Dispersion measurement in clogged filter beds: A diagnostic study on the morphology of particle deposits

Abstract

The use of tracer dispersion measurements in conjunction with associated pressure drop data, as an indirect diagnostic technique for the determination of particle deposit morphology in deep‐bed filters, was investigated. The dispersion measurements consisted of the injection of an electrolyte tracer pulse at the inlet and the monitoring of the tracer peak as it traveled down the bed, while the pressure drop data consisted of the axial pressure gradient histories as deposition took place. These data are interpreted using dispersion and pressure drop theories established on the basis of assumed models of deposit morphology. The validity of this technique was confirmed experimentally.

Permeability reductions induced by sorption of surfactant

“…The addition of the montmorillonite clay significantly reduces the permeability of the medium k c and generally increases the dispersivity. Increased dispersion in the presence of clay has been observed previously and is likely due to the dual porosity created by the imperfectly mixed clays and to the fact that bromide is not a fully conservative tracer in the presence of clays [Pendse et al, 1978;Bibby, 1981].…”

Dynamic modeling of deep‐bed filtration

“…Wnek et al (1975) presented a model using the Happel (1958) sphere-in-cell unit collector together with a charge balance equation. However, they assumed that the deposit formed a smooth uniform coating around the grains, an assumption that Pendse et al (1978) have shown to be inadequate.…”

“…A more important point is that the model takes no account of the possibility either of pores being blocked or of deposited particles (or particle clusters) being dislodged although there is considerable evidence to indicate that these events do occur (Payatakes et al,198 1; Maroudas and Eisenklam, 1965;Pendse et al 1978). We consider that the model should be further developed to take account of the possibility of pore blocking and deposit dislodgement occurring.…”

Flow of dispersed particles through porous media — Deep bed filtration

“…The deposit porosity is meaningful when the extent of deposition is significant. Pendse et al (1978) developed an experimental procedure for the determination of the morphology of particle deposits in a clogged filter bed. They used tracer dispersion measurements and pressure drop data along the bed to develop relationships between pressure drop increase and the change in bed structure due to clogging corresponding to assumed deposit morphologies.…”