Paddlepump

[zhkent]

Hi PDs
Looking for input on building a paddle wheel pump to be used as a pond circulator.
Would prefer to keep the power requirement low enough to use 2 12v's in series for 24v, and solar to charge the batteries.
Plan a;
Paddle wheel around 1.5 meter tall, 50 cm wide, paddles fairly close.
A trough the same radius as the outside of the paddle.  This would keep water from going under or around the paddles.  The trough would start at dead center under the wheel, then go about 1/8 the way around the loaded side to where it ends, dumping the water out, say 20 cm above water level.
Figuring the paddles run 15 cm deep:
circumference * width * depth= volume per revolution
4 * .50 * .15 = .3 m cube = 300 liter pumped each revolution?
Does this look possible and/or correct  and if so any ideas on the power required to turn it?  RPM's are a variable, but keeping hp requirements down are key so would probably look at 1 - 10 rpm?
Thanks for your time looking at this,
feedback appreciated!

Kent

[chipmonk]

Hi there. I can't think of any reason while it won't work. You will have to watch the clearance between the blades and the trough, as at low speeds the water will try to flow back. The slower the RPM the worse the problem will get. Have you looked at old historical methods of water pumping some of them used a slow wheel with buckets to lift water.
An interesting idea though. Good Luck with the project.
Chris M

[steamboatmodel]

When I was in the Machining trade, we used a device called a skimmer to remove tramp oil from the coolant. I was a plastic disk that revolved with the lower third in the coolant, at the mid point there were two wiper blades rubbing the disk with there lower ends in a tray that collected the oil. You might try something like that.
Regards,
Gerald.

[Red_Hamish]

A suggestion using the two ideas above, good ideas chaps, would be to use the close tolerance of the wheel into the trough with a flexible wiper blade along the wearing edges to maximise retention but minimise friction. this would in theory allow the need for buckets to be taken out of the equation. Admittedly there would be leakage but as the purpose is for keeping water moving  it shoudl work well enough.

cheers

Jim

[mjt60a]

....Have you looked at old historical methods of water pumping....buckets to lift water....

what, like this - http://www.romarchgroup.humanities.uwa.edu.au/__data/page/94340/RBTour2004_013.jpg
That device takes a lot of (human) power to make it work but is very large and lifts the water a long way up, with smaller buckets lifting water 20cm it might be workable