Analytical Modeling of Counter-Current Drying Process

Year 2024, , 27 - 36, 01.06.2024

Mehmet Turgay Pamuk

https://doi.org/10.5541/ijot.1330933

Abstract

In this analytical study, spray drying of detergent particles of diameters 0.4-1 mm by using counter-current air heated at around 300oC is investigated using Matlab©. Particle drying using hot gases is a mature process with a vast variety of applications ranging from dried food to powdered detergent production. The study shows a strong relationship between the drying process (final water content) and particle size, drying gas temperature, as well as the tower dimensions since cross-sectional area of the tower has a direct control on vertical gas velocity, thus heat and mass transfer coefficients while the height of tower is closely related to residence time of particles in tower which guarantees the targeted drying level. The conclusions of this study can be a guide to have a better set of drying parameters such as inlet temperatures and humidity/water content as well as exit temperatures and humidity/water content and valuable information on how these relate to heat energy consumption necessary to heat the air from atmospheric conditions to the desired drying gas temperature. It is also worth indicating that the measurement of the absolute humidity in tower exhaust is a good parameter to control the drying process in an effective way.

Keywords

Heat Transfer, Convection, Mass Transfer, Spray Drying, Counter-current Dryers

References

• A. S. Mujumdar and V. Jog, “Simple Procedure for Design of a Spray Dryer,” Journal of the Institution of Engineers (India): Chemical Engineering Division, vol. 57, pp. 134-138, Jun. 1977.
• P. Wawrzyniak, M. Podyma, I. Zbicinski, Z. Bartczak and J. Rabaeva, “Modeling of Air Flow in an Industrial Counter current Spray-Drying Tower,” Drying Technology, vol. 30, no. 2, pp. 217-224, Nov. 2011, doi:10.1080/07373937.2011.618282.
• M. Ali, “Numerical Modeling of a Counter-Current Spray Drying Tower,” Ph.D. dissertation, Ins. of Particle Sci. and Eng., School of Chemical and Process Eng., The Univ. of Leeds, Woodhouse, Leeds LS2 9JT, UK, 2014.
• E.A. Afolabi and K. R. Onifade, “Simulation of Air Residence Time Distributions of Spray Droplets in A Counter-Current Spray Dryer,” ARPN Journal of Engineering and Applied Sciences, vol. 9, no. 2, pp. 145-152, Feb. 2014.
• M. Ali, T. Mahmud, P.J. Heggs, M. Ghadiri, A. Bayly, H. Ahmadian and L. M. de Juan, “CFD Simulation of a Counter-Current Spray Drying Tower with Stochastic Treatment of Particle-Wall Collision,” Procedia Engineering, vol. 102, pp. 1284-1294, Jan. 2015, doi:10.1016/j.proeng.2015.01.259.
• M. J. Crosby, L. M. De Juan, E. Martin and G. Montague, “Particle size control of detergents in mixed flow spray dryers,” The Journal of Engineering, vol. 2015, no. 3, pp. 102–107, Feb. 2015, doi:10.1049/joe.2014.0250.
• S. Gonzalez‑Gallego, S. López and H. Alvarez, “A phenomenological‑based model for a spray drying tower,” Brazilian Journal of Chemical Engineering, Apr. 2023. [Online]. Available: https://link.springer.com/content/pdf/10.1007/s43153-023-00323-0.pdf
• B. Hernandez, B. Fraser, L.M. de Juan and M. Martin, “Computational Fluid Dynamics (CFD) Modeling of Swirling Flows in Industrial Counter-Current Spray-Drying Towers under Fouling Conditions,” Industrial & Engineering Chemistry Research, vol. 57, pp. 11988-12002, Aug. 2018, doi:10.1021/acs.iecr.8b02202.
• Y. Xia, J. Lu, S. Jin and Q. Cheng, “Effect of pressure on heat and mass transfer performance in spray drying tower with low inlet temperature,” Applied Thermal Engineering, vol. 218, pp. 1-15 Jan. 2023, doi:10.1016/j.applthermaleng.2022.119260.
• U. Jamil Ur Rahman, A.K. Pozarlik and G. Brem, “Experimental analysis of spray drying in a process intensified counter flow dryer,” Drying Technology, vol. 40, no. 15, pp. 3128-3148, Dec. 2021, doi:10.1080/07373937.2021.2004160.
• A.M. Sefidan, M. Sellier, J.N. Hewett, A. Abdollahi and G.R. Willmott, “Numerical model to study the statistics of whole milk spray drying,” Powder Technology, vol. 411, pp. 1-14, Oct. 2022, doi:10.1016/j.powtec.2022.117923.
• H. Jubaer, S. Afshar, J. Xiao, D.C. Xiao, C. Selomulya and M.W. Woo, “On the effect of turbulence models on CFD simulations of a counter-current spray drying process,” Chemical Engineering Research and Design, vol. 141, pp. 592-607, Jan. 2019, doi:10.1016/j.cherd.2018.11.024.
• B. Hernandez, R. Mondragon, M.A. Pintoa, L. Hernandez, J. E. Julia, J.C. Jarque, S. Chiva and M. Martin, “Single droplet drying of detergents: Experimentation and modelling,” Particuology, vol. 58, pp. 35-47, Oct. 2021, doi:10.1016/j.partic.2021.01.012.
• L. Chen, C. Chen, J. Yu and S. Jin, “Study on the heat and mass transfer characteristics of spray separation tower at low temperature and normal pressure,” International Journal of Heat and Mass Transfer, vol. 153, pp. 1-17, Jun. 2020, doi:10.1016/j.ijheatmasstransfer.2020.119662.
• Y.A. Çengel and A.J. Ghajar, “Mass Transfer”, in Heat and Mass Transfer: Fundamentals & Applications, 5th ed., New York, NY, USA: McGraw-Hill, 2015, ch. 14, sec. 1-6, pp. 835-854.
• M. Parti, “Mass Transfer Biot Numbers,” Periodica Polytechnica Ser. Mech. Eng., vol. 38, no. 2-3, pp. 109-122, Feb. 1994.
• W.W. Pulkrabek, “Thermochemistry of fuels” in Engineering Fundamentals of the Internal Combustion Engine, 2nd ed., Essex, UK: Pearson, 2014, ch. 4, sec. 1, pp. 153-155.
• F.C. McQuiston, J.D. Parker and J.D. Spitler, “Moist Air Properties and Conditioning Processes” in Heating Ventilating and Air Conditioning – Analysis and Design, 6th ed., Hoboken, NJ, USA: Wiley, 2005, ch. 3, sec. 2, pp. 51-53.
• S. Whitaker, “Forced convection heat transfer correlations for flow in pipes, past flat plates, single cylinders, single spheres, and for flow in packed beds and tube bundles,” AIChE Journal, vol. 18, no. 2, pp. 361-371, Mar. 1972.