Low NOx burner apparatus and method

A burner providing reduced NOx emissions for use in a beating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end;
• said burner having only a single combustion stage, said single combustion stage having a beginning end located substantially at said forward end of said burner wall;
• a plurality of fuel gas ejectors positioned longitudinally rearward of an laterally outward from said forward end of said burner wall;
• and
• a plurality of fuel gas ejectors positioned longitudinally rearward of and laterally outward from said forward end of said burner wall;
• and
• said fuel gas ejectors being configured and positioned to deliver fuel gas to said single combustion stage in ejection flow paths outside of said burner wall in a manner effective such that at least a portion of said fuel gas delivered by said fuel gas ejectors will be combusted at said beginning end of said combustion zone and at least a sufficient portion of said flue gas is entrained in said fuel gas to yield total NOx emissions of less than 10 parts per million by volume of all combustion product gases produced by said burner,
• wherein said burner comprises at least ten of said fuel gas sectors positioned in series and spaced from about 1 inch to about 4 inches apart.

A burner providing reduced NOx emissions comprising:

• a burner wall having a forward end;
• at least one fuel gas nozzle positioned longitudinally rearward of and laterally outward from said forward end of said burner wall;
• at least one fuel gas delivery port positioned in said fuel gas nozzle to deliver fuel gas in a flow path outside of said burner wall to a combustion zone at said forward end of said burner wall;
• and
• at least one exterior ledge provided on said burner wall and positioned between said fuel gas delivery port and said forward end of said burner wall such that at least a portion of said fuel gas traveling in said flow path will contact said exterior ledge;
• said exterior ledge being spaced apart from said forward end.

A burner providing reduced NOx emissions comprising:

• a burner wall having a forward end;
• at least one fuel gas nozzle having at least one fuel gas delivery port positioned therein to deliver fuel gas in a flow path outside of said burner wall to a combustion region at said forward end of said burner wall;
• and
• a plurality of impact structures, not including said forward end of said burner wall, positioned such that each of said impact structures will be contacted by at least a portion of said fuel gas traveling in said flow path.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end;
• a series of fuel gas ejectors, each having only a single fuel gas ejection port provided therein, said ejectors and said single fuel gas ejection ports provided therein being positioned and said fuel gas ejection ports being configured to deliver fuel gas from said ejectors in a plurality of adjacent fee jet flow streams outside of said burner wall toward a combustion zone at said forward end of said burner wall, each of said adjacent free jet flow streams being effective for entraining a portion of said flue gas in said fuel gas and said fuel gas ejection ports being positioned longitudinally rearward laterally outward with respect to said forward end of said burner wall;
• and
• an impact structure positioned between said fuel gas ejection ports and said forward end of said burner wall such that said impact structure will be contacted by at least a portion of said fuel gas traveling in said flow streams.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end;
• a series of fuel gas ejectors, each having only a single fuel gas ejection port provided therein, said ejectors and said single fuel gas ejection ports provided therein being positioned and said fuel gas ejection ports being configured to deliver fuel gas from said ejectors in a plurality of adjacent free jet flow streams outside of said burner wall toward a combustion zone at said forward end of said burner wall, each of said adjacent free jet flow streams being effective for entraining a portion of said flue gas in said fuel gas and said fuel gas ejection ports being positioned longitudinally rearward and laterally outward with respect to said forward end of said burner wall;
• said fuel gas ejection ports being oriented such that said forward end of said burner wall will be contacted by at least a portion of said fuel gas traveling in said flow streams;
• and
• a plurality of impact structures positioned between said fuel gas ejection ports and said forward end of said burner wall such that each of said impact structures will be contacted by at least a portion of said fuel gas traveling in said flow streams.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end and
• a series of fuel gas ejectors, each having only a single fuel gas ejection port provided therein, said ejectors and said single fuel gas ejection ports provided therein being positioned and said fuel gas ejection ports being configured to deliver fuel gas from said ejectors in a plurality of adjacent free jet flow streams outside of said burner wall toward a combustion zone at said forward end of said burner wall,
• each of said adjacent free jet flow streams being effective for entraining a portion of said flue gas in said fuel gas and
• said burner having a pressure reduction region at said forward end of said burner wall.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end and
• a series of fuel gas ejectors, each having only a single fuel gas ejection port provided therein, said ejectors and said single fuel gas ejection ports provided therein being positioned and said fuel gas ejection ports being configured to deliver fuel gas from said ejectors in a plurality of adjacent free jet flow streams outside of said burner wall toward a combustion zone at said forward end of said burner wall,
• each of said adjacent free jet flow streams being effective for entraining a portion of said flue gas in said fuel gas and
• wherein said burner wall has an interior passageway for flow of air or other oxygen-containing gas out of said forward end and said burner further comprises a shoulder in said interior passageway adjacent said forward end of said burner wall for creating a reduced pressure region at said forward end.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end and
• a series of fuel gas ejectors, each having only a single fuel gas ejection port provided therein, said ejectors and said single fuel gas ejection ports provided therein being positioned and said fuel gas ejection ports being configured to deliver fuel gas from said ejectors in a plurality of adjacent free jet flow streams outside of said burner wall toward a combustion zone at said forward end of said burner wall,
• each of said adjacent free jet flow streams being effective for entraining a portion of said flue gas in said fuel gas and
• wherein said burner wall has an interior passageway for flow of air or other oxygen-containing gas out of said forward end and said burner further comprises an angled surface in said interior passageway for creating a reduced pressure region at said forward end.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end and
• a series of fuel gas ejectors, each having only a single fuel gas ejection port provided therein, said ejectors and said single fuel gas ejection ports provided therein being positioned and said fuel gas ejection ports being configured to deliver fuel gas from said ejectors in a plurality of adjacent free jet flow streams outside of said burner wall toward a combustion zone at said forward end of said burner wall,
• each of said adjacent free jet flow streams being effective for entraining a portion of said flue gas in said fuel gas and
• wherein said series comprises at least ten of said fuel gas ejectors and said fuel gas ejectors are spaced from about 1 inch to about 4 inches apart.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end and
• a series of fuel gas ejectors, each having only a single fuel gas ejection port provided therein, said ejectors and said single fuel gas ejection ports provided therein being positioned and said fuel gas ejection ports being configured to deliver fuel gas from said ejectors in a plurality of adjacent free jet flow streams outside of said burner wall toward a combustion zone at said forward end of said burner wall,
• each of said adjacent free jet flow streams being effective for entraining a portion of said flue gas in said fuel gas and
• wherein said series of said fuel gas ejectors surrounds said burner wall and said fuel gas ejectors are spaced from about 1 inch to about 4 inches apart.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end;
• said burner having only a single combustion stage, said single combustion stage having a beginning end located substantially at said forward end of said burner wall;
• a plurality of fuel gas ejectors positioned longitudinally rearward of and laterally outward from said forward end of said burner wall;
• and
• said fuel gas ejectors being configured and positioned to deliver fuel gas to said single combustion stage in ejection flow paths outside of said burner wall in a manner effective such that at least a portion of said fuel gas delivered by said fuel gas ejectors will be combusted at said beginning end of said combustion zone and at least a sufficient portion of said flue gas is entrained in said fuel gas to yield total NOx emissions of less than 10 parts per million by volume of all combustion product gases produced by said burner,
• wherein said fuel gas ejectors surround said burner wall and are spaced from about 1 inch to about 4 inches apart.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end;
• said burner having only a single combustion stage, said single combustion stage having a beginning end located substantially at said forward end of said burner wall;
• a plurality of fuel gas ejectors positioned longitudinally rearward of and laterally outward from said forward end of said burner wall;
• said fuel gas ejectors being configured and positioned to deliver fuel gas to said single combustion stage in ejection flow paths outside of said burner wall in in a manner effective such that at least a portion of said fuel gas delivered by said fuel gas ejectors will be combusted at said beginning end of said combustion zone and at least a sufficient portion of said flue gas is entrained in said fuel gas to yield total NOx emissions of less than 10 parts per million by volume of all combustion product gases produced by said burner;
• and
• an impact structure positioned between said fuel gas ejectors and said forward end of said burner wall such that at least a portion of said fuel gas traveling in said flow paths will contact said impact structure.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end;
• said burner having only a single combustibe stage, said single combustion stage having a beginning end located substantially at said burner wall;
• a plurality of fuel gas ejectors positioned longitudinally rearward of and laterally outward from said forward end of said burner wall;
• said fuel gas ejectors being configured and positioned to deliver fuel gas to said single combustion stage in ejection flow paths outside of said burner wall in a manner effective such that at least a portion of said fuel gas delivered by said fuel gas ejectors will be combusted at said beginning end of said combustion zone and at least a sufficient portion of said flue gas is entrained in said fuel gas to yield total NOx emissions of less than 10 parts per million by volume of all combustion product gases produced by said burner;
• and
• a plurality of impact structures positioned between said fuel gas ejectors and said forward end of said burner wall such that each of said impact structures will be contacted by at least a portion of said fuel gas traveling in said flow paths.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein said burner comprising:

• a burner wall having a forward end;
• said burner having only a single combustion stage, said single combustion stage having a beginning end located substantially at said forward end of said burner wall;
• a plurality of fuel gas sectors positioned longitudinally rearward of and laterally outward from said forward end of said burner wall;
• said fuel gas ejectors being configured and positioned to deliver fuel gas to said single combustion stage in ejection flow paths outside of said burner wall in a manner effective such that at least a portion of said fuel gas ejectors will be combusted at said beginning end of said combustion zone and at least a sufficient portion of said flue gas is entrained in said fuel gas to yield total NOx emissions of less than 10 parts per million by volume of all combustion product gases produced by said burner;
• and
• a pressure reduction region at said forward end of said burner wall.

A burner providing reduced NOx emissions for use in a heating system having a flue gas therein, said burner comprising:

• a burner wall having a forward end;
• said burner having only a single combustion stage, said single combustion stage hang a beginning end located substantially at said forward end of said burner wall;
• a plurality of fuel gas ejectors positioned longitudinally rearward of and laterally outward from said forward end of said burner wall;
• and
• said fuel gas ejectors being configured and positioned to deliver fuel gas to said single combustion stage in ejection flow paths outside of said burner wall in a manner effective such that at least a portion of said fuel gas delivered by said fuel gas ejectors will be combusted at said beginning end of said combustion zone and at least a sufficient portion of said flue gas is entrained in said fuel gas to yield total NOx emissions of less than 10 parts per million by volume of all combustion product gases produced by said burner,
• wherein said burner wall has an interior passageway for flow of air or other oxygen-containing gas out of said forward end.