Dave Johnston Units 3 & 4 FGD ProjectSubmitted by The Industrial Co. Wyoming Inc.
The Dave Johnston Units 3 & 4 FGD project reduced sulfur and particulate emissions for Unit 3 (230 MW) and Unit 4 (330 MW) with tie-ins for each unit scheduled for March 2010 and March 2012, respectively.

Major installations included a 500-ft-tall chimney housing, parallel flues for each FGD train, two 5000 HP ID fans for Unit 3, two 7000 HP ID fans for Unit 4, ductwork to tie in each FGD train to the air heater for each respective boiler, one waste ash silo, one lime storage silo, a reagent preparation building housing lime and recycle ash day bins, with bin bottom activators, slakers, rotary feeder valves, grit screens, agitators, mix tanks, two recycle ash slurry tanks, one lime slurry tank, recycle ash and lime slurry feed pumps, a compressor building housing three 6900V air compressors, two air dryers and two air receivers.

Systems installed include two spray dryer absorbers with atomizers, head tanks, and associated slurry feed piping and drain lines, two bag houses with recycle ash reclaim and disposal piping and associated compressors.

Glenrock, Wyo.

Owner: PacifiCorp Energy
Contractor: The Industrial Co. Wyoming Inc.
Engineers: Kiewit Power Engineers Inc.
Among the Subcontractors: Sargent & Lundy, The Babcock and Wilcox Co.
Start: March 2008 Finish: May 2010