Restricted Flow of Hypochlorinators
Introduction
In Honduras, a Calcium Hypochlorite solution is used in the Agua Clara flow controllers to disinfect the drinking water. Unfortunately, due to the precipitation of calcium carbonate, the system clogs which leads to large decrease in the flow rate (and thus dosing) of the chlorine solution. These experiments have been developed in order to determine the point of restricted flow and to devise a method to diminish the clogging.
Experimental Model
A model very similar to the model used during the Summer 2008 Demo Plant team was used. A slightly more analytical approach was taken in developing this semesters model. A pressure sensor was inserted by means of a t-joint at the bottom of the constant head tank. The sensor would collect information on what the height of solution in the constant head tank was at any given time. By using the Easy Data to analyze the data, we would have a more accurate idea of when clogging occurred. In addition, a pH meter was added to the 5 gallon stock tank. This was done in order to aide future studies on the effects of alkalinity on calcium bicarbonate precipitation. The final change was that the flow rate was determined by changing the angle of opening within the valve at the exit of the constant head tank. Shown below is the experimental model from the summer with the changes written on the image.
The values used to run the experiment were as follows. We chose to use 9.336 mg/L of calcium hypochlorite for this lab experiment because it is half way between 12201 mg/L and 6470 mg/L, which were the average concentrations used at Tamara and 4 Communidades (The two towns with the most severe precipitation problems). The flowrate
