초록 ▼

A method and system for flue gas recirculation is disclosed which will minimize NOx production from hydrocarbon combustion. In the present invention a furnace having an oxygen-bearing primary source of combustion air, a mixing chamber, a combustion chamber in downstream communication with the mixing

A method and system for flue gas recirculation is disclosed which will minimize NOx production from hydrocarbon combustion. In the present invention a furnace having an oxygen-bearing primary source of combustion air, a mixing chamber, a combustion chamber in downstream communication with the mixing chamber and an exhaust section downstream of the combustion chamber is provided with a flue gas recirculation line. The recirculation line establishes communication between the exhaust section and the mixing chamber for the return of combustion products as a secondary source of combustion air which is relatively lean in oxygen and is combined with the primary source of combustion air in the mixing chamber. The ratio of flow rates for the primary and secondary sources of combustion air is controlled by a signal generated by a sensor which senses the oxygen concentration in the mixing chamber.

대표청구항 ▼

A steam-generating device, comprising: a furnace unit comprising: an air intake regulating device which provides a primary source of combustion air which is relatively rich in oxygen; a mixing chamber in downstream communication with the air intake regulating device; a combustion chamber in downstre

A steam-generating device, comprising: a furnace unit comprising: an air intake regulating device which provides a primary source of combustion air which is relatively rich in oxygen; a mixing chamber in downstream communication with the air intake regulating device; a combustion chamber in downstream communication with the mixing chamber; and an exhaust section in downstream communication with the combustion chamber; a flue gas recirculation system comprising: a recirculation line establishing communication between the exhaust section and the mixing chamber to provide a secondary source of combustion air to the mixing chamber which is relatively lean in oxygen; and a control system comprising: a sensor for monitoring the oxygen concentration in the mixing chamber and generating a signal which is a function thereof; and a means responsive to the signal for controlling the flow rate of the flue gas through the recirculation line; and a heat exchange system comprising: a heat exchanger in thermal communication with the furnace unit; and a circulation system extending through the heat exchanger through which water passes and is converted to steam.