Choosing Horizontal vs. Vertical Flocculation

To create a consistent relation between vertical and horizontal flow, generic notation is used. J represents the distance to turn. The flow area, which is the cross sectional area that is perpendicular to the flow of the water, is P*S.

The first step in the flocculator design is to choose whether to use horizontal or vertical flocculation. This is largely dependent on the flow rate and depth. The following steps are taken to determine which one to use.

Determine the height of water at the end of the flocculation tank. The user has three options: Minimum depth for horizontal flow, same as depth in sedimentation tank, or a user specified value.

Set the J/S value equal to 3 (this is the optimal value and will be used for horizontal flocculation). Set S to it's minimum value of 45 cm (minimum for a human to walk through for maintenance).

Calculate the minimum flow rate for using the following equation:

There is a more detailed flow chart outlining the decision steps for each scenario.