Apparatus and method to control emissions of nitrogen oxide
AssigneeEntropy Technology and Environmental Consultants, LP
InventorsStephen C. Wood, Ravindra K. Agrawal
Life of this patent
Estimating the term…
Abstract
A combustion apparatus which has a post combustion hot gas fan and a recirculation duct positioned down stream from the fan to reduce NOx emissions by returning a portion of the exhaust from the combustion zone back to the combustion zone. For example, in one embodiment the increased velocity of the exhaust gas stream from the post combustion hot gas fan which is required to overcome the pressure drop in a post combustion treatment unit is used as the motive force for the recirculation of a portion of the exhaust to the combustion zone to reduce the NOx exiting the apparatus to a level below that of the post combustion treatment alone.
Claims11
An apparatus for flue gas recirculation to reduce NOx emissions comprising:
- a combustion unit, an air feed line, a fan to provide airflow through said air feed line, an exhaust duct for removing flue gas from the combustion unit, a post combustion hot gas fan for exhausting flue gas, positioned downstream of said combustion unit, a recirculation line penetrating into the exhaust duct, extending into said air feed line and having an extractor for capturing and directing a portion of said exhausting flue gas into said combustion unit through said air feed line for combustion therein and a separate post combustion treatment unit in gaseous communication with said exhaust duct.
An apparatus comprising:
- a combustion unit, an exhaust duct for removing flue gas from the combustion unit, a separate post combustion treatment unit in gaseous communication with said combustion unit, a hot gas fan positioned between said combustion unit and said post combustion treatment unit for delivering flue gas through said post combustion unit, and a recirculation line penetrating into the exhaust duct between said hot gas fan and said post combustion unit said recirculation line having an extractor for capturing and directing a portion of said flue gas into said combustion unit for combustion therein.
Dependencies are inferred from the claim text.