Method and apparatus for injecting a gas into a two-phase stream

An apparatus for improved mixing of oxygen and a mixture of a non-gaseous fuel and conveying gas for improved combustion in a combustion chamber, said apparatus comprising:

• a) a source of a mixture of non-gaseous fuel and conveying gas, wherein said non-gaseous fuel is coal and said conveying gas is air;
• b) a source of oxygen;
• c) a burner operatively associated with a combustion chamber;
• d) a fuel duct in fluid communication with said source of mixed non-gaseous fuel and conveying gas, wherein said fuel duct is tubular and includes a portion that extends along an axis towards said burner;
• e) a tubular oxygen lance fluidly communicating with said source of oxygen, wherein said lance is disposed along said axis and has a diameter D;
• and
• f) at least first and second injection elements in fluid communication with said source of oxygen and configured to inject oxygen into, and mix therewith, a flow of said mixture upstream of, or at, said burner, wherein at least one of said first and second injection elements receives oxygen from said lance, and the first and second injection elements are spaced apart by a distance X, which is greater than the length of diameter D, wherein said first injection element is upstream of said second injection element, wherein said first and second injection elements are disposed at a same axial position along said axis, said first injection element is disposed adjacent to an inner wall of said duct, and said second injection element is disposed at said axis, wherein each of said at least first and second injection elements comprises a leg extending outwardly and axially from said lance, and at least one aperture disposed at an end of said leg facing said burner, wherein said leg and at least one aperture are configured to receive a flow of oxygen from said lance and inject it into a flow of said mixed non-gaseous fuel and conveying gas, wherein said leg and said aperture, are further configured to inject said oxygen towards said axis, wherein said at least first and second injection elements comprises first, second, third, and fourth injection elements, each of said injection elements comprises a leg extending outwardly and axially from said lance and at least one aperture disposed at an end of said leg facing said burner, each of said legs and said apertures are configured to receive a flow of oxygen from said lance and inject it into a flow of said mixed non-gaseous fuel and conveying gas, and each of said legs is radially spaced from one another with respect to said axis.

A method of improved combustion of oxygen and a mixture of a non-gaseous fuel and conveying gas for improved combustion in a combustion chamber, said method comprising the steps of:

• a) providing an apparatus comprising:
• i) a source of a mixture of non-gaseous fuel and conveying gas;
• ii) a source of oxygen;
• iii) a burner operatively associated with a combustion chamber;
• iv) a fuel duct in fluid communication with said source of mixed non-gaseous fuel and conveying gas, wherein said fuel duct includes a portion that extends along an axis towards said burner;
• v) a tubular oxygen lance fluidly communicating with said source of oxygen, wherein said lance is disposed along said axis and has a diameter D;
• and
• vi) at least first and second injection elements are in fluid communication with said source of oxygen and configured to inject oxygen into, and mix therewith, a flow of said mixture upstream of, or at, said burner, wherein at least one of said first and second injection elements receives oxygen from said lance, and said first and second injection elements are spaced from each other by a distance X, which is greater than the length of diameter D;
• b) allowing said mixture of non-gaseous fuels and conveying gas to flow into the fuel duct;
• c) allowing said oxygen to flow from the first and second injection elements such that said oxygen and said mixture are mixed;
• and
• d) allowing the thus-mixed said oxygen, and said non-gaseous fuel and conveying gas mixture to be combusted within the combustion chamber.