The alloy has been selected for the fabrication of the heat exchangers used to reheat the acid in the concentration loop. These heat exchangers are widely used in USA. Their technical as well as economical performances surpass the graphite heat exchangers previously used. They bring better reliability and additional safety. The replacement of the graphite heat exchanger by a G-35 alloy metallic one can be done without any other modification of the units, since the thermal performance is very similar. The return on investment is done in months thanks to the productivity gains which allow an output increase and thanks to the savings on the cost of production and maintenance.