Client: Iowa State University
Location: Ames, Iowa
This project consisted of converting two coal fired stoker boilers, Boilers 3 and 4 at Iowa State University (ISU), to burn natural gas only. The boilers were originally equipped with rear wall mounted gas burners. Boiler 3 was periodically fired on gas and Boiler 4 was never fired on gas. Due to fuel cost, the gas burners on both boilers had been sealed off from the furnaces essentially removing gas firing capability sometime in the past. During this project, modifications were made to the furnaces, grates, undergrate combustion air, coal feed, ash systems, and controls to permanently remove coal firing. Also during this project, the gas burners, fuel trains, and associated controls were refurbished and/or upgraded to restore gas firing capability. POWER’s engineering, design, and control services included the evaluation of the existing gas burners, gas supply, fuel trains, combustion air supply, & controls; the investigation of potential steam temperature issues related to gas firing, the design of main & igniter gas supply, fuel trains, vents, & burner management systems to meet current NFPA standards. POWER also designed the furnace/combustion air supply modifications to eliminate coal firing & refurbish gas firing. Additionally, POWER modified the existing combustion controls configurations for gas firing only and provided new programmed & tested burner management systems for multiple burner gas firing.