Effect of pulsating flow on mass transfer in packed bed is studied by taking Fe
3+-iron particle system as an example of liquid-solid system, because of the industrial requirement of iron plating. Spherical and cubic particles are used as packing materials having very different shapes. Pulsation is generated by a rotary cock or a piston.
Mass transfer coefficient
kL for cube-packed bed under steady flow is larger than that for sphere one. Comparison of
kL under steady and pulsating flow without reverse flow (by rotary cock) shows no effect of pulsating flow on mass transfer for both sphere- and cube-packed bed. In comparison with
kL under steady and pulsating flow with reverse flow (by piston), however, remarkable difference reveals. That is, mass transfer for sphere-packed bed is accelerated under quasi-steady state and that for cube-packed bed is promoted much more than in quasi-steady state, where mass transfer is assumed to proceed depending on the absolute value of velocity.
Velocity fluctuations just after the bed are measured by a hot film probe and the difference between the flow fields for sphere- and cube-packed bed is discussed in connection with the difference of the mass transfer under steady and pulsating flow.
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