James J Souza33426 Canvas Back St, Woodland, CA 95695

2011003, Feb 17, 2011

Aug 12, 2009

12/462958

Jeffrey Shallcross - Pleasanton CA, US
Larry Day - Fremont CA, US
David Spain - Fremont CA, US
James Souza - Modesto CA, US

F23J 15/04

110215, 432 41

The invention uses an input signal directly from a fuel flow device to control the amount of ammonia injected into a flue gas stream for NOx reduction for boilers. The control system receives a signal directly from a fuel flow device that indicates the amount of fuel flow and corresponding NOx emissions. The signal is processed using an algorithm with a multi-loop controller and an ammonia mass flow control valve with temperature and pressure corrections to determine how much ammonia must be injected into the flue gas in the presence of a catalyst to achieve the desired NOx emissions reductions. A dilution air blower transports ammonia to an injection grid and subsequently, the ammonia reacts with the flue gas in the presence of a catalyst to reduce the amount of NOx emissions to the desired level.A bias function that allows a boiler operator to manually increase or decrease the flow of ammonia in order to vary the amount of NOx reduction is included and can be used as an alternate to automatic operation, thus allowing an operator to dictate the amount of ammonia to be injected into the system. Air temperature and pressure correction functions are also included to adjust the ammonia flow based on a given temperature and fuel flow.