Colloid Particle Adsorption in the Slot Impinging Jet Cell.

A detailed description of flow distribution in the slot impinging jet cell (SIJ) is presented. Numerical solutions of the governing Navier-Stokes equation showed that for Re < 30 the flow resembles closely the one occurring near a cylinder placed in a uniform flow. It was also shown that for tangential distances x/d < 0.25 the flow configuration in the vicinity of the solid can be approximated by the plane-parallel stagnation flow with the perpendicular velocity component independent of this distance. This flow field was used for deriving the mass transfer equation, which was then numerically solved to obtain the initial flux (adsorption rate) for various transport conditions. These theoretical predictions were verified experimentally using polystyrene latex particles of the size 1 and 1.48 µm. A good agreement between predicted and measured initial flux values was found for a broad range of Reynolds number and ionic strength of the particle suspension. This confirmed that the SIJ cell surface was uniformly accessible for particles at distances x/d < 0.5. At larger distances a systematic deviation from uniform deposition rates was observed, becoming important for higher coverages and Re. This effect was attributed to the hydrodynamic scattering of adsorbing particles on particles already attached to the surface. This phenomenon was quantitatively accounted for by the Brownian dynamics type simulations. Copyright 1999 Academic Press.