The poor performance of a particular corrosion inhibitor package in an open evaporative cooling system resulted in increased efforts to find alternate inhibitors, which would give acceptable corrosion results. Through the molybdate-based inhibitor is used with very good results in other towers with similar waters the results in this tower were marginal to poor. A laboratory investigation was undertaken to assess the performance of a conventional HEDP-Zinc package and HEDP-Low Zinc package and a proprietary Phosphonate-Low Zinc (PPLZ) package relative to that of the existing program. This paper presents the results of both the laboratory evaluation and field trial that resulted.

89-11: Investigation of Alternative Inhibitor Programs for Highly Corrosive