*** This version of Confluence is for testing only and contains a copy of content from June 29th 2026. No changes will be preserved. ***
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- make sure G¿ is high enough for entire system (minimum of 20,000)
- make sure G is not so big it is going to break up flocs (flocs will be smallest in this tank though, and small flocs are harder to break)
- perhaps it would be best to use multiple baffle spacings
- The space above a down baffle should be 1.5b under a condition of no headloss
- The first baffle should be an underflow
- try to maintain a design that will allow 3 baffles to be cut from 1 12 ft sheet of polycarbonate
Constraints:
- width of tank (w): 98 cm
- flow rate (Q): 500 gpm
- K: 3
- Height at end of flocculator(h0): 140 cm (this is a bit confusing because of the sloped floor. The height at the end of the tank is actually 155 cm, but at the beginning the tank is only 145 cm. I set the water height to be 140 cm at the end after headloss, this ensures that the water level at the beginning of the tank will be less than 145cm)
- Headroom (hroom): 5 cm
- Ratio between baffle spacing and the height of the horizontal channel (hratio): 1.5
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Tank | Baffle spacing | No. of baffles | Gmax | Gavg | G¿ | baffle length |
|---|---|---|---|---|---|---|
A | 17 cm | 4 | 244.74 s^-1 | 83.52 s^-1 | 2647 | 114.5 cm |
A | 20 cm | 6 5 | 176.8 s^-1 | 65.3 s^-1 | 3652 3044 | 110 cm |
A | 23 22 cm | 8 6 | 133146.7 14 s^-1 | 5256.8 55 s^-1 | 4534 3479 | 105.5 107 cm |
A | 28 cm | 6 5 | 90.2 s^-1 | 39.3 s^-1 | 3076 2563 | 98 cm |
B | 34 cm | 1 | 61.18 s^-1 | 29.319 s^-1 | 465 | |
B | 40 cm | 11? | 53.974 s^-1 | 26.675 s^-1 | 4950 | |
C | 73.35 cm | 1 | 13.855 s^-1 | 9.58 s^-1 | 319 | |
C | 55.25 cm | 3 | 26.72 s^-1 | 15.707 s^-1 | 1130 | |
C | 58.4 cm | 3 | 23.726 s^-1 | 14.363 s^-1 | 1096 | |
D | 60 cm | 1 | 20.953 s^-1 | 13.08 s^-1 | 354 | |
D | 70 cm | 5 | 16.139 s^-1 | 10.746 s^-1 | 1658 | |
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| sum: | 21234 23150 |
Drawing is attached.
Marcala Tank A Drawing
Comments on design
- Since I do not have all the elevation information for the Marcala plant, i was unable to calculate the minimum water level for the flocculators. The lower baffles need to be cut to such at length that even at low flow the water will be able to pass over them. This constraint should be verified on site.