Empire District Electric Company Joplin, Missouri, United States
Cleaner air, under budget and ahead of schedule
Commitment to clean air
Alberici led a joint venture to engineer, procure, and construct a new Air Quality Control System (AQCS) at Empire District’s Asbury Power Plant. The AQCS system provides the 198 MW coal-fired power plant with the controls necessary to remove sulfur dioxide and other pollutants, cleaning their emissions by over 98 percent.
A best-in-class system
Major elements of the project included a circulating fluid bed dry scrubber, pulse-jet fabric filter, powdered activated carbon handling and injection system, and continuous emissions monitoring technology. In addition, balance-of-plant work included a new 465-foot chimney, an induced draft fan, ductwork modifications, and conversion of the boiler from pressurized to balanced draft.
Ingenuity and collaboration
The final tie-in of the new AQCS ductwork to the existing air heater had to be accomplished within tight confines beneath the existing SCR unit leaving no access for a crane. Recognizing this would be one of the more challenging aspects of construction, the team began planning for the tie-in before site mobilization. The team’s rigging engineers developed a monorail system which provided access to remove the existing ductwork and set new support steel. The new support steel was designed with rails, enabling a Manitowoc 2250 to set large sections of the duct that were then rolled into place. This innovative solution ensured the team completed the tie-in of the AQCS system within the plant’s tight outage schedule.
Beating an aggressive schedule
The complexities of the AQCS project were exacerbated by an aggressive timetable driven by the owner’s commitments to the EPA, shareholders, and customers. To maintain control of the schedule, Alberici self-performed foundations, piping, steel erection, boilermaker work, and equipment installation. Weather proved a significant threat to the plan. Foundation crews fought through one of the hottest summers on record with temperatures averaging over 100° in July and August. A harsh winter also took its toll, requiring overtime to make up lost days. Despite these challenges, the project was completed early and under budget. The team’s diligence with a strategic approach to scheduling allowed the project to reach substantial completion more than six weeks ahead of schedule.