SCR Installation – Unit 1
Client / Owner
American Electric Power
Architect / Engineer
AEP’s power plant in Spencer County, Indiana, received an environmental upgrade to its Unit 1. The 2,600-megawatt plant—operated by AEP subsidiary Indiana Michigan Power—is comprised of two Babcock & Wilcox coal-fired units, among the largest built. In October 2015, Graycor Industrial began reinforcing the existing boiler house and air heater building structural steel to support a selective catalytic reduction (SCR) unit with three trains that would be retrofitted to the 1,300-megawatt unit, originally commissioned in 1984.
The nearly 21-month-long project, which expended a total of 1,136,000 craft and subcontracted man-hours, was performed to meet federal-regulated air quality mandates. WorleyParsons engineered the project’s balance-of-plant (BOP) portion; Babcock Power Inc. served as SCR OEM; and Structural Steel Services Inc. fabricated the steel.
Graycor’s work scope involved installing the SCR unit, associated ductwork and support steel. The team significantly reinforced existing structural steel in the boiler and air pre-heater areas, which continued throughout the work areas. The scope also included a new anhydrous ammonia system and the necessary BOP support systems. For thermal protection, Graycor provided and installed heat tracing and insulation and lagging systems. The project culminated with catalyst installation during a 10-week tie-in outage.
Installation quantities for the project included:
Steel: 1,130 tons (718 tons for BOP steel and 212 tons for SCR steel)
Ducts: 2,493 tons
Piping: 24,844 linear feet
Welds: Approximately 16 miles