Power plants must meet both stringent NOx reduction regulation and their customers’ needs of varying electricity demands by reducing their boiler’s steam production. Reducing boiler load causes lower flue gas temperatures reducing the operating abilities of NOx control equipment such as selective catalytic reduction (SCR) reactors. Forney Corporation utilized its vast combustion experience to develop a line of SCR reheaters to supplement flue gas temperatures. When firing conditions dictate the need for this additional heat, Forney’s SCR reheaters pump heat into the flue gas stream, thereby maintaining a flue gas temperature that ensures maximum SCR efficiency. Forney can design a system for any configuration using one of three solutions, sure to satisfy your installation requirements.
Forney was the first to introduce an external firing solution. This remedy is ideal for high ash environments because it eliminates the problems of slagging, ash build-up, and burner fouling by designing the combustion equipment to operate outside the boiler flue gas duct. Also, the external burners do not increase system pressure drop, making them ideal for retrofit applications.
When boiler arrangement or customer preference does not permit an external SCR reheater system, particularly in low dust flue gas streams, Forney’s reliable duct burner provides a compact in-duct burner system for flue gas temperature control. The duct burner solution minimizes heat input requirements and ongoing operating costs by providing reliable and even heat distribution for effective SCR operation.
Forney’s Perimeter-firing system combines the benefits of both in-duct and external duct firing solutions. Strategically mounted directly on the flue gas duct work, perimeter burners inject a high velocity, high temperature stream directly into the flue gas creating excellent heat distribution to the SCR, in either low or high dust applications.
SCR Reheating Technical Bulletin
Publication Number 404002-13