I want to specify the conical tank I need from the supplier, please any information/heuristics to design a settling tank. I'm treating 10 000 Litres/day of effluent every day from our plant before discharge. However I'm still doing the treatment in a sump (collection sump) but I want to have a conical tank to achieve good settling and give my system enough settling time without disturbances. Thank you
generaly speaking,
estimate your settling velocity according to the characteristics of the solids. you can use Stoke law for this Vs=((g*(P1-P)*D1^2)/18u
Estimate your overflow rate (flow/area)
and some general rules:
- basin floor area of 41 Lpm per m2 of flow.
- 250 to 410 Lpm per m width of weir for outflow.
- submerge inlet weir 15% of basin water depth.
- use 25 cm wide weirs and use rounded edges .
some general characteristics (for circular tanks):
diameter: 12-45 m
height: 3-5 m
slope: 80 mm/m
Hope this helps a bit
Upward flow velocity (flow rate/surface area) in m3/m2/hr. This depends on nature of material - if typical activated sludge this would be 0.8 to 1.2 m/hr.
the following link provides very good reference for settlement tank design:
http://www.aquavarra.ie/Utpbkpdf/chap4.pdf
http://www.aquavarra.ie/Utpbkpdf/chap4.pdf
If you want to work with a simple conical tank with 60° slope the best design guide line will be found in the German ATV 131 rule for activated sludge design Published By DWA.
great contributions i guess and i am keenly following.
see what i just found:
http://nptel.ac.in/courses/105104102/Lecture%206.htm
http://nptel.ac.in/courses/105104102/Lecture%206.htm
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