Graycor Industrial recently completed a major Air Quality Control System (AQCS) project for Alliant Energy. Graycor completed a two-phased project to install a new Selective Catalytic Reduction (SCR) system at Alliant Energy subsidiary Wisconsin Power and Light Company’s (WPL) Edgewater Generating Station, Unit 5 facility located in Sheboygan, Wisconsin. The SCR further reduced nitrogen oxides (NOx) emissions from Unit 5 to comply with Wisconsin’s Reasonably Available Control Technology (RACT) requirements. Construction on the approximately $153 million investment began in September 2010 and the SCR was operational by the end of 2012.
Phase I of the project included relocation of the existing 250 ton precipitator inlet duct section using a jack and slide system during the fall 2010 outage. After the outage, over 80 low head room micropiles were installed in the existing fan room for future structural steel installation, including the grillage system, to support the new SCR. The micropiles extended approximately 80 feet to bedrock through an average five feet of concrete floor slab within the existing facility. The micropiles were then further cored approximately 10 feet into the bedrock.
Phase II entailed installation of the SCR and associated equipment for the 430-megawatt Unit 5. During Phase II, the existing ductwork air flow was rerouted into the new SCR box. Phase II also entailed the construction of an ammonia tank farm and a mechanical electrical building to support the SCR system. Two outages were planned for and occurred during Phase II of the project and manpower peaked at 250 employees on site.
One of the unique elements of the project was the tight constraints in which the Graycor team had to work. The Edgewater facility is essentially on the shore of Lake Michigan so the team had very little room to maneuver in and to place the Kobelco 600 ton crane which had to execute some very difficult and precise vertical lifts. It also had the challenge of working along the lake for two winter seasons. To make the project go as smooth as possible, the Graycor team geared its construction schedule around WPL’s outages, engineering progress, and equipment and material deliveries, while maintaining the highest of safety standards.
“This was a great opportunity to work with the team at WPL. This was a sophisticated project that took place in very tight quarters. It took careful planning, timely execution and a commitment to safety. The entire team developed the appropriate strategic framework and took the right technical steps to ensure the ultimate success of the project”, said Lee Petcu, Senior Vice President at Graycor Industrial.
Alliant Energy Corporation is an electric and gas utility holding company headquartered in Madison, Wisconsin. Through its subsidiaries Interstate Power and Light Company (IPL) and Wisconsin Power and Light Company (WPL), Alliant Energy serves approximately one million electric and 415,000 natural gas customers in parts of Iowa, Minnesota and Wisconsin.
Graycor Industrial is a market leader in the Air Quality Control System market having recently worked on over 20 AQCS projects for major power producers throughout the U.S., including recent projects for American Electric Power, Duke Energy, Midwest Generation, NIPSCO, Otter Tail Power and Xcel Energy.