Low nox gas burner with cooled flue gas recycle
AssigneeHoneywell International Inc.
InventorsKurt E. Kraus, Dusty Ray Richmond, Mohammad Reza Mostofi-Ashtiani, Zhili Qin
Life of this patent
Estimating the term…
Abstract
A burner and methods of using the burner. The burner produces a flame from combustion air and fuel gas. Flue gas, also produced, can be withdrawn and recycled to the burner. A cooling or condition gas, such as ambient air, may be mixed with the flue gas to reduce its temperature. The burner may also utilize a stage injection so that a portion of the produced flue gas is recycled internally.
Claims20
A burner configured to receive a fuel gas and a combustion air which react and produce a flame and a flue gas in a combustion zone, the burner comprising:
- primary injection ports configured to inject fuel gas into a primary combustion zone;
- secondary injection ports spaced from the primary combustion zone and configured such that as fuel gas is injected a first portion of the flue gas is drawn to the primary combustion zone;
- and,
- a duct configured to remove a second portion of the flue gas from the combustion zone and return the second portion of the flue gas to the primary combustion zone.
A heating system comprising:
- a burner configured to receive a fuel gas and a combustion air which react and produce a flame and a flue gas in a combustion zone;
- a duct configured to remove a first portion of the flue gas from the combustion zone as a recycled flue gas, wherein the first portion of the flue gas is mixed, upstream of the combustion zone, with the fuel gas and the combustion air;
- and
- a second duct configured to remove a second portion of the flue gas from the heating system,
- wherein the second portion of the flue gas has passed through a convection zone of the heating system,
- wherein the convection zone is disposed downstream from the combustion zone, and
- wherein the second portion of the flue gas is mixed, upstream of the combustion zone, with the fuel gas and the combustion air.
A method of controlling a burner, the method comprising:
- reacting, in a combustion zone of a heating system, a fuel gas and a combustion air to produce a flame and a flue gas;
- removing a first portion of the flue gas from the combustion zone as a recycled flue gas;
- mixing the first portion of the flue gas, upstream of the combustion zone, with the fuel gas and the combustion air;
- removing a second portion of the flue gas from the heating system, wherein the second portion of the flue gas has passed through a convection zone, wherein the convection zone is downstream of the combustion zone;
- and,
- mixing the second portion of the flue gas, upstream of the combustion zone, with the fuel gas and the combustion air.
Dependencies are inferred from the claim text.