Intake Design
Intake Design
(OP)
I am looking for some input on how to size a water intake.
It is for a smaller distribution system. Phase 1 max day is 882m3/day and ultimate is 3628.8m3/day. The intake has to be HDPE, and I think it will be in the 300mm diameter range.
Also, are there manufacturers in Ontario that supply pre-cast pipe anchors for sinking?
Thanks
Joe
It is for a smaller distribution system. Phase 1 max day is 882m3/day and ultimate is 3628.8m3/day. The intake has to be HDPE, and I think it will be in the 300mm diameter range.
Also, are there manufacturers in Ontario that supply pre-cast pipe anchors for sinking?
Thanks
Joe





RE: Intake Design
A common method to install intakes is to install the intake pipe with a directional drill out to the intake location. Then you come up to the surface and install a well screen intake.
A riverbank filtration intake may also be an attractive option.
http://publications.usace.army.mil/publications/en...
The water flow velocity objective in the intake pipe should be to achieve an approximate velocity minimum of 0.9 m/s to a maximum of 1.2 m/s (3-4 ft/sec). The minimum flow is to prevent the deposition of solids.
https://www.google.com/webhp?hl=en&tab=ww#hl=e...
RE: Intake Design
RE: Intake Design
http://www.armtec.com/en-ca/products-and-services....
RE: Intake Design
The intake is into a lake, about 250m. We will require the first 100m or so to be dredged or directional drilled to obtain sufficient cover over the intake since it is shallow before the water drops off.
If you directional drill, how can you ensure the pipe wont float in the future? I expect you cannot install concrete pipe anchors on the portion of pipe that is directionally drilled?
RE: Intake Design
ACB mattress is often used.
RE: Intake Design
RE: Intake Design
although 'just' floating when full of water
RE: Intake Design
dont belive everything you see on wikipedia
RE: Intake Design
Q: Will HDPE pipe float in water?
A: Yes, HDPE pipe has a specific gravity of about 0.95, so it will float. For underwater anchored pipeline installation, it is important to specify the proper weights and spacing of the weights. Screw-anchors are a practical alternative. Whenever possible, an underwater pipeline should be installed in a trench with protective crushed rock cover.
http://iusco.com/FAQs
RE: Intake Design
http://www.dynalabcorp.com/technical_info_hd_polye...
http://www.maropolymeronline.com/Properties/HDPE%2...
All list HDPE around 0.95, including the last one, which also references ASTM D792
TTFN

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RE: Intake Design
guess what, it floated
RE: Intake Design
The water intake in a lake shall be type floating supported by a floating pontoon with a screen basket for the intake. This is to have the intake always under the surface level but far from the lake bottom where sediments will clog the pipe.
Drilling is ok if having a gravity pipe to the storage/treatment tank.But having a pump you do not need to drill. In case the water drops down bellow the dam level and you discharge is still bellow the water level, a vaccum pump is good idea: it works a siphon.
RE: Intake Design
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/
RE: Intake Design
RE: Intake Design
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/
RE: Intake Design
At the shoreline, I only have about 3 feet of depth from the water surface to bedrock. Has anyone ever installed a shallow raw water intake. My fear is it getting hit by boat traffic and of course freezing.
Any thoughts?
RE: Intake Design
When in doubt, call the blasters. And it is fun to watch. You can have them blast you a trench till you get to a grade you like.
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Intake Design
What about a riverbank filtration system?
RE: Intake Design
From a pipe protection point of view definetly the pipe should be trenched into the bedrock
I think you need more senior help.
RE: Intake Design
1. You need to determine what the historical high water level (HWL) and the historical low water level (LWL) is where your intake is located. There are government publications that can tell you that. That gives you your design envelope.
2. You then figure out the head loss in the intake piping to determine what the HGL is in the low lift wetwell at HWL and LWL conditions. At LWL you will need to ensure the pump is flooded with adequate submergence to prevent vortexing. This will set depth of your wet well.
3. Always check that on power failure, the oscillating surging water in the wetwill will be contained by the walls of the wetwell or there is an overflow pipe set at the proper elevation.
4. For a small system like yours, it may very well be that there is not much head loss in the HGL and the wetwell may not be required to be very deep. Therefore protecting the intake pipe close to the shoreline becomes the governing factor and that in turn forces the wetwell to be deeper in order to have the pipe trenched into the bedrock.
RE: Intake Design
RE: Intake Design
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/