Abstract
The mass transfer coefficients between particles and liquid were correlated for single particles and for fixed beds with specific power group including the energy dissipation rate defined for a particle. The following empirical equations were obtained over a wide range from laminar to turbulent flow, assembling the published data including those of the authors for fixed beds:
for single particles
Sh=2+0.59(ε1/3Dp4/3/v)0.57Sc1/3
2<(ε1/3Dp4/3/v)<63000, 570<Sc<1420
for fixed beds
Sh=2+0.51(ε1/3Dp4/3/ν)0.60Sc1/3
0.2<(ε1/3Dp4/3/ν)<4600, 505<Sc<70600
where e is energy dissipation rate per unit mass of liquid flowing around a particle, Dp is particle diameter, and ν is kinematic viscosity of liquid. These equations, almost identical, are also practically the same as published ones for stirred tanks, suspended bubble columns, and twophase tube-flow. The agreement suggests that specific power group may be useful as a general parameter in the study of mass-transfer phenomena between liquid and particles where the liquid is either quiescent or turbulent and the particles are either fixed or suspended.
