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Vup flow: Velocity of the inlet flow.
As top: Superficial area at the top of the tube.
Qlime feeder: Flow rate employed on the experiment.
DESCRIPTION
This experiment consisted of measuring the upflow velocity with different flow rates and different quantities of lime, while always maintaining a suspended column of lime. This was an initial experiment and hence most of the quantities were taken through approximation.
The experimental set up can be seen in Figure 1. It consists in a vertical column that is fed by the bottom with water; the water flow rate is controlled by an automatic pump. Lime is added at the top of the column before running it. Once it is running, the effluent comes by the top; it is water hyper saturated with lime.
Figure 1: Schematic Diagram of Experimental Set up
The Figure 2 shows the actual apparatus used for the first trial. A glass column connected with a water source regulated by a peristaltic pump.
!Picture7.jpg|align=center!
Figure 2: Experimental Apparatus
RESULTS
The optimum flow rate which could keep the lime suspended without excessive lime coming out (as observed visually) was found to be about 85ml/min. Which corresponds to an up flow velocity of 22.7 cm/min.
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Q (ml/min) | V (cm/min) | Suspension (cm) | Clear water | align=center |
|---|---|---|---|---|
100 | 26.79 | 60 | NO | |
90 | 24.11 | 60 | NO | |
85 | 22.77 | 60 | GOOD | |
80 | 21.43 | 37 | GOOD | |
75 | 20.09 | 35 | GOOD | |
70 | 18.75 | 30 | OK | |
65 | 17.41 | 28 | OK |
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