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To evaluate the new design, the team studied the feasibility to implement it in Cuatro Communidades plant. From figure 3, it can be seen that a flow ratio of 5*10^-3 between lime feeder flow over raw water could result a pH of 6.75, notice that the lime feeder effluent flow has a pH of 12.6 under the scenario behind this model( see Flow rate required in Lime-feeder), it is also known the plant flow of Cuatro Communidades is at 100 gpm. Based on these information, the required lime per day could be calculated, which is 2.5 kg/day. Under the assumption that the concentration in lime stocking tank is 5 gm/Liter, the required tank volume is then calculated to be 0.5 cubic meter. Because the required lime in stock tank is caculated on a daily basis, so the flow rate through stock tank into entrance tank could simply use the volume divided by 24 hours, which is 0.093 gpm. Figure 1 and 2 below are the demonstration of this possible design in Cuatro Communidades.
There are three major challanges with this new design, the first one is to get enough energy from influent water to create the turbin in stock tank, the second one is to avoid clogging in orifice, the last one is to maintain the flow rate through orifice constant.


Fig 1. Autocad drawing of new design with dimension description


Fig2. Propeller and Orifice position


Fig 3. ANC and pH as a funtion of flow ratio between lime feeder over raw water