Flow distribution from ports exiting a manifold is controlled by the change in piezometric head inside the manifold and the change in piezometric head as the water exits through a port. The reason that the flow from each port is not identical is because of changes in piezometric head in the manifold. These changes are caused by major losses due to shear on the manifold walls and due to pressure recovery as the velocity in the manifold decreases

The flocculator is more complex to design than the CDC, as it has more details and parameters and the equations for those details and parameters are very interdependent. Therefore, there are many ways to design an AguaClara flocculator, and many different sets of critical design criteria to begin with. Below are design approaches for several of the different potential flocculator geometries.

The challenge of constant head in chemical dosing for water treatment plants is not just providing one continuous flow of chemicals; it is also varying that flow of chemicals as the flow rate through the plant changes, so that the concentration of chemicals in the raw water stays the same.

We can use the proportionality Q∝h‾√Q∝hQ \propto \sqrt{h}, which applies to both minor losses and orifices to form a relationship between water level in the tank hhh and time ttt. This proportionality comes from rearranging the minor loss Equation h=KQ22gA2h=KQ22gA2h = K \frac{Q^2}{2 g A^2} for QQQ instead of hhh. A table of proportionality between QQQ and hhh can be found in Table 3

The terminal velocities of particles in surface waters range over many orders of magnitude especially if you consider that mountain streams can carry large rocks. But removing rocks from water is easily accomplished, gravity will take care of it for us. Gravity is such a great force for separation of particles from water that we would like to use it to remove small particles too. Unfortunately, gravity becomes rather ineffective at separating pathogens and small inorganic particles such as clay

The first reason for the lack of safe water has been the poor track record of water treatment infrastructure. The frequent failures and high operating costs of municipal scale water treatment systems have led many decision makers to conclude water treatment infrastructure isn’t a worthwhile investment. Politicians who invest political capital to bring water treatment to their community often find that after the initial ribbon cutting there is little political benefit because the system doesn’t deliver the benefits to the community that they had promised.

The trash rack is specifically designed to remove low density debris that could easily be carried through the plant and clog any small flow passages. In an AguaClara plant, there are critical flow passages in the clarifier inlet manifold diffusers and in the flow injection system in the stacked rapid sand filters. The inlet manifold diffusers have flared nozzles which currently have a minimum dimension of about 4 mm. The opening dimension for the trash rack must therefore be less than the opening size of the inlet manifold nozzles.