A power plant in Minnesota was experiencing scale and white rust build-up inside their cooling tower condenser tubes, creating obstacles cooling the inverter. If left untreated, the built-up could result in a costly asset replacement and unscheduled down-time. The Minnesota Pollution Control Agency (MPCA) was also in the process of instituting new phosphate discharge limits, which encouraged plant management to take proactive steps to meet these new state limits before implementation.
The existing water treater’s ineffective treatment program had resulted in years of built-up galvanized corrosion on the condensor tubes which impacted the inverter cooling and eventually, could result in permanent damage to the asset. The phosphorus discharge was also outside of the new state regulated limits, leaving the plant in need of an environmentally friendly solution that provided scale and corrosion control without the discharge or aquatic toxicity concerns of traditional phosphorus chemistries.
U.S. Water worked with plant maintenance team to implement PhosZero into the system. The PhosZero chemistry provided low enough toxicity to gain approval by the MCPA, yet strong enough scale inhibition properties and corrosion protection to keep their system running efficiency.
The PhosZero program was paired with a TowerAssureTM automation system. TowerAssure’s wireless communications program monitors the power plant’s chemical program for consistency and instantly alerts the plant’s maintenance team if the system is experiencing any irregularities. The alerts allow the team to respond immediately and make adjustments from the site or home via U.S. Water ReportsTM.
Before (top) and after (bottom) corrosion coupon shows success of PhosZero’s corrosion protection on both mild metal and zinc.
Immediately after the PhosZero chemistry was introduced into the system, hardness balance testing showed that the scale was being removed. Upon inspection from the maintenance team, it was obvious that tubes were cleaner and corrosion rates were excellent.
Implementing U.S. Water’s solution did not cause any downtime, avoiding a costly shutdown of approximately $150,000/yr. The plant was also able to forgo the need to rent an anion exchange resin to remove phosphate from their system, saving approximately $35,000/yr.