本研究成功建立一雙重管底吹煉鋼之水模實驗系統，模擬氧氣底吹製程雙重管口固凝物之生成情形，並觀察不同製程參數對於固凝物型態及尺寸之影響。研究在雙重管內管、外管分別吹入常溫及低溫氣體，模擬氧氣放熱及碳氫氣體吸熱反應，並改變不同操作條件，包含水溫、氣體流量及底吹管材質進行實驗。實驗結果可觀察到固凝物呈半球狀生成於底吹管口上方其形成可隔絕回擊氣體及液體與底吹元件的直接接觸，進而保護爐底。固凝物內可觀察到內管氣體吹出之單一中空圓柱通道，以及提供外管氣體吹出的大量樹枝狀小通道，其分流結構亦可避免內外管氣體吹入瞬間立即接觸，此結構與文獻顯示之鐵水固凝物示意圖相同。於不同操作條件實驗中，可發現水溫下降、外管氣體流量增加及內管氣體流量減少時，固凝物尺寸隨之增大。研究也進一步分析固凝物系統之熱傳行為，發現熱傳導佳的金屬底吹管有助於固凝物尺寸增加與穩定成長。此外，根據壓力變化形態，可將固凝物的成長型態分為三個操作區間。1. 壓力穩定型：底吹氣體壓力足夠突破固凝物阻擋，此時固凝物相對穩定（或無固凝物產生），其尺寸決定於氣體整體冷卻能力；2. 壓力累積型：氣體無法突破固凝物阻擋，造成壓力持續上升，此時氣體通道易受固凝物阻擋使流量下降；3. 壓力震盪型：氣體突破能力介於前兩類，氣體需一段時間累積才能突破固凝物阻擋，突破瞬間固凝物快速成長再次阻擋氣體，因此會造成氣體壓力持續震盪，此時固凝物相對不穩定。此壓力變化形態可協助判斷固凝物之成長狀態，作為煉鋼底吹之操作參考。

This study successfully established a water-model experiment to investigate the solid accretion on the tip of the double bottom-blowing tuyere. This study observes the effects of different parameters on the type and size of the solid accretion. In the experiment, the outer and inner tubes respectively blow gases of normal temperature and extremely low temperature to simulate oxygen-exothermic and hydrocarbon-gas-endothermic reaction. This study changes the operating conditions, including water temperature, gas flow and material for experiment. It is found that, the shape of solid accretion is hemispherical. The solid accretion can protect the bottom of the furnace from back-attack and contacting with liquid. Furthermore, in the solid accretion, a lot of small channels are above the outer tube and a main waterway is above the inner tube. The gases from the outer and inner tube are separated by the solid accretion and the structure of the solid accretion is similar to the schematic from existing document. The experiment operation was varied to understand the effects on the solid accretion. It is found that the solid accretion’s size increases when water temperature drops, outer gas flow rate increases, and inner gas flow rate decreases. In addition, according to the heat-transfer analysis, the material with good thermal conductivity contributes to the increase of solid accretion’s size and stable growth. Furthermore, the gas flow rates were varied to understand the effects on the solid accretion. It is found that in accordance with pressure change, the formation of accretion can be divided into three types: 1. the pressure is stable and the size of solid accretion depends on cooling capacity; 2. the pressure continues to increase and the gas flow is blocked by the solid accretion; 3. the pressure is oscillating and the solid accretion on the top of inner tube forms and disappears alternately. As a result, the pressure pattern curve with these three types can be a reference.

論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目錄 v
圖目錄 vii
表目錄 xi
符號說明 xii
第1章、 緒論 1
1.1 研究背景 1
1.2 轉爐發展與廢鋼回收 2
1.3 氣體底吹技術 5
1.3.1 底吹元件之破壞 5
1.3.2 底吹元件之種類 7
1.3.3 底吹氣體之選擇 8
1.4 固凝物文獻 9
1.5 研究目的 12
第2章、 研究方法及實驗設備 13
2.1 實驗規劃 13
2.2 實驗設備 14
2.3 底吹管設計 20
2.3.1 溫度量測點 22
2.3.2 底吹管材質 27
2.4 實驗步驟 29
2.5 系統熱傳解析 31
2.5.1 底吹管系統之熱傳解析 31
2.5.2 固凝物系統之熱傳解析 35
第3章、 結果與討論 39
3.1 固凝物生成與結構 39
3.2 水溫對固凝物之影響 43
3.3 底吹氣體流量對固凝物之影響 44
3.3.1 氣體流量與熱傳行為解析 44
3.3.2 氣體流量對固凝物尺寸之影響 49
3.4 底吹管材質對固凝物之影響 53
3.4.1 底吹管材質對固凝物型態之影響 53
3.4.2 底吹管材質與熱傳行為解析 55
3.4.3 底吹管材質對與固凝物型態之影響 58
3.5 固凝物成長與壓力變化 63
3.5.1 底吹管材質對壓力變化形態影響 67
第4章、 結論與未來展望 71
參考文獻 72
附錄 76

[1] 中國礦冶工程學會, 鋼鐵冶金學，鋼鐵冶煉之基礎,中國礦冶工程學會,1986.
[2] 謝之駿, 百鍊成鋼-煉鐵煉鋼的真功夫, 科學發展, 2007.
[3] 野崎努, 底吹轉爐法-引進、攪拌效果、頂底複合吹煉, 冶金工業出版社, 2008.
[4] E. G. Schempp, Increased scrap melting capacity for oxygen steelmaking―the new OBM‐S process, Iron and Steel Engineer, 1979.
[5] H. Klein, J. Liesch, H. Iso, K. Nakamura, Scrap ratio increase by coal injection in the BOF, Steelmaking Conf. Proc, 1985
[6] K. Ohnuki, K. Umezawa, T. Hiraoka, N. Matsumoto, T. Inoue, Development of steel scrap melting process, Nippon Steel Tech. Rep, 1994.
[7] T. Aoki, The Mechanism of the Back-attack Phenomenon on a Bottom Blowing Tuyere Investigated in Model Experiments, 鉄と鋼, 1990.
[8] T. Aoki, Elimination of the Back-attack Phenomenon on a Bottom Blowing Tuyere Investigated in Model Experiments, 鉄と鋼, 1990.
[9] M. Iguchi, O. J. Ilegbusi, H. Ueda, T. Kuranga and Z. I. Morita, Water Model Experiment on the Liquid Flow Behavior in a Bottom Blown Bath with Top Layer, Metallurgical and Materials Transactions B, 1996.
[10] D. Mazumdar and R. I. L. Guthrie, Hydrodynamic Modeling of Some Gas Injection Procedures in Ladle Metallurgy Operations, Metallurgical Transactions, 1985.
[11] J. Tang, S. Li, N. Wang, Y. Wei and W. Shyy, Flow Structures of Gaseous Jet Injected into Liquid for Underwater Propulsion, American Institute of Aeronautics and Astronautics, 2010.
[12] C. J. Su, J. M. Chou and S. H. Liu, Effect of Bottom Blowing Condition on Mixing Molten Iron and Slag inside Ironmaking Smelter, Materials Transactions, Vol, 2009.
[13] Q. X. Yang, H. Gustavsson, E. Burstrom, Erosion of refractory during gas injection - A cavitation based model, Scandinavian Journal of Metallurgy, 1990.
[14] A. Patuzzi, K. Antlinger, H. Grabner, W. Krieger, Comparative study of modern scrap melting processes, Proceedings of the Sixth Iron and Steel Congress, 1990.
[15] H.I. Iso, Y. Jyono, K. Arima, M. Kanemoto, M. Okajima, H. Narita, Development of Bottom-blowing Nozzle for Combined Blowing Converter, Transactions ISIJ, 1988.
[16] N. A. Molloy, T. Evans, P. Tapp, J. Lucas and M. Lee, Tuyere Geometry Effects on Flow Performance, The Howard Worner International Symposium on Injection in Pyrometallurgy Edited by M. Nilmani and T. Lehner. The Minerals, Metals and Materials Society, 1996.
[17] M. S. Lee, T. J. Evans and N. A. Molloy, Tuyere Geometry Effects on Flow Performance, Ironmaking and Steelmaking, 2001.
[18] 龍貽菊, 重鋼復吹轉爐工藝優化研究, 重慶大學, 2005.
[19] H.I. Iso, Y. Jyono, K. Arima, M. Kanemoto, M. Okajima, H. Narita, Development of Bottom-blowing Nozzle for Combined Blowing Converter, Transactions ISIJ, 1988.
[20] A. K. Kyllo and G. G. Richards, Accretion Formation in Gas Injection, the Howard Worner International Symposium on Injection in Pyrometallurgy Edited by M. Nilmani and T. Lehner. The Minerals, Metals and Materials Society, 1996.
[21] E. Fritz, W. Pirklbauer, R. Zechner, Y. Zhai, The K-BOM and KMS converter for the flexible production of carbon and stanless steels and ferro-alloys, Steel Times International, 1997.
[22] T. Ohta, M. Saigusa, F. Sudo, T. Nozaki, Improvement of Higher Productivity Using Bottom Blown Converter, Tetsu-to-Hagane, 1981.
[23] E. Fritz, W. Pirklbauer, R. Zechner, Y. Zhai, The K-OBM and KMS converter-for the flexible production of carbon and stainless steels and ferro-alloys, Steel Times International, 1997.
[24] A. K. Kyllo and G. G. Richards, Accretion Growth on Single-Pipe Tuyeres: Part I. Model Development and Preliminary Analysis, Metallurgical Transactions B, 1993.
[25] A. K. Kyllo and G. G. Richards, Accretion Growth on Single-Pipe Tuyeres: Part I. Model Result and Discussion, Metallurgical Transactions B, 1993.
[26] M. Iguchi, O. J. Ilegbusi, H. Ueda, T. Kuranaga and Z. I. Morita, Water Model Experiment on the Liquid Flow Behavior in a Bottom Blown Bath with Top Layer, Metallurgical and Materials Transactions B, 1996.
[27] M. Iguchi, H. Tokunaga, H. Tatemichi and Z. Morita, The Mechanism of Thermal Accretion (Mushroom) Formation and The Bubble and Flow Characteristic during Cold Gas Injection, Int. J. Multiphase Flow, 1993.
[28] Y.L. Huang, Water Modeling of Mushroom Formations in Gas Bottom-Blowing BOF Steelmaking Process, China Steel Technical Report, 2014.
[29] Y.P. Huang, W. S. Hwang, J. S. Shiau and S. H. Liu, Development and Verification of Accretion Similarity Conversion Method for Gas Bottom-Blowing Process inside Pyrometallurgical Vessels, Materials Transactions, 2007.
[30] F. Y. Su, W. Zhi, Hydraulic experiment on mushroom head in bottom-blown smelting furnace, Journal of Iron and Steel Research, International, 2017.
[31] Y. L. Huang, Y. C. Liu, L. K. Lin, C. S. Wang, S. Y. Hsu, C. S. Tsai, Study of Solid Mushroom Formation in Oxygen Bottom-Blown Steelmaking Process Using a Low Temperature Water Model, 7th International Conference on Modeling and Simulation of Metallurgical Process in Steelmaking, Qingdao, China, 2017.