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Show 8 c 4.3 Characteristics of heat flux distribution One of the problems to be taken into consideration in executing NOx reduction measures for the existing furnaces is the heat flux distribution in the furnace. This is particularly important for petroleum refinery furnace, etc.. In the case of two stage fuel combustion, it is often misunderstood as if the heat flux distribution is largely changed, as the temperature peak becomes low. Fig. 11 shows the result of measurement of heat flux distribution in the wall of the above-mentioned large horizontal cylindrical furnace by the heat flux gage. There is hardly any difference between the results of two stage fuel combustion and ordinary combustion. This is due to the fact as is observed in Fig. 12. In other words, as the temperature near the burner indicates, the temperature peak of the primary combustion zone in the burner axis becomes low in two stage fuel combustion; While the temperature of the outer circumference of the primary combustion becomes higher than the case of ordinary combustion. This temperature pattern compensates the decrease of the amount of radiant heat transmission due to decrease in temperature at the burner axis. This shows that this burner can be applied to the various furnaces which need the flat heat flux distribution. 5. Application for industrial furnace : The two stage fuel burners have already been adopted to boilers, annealing furnaces, etc.. They have been in good operation with expected performance. As shown below the standard specification of this burner is nearly same as that of the conventional forced draft burner. The dimensions of burner installation are nearly same as those of conventional ones. Therefore, the new burner can be applicable to the existing furnaces without modifications. C 1 0 -8 |