FIBROUS BED COALESCENCE OF WATER - STEPS IN COALESCENCE PROCESS

The coalescence phenomena in a fibrous filter bed have been analyzed on the basis of three major steps: approach of a dispersed water droplet to a fiber, attachment of the droplet, and release of enlarged droplets from the downstream side of the filter. For approach the interception process is important, while diffusion and inertial impaction processes are insignificant in the total efficiency of this step. Surfactants that increase the water-hydrocarbon interfacial viscosity may interfere with the attachment of the small water droplets in the initial part of the filter or the attachment of a coalesced water thread as it snakes through the fibrous bed. They also interfere with the release process by altering the interfacial tension. The latter property influences the size of a water thread at rupture and thus controls released water droplet size. Rayleigh instability can occur when the interfacial tension is decreased. © 1969, American Chemical Society. All rights reserved.