مطالعۀ دینامیک سیالات محاسباتی و بهینه‌سازی انرژی سیکلون دوتایی صنعتی در خشک‌سازی پلی اتیلن سنگین

نویسندگان

Department of Chemical Engineering, Faculty of Engineering, University of Kashan, Kashan, I.R.Iran

چکیده

در این مقاله، سیکلون دوتایی به‌عنوان جداکنندۀ گاز- جامد در فرایند خشک‌سازی بستر سیال تولید پودر خشک پلی اتیلن سنگین از 56000 کیلوگرم بر ساعت خوراک مرطوب استفاده می‌شود. کیفیت محصول به‌شدت به رفتار ذرات و الگوی جریان خشک‌کن وابسته است که سیکلون‌های دوتایی را به‌عنوان تجهیزی مهم، تحت‌تأثیر قرار می‌دهد. کنترل گاز حامل ورودی، سبب الگوی جریانی مناسب، رطوبت نهایی مطلوب و بازده جداسازی بالا در میان گریدهای مختلف پلی اتیلن سنگین می‌شود. شدت جریان کمتر ذرات فراری از سیکلون‌ها منجر به مصرف پایین انرژی در دمنده‌ها و باعث عدم وجود گردوغبار در سوراخ‌های توزیع‌کنندۀ خشک‌کن و وجود سینی‌هایی پاک در برج تمییزکنندۀ جریان می‌شود. شبیه‌سازی عددی میدان جریانی سیال و دینامیک ذرات در سیکلون با تکنیک دینامیک سیالات محاسباتی، در تعیین افت فشار و متغیرهای اغتشاش، ما را برای ارزیابی این فرایند یاری می‌کند. معادله‌های ناویر- استوکس در چهارچوب اولری- لاگرانژی با مدل تلاطمیRNG k-ɛ ، به‌عنوان روش ریاضی استفاده می‌شوند. حل میدان جریانی، با روش حجم محدود بر اساس الگوریتم PISO، برای همپوشانی فشار- سرعت در دامنۀ محاسباتی انجام می‌شود؛ به‌طوری که نتایج محاسباتی در توافق قابل قبولی با متغیرهای عملیاتی صنعتی، مانند افت فشار سیکلون است.

کلیدواژه‌ها


[1] Rhodes, M.J., "Introduction to Particle Technology", John Wiley & Sons, 2008.
[2] Groenewold, H. and Tsotsas, E., "Drying in Fluidized Beds with Immersed Heating Elements", Chem. Eng. Sci., Vol. 62, pp. 481-502, 2007.
[3] Mujumdar, A.S., "Handbook of industrial drying", CRC press, 2014.
[4] Harichandan, A.B. and Shamim, T., "CFD Analysis of Bubble Hydrodynamics in a Fuel Reactor for a Hydrogen-Fueled Chemical Looping Combustion System", Energy. Convers. Manage., Vol. 86, pp. 1010-1022, 2014.
[5] Luo, S., Xiao, B., Hu, Z., Liu, S. and He, M., "Experimental Study on Combustion of Biomass Micron Fuel (BMF) in Cyclone Furnace", Energy. Convers. Manage., Vol. 51, pp. 2098-2102, 2010.
[6] Alavi, S.R. and Lay, E.N., "Industrial Challenges of HDPE Fluid Bed Drying in Different Grades. QUID: Investigación, Cienciay Tecnología,  pp. 555-566, 2017.
[7] Han, Y.-L., Chyang, C.-S., Hsiao, W.-M. and Lo, K.-C., "Effect of Fines Hold-up in the Freeboard on Elutriation from a Fluidized Bed", J. Taiwan. Inst. Chem. Eng., Vol. 42, pp. 120-123, 2011.
[8] Chang, Y.-M., Chou, C.-M., Su, K.-T., Hung, C.-Y. and Wu, C.-H., "Elutriation Characteristics of Fine Particles from Bubbling Fluidized Bed Incineration for Sludge Cake Treatment", Waste. manage., Vol. 25, pp. 249-263, 2005.
[9] Altmeyer, S., Mathieu, V., Jullemier, S., Contal, P., Midoux, N., Rode, S.  and et al., "Comparison of Different Models of Cyclone Prediction Performance for Various Operating Conditions Using a General Software", Chem. Eng. Process. Process Inten., Vol. 43, pp. 511-522, 2004.
[10] Van't Land, C., "Drying in the process industry", John Wiley & Sons, 2011.
[11] Winfield, D., Cross, M., Croft, N., Paddison, D. and Craig, I., "Performance Comparison of a Single and Triple Tangential Inlet Gas Separation Cyclone: A CFD Study", Powder. Technol., Vol. 235, pp. 520-531 2013.
[12] Misiulia, D., Elsayed, K. and Andersson, A.G., "Geometry optimization of a deswirler for cyclone separator in terms of pressure drop using CFD and artificial neural network", Sep. Purif. Technol., Vol. 185, pp. 10-23, 2017.
[13] Liu, F., Chen, J., Zhang, A., Wang, X. and Dong, T., "Performance and flow behavior of four identical parallel cyclones", Sep. Purif. Technol., Vol. 134, pp. 147-157, 2014.
[14] Rosin, P., Rammler, E. and Intelmann, W., "Grundlagen und grenzen der zyklonentstaubung. VDI Zeitschrift", Vol. 76, pp. 433-437, 1932.
[15] Barth, W., "Design and Layout of the Cyclone Separator on the Basis of New Investigations", Brenn Warme Kraft., Vol. 8, pp.  9, 1956.
[16] Dietz, P., "Collection Efficiency of Cyclone Separators", AIChE. J., Vol. 27, pp. 888-892, 1981.
[17] Mothes, H. and Löffler, F., "Prediction of Particle Removal in Cyclone Separators", Int Chem Eng., Vol. 28, pp. 231-240, 1988.
[18] Dirgo, J. and Leith, D., "Performance of Theoretically Optimised Cyclones", Filtr. Sep., Vol. 22, pp. 119-125, 1985.
[19] Leith, D., "The Collection Efficiency of Cyclone Type  Particle Collectors-a New Theoretical Approach", AIChE Symp Ser., pp. 196-206, 1972.
[20] Song, C., Pei, B., Jiang, M., Wang, B., Xu, D. and Chen, Y., "Numerical Analysis of Forces Exerted on Particles in Cyclone Separators", Powder Technol., vol. 294, pp. 437-448, 2016.
[21] Ter Linden, A., "Investigations into Cyclone Dust Collectors, Process", Inst. Mech. Eng., Vol. 160, pp. 233-251, 1949.
[22] Hoekstra, A.J., "Gas Flow Field and Collection Efficiency of Cyclone Separators", 2000.
[23] Smith, J., "An Experimental Study of the Vortex in the Cyclone Separator", ASME J Basic Eng., Vol. 84, pp. 602-608, 1962.
[24] Solero, G. and Coghe, A., "Experimental Fluid Dynamic Characterization of a Cyclone Chamber", Exp. Therm. Fluid. Sci., Vol. 27, pp. 87-96, 2002.
[25] Syred, N., "A Review of Oscillation Mechanisms and the Role of the Precessing Vortex Core (PVC) in Swirl Combustion Systems", Progress Energy. Combust. Sci., Vol. 32, pp. 93-161, 2006.
[26] Cortes, C. and Gil, A., "Modeling the Gas and Particle Flow Inside Cyclone Separators", Progress Energy. Comb. Sci., Vol. 33, pp. 409-452, 2007.
[27] Su, Y. and Mao, Y., "Experimental Study on the Gas–Solid Suspension Flow in a Square Cyclone Separator", Chem. Eng. J., Vol. 121, pp. 51-58, 2006.
[28] Chan, C., Seville, J., Fan, X., Dewil, R. and Baeyens, J., "CFB Cyclones: Pressure Drop and Particle Motion, Viewed by Positron Emission Particle Tracking", 2008.
[29] Li, S., Yang, H., Zhang, H., Yang, S., Lu, J. and Yue, G., "Measurements of Solid Concentration and Particle Velocity Distributions Near the Wall of a Cyclone", Chem. Eng. J., Vol. 150, pp. 168-173, 2009.
[30] Cocco, R., Karri, S.R. and Knowlton, T., "Introduction to fluidization", Chem. Eng. Progress, Vol. 110, pp. 21-29, 2014.
[31] Drake, J.B., "Hydrodynamic Characterization of 3D Fluidized Beds Using Noninvasive Techniques", Iowa State University, 2011.
[32] Lay, E.N., Razavi Alavi, S.A., Afzali, K. and Alizadeh Makhmali, A.H., "Investigation of Effective Operational Parameters on an Industrial Double-Cyclone of HDPE Fluidized Bed Drying", The 9th Int. Chem. Eng. Congress  Exhibition, IRAN, 2015.
[33] Safikhani, H. and Mehrabian, P., "Numerical Study of Flow Field in New Cyclone Separators", Adv. Powder. Technol., Vol. 27, pp. 379-387, 2016.
[34] Lee, J.W., Yang, H.J. and Lee, D.Y., "Effect of the Cylinder Shape of a Long-Coned Cyclone on the Stable Flow-Field Establishment", Powder Technol., Vol. 165, pp. 30-38, 2006.
[35] Gimbun, J., Chuah, T., Fakhru’l-Razi, A. and Choong, T.S., "The Influence of Temperature and Inlet Velocity on Cyclone Pressure Drop: a CFD Study", Chem. Eng. Process. Process Inten., Vol. 44, pp. 7-12, 2005.
[36] Su, M., Zhao, H. and Ma, J., "Computational Fluid Dynamics Simulation for Chemical  Looping Combustion of Coal in a Dual Circulation Fluidized Bed", Energy. Convers. Manage., Vol. 105, pp. 1-12, 2015.
[37] A. Kasaeian, A.R. Mahmoudi, F.R. Astaraei, A. Hejab, "3D Simulation of Solar Chimney Power Plant Considering Turbine Blades", Energy. Convers. Manage., Vol. 147, pp.  55-65, 2017.
[38] A. Fluent. 12.0 Theory Guide. Ansys Inc. 5, 2009.
[39] A. Fluent. Fluent theory guide. SAS IP, Inc, Canonsburg, PA., 2010.
[40] Ghasemian, M., Ashrafi, Z.N. and Sedaghat, A., "A Review on Computational Fluid Dynamic Simulation Techniques for Darrieus Vertical Axis Wind Turbines", Energy. Convers. Manage., Vol. 149, pp. 87-100, 2017.
[41] Jayaraju, S.T., "Study of the Air Flow and Aerosol Transport in the Human Upper Airways Using LES and DES Methodologies", Mech. Eng., pp. 196, 2009.
[42] Stairmand, C.J., "The Design and Performance of Cyclone Separators", Trans Inst Chem Engrs., Vol. 29, pp. 356-362, 1951.
[43] Shephered, C. and Lapple, C., "Flow Pattern and Pressure Drop in Cyclone dust Collectors", Ind. Eng. Chem., Vol. 31, pp.  972-984, 1939.
[44] A. Ogawa, "Separation of Particles from air and Gases",  1984.
[45] Ficici, F., Ari, V. and Kapsiz, M., "The Effects of Vortex Finder on the Pressure Drop in Cyclone Separators", Int. J. Physical. Sci., Vol. 5, pp. 804-813, 2010.
[46] Bernardo, S., Mori, M., Peres, A. and Dionisio, R., "3-D Computational Fluid Dynamics for Gas and Gas-Particle Flows in a Cyclone with Different Inlet Section Angles", Powder Technol., Vol. 162, pp. 190-200, 2006.
[47] Chuah, T., Gimbun, J. and Choong, T.S., "A CFD Study of the Effect of Cone Dimensions on Sampling Aerocyclones Performance and Hydrodynamics", Powder Technol., Vol. 162, pp. 126-132, 2006.
[48] Dyakowski, T. and Williams, R., "Modelling Turbulent Flow within a Small-Diameter Hydrocyclone", Chem. Eng. Sci., Vol. 48, pp. 1143-1152, 1993.
[49] Griffiths, W. and Boysan, F., "Computational Fluid Dynamics (CFD) and Empirical Modelling of the Performance of a Number of Cyclone Samplers", J. Aerosol Sci., Vol. 27, pp.  281-304, 1996.
[50] Peng, W., Hoffmann, A., Boot, P., Udding, A., Dries, H., Ekker, A. and et al., "Flow Pattern in Reverse-Flow Centrifugal Separators", Powder Technol., Vol. 127, pp. 212-222, 2002.
[51] Xiang, R. and Lee, K., "Numerical Study of Flow Field in Cyclones of Different Height", Chem. Eng. Process. Process Inten., Vol. 44, pp. 877-883, 2005.
[52] Zhou, L. and Soo, S., "Gas—Solid Flow and Collection of Solids in a Cyclone Separator", Powder Technol., Vol. 63, pp. 45-53, 1990.
[53] Houben, J., Weiss, C., Brunnmair, E. and Pirker, S., "CFD Simulations of Pressure Drop and Velocity Field in a Cyclone Separator with Central Vortex Stabilization Rod", J. Appl. Fluid. Mech., Vol. 9, 2016.
[54] Huang, A.-N., Ito, K., Fukasawa, T., Yoshida, H., Kuo, H.-P. and Fukui, K., "Classification Performance Analysis of a Novel Cyclone with a Slit on the Conical part by CFD Simulation", Sep. Purif. Technol., Vol. 190, pp. 25-32, 2018.
[55] Thompson, J.F., Warsi, Z.U. and Mastin, C.W., "Numerical Grid Generation: Foundations and Applications", North-holland Amsterdam, 1985.
[56] Ansys. I., CFD. ICEM CFD theory guide, Ansys inc.  2015.
[57] Zhao, B., Su, Y. and Zhang, J., "Simulation of Gas Flow Pattern and Separation Efficiency in Cyclone with Conventional Single and Spiral Double Inlet Configuration", Chem. Eng. Research. Design., Vol. 84, pp. 1158-1165, 2006.
[58] Jiao, J., Zheng, Y. Sun, G. and Wang, J., "Study of the Separation Efficiency and the Flow Field of a Dynamic Cyclone", Sep. Purif. Technol., Vol. 49, pp. 157-166, 2006.
[59] Orszag, S.A., "Renormalisation Group Modelling and Turbulence Simulations. Near-wall Turbulent Flows", 1993.
[60] Choudhury, D., "Introduction to the Renormalization Group Method and Turbulence Modeling. Fluent Incorporated, 1993.
[61] Morsi, S. and Alexander, A., "An Investigation of Particle Trajectories in Two-Phase Flow Systems", J. Fluid. Mech., Vol. 55, pp. 193-208, 1972.
[62] Curtis, J.S. and Van Wachem, B., "Modeling ParticleLaden Flows: A research outlook", AIChE. J., Vol. 50, pp. 2638-2645, 2004.
[63] Ferziger, J.H. and Peric, M., "Computational Methods for Fluid Dynamics", Springer Science & Business Media, 2012.
[64] Wang, B., Xu, D., Chu, K. and Yu, A., "Numerical Study of Gas–Solid Flow in a Cyclone Separator", Appl. Math. Modelling, Vol. 30, pp. 1326-1342, 2006.
[65] McCabe, W.L., Smith, J.C. and Harriott, P., "Unit Operations of Chemical Engineering", McGraw-Hill, New York, 1993.
[66] Sgrott, O.L., Noriler, D., Wiggers, V.R. and Meier, H.F., "Cyclone Optimization by COMPLEX Method and CFD Simulation", Powder Technol., Vol. 277, pp. 11-21, 2015.
[67] Li, Q., Xu, W., Wang, J. and Jin, Y., "Performance Evaluation of a New Cyclone Separator–Part I Experimental Results", Sep. Purif. Technol., Vol. 141, pp. 53-58, 2015.
[68] Ghodrat, M., Kuang, S., Yu, A., Vince, A., Barnett, G. and Barnett, P., "Computational Study of the Multiphase Flow and Performance of Hydrocyclones: Effects of Cyclone Size and Spigot Diameter", Ind. Eng. Chem. Research., Vol. 52, pp.  16019-16031, 2013.
[69] Safikhani, H., Hajiloo, A. and Ranjbar, M., "Modeling and Multi-Objective Optimization of Cyclone Separators Using CFD and Genetic Algorithms", Comp. Chem. Eng., Vol. 35, pp.  1064-1071, 2011.
[70] Elsayed, K. and Lacor, C., "CFD Modeling and Multi-Objective Optimization of Cyclone Geometry Using Desirability Function, Artificial Neural Networks and Genetic Algorithms", Appl. Math. Modelling., Vol. 37, pp. 5680-5704, 2013.