New Design Proposal

*New Design Proposal*

*Concept*

What the current design aims on is to create a lime feeder which could provide an effluent pH at around 12 for 24 hours under a certain flow rate, but based on the required lime demand for neutralizing the alum, the current design is hard to scale up in terms of the constraint of its flow rate. The new idea is to construct a lime stocking tank besides entrance tank (see figure 1), operator could pour the lime and water into the tank based on the mass balance, and disturb the solution for a while in order to get a better mixing. 

In addition, in order to create a good turbine in the tank to prevent lime particle settling down, and the fact that is not realistic for operator to do it manually, the team's proposal is to set a couple of propeller as shown in figure 2, the idea is to utilize the energy from influent flow to push the propeller in lime stocking tank. The way to dose the lime into the entrance tank is also shown in figure 2, by using an appropriate orifice it is expected to provide a relatively constant flow for 24 hours.     

*Case study*

To evaluate the new design, the team studied the feasibility to implement it in Cuatro Communidades plant, 
   
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