Files in this item



application/pdf8502280.pdf (3MB)Restricted to U of Illinois
(no description provided)PDF


Title:Application of Laser-Doppler Velocimetry to the Study of Coagulation and Sedimentation
Author(s):Richardson, James H.
Department / Program:Chemical Engineering
Discipline:Chemical Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Engineering, Chemical
Abstract:The coagulation and subsequent sedimentation of model colloidal systems was measured by laser-Doppler velocimetry. This technique allows for rapid stability tests of dilute suspensions which affords a great savings of material over standard methods. The relative stability of dilute polystyrene latex particle (0.198 (mu)m diameter) suspensions was determined by comparing floc settling velocities. These suspensions are found to be stabilized in basic pH; the addition of sodium dodecyl sulfate (SDS) is insufficient to prevent coagulation of polystyrene suspensions in the presence of an added electrolyte. In a coagulating system of SDS and CaCl(,2), measurement of the time needed for flocs to reach a maximum settling velocity was found to adequately represent coagulation kinetics. Velocity profiles for various depths in a settling cell were recorded for the SDS, CaCl(,2) system. Maximum settling velocity was found to be a constant regardless of concentration or depth in the cell. The upward fluid velocity, emanating from compaction layers at the bottom of the cell and indicated by the slowing of particle settling rates in higher levels of the cell, was approximately equal to the maximum downward particle velocity. This supports the D'Arcian flow assumption made in theoretical settling equation development.
Issue Date:1984
Description:104 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.
Other Identifier(s):(UMI)AAI8502280
Date Available in IDEALS:2014-12-15
Date Deposited:1984

This item appears in the following Collection(s)

Item Statistics