Double-staged oxy-fuel burner

An oxy-fuel burner comprising:

• a central burner element comprising:
• a central conduit having a central axis and terminating in a central nozzle;
• and
• an annular conduit terminating in an annular nozzle surrounding and coaxial with the central conduit, the annular conduit and the central conduit being separated by an annular wall;
• the central conduit being arranged to flow a first reactant and the annular conduit being arranged to flow a second reactant;
• a first staging conduit spaced apart from a side of the central burner element and terminating in a first staging nozzle;
• a second staging conduit spaced apart from an opposite side the central burner element and terminating in a second staging nozzle;
• a first mechanism arranged to apportion a flow of the second reactant into a non-zero primary flow of the second reactant directed to the annular conduit and a non-zero secondary flow of the second reactant;
• and
• a second mechanism arranged to selectively apportion the secondary flow of the second reactant between the first staging conduit and the second staging conduit;
• wherein one of the first and second reactants is a fuel and the other of the first and second reactants is oxygen.