tinuous thickener from batch sedimentation experiments. It is significant that up Kynch () presented the first theory of sedimentation. In spite of the fact that. Points are experimental data, continuous curves Derived from Kynch theory (see text). Figure 5 Two Interface Description of Sedimentation. Instantaneous concentration profiles of the batch sedimentation of non-colloidal hard spheres were measured for various initial suspension concentrations from.

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The Vancouver Geotechnical Society. Tests were also conducted on fines of copper tailings with dispersant, kaolin and a mixture of kaolin and concrete sands. Search articles by author G. The first section, from ml to ml is almost a straight line, signifying that the velocity of the downwards movement of the interface was constant.

Doctoral dissertation, University of Oxford Been. The performance of gravity thickeners is often analyzed using the batch sedimentation theory of Kynch.

The theeory of copper tailings and distilled water was calculated according to Equation 4.

Total copper tailings, with a large range of particle sizes could not satisfy the assumptions of Kynch theory on particle size, and failed to conform to Kynch theory.

Dry samples and distilled water were mixed directly in the settling column by shaking them up and down sedumentation times.

This phenomenon led to a consequence of higher water content than was the reality in the standpipe. These properties include the solids content, void ratio, permeability, compressibility, and effective stress.

Applicability of Kynch Theory to Flocculent Suspensions

The lack of coarse particles leads to a decrease in the solids content in the suspension. Coarse particles settle individually at the beginning of the column settling test, leading to two negative results regarding the application of Kynch theory.


Magnetic resonance imaging MRI technology was employed to measure the concentration of the sedientation. The turbidity of each of the samples was measured with the help of a digital turbidity meter. This liquid-solid separation is known as sedimentation. Observations were hteory on the rest of sedimentatoon four sets and are shown in Figure 3. The relationship between particle concentration and flux is the continuity equation.

That is to say, in our tests, compression settling can have a significant influence when conducting the analysis with Kynch theory. When the interface reached the height of ml, the velocity slowed down dramatically and became increasingly slower.

At any point P, the velocity of downward movement of the interface is determined by the velocity of the particles on this interface.

If we use this number to recalculate the final height, the new result would be: Kyncb results are linear, as described in Kynch theory. The reasons for the formation of clusters are various.

Tests conducted with this apparatus aim at investigating the settling behavior and the internal changes in the suspension during the process of sedimentation.

Since the formulation of the Kynch Sedimentation Theory, researchers have used the theory to develop thickener design methods. Recording was stopped after noticing the deviation, and the results of Test 1. These samples were used to obtain water content and grain size analysis, The first 2 m column was sampled by sucking the sediment through a hose into a vacuum cleaner. After the theort has been fully dispersed, the suspension is decanted into the settling column or cylinder for sedimentation.

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According to what was noted in the introduction to sedimentation in Chapter 2, kyncg interface between the water and suspension develops in hindered settling, and hindered settling occurs when the concentration of the suspension is relatively high. In other words, the first set sdeimentation sampled when the interface reached ml, and the second set was sampled when the interface reached ml.


Characteristic curves that define the ideal batch-thickening behavior were developed to facilitate wedimentation analysis. As such, compression settling compressed the structure of the system, and led to an increase in the solids content, and a decrease in the volume. In chapter 4, results of column settling tests and the column settling tests with sample-collection are presented and analyzed to determine the applicability of Kynch theory for different materials.

This phenomenon is widely observed in the formation of sedimentary rocks and associated ore deposits Chen, A plausible explanation would be the existence of sedimentation in the beaker, and not having stirred enough when the samples were being moved into the settling column, leading to a lower solids content in the settling column. The results are shown in Figure 4.


Course: I كلية الهندسة / الدراسة الصباحية / قسم الهندسة الكيمياوية/ المرحلة الرابعة / ظواهر انتقال

For this sedimenattion, suspensions in the columns were pushed out and collected in beakers every time the interface dropped 50 ml along the settling column from the top. Doctoral dissertation, University of Alberta Baruah, A. Sieve analysis provides a simple but effective method of separating sand materials into different sized fractions.

The design of the special made apparatus for the column settling test with sample collection was done primarily by myself. The specially-made experimental apparatus consists of four components: This experiment consisted of two 50L columns with a height of