Flue Gas Recirculation (FGR) acts to reduce NOx formation by reducing peak flames temperatures. In conventional applications, the recirculated flue gas is typically extracted from the boiler outlet duct upstream of the air heater. The flue gas is then returned through a separate duct and hot gas fan to the combustion air duct that feeds the windbox. The recirculated flue gas is mixed with the combustion air via air foils or other mixing devices in the duct. This technology is known as windbox FGR (WFGR). WFGR systems require installation of a separate hot gas FGR fan to move flue gas from the boiler exit to the air supply ducting at the windbox inlet, where mixing of the air and flue gas must be uniformly achieved by installation of appropriate mixing devices.
IFGR is a very effective technique in reducing NOx emissions due to:
- low total cost relative to competing technologies such as low-NOx burners or selective catalytic reduction
- speed of application installation;
- fxproviding the same levels of NOx reduction as competing technologies.
Contact us to find out more information on how we can provide IFGR solutions for your gas-fired boiler.
