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Show Table 3 - Computer model results COIiPunR IIODEL R.SUL,.. FOR A CHANG. IN TH. LENGTH OF TH. UNFIRED PREHEAT ZON. CASE 1 CASE 2 CASE 3 ~ ~ oXYaEN Steel ttvouhgput (ton/hl) Length d unflred zone 'III ConvenIion to oxygen Arlng Rat. (MMBTU/hI) PI'et-' No.1 He.t No.2 He.t Soek Bottom TotIII SpedIIc Fuel Cone. (MMBTU/1on steeO Oxygen (ton Oz/ton steeO Fuel Savinga (MMBTU/ton steel) Fuel Savings (MMBTU/ton oxygen) 'III ToIa! Fuel SavInga Flue OM Temperature iF) 90 10' o 51 .0 57.7 13.3 12.4 65.4 199.8 2.22 1898" 90 f1 ~ 37.8 22.7 13.4 12.3 82.0 148.2 3.0 1.8 4.8 1.85 0.053 .57 1o.et 25.7'11 1548" 90 14' 52'111 22.5 26.0 14.0 12.5 70.0 145.0 1.8 2.0 3.8 1.81 0.043 .81 1 ... 27.5CIb 1402" Note that there is a significant improvement in fuel savings in terms of MMBTU saved per ton of oxygen consumed and a much lower oxygen consumption in Case 3 compared to Case 2. Having burners closer to the flue as in Case 2 results in a higher flue gas temperature and a higher conversion level because of the increased firing in the oxygen zones. Both of these factors contribute to the lower fuel savings. The effect of changing the length of the unfired section in the model corresponded to what was experienced in actual operation. In this way, computer modeling studies have proved useful in analyzing effects of changes in production rate, zone set point temperatures, burner placement, and delays in operation. SUMMARY This paper has intended to show: 1) the fuel savings potential of replacing air with oxygen for combustion particularly in continuous furnaces, 2) the operating results of the Linde "A" Burner Oxygen Combustion System in a continuous furnace in the 18-2 Bar Mill at U. S. Steel, Gary, Indiana, 3) the use of Linde I s computer modeling capabilities and data analysis in order to make improvements in furnace operation. ACKNOWLEDGEMENT The authors would like to express their appreciation to the personnel of u.S. Steel for their valuable assistance and cooperation in conducting this program. 265 |