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The lime feeder water flow rate required for the experiment was calculated with Mathcad. The analysis was made according with the dosage of lime, the operation time, water velocities, water pH and other variables, most of them were taken from the previous team report.
We assume the The team used a raw water with hardness of 0.02gm/L, and the initial pH is 6.5 based on the previous team spreadsheet report, the lime dosage we want is to increase the pH to 7, while neutralizing the alum added. We caculate the Alkalinity under the orginial pH and pH at 7, so we get the hydrogen demand to rasie to this ANC, the equation is , the lime consumed to neutralize the alum is caculate with the relationship between the equivalent weight of Alum and Lime, the total lime required is the sum of these two parts, the equations are shown below.
The relationship between the ratio of flow rates and pH
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