Studies on gas–solid heat transfer during pneumatic conveying

• Published in: International journal of heat and mass transfer Vol. 51; no. 11; pp. 2801 - 2813
• Main Authors: Rajan, K.S., Dhasandhan, K., Srivastava, S.N., Pitchumani, B.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.2008; Elsevier
• Subjects: Air–solid heat transfer; Analytical and numerical techniques; Applied sciences; Continuous conveyors: mechanical, hydraulic, pneumatic, etc; Dense-phase; Devices using thermal energy; Dilute-phase; Dryers; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Heat exchangers (included heat transformers, condensers, cooling towers); Heat transfer; Material handling, hoisting. Storage. Packaging; Nusselt number; Physics; Pneumatic conveying; Pneumatic conveying; Nusselt number; Air–solid heat transfer; Dense-phase; Dilute-phase; Pneumatic cylinder; Vertical cylinder; Correlation; Particle size; Multiphase flow; Vertical pipe; Empirical method; Gypsum; Pneumatic conveyance; Experimental study; Heat exchanger; Penetration rate; Gas solid; Preheating; Heat transfer; Drying
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2007.09.042

Interactions between solids and gas during pneumatic conveying can be utilized for variety of applications including flash drying, solids preheating etc. Experiments on air–solid heat transfer were carried out in a vertical pneumatic conveying heat exchanger of 54 mm inside diameter, using gypsum as the solid material. The effect of solids feed rate (0.6–9.9 g/s), air velocity (4.21–6.47 m/s) and particle size (231–722.5 μm) on air–solid heat transfer rate, heat transfer area and air–solid heat transfer coefficient has been studied. Empirical correlations have been proposed for the prediction of Nusselt number based on the present experimental data. The proposed correlations predict Nusselt number within an error of ±15% for the present data.