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Human-powered impellar pump question

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bd103dall

Mechanical
Jun 11, 2007
8
US
I am part of a humanitarian group which is designing an irrigation pump for farmers in Malawi. The pump itself is powered by an individual pedaling a bicycle, where an additional chain is connected from the rear bicycle gears to a gear around a shaft (a few feet behind the pump). The shaft then rotates and in turn powers an impellar pump which pumps the water through a hose (impellar is a propellar designed for water that as it turns pumps water).

Does anyone know a company that designs impellar pumps that work with the low power input of our device (approximately 1/8th a horsepower)? Most pumps that I have found are designed to be used in conjunction with a motor which has a much higher power output and in turn much higher rpms than are possible from our human powered device.

Any help is appreciated, thank you.
 
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My suggestion is to look at the World Bank website - you might find something of use there.
 
bd,
I hope this post is only a joke (of a bad taste). I would however, suggest to buy an irigation pump driven by a small diesel engine.
 
gr2vessels

If you haven't been to that part of the world, you may not know that simply getting the additional chain for the bicycle gear is a major feat.

There is no diesel supply, tools, money or skills to buy, install and maintain a diesel pump. Working in this part of the world at the moment, I can assure you the post is not in gest and the man is looking for a solution to a real problem.

bd103dall

As far as company's that supply those - you might try Northern Industrial or Grainger. Grainger has a nice catalogue on line.

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:
 
bd103dall

I had a quick look at the World Bank site for you but couldn't come up with anything but I'm pretty sure they would have some info' somewhere on their site or at least a lead for you to follow, however, I have located the following link - this could well be what you are looking for and at least it's a good start for you.

 
I realise you asked about impeller design for your application and after thinking about it for awhile it is not really a great problem - you can use a small diameter axial flow or mixed flow impeller of 2 or 3 inch diameter to give you a low flow and head within the power rating of 1 or 2 people -unfortunately I can not give you a manufacturer, although any manufacturer making small diameter borehole (well) pumps could have something suitable and would be well worth contacting.
 
I'd use one of those positive displacement pumps with the rubber star vaned impeller. I'd feel bad wasting so much of the effort of a well intentioned slow pedaler with a centirfugal
 
Positive displace pumps would be better. If you only have 1/8 HP, then at 50% effiency you get a net 1/16 HP with centrifugal pumps. With positive displacement you'll get 95% of the 1/8 HP. A screw pump would be an example.

By the time you find or design a pump that will do what you want, you could buy a 24 volt DC pump off the shelf. Then getting a generator afixed to a bike would be easier.
 
I worked on a similar project years ago. I'll try to contact the guy that I worked with.
These projects are a real engineering challenge. Take a product that is available in the developed world for $100, then re-design it so that it can be made for $20, and then figure out how to do the same job for $5.
These pumps only need to last for a year. You can help a couple of farmers increase their yields enough to have more food and to pay for them.
I recall seeing a treadle pump, this might be a basis for you.

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formerly Trent Tube, now Plymouth Tube
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or edstainless@earthlink.net
 
It would help if you provided the required flow rate and the pressure it must pump against.

 
I think that trying to use a centrifugal (impeller) style pump for something human powered will probably not turn out to be too effective. I would suggest that you look into the old style plunger pumps, they would probably be more adaptable.
 
In the old days, Archimedes had a pump that was turned by hand, animal and etc. You build it up as large as the power source available to turn it - or even better, put 2 or more in parallel to match the available power.

PD pumps, centrifugal pumps, and other modern day design really isn't a good fit with human power. Look back into history. If it was good enough for the Greeks, it should be good enough for most applications today, given the same "category" of technological advancement.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
 
a archimedes screw is a good option for this application. but for a more up to date solution. i have just done a course at the poul due jensen academy and grundfos have a bore hole pump that can be ran from solar power, wind turbine and they have an test rig set up in the academy to run from a bike. this pump is a sp type pump with perminant magnet motor best to look on there wed site under webcaps and it will spec the pump you require.
 
All the high tech. knowledge and solutions are ok - but bear in mind what GregLamberson had to say (below), he is spot on with his comments - the OP wants a cheap, basic minimum maintenance easy to install and operate solution.

I agree with Ashereng as to the benefits of an Archimedes style pump but even this could be cost prohibitive in this situation as they are fairly expensive to manufacture.

"GregLamberson (Petroleum) 23 Oct 07 3:53
gr2vessels

If you haven't been to that part of the world, you may not know that simply getting the additional chain for the bicycle gear is a major feat.

There is no diesel supply, tools, money or skills to buy, install and maintain a diesel pump. Working in this part of the world at the moment, I can assure you the post is not in gest and the man is looking for a solution to a real problem."

But so far we haven't heard anything back from the OP so maybe he has solved (hopefully) the problem
 
the pump i am talking about needs no diesel it runs on very low voltsge and can be powered from a bike but if the option of going to wind poweter or solar power was there i would take it. look up grundfos sq solar wind these pumps are the future
 
There is no argument that the Grudfos pump is a good unit and ideally suited in areas where they can be afforded - however, having been involved in aid projects such as this, the OP is looking for something that can be built locally with minimum labour skills for a few dollars.
 
Gents,
I applaude the strive to provide the best engineering solution to the PO request. I have, however, serious reservations over the whole issue and the morality of it. We are looking in the wrong direction, is not the PO who counts, is the bunch of starved people, who need a "new pair of pants", not another "patch" on the old one. As such, I refuse to give any ideas to the PO, who ultimately harm the people intended for help.
Can anyone in this forum build an unmanned pumping station? Let's put a "buck" where the mouth is and send one to Malawi, present from this forum!
Howzat?
gr2vessels
 
gr2vessels (Mechanical)

I fail to see how ever "primitive" the equipment that is required to do this job can be considered as immoral and what would constitute reservations to actually curtail any useful input.

If sending money makes you feel good - go right ahead and send some, however, what is probably of more use in this situation is advise in how to solve the problem as requested.
For me, I am trying to contact someone I worked with over 20 years ago who could have the solution to the OP request and if this turns out as I hope it will - I will be more than happy to pass this information on.
 
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