Project Scope

For a regional generation and transmission cooperative, Graycor installed a new selective catalytic reduction (SCR) system on Unit 1 at the power producer’s generating station in Laramie, Wyoming. Of the station’s three coal-based units, Unit 1 is equipped with a cold-side electrostatic precipitator, followed by a wet flue gas desulphurization system. The environmental retrofit work on Unit 1 will improve the existing environmental systems by adding a new SCR consisting of two Riley SCR reactors.

The project scope included installation of the SCR structural support steel, access galleries, siding enclosure and SCR ductwork. To install the new Riley system, Graycor’s team modified the existing Unit 1 boiler structure, FD fan room and economizer outlet ductwork in preparation for the new SCR tie-in. Three outages took place during the project.

Self-perform work included structural steel, ductwork, concrete and piping. Subcontracted work included electrical, insulation, siding, roofing, fencing, HVAC, scaffolding and painting.

Ductwork: 400+ pieces of material and equipment weighing over 3,100 tons were lifted and set into place. Heaviest single lift: 341,000 lbs.

Structural Steel: 10,000+ pieces of steel weighing nearly 2,800 tons were erected for the SCR’s two tiers and balance-of-plant reinforcement.