Building a Minto Wheel and Archimedean Screw

Please explain how it is able to lift water 80 feet? I am quite interested in this...

Check this link. This site will explain the concepts much better than I can within the forum.

http://lurkertech.com/water/pump/tailer/

Okay, thanks.

The spiral wheel will work but the eventual economic worth might be too small for the investment.

If One can find (In the arid environment of SA) a stream running for at least 3 months in a year at the required velocity the 6' spiral wheel will deliver approx 0.2 l/s which may be enough for irrigating just about 100 square meter of land. (flood irrigation).

In real (African) life one will only expect about 20 bags of potatoes per year.

The school project will deliver at a much lower head.

That's fine; my proposed pilot plant is to be carried out in a school, and it's intended for educational and experimental purposes. If it proves feasible, we'll try to build a much larger one for to see just how well it will function. For now, what I have in mind to to develop a non-electrical automated pump that can be fabricated from recycled material, hence the coupling to a Minto wheel. If it works out, we'll teach the process to low income families so as to help create jobs and a source of income for them.

One other thing: only 5% of the water used for irrigation is actually taken up by the plants. The remaining 95% is lost through evapotranspiration or into the ground. What I'm thinking of is to create a garden with a cascading irrigation system, so that water drained out from 1 tier will be used to irrigate the next. My prelimary experiments have sohwn that the system holds promise.

GA for your original answer by the way, Sparkchaser.

A normal flood irrigation system should work at 50% but with proper preparation it can reach 65%.

Such projects are good but when it is promoted as a solution to food shortages or poverty alleviation I strongly disagree. The same water could be used by a commercial irrigation farmer to produce 20 to 200 times the food because he starts off with a irrigation system with 95% or better water distribution efficiency and more if scheduling is done.

Hi, Hendrik,

" ... should work at 50% but with proper preparation it can reach 65% ... "

Not being contentious, but what do those %ages refer to? % of what?

John

An ideal irrigation system (100%) will be capable of distributing the water evenly to all plants without leaving puddle at the top that will evaporate or over irrigate and have water infiltrate deeper than where the plant can reach it.

Unfortunately no system is perfect. A good system like a center pivot however can reach 95%. That means that extra water (100/95 x req) must be applied to achieve the desired effect.

Most flood irrigation systems actually require double the water ( that is 50% efficient). The extra water will evaporate from the surface or infiltrate too deep.

One can however improve the efficiency by adjusting flow rates and irrigation bed dimensions and slopes etc.

Maybe I am too critical to these wonderful irrigation proposals (I view it in the same light as over unity machines). A system where only 5% of the water can be used by a plant is a total waste and that idea should be abandoned.

In SA there are ideas to subsidize such irrigation projects. It would actually be more economical to supply food instead.

Can you advice on what would be a better way to do it then? What I'm attempting to do is to plant the vegetables vertically so that I can get more output for a smaller footprint. Also, I intend to use treated and recycled graywater for this purpose, with the runoff from the final teir eventually flowing into a pond where fish are being reared for food. The waste output from the fish will then be sent to a constructed wetland that will also treat the graywater. It is this water that I intend to use for irrigating the crops. The original source of water will be mostly harvested rainwater, so neglecting evapotranspiration, I'm attempting to create as much of a closed-loop system as possible.

Yes, the spiral pump the team built would only pump to about 12' of head.

Back in the seventies, I read about the Mintos wheel and thought what a great idea it was. The one I read about was made up of barrels, cross connected with a pipe or tube to allow fluid to flow between them. I suppose there may have been six or eight barrels, so three or four cross connected pairs to form a wheel. The lower end of the wheel would become partially immersed in water trough (may solar heated) as it rotated. One barrel of each pair would be filled with freon at atmospheric pressure; so a liquid. The way I understood its workings was, the water being warmer than the surrounding air, would force the freon to the opposite end of the paired barrel, putting the weight at the top and gravity pulling down that end. This would continue with the other pairs as the wheel rotated. The torque was supposed to be great though I'm sure the longer the arms, the greater the torque. The direction could be determined by ensuring the first empty barrel was to the left (or right) of plumb in the direction you wanted it to turn. I thought this would be a great way to drive a DC generator to power batteries and through them a power inverter. But I am infuriatingly lazy and now freon is (a) not to be had, or (2) is expensive and causes cancer. So wise folks, who will build the Mintos wheel and tell us all about it?

Does anybody here know the equations or formulae needed to design and build a Minto wheel?

Have a look at the Minto Wheel Yahoo group -- a few of the more analytically inclined members have posted their analyses there:

http://tech.groups.yahoo.com/group/MintoWheel/

Thanks guys.

One HP will raise so many pounds on foot in a minute.

If you know the amount of pounds of liquid lifted and how many feet it was lifted you would have a good start.

33,000 pounds a min one foot

or 3300 pounds to 10 feet in one minute.

or 330 pounds to 100 feet.

I hopes that helps joedupont at juno dot com