Case Study - Tennessee Valley Authority, Kingston Fossil Plant

Challenge:

A six-month field test of Mexel 432/0 water treatment was conducted in a condenser cooling water system at a 1450 MW coal-fired power plant. Mexel was evaluated for its prevention of fouling in a 200 MW power cooling water circuit unit against an identical untreated unit. Mexel was quantitatively and qualitatively evaluated in relation to a condenser’s performance in which it was determined to improve performance, reduce corrosion, metal discharges, biofouling and simplify maintenance.

Treatment:

Kingston’s cooling water is drawn from a canal connected to the Clinch River. The tested units were supplied from two pumps rated at 65,000 gpm with a typical combined flow rate of 110,000 to 120,000 gpm. The cooling water was then discharged to Watts Barr Lake. The tested dosing equipment was installed in a small area on the pump deck and Mexel was injected into the intake bay before the main circulating pumps. Depending on water parameters, Mexel was dosed daily at a rate of 4 ppm to 5 ppm for 30 minutes per day

Results:

Mexel was qualitatively evaluated for performance and was determined to improve condenser performance, reduce corrosion, metal discharges, biofouling, and simplify maintenance on the whole. In-house methods for evaluating condenser performance indicated that Mexel was successful in reducing the efficiency losses and lowering maintenance costs. Furthermore, results showed proportional improvements in air emissions from efficiency gains and a significantly safer environment for workers due to Mexel’s nontoxic properties.  

Without Mexel treatment
With Mexel treatment
Biofilm coupons without (left) and with (right) Mexel treatment