EVAPCO initiated an in-depth study to investigate the formation and control of white rust. This study, which began over three years ago, led to the development of industry-leading research equipment specifically designed to evaluate white rust formation on evaporative heat transfer surfaces. A small-scale closed circuit cooler was designed and built to replicate the dynamic conditions associated with evaporative cooling equipment commissioned with immediate heat load.

In addition to proprietary research, controlled testing was performed using commercially available products marketed as either white rust inhibitors or passivation aids for evaporative cooling systems containing galvanized materials of construction. The controlled testing included routine wet chemistry, visual inspections, and photography to determine how quickly area impacted. Additional research was conducted to focus on innovative pre-treatment technologies for the galvanized coils utilized in closed-circuit coolers and evaporative condensers. This research effort continued with a goal of providing a factory applied pre-treatment capable of minimizing the formation of white rust in evaporative cooling equipment commissioned with immediate heat load across a wide variety of makeup water qualities and water treatment formulations.

Read the full article, Beyond Laboratory Research on White Rust and Passivation, published in the Analyst, Volume 24 Number 3.