Choosing Horizontal vs. Vertical Flocculation
To create a consistent relation between vertical and horizontal flow, generic notation is used. Tau represents the distance to turn. The flow area, which is the cross sectional area that is perpendicular to the flow of the water, is Rho*S.
Generic |
Vertical |
Horizontal |
Ρ |
W |
H |
S |
S |
S |
J |
H |
W |
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. The following steps are taken to determine which one to use.
Determine the height of the water in the sedimentation tank and set it to the height of the water at the end of the flocculation tank.
$$
= HW_
$$
Set the T/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).
$$
P{i_{TSMin}} = 3
$$
$$
{S_{FlocBaffleMin}} = 45cm
$$
$$
{T_{Min}} = P{i_{TSMin}}\cdot{S_{FlocBaffleMin}}
$$
Calculate the minimum flow rate for using the following equation:
$$
{Q_{MinHorizontal}} = {P_{FlocChannel}}\cdot{\rm{ }}{S_{FlocBaffleMin}}\cdot{\left( {{T_{Min
\cdot2E{D_{Flo{c_0}}}} \over {Kp\cdot{\alpha _\varepsilon }}}} \right)^1 \over 3
}
$$