Engineering and Technology Journal

Heat Transfer Coefficients in Air-Solid Fluidized Bed Using Vertical Heating Element

Document Type : Research Paper

Authors

1 Chemical Engineering Dept., University of Technology-Iraq, Alsina’a Street, 10066 Baghdad, Iraq.

2 Chemical Engineering Dept., University of Al-Nahrain, Baghdad, Iraq.

Abstract

In various chemical industrial applications such as hydrocracking, drying, and Fischer-Tropsch, the utilization of fluidized bed systems is prevalent. Efficient heat transfer is crucial for maintaining stable temperatures and ensuring product quality in industrial processes. Gas-solid fluidized beds, which involve gas circulation through a bed of solid particles, offer a means to achieve efficient heat exchange. However, factors such as particle size, gas velocity, and heating methods can influence the effectiveness of these systems. To investigate the impact of internal heating on heat transfer in gas-solid fluidized beds, an experimental study was conducted using glass beads of 200 and 600 μm. A Perspex fluidization column with an inner diameter of 10 cm and a total height of 2 m was packed with these beads. The experiments were performed under superficial gas velocities ranging from 0.1 to 0.5 m/s. Highly responsive sensors were employed to measure temperatures and calculate the heat transfer coefficient. Additionally, the position of the heating element and local heat transfer coefficients at different gas velocities were examined. The experimental results were compared to a mathematical model developed to simulate laboratory findings. The total heat transfer coefficient was evaluated in a gas-solid fluidized bed at different bed temperatures. Furthermore, a comparison was made between the experimental results and the model to validate the practical application, while the practical results were also compared with previous studies.

Graphical Abstract

Highlights

  • Local heat transfer coefficient in fluidized bed increases with increasing superficial gas velocity and higher for smaller particle sizes
  • The heat transfer coefficient is increased with increasing the voidage between particles
  • Higher velocities and higher heating power can further enhance the heat transfer coefficient
  • A mathematical correlation was developed depending on the experimental data with the aid of Using LABFIT software, showing a 5% deviation
  • Smaller particles increase the turbulence within the fluid, enhancing the convective heat transfer

Keywords

Main Subjects

References
  1. Aronsson, D. Pallarès, M. Rydén, A. Lyngfelt, Increasing Gas–Solids Mass Transfer in Fluidized Beds by Application of Confined Fluidization—A Feasibility Study, Appl. Sci., 9 (2018). https://doi.org/10.3390/app9040634
  2. Aronsson, E. Krymarys, V. Stenberg, T. Mattison, A. Lyngfelt, M. Rydén, Improved Gas−Solids Mass Transfer in Fluidized Beds: Confined Fluidization in Chemical-Looping Combustion, Energy Fuels, 33 (2019) 4442–4453. https://doi.org/10.1021/acs.energyfuels.9b00508
  3. Sköldberg, L. Öhrby, Determination of heat transfer coefficient to tube submerged in bubbling fluidized bed reactor, Chalmers Univ. Technol., Gothenburg, Sweden, 2018.
  4. Stenberg, V. Sköldberg, L. Öhrby, M. Rydén, Evaluation of bed-to-tube surface heat transfer coefficient for a horizontal tube in bubbling fluidized bed at high temperature, Powder Technol., 352 (2019) 488-500. https://doi.org/10.1016/j.powtec.2019.04.073
  5. Welty, C. Wicks, R. Wilson, G. Rorrer, Fundamentals of Momentum, Heat and Mass Transfer, 5th ed., Hoboken, NJ, USA, John Wiley & Sons, Inc., 2007.
  6. K. Sinnott, J. M. Coulson, J. F. Richardson, Coulson and Richardson’s Chemical Engineering, Volume 6, Chemical Engineering Design, 4th ed., San Diego, CA, USA, Butterworth-Heinemann, 2005.
  7. A. Shrshab, Y. I. Abdulaziz, Determination of Heat Transfer Coefficients in Air-Solid Fluidized Bed, IOP Conf. Ser. Mater. Sci. Eng., 2nd Int. Sci. Conf. Al-Ayen Univ., Thi-Qar, Iraq, 928 (2020). https://doi.org/10.1088/1757-899X/928/2/022067
  8. A. Abid, J. M. Ali, A. A. Alzubaidi, Heat transfer in a gas-solid fluidized bed with various heater inclinations, Int. J. Heat Mass Transf., 54 ( 2011) 2228–2233. https://doi.org/10.1016/j.ijheatmasstransfer.2010.12.028
  9. Hou, Z. Zhou, A. Yu, Computational Study of the Effects of Material Properties on Heat Transfer in Gas Fluidization, Ind. Eng. Chem. Res., 51 (2012) 11572−11586. https://doi.org/10.1021/ie3015999
  10. H. Bartholomew and R. J. Farrauto. 2010. Fundamentals of Industrial Catalytic Processes, 2nd Edition, Hoboken, NJ, USA: John Wiley & Sons, Inc., 2005. http://dx.doi.org/10.1002/9780471730071
  11. Efhaima, Scale-up Investigation and Hydrodynamics Study of GasSolid Fluidized Bed Reactor Using Advanced Non-Invasive Measurement Techniques, PhD Thesis, Missouri University of Science and Technology, 2016.
  12. Poós, S. Viktor, Volumetric Heat Transfer Coefficient in Fluidized‐Bed Dryers, Chem. Eng. Technol., 41 (2018) 628-636. Cited from W. E. Ranz, W. R. Marshall, Chem. Eng. Progr. 1952, 48 (3) 141-146 https://doi.org/10.1002/ceat.201700038
  13. Das, S. Sneijders, N. G. Deen, J. A. M. Kuipers, Drag and heat transfer closures for realistic numerically generated random open–cell solid foams using an immersed boundary method, Chem. Eng. Sci., 183 (2018) 260–274. https://doi.org/10.1016/j.ces.2018.03.022
  14. O. KAGUMBA, Heat Transfer and Bubble Dynamics in Bubble and Slurry, Ph.D. Thesis, Missouri University of Science and Technology, 2013.
  15. Pisters; A. Prakash, Investigations of Axial and Radial Variations of Heat Transfer Coefficient in Bubbling Fluidized Bed with Fast Response Probe, Powder Technol., 207 (2011) 224–231. https://doi.org/10.1016/j.powtec.2010.11.003
  16. Stefanova, H. T. Bi, J. C. Lim, J. R. Grace, Local Hydrodynamics and Heat Transfer in Fluidized Beds of Different Diameter, Powder Technol., 212 (2011) 57–63. https://doi.org/10.1016/j.powtec.2011.04.026
  17. Lee, E. Lim, Heat transfer in a pulsating turbulent fluidized bed, Appl. Therm. Eng., 174 (2020) 115321. https://doi.org/10.1016/j.applthermaleng
  18. Blaszczuk, W. Nowak, Heat transfer behavior inside a furnace chamber of large-scale supercritical CFB reactor. Int. J. Heat Mass Transfer, 87 (2015) 464-480. https://doi.org/10.1016/j.ijheatmasstransfer.2015.04.037
  19. F. Hou, S. B. Kuang, A. B. Yu, A DEM-based approach for analyzing energy transitions in granular and particle-fluid flows, Chem. Eng. Sci., 161 (2017) 67-79. https://doi.org/10.1016/j.ces.2016.12.017
  20. Qiu, F. Wu, S. Yang, K. Luo, K. K. Luo, and J. Fan. Heat transfer and erosion mechanisms of an immersed tube in a bubbling fluidized bed: A LES-DEM approach, Int. J. Therm. Sci., 100 (2016) 357- 371. https://doi.org/10.1016/j.ijthermalsci.2015.10.001
  21. Jiang, X. Dong, G. Qi, P. Mao, Heat-transfer performance and pressure drop in a gas-solid circulating fluidized bed spiral-plate heat exchanger, Appl. Therm. Eng., 171 (2020) 115091. https://doi.org/10.1016/j.applthermaleng.2020.115091
  22. Logie, E. Frank, M. Haller, M. Rommel, Investigation of immersed coil heat exchangers in regard to heat transfer and storage stratification, Graz, Austria, 2010.
Engineering and Technology Journal
Volume 41, Issue 9
Chemical Engineering
5 articles
September 2023
Page 1193-1203
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