Direct measurement of floc breakage in flowing suspensions

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Journal of Colloid and Interface Science; (United States)

DOI:https://doi.org/10.1006/jcis.1994.1302· OSTI ID:6982842

Peng, S J; Williams, R A ^[1]

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1. Univ. of Exeter, Redruth (United Kingdom). Camborne School of Mines

Direct measurements of floc breakage behavior of silica and latex dispersions in a stirred tank and process pipeline have been performed using in situ scanning laser microscopy. The results show the effect of agitation intensity, flocculant dosage, and solids concentration on the floc formation and breakup in a stirred tanks. The effect of the rms velocity gradients on the floc breakage behavior in a process pipeline is also demonstrated and modeled using a quantitative relationship between the breakage constant (K) and the rms velocity gradient (G). These data provide a means of assessing, quantitatively, the strength of a floc population. Expressions for the mean dimensionless floc size R (scaled to the mean diameter of the primary particles) have been obtained for polymer-flocculated suspensions flowing in tubes. Typically R is given by (1 + aG[sup b]), where a and b depend on the volume concentration of solids. For 0.5% solids, a = 34.7, b = [minus]0.67; for 1.0% solids, a = 4.85, b= [minus]0.29.

• OSTI ID: 6982842
• Journal Information: Journal of Colloid and Interface Science; (United States), Vol. 166:2; ISSN 0021-9797
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
PIPES
TWO-PHASE FLOW
SOLID CLUSTERS
FRAGMENTATION
COLLOIDS
FLOCCULATION
LATEX
PIPELINES
SILICON OXIDES
TANKS
CHALCOGENIDES
CONTAINERS
DISPERSIONS
ELASTOMERS
FLUID FLOW
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OXIDES
OXYGEN COMPOUNDS
POLYMERS
PRECIPITATION
RUBBERS
SEPARATION PROCESSES
SILICON COMPOUNDS
420400* - Engineering- Heat Transfer & Fluid Flow