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Three-Phase Fluidization Systems 675

Paz, E. D. D., Santana, M. H. A., and Eguchi, S. Y., “Enhancement of the Oxygen Transfer in a Circulating Three-Phase Fluidized Bed Bioreactor,” Appl. Biochem. Biotechnol., 39/40:455 (1993)

Petersen, J. N., and Davison, B. H., “Development of a Predictive Description of an Immobilized-Cell, Three-Phase, Fluidized-Bed Bioreactor,” Biotechnol. Bioeng., 46:139 (1995)

Petrov…i…, J., Hvala, N., Bitenc, A., and Strm…nik, S., “Low-Cost Steam Consumption Control System for Batch Pulp Cooking,” Control Eng. Practice, 3(3):357 (1995)

Petrozzi, S., Kut, O. M., and Dunn, I. J., “Protection of Biofilms Against Toxic Shocks by the Adsorption and Desorption Capacity of Carriers in Anaerobic Fluidized Bed Reactors,” Bioproc. Eng., 9:47 (1993)

Petrozzi, S., and Dunn, I. J., “Biological Cyanide Degradation in Aerobic Fluidized Bed Reactors: Treatment of Almond Seed Wastewater,” Bioproc. Eng., 11:29 (1994)

Pfeffer, J. T., and Suidan, M. T., “Continuous Processing of Toxic Organics in a Fluidized-Bed GAC Reactor Employing Carbon Replacement,” Biotechnol. Bioeng., 33:139 (1989)

Potthoff, M., and Bohnet, M., “Influence of Solids Concentration and Static Mixers on Fluid Dynamics in Three-Phase Fluidized Bed Bioreactors,”

Chem. Eng. Technol., 16:147 (1993)

Probstein, R. F., and Hicks, R. E., Synthetic Fuels, McGraw-Hill, New York, (1982)

Puhakka, J. A., Herwig, R. P., Koro, P. M., Wolfe, G. V., and Ferguson, J. F., “Biodegradation of Chlorophenols by Mixed and Pure Cultures from a Fluidized-Bed Reactor,” Appl., Microbiol. Biotechnol., 42:951 (1995)

Qureshi, N., and Maddox, I. S., “Reactor Design for the ABE Fermentation Using Cells of Clostridium acetobutylicum Immobilized by Adsorption onto Bonechar,” Bioproc. Eng., 3:69 (1988)

Qureshi, N., and Maddox, I. S., “A Mathematical Model of a Fluidized Bed Reactor for the Continuous Production of Solvents by Immobilized

Clostridium acetobutylicum,” J. Chem. Tech. Biotechnol., 48:369 (1990)

Qureshi, N., and Maddox, I. S., “Application of Novel Technology to the ABE Fermentation Process: An Economic Analysis,” Appl. Biochem. Biotechnol., 34/35:441 (1992)

Racher, A. J., and Griffiths, J. B., “Investigation of Parameters Affecting a Fixed Bed Bioreactor Process for Recombinant Cell Lines,” Cytotechnol., 13:125 (1993)

Ramsay, B. A., Wang, D., Chavarie, C., Rouleau, D., and Ramsay, J. A., “Penicillin Production in an Inverse Fluidized Bed Bioreactor,” J. Ferm. Bioeng., 72:495 (1991)

676 Fluidization, Solids Handling, and Processing

Reese, J., Jiang, P., and Fan, L. S., “Bubble Characteristics in Three-Phase Systems used for Pulp and Paper Processing,” Chem. Eng. Sci., 51:2501 (1996)

Reiter, M., Buchacher, A., Blüml, G., Zach, N., Steinfellner, W., Schmatz, C., Gaida, T., Assadian, A., and Katinger, H., “Production of the HIV-1 Neutralising Human Monoclonal Antibody 2F5: Stirred Tank Versus Fluidized Bed Culture,” Animal Cell Technology, (R. E. Spier, J. B. Griffith, and W. Berthold, eds.), p. 333, Butterworth-Heinemann, Oxford (1994)

Richardson, J. F., and Zaki, W. N., “Sedimentation and Fluidization Part I,”

Trans. Inst. Chem. Engrs., 32:35 (1954)

Rickard, J. C., “The 2020 Mill-Utility Requirements for Market Kraft Pulp,”

AIChE Symp. Series: Advances in Forest Products Environmental and Process Eng., The 1993 Forest Products Symp., (C. L. Verrill, ed.), 90(302):167, AIChE, New York (1994)

Rihar, M., “The Software Simulator as an Effective Tool for Testing Control Algorithms,” Simulation, 63(1):6 (1994)

Romenets, V. A., “Process of Liquid Phase Reduction of Iron: Development and Implementation,” Steel in the USSR, 20:366 (1990)

Romli, M., Greenfield, P. F., and Lee, P. L., “Effect of Recycle on a Two-Phase High-Rate Anaerobic Wastewater Treatment System,” Wat. Res., 28:475 (1994)

Roustan, M., Capdeville, B., and Bastoul, D., “Influence of the Hydrodynamic Behaviour of a Three-Phase Fluidised Bed Used for Effluent Treatment,”

3rd Int. Conf. on Bioreactor and Bioprocess Fluid Dynamics, (A. W. Nienow, ed.), p. 323, Information Press, Ltd., Oxford (1993)

Ruggeri, B., Caire, G., Specchia, V., Sassi, G., Bosco, F., and Gianetto, A., “Determination of Optimal Biofilm Activity in a Biological Fluidized Bed (BFB) Reactor,” Wat. Sci. Tech., 29(10-11):347 (1994)

Ryhiner, G., Petrozzi, S., and Dunn, I. J., “Operation of a Three-Phase Biofilm Fluidized Sand Bed Reactor for Aerobic Wastewater Treatment,”

Biotechnol. Bioeng., 32:677 (1988)

Sajc, L., Obradovic, B., Vukovic, D., Bugarski, B., Grubisic, D., and VunjakNovakovic, G., “Hydrodynamics and Mass Transfer in a Four-Phase External Loop Air Lift Bioreactor,” Biotechnol. Prog., 11:420 (1995)

Samejima, H., Nagashima, M., Azuma, M., Noguchi, S., and Inuzuka, K., “Semicommercial Production of Ethanol using Immobilized Microbial Cells,” Annals New York Academy of Sciences, 434:394 (1984)

Sanz, I., and Fdz-Polanco, F., “Low Temperature Treatment of Municipal Sewage in Anaerobic Fluidized Bed Reactors,” Wat. Res., 24:463 (1990)

Three-Phase Fluidization Systems 677

Saraiva, P. M., and Stephanopoulos, G., “Continuous Process Improvement through Inductive and Analogical Learning,” AIChE J., 38:161 (1992)

Saxena, S. C., Rosen, M., Smith, D. N., and Ruether, J. A., “Mathematical Modeling of Fischer-Tropsch Slurry Bubble Column Reactors,” Chem. Eng. Comm., 40:97 (1986)

Schneeberg, E., “Increase of Efficiency of an Activated Sludge Plant in Paper Manufacturing Industry by Application of a Fluidized Bed System,” Wat. Sci. Tech., 29(12):177 (1994)

Schoutens, G. H., Guit, R. P., Zieleman, G. J., Luyben, K. C. A. M., and Kossen, N. W. F., “A Comparative Study of a Fluidised Bed Reactor and a Gas Lift Loop Reactor for the IBE Process: Part I. Reactor Design and Scale Down Approach,” J. Chem. Tech. Biotechnol., 36:335 (1986a)

Schoutens, G. H., Guit, R. P., Zieleman, G. J., Luyben, K. C. A. M., and Kossen, N. W. F., “A Comparative Study of a Fluidised Bed Reactor and a Gas Lift Loop Reactor for the IBE Process: Part II. Hydrodynamics and Reactor Modelling,” J. Chem. Tech. Biotechnol., 36:415 (1986b)

Schoutens, G. H., Guit, R. P., Zieleman, G. J., Luyben, K. C. A. M., and Kossen, N. W. F., “A Comparative Study of a Fluidised Bed Reactor and a Gas Lift Loop Reactor for the IBE Process: Part III. Reactor Performances and Scale Up,” J. Chem. Tech. Biotechnol., 36:565 (1986c)

Schügerl, K., “Biofluidization: Application of the Fluidization Technique in Biotechnology,” Can. J. Chem. Eng., 67:178 (1989)

Scott, C. D., “Ethanol Production in a Fluidized-Bed Bioreactor Utilizing Flocculating Zymomonas Mobilis with Biomass Recycle,” Biotechnol. Bioeng. Symp. Ser., 13:287 (1983)

Scragg, A. H., “Bioreactors for the Mass Cultuire of Plant Cells,” Plant Biotechnology: Comprehensive Biotechnol., (M. W. Fowler, and G. S. Warren, eds.), p. 45, Second Supplement, Pergamon Press, Oxford (1992)

Seifert, P., “Recent Innovation in Paper Recycling,” Tappi J., 77(2):149 (1994)

Seki, M., Naito, K. I., and Furusaki, S., “Effect of Co-Immobilization of Microporous Particles on the Overall Reaction Rate of Immobilized Cell Biocatalysts,” J. Chem. Eng. Jpn., 26:662 (1993)

Shah, Y. T., Gas-Liquid-Solid Reactor Design, McGraw-Hill, New York, (1979)

Shen, B., Greenfield, P., and Reid, S., “Calcium Alginate Immobilized Hybridomas Grown Using a Fluidized-Bed Perfusion System with a Protein-Free Medium,” Cytotechnol., 14:109 (1994)

Shinotake, A., and Takamoto, Y., “Combustion and Heat Transfer Mechanism in Iron Bath Smelting Reduction Furnace,” La Revue de Metallurgie - CIT, p. 965 (1993)

678 Fluidization, Solids Handling, and Processing

Shirai, Y., Yamaguchi, M., Kobayashi, A., Nishi, A., Nakamura, H., and Murakami, H., “Change in Growth Kinetics of Hybridoma Cells Entrapped in Collagen Gel Affected by Alkaline Supply,” Cytotechnol., 14:129 (1994)

Shu, C. H., and Yang, S. T., “Effect of Particle Loading on GM-CSF Production by Saccharomyces cerevisiae in a Three-Phase Fluidized Bed Bioreactor,”

Biotechnol. Bioeng., 51:229 (1996)

Siegel, M. H., and Robinson, C. W., “Applications of Airlift Gas-Liquid-Solid Reactors in Biotechnology,” Chem. Eng. Sci., 47:3215 (1992)

Siegell, J. H., “Liquid-Fluidized Magnetically Stabilized Beds,” Powder Tech., 52:139 (1987)

Silbiger, E., and Freeman, A., “Continuous 1-Hydrocortisone Dehydrogenation with in Situ Product Recovery,” Enzyme Microb. Technol., 13:869 (1991)

Smook, G. A., Handbook for Pulp & Paper Technologists, 2nd ed., Angus Wilde Publications, Vancouver (1992)

Sreekrishnan, T. R., Ramachandran, K. B., and Ghosh, P., “Effect of Operating Variables on Biofilm Formation and Performance of an Anaerobic FluidizedBed Bioreactor,” Biotechnol. Bioeng., 37:557 (1991)

Steffen, R., “Direct Reduction and Smelting Reduction - An Overview,” Steel Res., 60:96 (1989)

Stenuf, T. J., and Unbehend, J. E., “Hydrodynamics of Fiber Suspensions,”

Encyclopedia of Fluid Mechanics, Slurry Flow Technol., (N. Cheremisinoff, ed.), 5:291, Gulf Publishing Co., Houston (1986)

Suh, I. S., Schumpe, A., Deckwer, W. -D., “Xanthan Production in Bubble Column and Air-Lift Reactors,” Biotechnol. Bioeng., 39:85 (1992)

Sun, Y., and Furusaki, S., “Mean Bubble Diameter and Oxygen Transfer Coefficient in a Three-Phase Fluidized Bed Bioreactor,” J. Chem. Eng. Jpn., 21:20 (1988)

Sun, Y., and Furusaki, S., “Continuous Production of Acetic Acid Using Immobilized Acetobacter aceti in a Three-Phase Fluidized Bed Bioreactor,” J. Ferm. Bioeng., 69:102 (1990)

Takahashi, K., Muroya, M., Kondo, K., Hasegawa, T., Kikuchi, I., and Kawakami, M., “Post Combustion Behavior in In-Bath Type Smelting Reduction Furnace,” ISIJ Int., 32:102 (1992)

Takashiba, N., Nira, M., Kojima, S., Take, H., and Yoshikawa, F., “Development of the Post Combustion Technique in Combined Blowing Converter,”

Tetsu to Hagane, 75:89 (1989)

Tanabe, H., Takahashi, K., Ariyama, Y., Kitagawa, T., Ozeki, A., and Yamaga, M., “The Primary Stage of the Development of Smelting Reduction Process in NKK,” AIME Ironmaking Conf. Proc., p. 89 (1989)

Three-Phase Fluidization Systems 679

Tanaka, H., Enoki, N., Kaneki, N., Sakai, H., Shimada, K., and Hara, H., “A Three-Phase Fluidized Bed Fuel Cell,” J. Electrochem. Soc., 137:2798 (1990)

Tanemura, K., Kida, K., Ikbal, Matsumoto, J., and Sonoda, Y., “Anaerobic Treatment of Wastewater with High Salt Content from a Pickled-Plum Manufacturing Process,” J. Ferm. Bioeng. 77:188 (1994a)

Tanemura, K., Kida, K., Teshima, M., and Sonoda, Y., “Anaerobic Treatment of Wastewater from a Food-Manufacturing Plant with a Low Concentration of Organic Matter and Regeneration of Usable Pure Water,” J. Ferm. Bioeng., 77:307 (1994b)

Tang, W. T., and Fan, L. -S., “Steady State Phenol Degradation in a Draft-Tube, Gas-Liquid-Solid Fluidized-Bed Bioreactor,” AIChE J., 33:239 (1987)

Tang, W. T., Wisecarver, K., and Fan, L. S., “Dynamics of a Draft Tube Gas- Liquid-Solid Fluidized Bed Bioreactor for Phenol Degradation,” Chem. Eng. Sci., 42:2123 (1987)

Tang, W. T., and Fan, L. -S., “Hydrodynamics of a Three-Phase Fluidized Bed Containing Low-Density Particles,” AIChE J., 35:355 (1989)

Tang, W. -T., and Fan, L. -S., “Gas-Liquid Mass Transfer in a Three-Phase Fluidized Bed Containing Low Density Particles,” Ind. Eng. Chem. Res., 29:128 (1990)

Tarmy, B. L., Chang, M., Coulaloglou, C. A., and Ponzi, P. R., “The Three-Phase Hydrodynamic Characteristics of the EDS Liquefaction Reactors: Their Development and use in Reactor Scaleup,” Proc. 8th Int. Symp. Chem. Reaction Eng., 30:239 (1984)

Tarmy, B. L., and Coulaloglou, C. A., “Alpha-Omega and Beyond - Industrial View of Gas/Liquid/Solid Reactor Development,” Chem. Eng. Sci., 47:3231 (1992)

Terashima, S., Kamihira, M., Ogawa, T., Ohno, M., Iijima, S., and Kobayashi, T., “Continuous Production of Human Erythropoietin by Immobilized Recombinant L-929 Cells,” J. Ferm. Bioeng., 77:52 (1994)

Terranova, B. E., and Burns, M. A., “Continuous Cell Suspension Processing Using Magnetically Stabilized Fluidized Beds,” Biotechnol. Bioeng., 37:110 (1991)

Tikka, P. O., Virkola, N. E., Pursiainen, S. A., and Haemaelae, I. T., “Process Chemistry and Control of Rapid-Displacement Heating,” Tappi J., 71(2):51 (1988)

Tong, C. C., and Fan, L. S., “Concentration Multiplicity in a Draft Tube FluidizedBed Bioreactor Involving Two Limiting Substrates,” Biotechnol. Bioeng., 31:24 (1988)

680 Fluidization, Solids Handling, and Processing

Toseland, B. A., Brown, D. M., Zou, B. S., and Dudukovi…, M., “Flow Patterns in a Slurry-Bubble-Column Reactor Conditions,” Trans. Inst. Chem. Engrs., 73:297 (1995)

Trinet, F., Heim, R., Amar, D., Chang, H. T., and Rittmann, B. E., “Study of Biofilm and Fluidization of Bioparticles in a Three-Phase Liquid-Fluidized- Bed Reactor,” Wat. Sci. Tech., 23:1347 (1991)

Tseng, S. -K., and Lin, M. -R., “Treatment of Organic Wastewater by Anaerobic Biological Fluidized Bed Reactor,” Wat. Sci. Tech., 29(12):157 (1994)

Tsuchiya, K., Song, G. H., Tang, W. T., and Fan, L. S., “Particle Drift Induced by a Bubble in a Liquid-Solid Fluidized Bed with Low Density Particles,” AIChE J., 38:1847 (1992)

Tsujino, R., Mukai, T., Hirai, M., Nakamura, K., and Harada, T., “Investigation of the Effect on Post Combustion in LD Converter (Study of Post Combustion in LD Converter-III),” Trans. ISIJ, 25:B-294 (1985)

Turvey, R. W., “Chemical use in Recycling,” Technol. of Paper Recycling, (R. W. J. McKinney, ed.), p. 130, Blackie Academic & Professional, London (1995)

Tzeng, J. W., Study of Fluidized Bed Reactors - Fluid Dynamics and Bioreactor Appl., Doctoral Dissertation, The Ohio State University (1991)

Tzeng, J. W., Fan, L. S., Gan, Y. R., and Hu, T. T., “Ethanol Fermentation Using Immobilized Cells in a Multistage Fluidized Bed Bioreactor,” Biotechnol. Bioeng., 38:1253 (1991)

Utigard, T. A., and Zamalloa, M., “Foam Behaviour in Liquid FeO-CaO-SiO2 Slags,” Scand. J. Metallurgy, 22:83 (1993)

van Wie, B. J., Brouns, T. M., Elliott, M. L., and Davis, W. C., “A Novel Continuous Centrifugal Bioreactor for High-Density Cultivation of Mammalian and Microbial Cells,” Biotechnol. Bioeng. 38:1190 (1991)

van der Jagt, M. H., Kleijntjens, R. H., van der Lans, R. G. J. M., and Luyben, K. C. A. M., “A Continuous Three Phase Suspension Reactor for the Microbial Decontamination of Excavated Polluted Soils,” 3rd Int. Conf. on Bioreactor and Bioprocess Fluid Dynamics, (A. W. Nienow, ed.), p. 335, Information Press, Ltd., Oxford (1993)

van der Wielen, L. A. M., Potters, J. J. M., Straathof, A. J. J., and Luyben, K. C. A. M., “Integration of Bioconversion and Continuous Product Separation by Means of Countercurrent Adsorption,” Chem. Eng. Sci., 45:2397 (1990)

Venkat, R. V., Stock, L. R., and Chalmers, J. J., “Study of Hydrodynamics in Microcarrier Culture Spinner Vessels: A Particle Tracking Velocimetry Approach,” Biotechnol. Bioeng., 49:456 (1996)

Vorlop, K. D., Estape, D., and Gòdia, F., “Design of Ca-Alginate Immobilized Yeast Cell Beads with Controlled Low Density to Enhance Their Fluidization Behaviour in Bioreactors,” Biotechnol. Tech., 7:287 (1993)

Three-Phase Fluidization Systems 681

Webb, O. F., Davison, B. H., Scott, T. C., and Scott, C. D., “Design and Demonstration of an Immobilized-Cell Fluidized-Bed Reactor for the Efficient Production of Ethanol,” Appl. Biochem. Biotechnol., 51/52:559 (1995)

Weng, D., Cheng,. L., Han, Y., Zhu, W., Xu, S., and Ouyang, F., “Continuous Ethanol Fermentation in a Three-Phase Magnetic Fluidized Bed Bioreactor,” AIChE Symp. Series, 88(289):107, AIChE, New York (1992)

Weuster, D., Aivasidis, A., and Wandrey, C., “Ethanolfermentation of Sugar Containing Wastes with Zymomonas mobilis in a Fluidized Bed Reactor,”

DECHEMA Biotechnol. Conf., 3:507 (1989)

Weuster-Botz, D., “Continuous Ethanol Production by Zymomonas mobilis in a Fluidized Bed Reactor. Part I. Kinetic Studies of Immobilization in Macroporous Glass Beads,” Appl. Microbiol. Biotechnol., 39:679 (1993)

Weuster-Botz, D., Aivasidis, A., and Wandrey, C., “Continuous Ethanol Production by Zymomonas mobilis in a Fluidized Bed Reactor. Part II. Process Development for the Fermentation of Hydrolysed B-Starch without Sterilization,” Appl. Microbiol. Biotechnol., 39:685 (1993)

White, D. E., Gandek, T. P., Pikulin, M. A., and Friend, W. H., “Importance of Reactor Design in High-Consistency Ozone Bleaching,” Pulp & Paper Can., 94(9):16 (1993)

Wisecarver, K. D., and Fan, L. S., “Biological Phenol Degradation in a Gas- Liquid-Solid Fluidized Bed Reactor,” Biotechnol. Bioeng., 33:1029 (1989)

Worden, R. M., and Donaldson, T. L., “Dynamics of a Biological Fixed Film for Phenol Degradation in a Fluidized-Bed Bioreactor,” Biotechnol. Bioeng., 30:398 (1987)

Wu, K. Y. A., and Wisecarver, K. D., “Biological Phenol Degradation in a Countercurrent Three-Phase Fluidized Bed Using a Novel Cell Immobilization Technique,” AIChE Symp. Series, 86(276):113 (1989)

Yabannavar, V. M., and Wang, D. I. C., “Extractive Fermentation for Lactic Acid Production,” Biotechnol. Bioeng., 37:1095 (1991)

Yang, S. T., “A Novel Gradient Particle Bed Bioreactor for Mixed Culture Fermentation,” presented at the AIChE Annual Meeting, New York (1987)

Yeager, R., “New Profits from Advanced Control,” PIMA Magazine (Paper Industry Management Association), 77(1):6 (1995)

Yee, C. J., Hsu, Y., and Shieh, W. K., “Effects of Microcarrier Pore Characteristics on Methanogenic Fluidized Bed Performance,” Wat. Res. 26:1119 (1992)

Yongming, L., Yi, Q., and Jicui, H., “Research on the Characteristics of Start Up and Operation of Treating Brewery Wastewater with an AFB Reactor at Ambient Temperatures,” Wat. Sci. Tech., 28(7):187 (1993)

682 Fluidization, Solids Handling, and Processing

Zellner, G., Geveke, M., de Macario, E. C., and Diekmann, H., “Population Dynamics of Biofilm Development During Start-Up of a Butyrate-Degrading Fluidized-Bed Reactor,” Appl. Microbiol. Biotechnol., 36:404 (1991)

Zellner, G., Neudörfer, F., and Diekmann, H., “Degradation of Lactate by an Anaerobic Mixed Culture in a Fluidized-Bed Reactor,” Wat. Res., 28:1337 (1994)

Zhang, L., and Oeters, F., “A Model of Post-Combustion in Iron-Bath Reactors, Part 1: Theoretical Basis,” Steel Res., 62:95 (1991a)

Zhang, L., and Oeters, F., “A Model of Post-Combustion in Iron-Bath Reactors, Part 2: Results for Combustion with Oxygen,” Steel Res., 62:107 (1991b)

Zhang, L., and Oeters, F., “A Model of Post-Combustion in Iron-Bath Reactors, Part 3: Theoretical Basis for Post-Combustion with Preheated Air,” Steel Res., 64:542 (1993a)

Zhang, L., and Oeters, F., “A Model of Post-Combustion in Iron-Bath Reactors, Part 4: Results for Post-Combustion with Preheated Air,” Steel Res., 64:588 (1993b)

10

Dense Phase Conveying

George E. Klinzing

1.0INTRODUCTION

The term dense phase became popular in the conveying business in the mid 1970’s when a particular pneumatic conveying vendor coined the phrase to mean the pulsed piston type of flow that is often encountered in the handling of plastic pellets. Before that date, dense phase usually meant a high concentration of solids moving with a heavy concentrated layer at the bottom of the pipe. Thus one is faced with a dilemma of the exact meaning of dense phase conveying. Presently, one must use the words dense phase with other descriptors attached so as not to confuse and mislead people of the exact condition of flow explored. Figures 1 and 2 were prepared by Dhodapkar (1991) and present a comprehensive grouping of terms that could all generically be called dense phase conveying. Figure 3 shows some specific terms that have been used by particular vendors in their search to be different and to have a better and unique system. A comprehensive review of dense phase transport has been prepared by Konrad (1986) and can be referred to for further details.

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