Oxy-fuel burner having coaxial fuel and oxidant outlets

A method of combining oxidant and fuel in an oxy-fuel burner to produce a flame, comprising:

• conducting an outer oxidant flow comprising at least 80% oxygen from an oxidant source through an outer oxidant-conducting passage, and discharging said outer oxidant flow through an outer oxidant outlet,
• conducting a fuel flow from an oxidant source through a fuel-conducting passage, and discharging said fuel flow through a fuel outlet arranged coaxially with respect to said outer oxidant outlet and spaced radially inwardly therefrom,
• conducting an inner oxidant flow comprising at least 80% oxygen through an inner oxidant-conducting passage and discharging said inner oxidant flow through an inner oxidant outlet arranged coaxially with respect to said fuel outlet and spaced radially inwardly therefrom, said inner oxidant flow and said outer oxidant flow providing a total oxidant flow, and
• controlling via valve means a percentage of the total oxidant flow which flows through the inner-oxidant conducting passage to control a characteristic of the flame.

An oxy-fuel burner comprising:

• an oxidant source comprising at least 80% oxygen;
• an outer oxidant-conducting passage forming an outer oxidant outlet in fluid communication with said oxidant source;
• an inner oxidant-conducting passage forming an inner oxidant outlet in fluid communication with said oxidant source;
• a fuel-conducting passage forming a fuel outlet;
• said outer oxidant outlet, said inner oxidant outlet, and said fuel outlet being coaxially arranged, with said fuel outlet disposed radially between said outer and inner oxidant outlets;
• and
• valve means for producing an oscillating flow of oxidant through the inner oxidant-conducting passage to control a characteristic of the flame.

A method of combining oxidant and fuel in an oxy-fuel burner to produce a flame, comprising:

• conducting an outer oxidant flow comprising at least 80% oxygen through an outer oxidant-conducting passage, and discharging said outer oxidant flow through an outer oxidant outlet;
• conducting a fuel flow through a fuel-conducting passage, and discharging said fuel flow through a fuel outlet arranged coaxially with respect to said outer oxidant outlet and spaced radially inwardly therefrom;
• conducting an inner oxidant flow comprising at least 80% oxygen through an inner oxidant-conducting passage and discharging said inner oxidant flow through an inner oxidant outlet arranged coaxially with respect to said fuel outlet and spaced radially inwardly therefrom, said inner oxidant flow and said outer oxidant flow providing a total oxidant flow;
• oscillating the oxidant flow through the inner oxidant-conducting passage by controlling a valve operatively associated with the inner oxidant-conducting passage to control a characteristic of the flame.