Experimental and modelling work has been carried out on separation performance, shock formation on pressurisation, adsorption dynamics, and mass transfer resistances. Current work, with Dr Bill Paterson , concerns optimisation of the process, design, aspects of fast cycling, and further development of the modelling. Transport properties in moving beds With Bill Paterson we are investigating heat transfer in downward moving beds of solids subject to countercurrent flow of gas. The work is of relevance to processes such as coal gasifiers, blast furnaces and continuous catalyst regeneration reactors. This effect is believed to be caused by gas maldistribution in the moving bed, which has been probed by tracer measurements of residence time distributions and radial profiles of gas axial velocity.
Current work is on solids flow characteristics, segregation and modelling.
Rotating cylinders are widely used in industry for, for example, calcining. With John Davidson we are studying particle motion in a slowly rotating cylinder with axis slightly inclined, with particular emphasis on flow in and out of the cylinder and over internal dam rings, and on unsteady state behaviour. In collaboration with Rex Thorpe we are carrying out an experimental and theoretical study into the dynamics of bubbles and gas entrainment in downflows of non-Newtonian liquids, and the effect of large bubbles on fermenter dynamics. Selected Publications E. Alpay, C.N. Kenney and D.M. Scott, Simulation of rapid pressure swing adsorption and reaction processes, Chem. J.P. Crawshaw, W.R. Paterson and D.M. Scott, Gas residence time distribution studies of fixed, moving and frozen beds of spheres, Chem.