臺灣博碩士論文加值系統

本研究使用高7m，內徑0.108m的循環式流體化床，使用空氣為氣相，平均粒徑204μm及344μm的砂為固相。以氣體速度為操作變數，來界定循環式流體化床中紊流及快速流體化區域。再由壓力探針量測上升床內的相對與絕對壓力擾動訊號，並經小波分析所得到的小波能量分佈圖來探討不同流態下之特徵。
由壓力擾動的分析可知，利用相對壓力擾動和絕對壓力擾動的測量方式，皆可以得到移轉速度Uc及Uk。而且，兩方式所得Uc及Uk皆隨粒子粒徑的增加而增大。與其他文獻比較，吾人以為Uk值會受到上升床頂部的擴大管影響。具有擴大管的設備會影響上升床中的流態，導致在絕對壓力擾動的分析中，無法得到Uk值。然而，沒有擴大管的設備卻有可能量測到Uk值。
另外，以相對和絕對壓力擾動信號做小波分析後，發現於氣泡流體化床及紊流流體化床流域時，主要能量分佈於D6與D7，而且Uc會出現在D6 + D7能量曲線的極大值之對應值。快速流體化床則分為濃相及稀相，其中濃相區主要能量分佈於D8與S8，稀相區主要能量分佈於D4與D5。當氣體流速到達Uk值時，D6 + D7的能量曲線會急速降低，而逐漸被D4 + D5或D8 + S8的能量曲線所取代。

The transition velocities Uc and Uk, discriminated the bubbling, turbulent and fast fluidization, were investigated by the traditional and wavelet analysis on instantaneous pressure fluctuation signals in a circulating fluidized bed (0.108m i.d. × 7m height) for Geldart group B powder (sand: Dp = 204μm, Dp = 344μm). The solid mass flow rate was measured by an impact-line solid flow meter and was controlled by a L-valve.
The results showed that Uc and Uk could be obtained by methods of differential and absolute pressure fluctuations. Both Uc and Uk by methods of differential and absolute pressure fluctuations increased with the particle size. Comparing with other literature data, the value of Uk was significantly influenced by the solid recycle type. Besides the solid recycle system from solid downcomer to riser bed, the solid recycle type could be influenced by the expanded top section on the riser bed. If there was an expanded top section on the riser, the value of Uk was not found by analysis of absolute pressure fluctuations. However, If there was not an expanded top section on the riser, the value of Uk could be found.
By means of the multi-resolution analysis of wavelet transform, the wavelet energy distribution profiles of absolute and differential pressure fluctuations in the three flow regimes were calculated. In bubbling and turbulent fluidization, the energy distribution was dominated by detail signals D6 and D7. Moreover, When the superficial gas velocity reached the value of Uc, the wavelet energy distribution at D6 + D7 was the maximum value. In fast fluidization regime, there were two sections, densely lower section and tenuously upper section. In lower section, the energy distribution was dominated by detail signals D8 and S8; in upper section, the energy distribution was dominated by detail signals D4 and D5. When the superficial gas velocity reached the value of Uk, the value of the wavelet energy distribution at D6 + D7 decreased quickly. When the superficial gas velocity exceeded the value of Uk, the energy distribution was dominated by detail signals D6 + D7 or D8 + S8.

中文摘要..………………………………………………………………...I 英文摘要...................................................................................................II 目錄......................................................................................................... IV 圖表索引.................................................................................................VII
第一章 緒論..............................................................................................1
1-1 前言.....................................................................................................1
1-2研究目的..............................................................................................7
第二章 文獻回顧..………………………………………………………8
2-1. 從氣泡流體化床到紊流流體化床的流態轉變.................................8
2-2. 從紊流流體化床到快速流體化床的流態轉變.................................9
2-3. 移轉區的探討...................................................................................12
2-4. 小波分析與信號處理.......................................................................18
2-4.1小波 (wavelet)轉換與傅立葉 (Fourier)轉換的比較............19
2-4.2小波的特點.............................................................................20
2-4.3小波分析於化工上之應用.....................................................21
第三章 實驗裝置與步驟........................................................................23
3-1. 實驗裝置...........................................................................................23
3-2. 實驗步驟...........................................................................................30
3-3. 固體控制元件之操作.......................................................................31
3-4. 壓力擾動訊號分析...........................................................................33
3-4.1 小波變換的定義.....................................................................33
3-4.2 小波分析函數.... ....................................................................34
3-4.3 小波的多分辨率分析 (multi-resolution analysis) ...............34
3-5 實驗所用的固體粒子性質..............................................................36
第四章 結果與討論................................................................................40
4-1. 紊流流體化區域的界定................................................................40
4-1.1 相對壓力擾動的量測........................................................40
4-1.2 絕對壓力擾動的量測.......................................................50
4-2. 紊流流體化流域之小波分析........................................................62
4-2.1 相對壓力擾動之小波分析..............................................68
4-2.1.1各流域之探討......................................................70
4-2.1.2定性及定量分析..................................................74
4-2.2 絕對壓力擾動之小波分析..............................................83
4-2.2.1各流域之探討......................................................83
4-2.2.2定性及定量分析..................................................87
第五章 結論............................................................................................96
第六章 符號說明....................................................................................98
第七章 參考文獻..................................................................................101
第八章 附錄..........................................................................................107
　　　附錄A. 衝擊式固體流量計操作原理說明……………..........107
附錄B. 衝擊式固體流量計校正說明……………............…..109
附錄C. Labview數據截取程式……………...………….........110
附錄D. db3父小波(father wavelet)與母小波(mother wavelet) ……………...…………………….................112
附錄E. S-PLUS軟體……………...……………………..........113
附錄F. 實驗數據之擬合(fitting) …………............................114

Avidan, A. A. and J. Yerushalmi, “Bed Expansion in High Velocity Fluidization”, Powder Technol., 32, 223-232 (1982).

Bakshi, B. R., H. Zhong, P. Jiang and L. S. Fan, “Analysis of Flow in Gas-Liquid Bubble Columns Using Multiresolution Methods”, Trans. Inst. Chem. Eng., 73, 608-614 (1995).

Bi, H. T., N. Ellis, I. A. Abba and J. R. Grace, “A State-of-the-Art Review of Gas-Solid Turbulent Fluidization”, Chem. Eng. Sci., 55, 4789-4825 (2000).

Bi, H. T. and L. S. Fan, “Existence of Turbulent Regime in Gas-Solid Fluidization”, AIChE J., 38, 297-301 (1992).

Bi, H. T. and J. R. Grace, “Effect of Measurement Method on Velocities Used to Demarcate the Onset of Turbulent Fluidization”, Chem. Eng. J., 57, 261-271 (1995).

Bi, H. T., J. R. Grace and K. S. Lim, “Transition from Bubbling to Turbulent Fluidization”, Ind. Eng. Chem. Res., 34, 4003-4008 (1995).

Brereton, C. M. H. and J. R. Grace, “The Transition to Turbulent Fluidization”, Trans. Inst. Chem. Eng., 70, 246-251 (1992).

Briens, L. A. and N. Ellis, “Hydrodynamics of Three-Phase Fluidized Bed Systems Examined by Statistical, Fractal, Chaos and Wavelet Analysis Methods”, Chem. Eng. Sci., 60, 6094-6106 (2005).

Briongos, J. V., J. M. Aragon and M. C. Palancar, “Phase Space Structure and Multi-Resolution Analysis of Gas-Solid Fluidized Bed Hydrodynamics: Part I: The EMD approach”, Chem. Eng. Sci., 61, 6963-6980 (2006).

Bruce, A. and H. Y. Gao, “Applied Wavelet Analysis with S-Plus”, pp. 11-67, Springer, New York, U. S. A. (1996).

Canada, G. S. and M. H. Mclaughlin, “Large Particle Fluidization and Heat Transfer at High Pressures”, AIChE Sym. Ser., 74 (176), 27-37 (1978).

Chehbouni, A., J. Chaouki, C. Guy, and D. Klvana, “Characterization of
the Flow Transition between Bubbling and Turbulent Fluidization”, Ind.
Eng. Chem. Res., 33, 1889-1898 (1994).

Cleveland, W. S., “Robust Locally Weighted Regression and Smoothing Scatterplots”, J. Am. Stat. Assoc., 74, 829-836 (1979).

Cleveland, W. S. and S. J. Devlin, “Locally Weighted Regression: An Approach to Regression Analysis by Local Fitting”, J. Am. Stat. Assoc., 83, 596-610 (1988).

Ellis N., L. A. Briens, J. R. Grace, H. T. Bi and C. J. Lim “Characterization of Dynamic Behaviour in Gas–Solid Turbulent Fluidized Bed Using Chaos and Wavelet Analyses”, Chem. Eng. J., 96, 105-116 (2003).

Farge, M., Kevlahan, N., Perrier, V. and Goirand, E. “Wavelets and Turbulence”, Proc. IEEE, 84, 639-669 (1996).

Geldart, D., “Types of Gas Fluidization”, Powder Technol., 7, 285-292 (1973).

Geldart, D. and M. J. Rhodes, “From Minimum Fluidization to Pneumatic Transport-A Critical Review of the Hydrodynamics”, in “Circulating Fluidized Bed Technology”, P. Basu, Ed., pp. 21-31, Pergamon Press, New York, U. S. A. (1986).

Goswami, J. C. and A. K. Chan, “Fundamentals of Wavelets: Theory, Algorithms, and Applications”, pp. 141-265, John Wiley and Sons, New York, U. S. A. (1999).

Grace, J. R.,“Contacting Modes and Behaviour Classification of Gas-Solid and Other Two-Phase Suspensions”, Can. J. Chem. Eng., 64, 353-363 (1987).

Guo, Q., G. Yue, T. Suda and J. Sato, “Flow Characteristics in a Bubbling Fluidized Bed at Elevated Temperature”, Chem. Eng. Proc., 42, 439-447 (2003).

Hashimoto, O., S. Mori, S. Hiraoka, I. Yamada, T. Kojima and KTsuji, “Heat Transfer to the Surface of Vertical Tubes in the Freeboard of a Turbulent Fluidized Bed”, Int. Chem. Eng., 30, 254-258 (1990).

Horio, M., H. Ishii and M. Nishimuro, “On the Nature of Turbulentand Fast Fluidized Beds”, Powder Technol., 70, 229-236 (1992).

Jin, Y., Z. Q Yu, Z. Wang and P. Cai, “A Criterion for Transition from Bubbling to Turbulent Fluidization”, in “Fluidization V”, K. Ostergarrd and A. Sorensen, Eds., pp. 289-296, Engineering Foundation, New York, U. S. A. (1986).

Judd, M. R. and R. Goosen, “Effects of Particle Shape on Fluidization Characteristics of Fine Particles in Freely Bubbling and Turbulent Regimes”, in “Fluidization VI”, J. R. Grace, L. W. Shermilt and M. A. Bergougnou, Eds., pp. 41-48, Engineering Foundation, New York, U. S. A. (1989).

Kehoe, P. W. K. and J. F. Davidson, “Continuously Slugging Fluidised Beds”, Inst. Chem. Eng. Sym. Ser., 33, 97-116 (1970)

Knowlton, T. M., “Solid Transfer in Fluidized Systems”, in “Gas Fluidization Technology”, D. Geldart, Ed., pp. 341-414, Wiley, New York, U. S. A. (1986).

Knowlton, T. M. and I. Hirsan, “L-valve Characterized for Solids Flow”, Hydrocarbon Processing, 57, 149-156 (1978).

Kunii, D. and O. Levenspiel, “Fluidization Engineering”, Butterworth-Heinemann, Boston, MA, U. S. A. (1991).

Lanneau, K. P., “Gas-Solid Contacting In Fluidized Beds”, Trans. Inst. Chem. Eng., 38, 125-137 (1960).

Lee, G. S., and S. D. Kim, “Pressure Fluctuations in Turbulent Fluidized Beds”, J. Chem. Eng. Japan, 21, 515-521 (1988).

Leung, L. S. and R. J. Wiles, “A Quantitative Design Procedure for Vertical Pneumatic Conveying Systems”, Ind. Eng. Chem. Proc. Des. Dev., 15, 552-557 (1976).

Lu, X. and H. Li, “Wavelet Analysis of Pressure Fluctuation Signals in a Bubbling Fluidized Bed”, Chem. Eng. J., 75, 113-119 (1999).

Mallat, S., “A Theory for Multiresolution Signal Decomposition: the Wavelet Representation”, IEEE Trans. Pattern Analysis and Machine Intelligence, 11, 674-693 (1989).

Mallat, S., “A Wavelet Tour of Signal Processing”, 2nd edition, pp.163-314, Cambridge University Press, Cambridge, U. K. (1999).

Matheson, G. L., W. A. Herbst and P. H. Holt, “Characteristics Fluid-solid Systems”, Ind. Eng. Chem., 41, 1099-1104 (1949).

Mori, S., O. Hashimoto, T. Haruta, K. Mochizuki, W. Matsutani, S. Hiraoka, I. Yamada, T. Kojima and K. Tuji, “Turbulent Fluidization Phenomena”, in “Circulating Fluidized Bed Technology II”, P. Basu and J. F. Large, Eds., pp. 105-112, Pergamon Press, Oxford, U. K. (1988).

Park, S. H., Y. Kang and S. D. Kim, “Wavelet Transform Analysis of Pressure Fluctuation Signals in a Pressurized Bubble Column”, Chem. Eng. Sci., 56, 6259-6265 (2001).

Perales, J. F., T. Coli, M. F. Liop, L. Puigjaner, J. Arnaldos and J. Casal, “On the Transition from Bubbling to Fast Fluidization Regimes”, in “Circulating Fluidized Bed Technology III”, P. Basu, M. Horio and M. Hasatani, Eds., pp. 73-78, Pergamon Press, Oxford, U. K. (1990).

Percival, D. B. and A. T. Walden, “Wavelet Methods for Time Series Analysis”, pp. 56-158, Cambridge University Press, London, U. K. (2002).

Ren, J., Q. Mao, J. Li and W. Lin, “Wavelet Analysis of Dynamic Behavior in Fluidized Beds”, Chem. Eng. Sci., 56, 981-988 (2001).

Rhodes, M. J., “What is Turbulent Fluidization?”, Powder Technol., 88, 3-14 (1996).

Rhodes, M. J. and D. Geldart, “Transition to Turbulence?”, in “Fluidization V”, K. Osterharrd and A. Sorensen, Eds., pp. 281-288, Engineering Foundation, New York, U. S. A. (1986).

Satija, S. and L. S. Fan, “Characteristics of Slugging Regime and Transition to Turbulent Regime for Fluidized Beds of Large Coarse Particles”, AIChE J., 31, 1554-1562 (1985).

Schnitzlein, M. G. and H. Weinstein, “Flow Characterization in High-Velocity Fluidized Beds Using Pressure Fluctuations”, Chem. Eng. Sci., 43, 2605-2614 (1988).

Shou, M. C. and L. P. Leu, “Identification of Transition Velcities in Fluidized Beds Using Wavelet Analysis”, J. Chem. Eng. Japan, 38, 409-421 (2005).

Son, J. E., J. H. Choi and C. K. Lee, “Hydrodynamics in a Large Circulating Fluidized Bed”, in “Circulating Fluidized Bed Technology II”, P. Basu and J. F. Large, Eds., pp. 113-120, Pergamon Press, Oxford, U. K. (1988).

Sun, G. and G. Chen, “Transition to Turbulent Fluidization and Its Prediction”, in “Fluidization VI”, J. R. Grace, L. W. Shermilt and M. A. Bergougnou, Eds., pp. 33-44, Engineering Foundation, New York, U. S. A. (1989).

Takeuchi, H., T. Hirama, T. Chiba, J. Biswas and L. S. Leung, “A Quantitative Definition and Flow Regime Diagram for Fast Fluidization”, Powder Technol., 47, 195-199 (1986).

Tsukada, M., D. Nakanishi and M. Horio, “The Effect of Pressure on the Phase Transition from Bubbling to Turbulent Fluidization”, Int. J. Multiphase Flow, 19, 27-34 (1993).

Weinstein, H., M. Meller., M. J. Shao and R. J. Parisis, “The Effect of Particle Density on Holdup in a Fast Fluidized Bed”, AIChE Sym. Ser., 80 (234), 52-59 (1984).

Yang, T. Y. and L. P. Leu, “Statistical and Wavelet Analysis of Pressure Fluctuations on Characterizing the Onset of Turbulent Fluidization”, in “The Ninth Asian Conference on Fluidized-Bed and Three-Phase Reactors”, L. P. Leu and C. S. Chyang, Eds., pp. 37-42, Wanli, Taiwan (2004).

Yerushalmi, J. and A. A. Avidan, “High Velocity Fluidization”, J. F. Davidson, R. Clift and D. Harrison, Eds., pp. 225-291, Fluidization, Academic Press, London (1985).

Yerushalmi, J. and N. T. Cankurt, “Further Studies of the Regimes of Fluidization”, Powder Technol., 24, 187-205 (1979).

Yerushalmi, J. and N. T. Cankurt, D. Geldart and B. Liss, “Flow Regimes in Vertical Gas-Solid Contact Systems”, AIChE Sym. Ser., 74 (176), 1-14 (1978).

Zenz, F. A., “Two–Phase Fluidized-Solid Flow”, Ind. Eng. Chem., 41, 2801-2806 (1949).

鮑金寶(Bao Chin Pao), “氣泡及紊流流體化床之流態轉變對床壁間熱傳系數的影響”, 國立台灣大學化學工程研究所碩士論文, 台北, 台灣 (1997)。

蕭明昌(Shou Ming Chang), “移轉速度的存在性及其對紊流流化床流態行為之研究”, 國立台灣大學化學工程研究所博士論文, 台北, 台灣 (2004)。

陶政隆(Tao Cheng Lung), “紊流流體化床的床-壁間熱傳現象”, 國立台灣大學化學工程研究所碩士論文, 台北, 台灣 (2006)。