Effect of pulsating flow on mass transfer in packed bed is studied by taking Fe3+-iron particle system as an example of liquid-solid system, because of the industrial importance 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 cubes under steady flow is larger than that for spheres. Comparison of kL under steady and pulsating flow without reverse flow (rotary cock) shows no effect of pulsating flow on mass transfer for both spheres and cubes. Comparison of kL under steady and pulsating flow with reverse flow (piston) reveals, however, excellent effect; mass transfer for spheres is accelerated under quasisteady state and that for cubes 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 spheres and cubes is discussed in connection with the difference of the mass transfer under steady and pulsating flow.
