generated by real time probing of the gas composition 2 feet directly under the flame at various furnace depths in a single pass laboratory furnace for about 2 minutes for each data point under stable burner firing and furnace temperature conditions the unit of measure of co in fig3 is different from that in modeling because only point concentrations can be measured in experiments the scale of the o 2 concentration measured was also relatively larger than the modeling results due to the sampling location being closer to the flame than modeled and due to the fact that the measurements are from dry samples after removing the moisture in the gas which can be significant in oxy fuel combustion the utility of increased co volume i e higher co concentration in order to reduce oxidation of the underlying charge or molten material was evaluated against the burner design in particular the fuel nozzle angle the central region of the curve in fig2 is a desirable operating regime as can be seen the fuel or natural gas u201c ng u201d nozzle angle with most of the points inside the curve is that of about 7 5 u00b0 the length of the nozzle offset can determine the amount of pre combustion which in turn can determine the size of the flame to reduce the free o 2 concentration it is useful to control the o2 concentration such that the o 2 preferentially mixes and reacts with ng ng is in effect sandwiched by a high velocity oxygen jet on the inside and a much slower moving layer.