ANC CONTROL

EXPERIMENT 1. GLASS COLUMN AS FLUIDIZED LIME FEEDER

INTRODUCTION

The first experimental task was to check the feasibility of a fluidized lime bed suspended in a tall column. This is was the simplest model that can could be used as a lime feeder. The aim was to find the optimum upflow velocity that would mix the lime uniformly and keep it suspended without causing a great amount of undissolved lime to go out with the effluent. Upflow velocity can be calculated by dividing the flow rate by the cross sectional area of the column. Since the area is constant, upflow velocity is directly proportional to the flow rate. The equation of up flow velocity is shown below. Image Removed

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$$
V_{upflow} *As_{top}  = Q_{\lim efeeder}
$$

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 The aim of this experiment was to ascertain a range of upflow velocities to maintain a fluidized bed of lime. This was an initial experiment and hence most of the quantities were taken through approximation.

PROCEDURE

The schematic diagram for 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

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Figure 1: Schematic Diagram of Experimental Set up

The apparatus consisted of a vertical column. Water flowed through the column from the bottom. The flow rate was controlled by an automatic peristaltic pump. Lime is was added at from the top of the column before running itoperation. Once it is the experiment was running, the effluent comes by the top; it is water hyper , super saturated with lime, came out from the top.
 
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Figure 12: Schematic Diagram of Experimental Set upApparatus
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Figure 2 above shows the actual apparatus used for the first trial. A The vertical glass column connected with a water source regulated by ( having 2.4cm inner diameter and 61cm length) is connected to the water source and is its flow rate is regulated by means of a peristaltic pump.
 
Figure 2: Experimental Apparatus
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RESULTS

The optimum flow rate which could keep kept the lime bed suspended without excessive lime coming out (as observed visually) was found to be about 85ml/min. Which This flow rate corresponds to an up flow velocity of 22.7 cm/min (3.78 mm/s).

The results are were summarized in Table 1.

The details of the exact quantities of lime and flow rates as well as the results obtained can be found on ANC-Initial Experiment Spreadsheet.