Water Intake Units

Could you give more details. How much water? Where are the storage tanks? What is the elevation from pump to storage tanks? Will you have your pumps low enough to use on shore pumps or will you need submersables? Have you got a tight budjet or a blank cheque?

I pump about 200-250 cubes an hour at my work with an expansion to take about 600 cubes ashore soon. Is this the scale you are looking at? Bigger or smaller?

I may be able to give my opinion but not till you tell me more.

The capacity must 1100 cubes an hour. Water height above the intake unit is 9 m, height of the intake unit must be 1,5~2 m, distance from the storage tank is 350 m in horizontal plane. Pipes are 1600mm HDPE. Shore pumps of course seems to be more convenient than submersable ones because of the high maintenance costs of sbmrsbles. But I will decide it according to my preliminary design.

But for my preliminary design I must estimate the local head losses at the entrance of intake unit and at the screening sections. According to them I will decide which alternative is cost effective. I can increase the dredging; decrease the elevation of the pipeline system and decrease the pumping need or vice versa. So that technical details of the intake head is very important for me. This is the reason of why i did not give any other details. If you can give the design specs and hydraulic properties of the screening section and entrance i will be very glad.

Best Regards

Just run a quick calculation and if I understand you right you will have 1600mm intake pipes. You will be pumping 1100cubes an hour. I just guessed that the intake would be 200m. The friction losses with this system are very low. I you have a straight pipe then the losses are pretty much not worth worrying about. This is worked out with an open ended pipe. Don't know what kind of screening you will use so you can work this out and get a NPSHa for your intake. This will be mainly based on the height of the pumps above water level. (Low tide!) It sounds as if you shouldn't have a problem getting a suitable pumping system.

Your situation is on a bigger scale than I'm using at the moment but it doesn't sound like you need anything that is not easily achieved.

For the calculations I use Darcy-Weisbach and Hazen-Williams equations to estimate the head losses. Can't remember off the top of my head how I did it now but I wrote a simple programme on excel using these equations. Makes life alot easier cos you just input your variables and it does the calculation for you. If you are just using sea water then you can make it even simpler.

Hope this helps. If I have misunderstood then please write again and I'll see if I can help.

No real information in your question.

So any answer would not be accurate.

I gather you are an Engineer in order to be working on a project like this, so act like one and give specific information about your needs.

Your are just wasting your and everyone else's time with such childish questions.

After all there cannot be more than 100,000 R/O plants in the world.

I have been involved in the design and operation of a system similar to the one you describe.

The most difficult part of the project was receiving the necessary permits from the government.

Consideration must be given to marine life and tidal and wave action at your particular location. In our application surface water could potentially be contaminated by fuel. Water near the sea floor contained much suspended sand.

Our summer solution was to suspend a screen enclosure containing a submersible pump 2' beneath a float held in place by piling.

In winter the float is removed from the water due to storms, the pump is then placed in another enclosure that is affixed to a piling. In this configuration we can only pump during high tides but our water usage is minimal during the winter.