Nu/Sh correlation for particle-liquid heat and mass transfer
coefficients in trickle beds based on Péclet similarity

F. Larachi,* C. Alix, , B.P.A. Grandjean,  A. Bernis

Department of Chemical Engineering and CERPIC; Laval University, Ste-Foy, Canada PQ G1K 7P4
&Laboratoire de génie des procédés, Université de Savoie, Domaine Scientifique, 73376 Le Bourget du Lac, France

Chem. Eng. Res. Des. (Trans IChemE part A),  81 , 689-694 (2003)

*Corresponding author (Email: flarachi@gch.ulaval.ca)
Tel. 1-418-656-3566; Fax 1-418-656-5993

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Abstract Knowledge of the particle to liquid heat and mass transfer coefficients in trickle beds is important particularly in contexts where exothermic reactions impede liquid replenishment over dried spots in the catalyst bed, or when the transport, especially in liquid-limited reactions, is curbed by excessive liquid-solid interfacial resistance. Although particle-liquid heat and mass transfer coefficients in trickle beds are linked to each other, the known Chilton-Colburn analogy or alike failed to yield a single Nu/Sh correlation to quantify both heat and mass transfer phenomena at the pellet scale. In this work, a single correlation embedding the heat and mass transfer information into a Péclet number was derived and validated over 1259 particle-liquid heat and mass transfer coefficients in trickle beds. Depending on whether a heat or a mass Péclet number is used, the proposed correlation predicted Nu and Sh numbers with average absolute relative errors of 18% and 22%, respectively. In particular, when equal heat and mass Péclet numbers occur, under physically and geometrically similar conditions, the correlation predicts true analogy between heat and mass transfer at the pellet level.

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Download the simulator for computing: tbr-nush.zip

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You may also download our Excel worksheets simulators for  Trickle-bed or Flooded Bed reactors.

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The neural correlation was developped with the software NNFit

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