Pilot Plant

Sedimentation Tank Maintenance

Tank Drainage Manifold

A tank drain system was designed to drain in 30 minutes (Q ~drain~ = 20 L/min. The design is similar to the effluent launder except this manifold is located at the bottom of the tank.

By the same method as was used for the tank effluent manifold the manifold diameter was determined to be 1.905cm (0.75") and the orifice diameter is 0.3572cm (9/64").
* The available head for the sludge ports is the total water depth (84.455cm or 33.25") minus the head loss in the manifold and minus the velocity head at the end of the manifold.
* Kminor was assumed to be 0 in the manifold and 1.0 for the pipe entrances and exits.
* The constant for the determining orifice diameter was found to be 0.63
*Qratio = 0.90
* 15 orifices were assumed to provide a similar layout to the effluent manifold.
The hole size in the drain manifold was increased to 1/4" to allow for faster tank drainage.

Troubleshooting

This section includes some minor issues the team (especially beginning team members) has come across.

Starting the alum pump

If the alum pump has been switched on, but no alum is flowing (i.e., the corresponding box in the process controller reads "0" [mg/L]):

• Go to configuration in the process controller
• In the top left corner there are methods, files, etc. buttons, and an icon that looks like an open folder. Click on the folder.
• Open the Fall 2008 folder (or a newer folder).
• Open Sept 9 2008 (or any configuration that may have been saved later).