Simulations of mono-sized solid particles in the reflux classifier under continuous process conditions

• Autorzy: Syed Naveedul Hasan , Khan Naseer Ahmed

Identyfikatory

DOI

10.5277/ppmp18175

• Języki publikacji: EN

Abstrakty

EN

In this study, a fluidized bed separator incorporating inclined channels, the Reflux Classifier (RC), was modeled to describe the transport behavior of mono-sized solid particles using a 2D computational segregation-dispersion model. The model is a volume flux-based model comprising the dispersion and segregation fluxes. Simulations were performed to examine variations in the solid volume fraction of particle species of size 0.163 mm and density 2450 kg/m3 by altering variables such as fluidization velocity, underflow rate and water flux in the feed. The system achieved a maximum solid volume fraction of 0.50 (v/v) near the base at a fluidization velocity 0.00020 m/s, that reduced to 0.20 at the fluidization velocity 0.0060 m/s. Overall, the results showed a decrease in the average solid volume fraction from 0.37 to 0.21 for the corresponding fluidization velocities. Simulation results also successfully demonstrated the capacity of the RC in retaining the solid particles at a superficial fluidization velocity 0.020 m/s, significantly higher than the terminal settling velocity, 0.015 m/s, of the solid particles, due to the presence of an inclined channel. Similarly, with increasing the underflow rate, the average solid volume fraction decreased from 0.29 to 0.055 due to the discharge of a larger quantity of solid particles from the base. Furthermore, a higher concentration of solid particles was observed in the inclined section at lower water flux in the feed stream. Additionally, flux balance calculations were carried out at different points within the RC to ensure the accuracy of the model predictions.

Słowa kluczowe

EN

beneficiation; fluidized beds; inclined channel; segregation; superficial velocity

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Physicochemical Problems of Mineral Processing
• Rocznik: 2019
• Tom: Vol. 55, iss. 3
• Strony: 631--642
• Opis fizyczny: Bibliogr. 38 poz., rys.

Twórcy

autor

Syed Naveedul Hasan

• University of Engineering and Technology Peshawar Pakistan, Department of Chemical Engineering, UET Peshawar, 25000 Peshawar, Pakistan

autor

Khan Naseer Ahmed

• University of Engineering and Technology Peshawar Pakistan, Department of Chemical Engineering, UET Peshawar, 25000 Peshawar, Pakistan

Bibliografia

• ABBASFARD, H., EVANS, G.M., KHAN, M.S., MORENO-ATANASIO, R., 2018. A new two-phase coupling model using a random fluid fluctuating velocity: application to liquid fluidized beds. Chemical Engineering Science, 180, 79 – 94.
• ASIF, M., 1997. Modelling of multi-solid liquid fluidized beds. Chemical Engineering Technology, 20, 485 – 490.
• ASIF, M., 2004. The complete segregation model for a liquid fluidized bed: formulation and related issues. Powder Technology, 140, 21 – 29.
• ASIF, M., and PETERSEN, J.N., 1993. Particle dispersion in a binary solid–liquid fluidized bed. A.I.Ch.E. Journal, 39 (9), 1465 – 1471.
• BOYCOTT, A.E., 1920. Sedimentation of blood corpuscles. Nature, 104, 532.
• DAVIS, R. H., and GECOL, H., 1996. Classification of concentrated suspensions using inclined settlers. International Journal of Multiphase Flow, 22 (3), 563 – 574.
• DAVIS, R.H., ZHANG, X., AGARWALA, J.P., 1989. Particle classification for dilute suspensions using an inclined settler. Industrial and Engineering Chemistry Research, 28, 785 – 793.
• Di FELICE, R., 2007. Liquid suspensions of single and binary component solid particles-An overview. China Particulogoy, 5, 312 – 320.
• DOROODCHI, E., FLETCHER, D.F., GALVIN, K.P., 2004. Influence of inclined plates on the expansion behaviour of particulate suspensions in a liquid fluidized bed. Chemical Engineering Science, 59, 3559 – 3567.
• DOROODCHI, E., GALVIN, K.P., FLETCHER, D.F., 2005. The influence of inclined plates on expansion behavior of solid suspensions in a liquid fluidized bed – a computational fluid dynamics study. Powder Technology, 160, 20 – 26.
• EPSTEIN, N., 2005. Teetering. Powder Technology, 151, 2 – 14.
• ESCUDIE, R., EPSTEIN, N., GRACEA, J.R., BIA, H.T., 2006. Layer inversion phenomenon in binary-solid liquid-fluidized beds: Prediction of the inversion velocity. Chemical Engineering Science, 61, 6667 – 6690.
• GALVIN, K.P., CALLEN, A., ZHOU, J., DOROODCHI, E., 2005. Performance of the reflux classifier for gravity separation at full scale. Minerals Engineering, 18, 19 – 24.
• GALVIN, K.P., DOROODCHI, E., CALLEN, A.M., LAMBERT, N., PRATTEN, S.J., 2002. Pilot plant trial of the reflux classifier. Minerals Engineering, 15, 19 – 25.
• GALVIN, K.P., ZHOU, J., WALTON, K., 2010. Application of closely spaced inclined channels in gravity separation of fine particles. Minerals Engineering, 23, 326 – 338.
• HUNTER, D. M., ZHOU, J., IVESON, S. M., GALVIN, K. P., 2016. Gravity separation of ultra-fine iron ore in the Reflux Classifier. Mineral Processing and Extractive Metallurgy, 125, 126 – 131.
• JEMWA, G.T., ALDRICH, CHRIS, 2012. Estimating size fraction categories of coal particles on conveyor belts using image texture modeling methods. Expert Systems with Applications, 39, 7947 – 7960.
• JUMA, A. K. A., and RICHARDSON, J. F., 1983. Segregation and mixing in liquid fluidized beds. Chemical Engineering Science, 38 (6), 955 – 967.
• KENNEDY, S.C., and BRETTON, R.H., 1966. Axial dispersion of spheres fluidized with liquids. A.I.Ch.E. Journal, 12, 24– 30.
• KHAN, M.S., MITRA, S., GHATAGE, S.V., DOROODCHI, E., JOSHI, J.B., and EVANS, G.M., 2017. Segregation and dispersion studies in binary solid-liquid fluidized beds: a theoretical and computational study. Powder Technology, 314, 400 - 411.
• LAW, H. S., MACTAGGART, R. S., NANDAKUMAR, K., MASLIYAH, J. H., 1988. Settling behavior of heavy and buoyant particles from a suspension in an inclined channel. Journal of Fluid Mechanics, 187, 301 – 318.
• LI, Y., LI, N., Qi, X., ZHANG, W., ZHU, R., 2018b. A sedimentation model for particulate suspensions in liquidsolid fluidized beds with inclined channels. Physicochemical Problems of Mineral Processing, 54(3), 837 – 846.
• LI, Y., LI, Y., XIA, W., HE, C., ZHU, R., 2017. A novel particulate sedimentation model in inclined channels of liquid–solid fluidized bed. Powder Technology, 305, 764 – 770.
• LI, Y., Qi, X., LI, N., WANG, A., ZHANG, W., ZHU, R., Peng, Z., 2018a. Motion characterisitics of binary solids in a liquid fluidized bed with inclined plates. Particuology, 39, 48 – 54.
• MASLIYAH, J. H., NASR-EL-DIN, H., NANDAKUMAR, K., 1989. Continuous separation of bidisperse suspensions in inclined channels. International journal of Multiphase Flow, 15 (5), 815 – 829.
• MORITOMI, H., YAMAGISHI, T., CHIBA, T., 1986. Prediction of complete mixing of liquid fluidized binary solid particles. Chemical Engineering Science, 41, 297 – 305.
• MUKHERJEE, A.K., MISHRA, B.K., KUMAR, R.V., 2009. Application of liquid/solid fluidization technique in beneficiation of fines. International Journal of Mineral Processing, 92, 67 – 73.
• NELSON, D., LIU, J., and GALVIN, K.P., 1997. Autogenous dense medium separation using an inclined counterflow settler. Mineral Engineering, 10, 871 – 881.
• NGUYENTRANLAM, G., GALVIN, K.P., 2001. Particle classification in the reflux classifier. Mineral Engineering, 14 (9), 1081 – 1091.
• PATEL, B.K., RAMIREZ, W.F., GALVIN, K.P., 2008. A generalized segregation and dispersion model for liquid fluidized beds. Chemical Engineering Science, 63, 1415 – 1427.
• PENG, Z., JOSHI, J.B., MOGHTADERI, B., KHAN, M.S., DOROODCHI, E., and EVANS, G.M., 2016. Segregation and Dispersion of Binary Solids in Liquid Fluidized Beds: a CFD-DEM Study. Chemical Engineering Science, 152, 65– 83.
• PONDER, P., 1925. On sedimentation and Rouleaux formation. Quarterly journal of experimental physiology, 15, 235– 252.
• RASUL, M.G., RUDOLPH, V., WANG, F.Y., 2000. Particles separation using fluidization techniques. International Journal of Mineral Processing, 60, 163 – 179.
• RICHARDSON, J.F., and ZAKI, W.N., 1954. Sedimentation and fluidization: Part I. Transactions of the Institution of Chemical Engineers, 32, 35 – 53.
• SYED NAVEED, DICKINSON, J., GALVIN, K.P., MORENO-ATANASIO, R., 2015. A continuum simulation model for the reflux classifier. APCChE 2015 Congress, Chemeca 2015, Melbourne, Sept 27 – 01 Oct.
• SYED, N.H., 2017. A continuous, dynamic and steady state segregation-dispersion model of the reflux classifier. PhD Thesis, The University of Newcastle, NSW, Australia.
• SYED, N.H., DICKINSON, J.E., GALVIN, K.P., MORENO-ATANASIO, R., 2018. Continuous, dynamic and steady state simulations of the reflux classifier using a segregation-dispersion model. Minerals Engineering, 115, 53 – 67.
• THOMPSON, P.D., and GALVIN, K.P., 1997. An empirical description for the classification in an inclined counter-flow settler. Minerals Engineering, 10, 97 – 109.