Abstract
As the flow rate through an AguaClara plant is increased, the plants design will need to be altered. More specifically, to achieve the required amount of energy dissipation for adequate alum mixing, we would need to redesign the entire entrance tank.
Gracias Design
The town of Gracias will be the largest design completed by the AguaClara team. The Gracias Plant will be the first AguaClara plant to have a flocculator built based on the energy dissipation theory of floc formation. Gracias is also the first plant to have sedimentation tanks with multiple sedimentation bays in a single sedimentation tank. In past designs the sedimentation tank was designed to have a set width, the same as one sheet of lamella. Three designs have been compiled having widths 2, 3, and 4 times as wide as one lamella sheet. Major design changes were also made to the entrance tank design. Because the entrance tank will be used to help removed dissolved oxygen from the inlet water before treatment, it was made significantly larger. The entrance tank was designed to be an additional channel, the same size as the floc channels to be placed prior to the first floc channel. A ferrous cement plate will be added to the channel as need to decrease cross sectional area until the desired upflow velocity is acheieved in the entrance tank. This velocity is to be determined by the floating floc team.
Design Assumptions
The majority of the assumptions made for this design were the same as in past designs, the only different assumptions made were in regard to the theory change made in the floc tank.
Design Specifics
The three designs compiled for Gracias can be seen below.
Design 1 has the shortest and widest sedimentation tanks. This design has 4 bays of inlet manifolds in the bottom of each tank. Design 2 is middle range design the sedimentation tanks have 3 bays and are a little longer. Design 3 has the longest and narrowest sedimentation tanks, having 2 bays of inlet manifolds. The longer sedimentation tank designs also have fewer flocculator channels.
Unknown macro: {excel}
Plant Drawings
The AutoCAD code is still under review and thus accurate plant drawings will be posted as soon as they are available.