Refractory block for low NOx burners with internal flue gas recirculation
AssigneeHoneywell International Inc.
InventorsUmesh Chandra Bhayaraju, Curtis Lynn Taylor, Bradley Dean Patterson, Ross Halstead
Life of this patent
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Abstract
A refractory apparatus may include a refractory block comprising a heat shield. The refractory block can include a group of flue gas ports that acts as a gateway for flue gas produced due to combustion downstream of a burner. A suction created in the burner drives the flue gas into the burner through the flue gas ports. A group of staged risers can be housed within the refractory block. The staged risers are protected in staged fuel riser housings in the refractory block. A discharge cone is located in the refractory block for flame stabilization in the burner.
Claims6
A burner, comprising:
- a housing having at least a first end, a second end, a combustion air inlet, and a housing inner surface that defines a housing chamber;
- a burner flange extending radially from the second end of the housing;
- a jet pump mounted within the housing chamber, the jet pump having a jet pump inlet and a jet pump outlet, the jet pump inlet in fluid communication with the combustion air inlet to receive a flow of combustion air therefrom;
- a flue gas recirculation tube mounted within the housing chamber and having at least an inner surface that defines a recirculation tube chamber for receiving a flow of flue gas;
- a mixing tube mounted within the housing chamber downstream of the jet pump outlet and having a mixing tube chamber that receives the flow of combustion air from the jet pump outlet and the flow of flue gas from the recirculation tube chamber;
- a fuel inlet tube mounted at least partially within the housing chamber and extending through the jet pump and into the mixing tube;
- a single refractory block disposed downstream of the second end of the housing and coupled to the burner flange, the single refractory block having:
- a plurality of flue gas recirculation ports formed therein, each flue gas recirculation port in fluid communication with the recirculation tube chamber for supplying the flow of flue gas thereto;
- an inner surface that defines a discharge cone downstream of the mixing tube;
- and
- a plurality of staged riser housings disposed therein, each staged riser housing having a stager riser housed therein,
- wherein:
- the flow of combustion air into the jet pump generates a suction that draws flue gas into and through the flue gas recirculation ports, into and through the flue gas recirculation tube, and into the mixing tube chamber,
- the combustion air and the flue gas in the mixing tube mix together to provide a combustible gas, and
- each flue gas recirculation port is sized such that the flue gas is up to 20% of the combustible gas.
Dependencies are inferred from the claim text.