Reconciliation Procedure for Gas-liquid Interfacial Area
& Mass Transfer Coefficient  in Randomly Packed Towers
Simon Piché, Bernard P.A. Grandjean  and Faïçal Larachi
 Department of Chemical Engineering and CERPIC
Université Laval, Ste-Foy, Québec, Canada, G1K 7P4
Corresponding author:

Ind. & Eng. Chem. Res. 41, 4911- 4920 (2002)

Abstract:  Interfacial areas (aw) and volumetric mass transfer coefficients (kLaw, KLaw, kGaw, KGaw) required for randomly packed tower design were gathered from the literature to generate a working database including over 3,780 measurements. A set of artificial neural network correlations for the gas-liquid interfacial area and the pure local mass transfer coefficients was proposed. Thus, the gas-liquid interfacial area and the pure local mass transfer coefficients were extracted using a reconciliation procedure which combined actually measured interfacial areas with pseudo interfacial areas inferred from the actually measured volumetric mass transfer coefficients. The neural network weights of the two aw and k? correlations were adjusted using a least-squared composite criterion simultaneously over the five mass transfer parameters. The first correlation representing the gas-liquid interfacial area [aw/aT = f (ReL, FrL, EoL, Lockhart Martinelli, K)] yielded an average absolute relative error (AARE) of 22.5% for the 325 measurements available. The second one, representing either kG or kL, was also implemented using the following structure [Sh = f (Re, Fr, Sc]. The combination of both correlation predictions (i.e. kaw) yielded an AARE of 24.4% for the local and global volumetric mass transfer coefficients (3455 data).

Keywords: packed bed, counter-current flow, mass transfer, interfacial area, neural network, database

You can get the  file that contains an Excel worksheet simulator to compute pressure drop, liquid holdup, loading/flooding capacities, film and overall volumetric mass transfer  coefficients.

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

The neural correlation was developped with the software NNFit