Water pumping windmill
By Dan 04617, Section Water Posted on Sat Jan 14, 2006 at 05:22:19 PM MST
Watering a large garden from a pond.

I've got about a two acre market garden.  It's on the opposite side of the road from the house and barn where the electric power is.  I've got a pond at the bottom end of the garden that I irrigate out of with a gas powered 2" pump.  I've been through a couple pump engines, and I don't like handling gasoline so near the water.  I'd rather not go through the trouble and expense of building a generator and getting an electric pump that would work with the variable voltage.  I can scavenge a lot of things locally, including black plastic water pipe.  I'd rather run that than wire.  What I want is a mechanical water pumping windmill.  I'd pump either directly into improvised drip lines in the garden or into cisterns made from pallets, old cable, worn out carpet, and blue tarpaulin. My plan so far is to build a moderately large blade set (~15') and put it on a relatively short tower (also about 15').  It would be pointed south-southwest, toward reliable summer sea breezes and away from storm winds.  (If there is danger of high winds, the mill could have a break set and spoiler covers put over the blades. (?) )  It would not pivot with the wind direction.  The blades would have a sprocket between them and the hub, which would chain drive a larger sprocket for speed reduction.  (Possibly there should be another chain and sprocket set to further reduce speed and increase torque.) The large sprocket would have a stud where a rod end bearing would attach, and that rod would drive a piston or diaphragm pump, which would run whenever the wind blew.  The mill would be about 300' horizontally and 20' vertically from the water. Airfoil: A NACA 4415 or a Clark Y looks easy enough to carve.  I keep my eye open though.  In the book Gaviotas, they use an airfoil for an airplane flap from a NASA catalog.  It has a concave lower surface, and I'm trying to figure out why that would be selected.  I'm also trying to decide what angle the foil should be at for any particular percentage of the radius.  I suppose this depends on tip speed to wind speed ratio.  Since I want modern airfoil efficiency but also want good starting torque, I have to consider some tradeoffs here.  I may be better with a larger chord size, and designed for a lower tip speed, resulting in a more angled blade set. Regarding built up blades rather than carved ones:  I could carve a leading edge and cut some ribs, glue them to the spar, and cover with thin marine plywood.  There's also a middle ground I've been thinking about, where several boards are laminated into a rough blank, then carved.  This would make it possible to carve relatively large blades without starting out with 4x12's.  In the blade carving PDF I downloaded from somewhere around here, the blades taper quite a bit.  I'm trying to decide why this is important, other than making the effective spar thicker where the sheer and bending moments are highest. Number of blades: I had started by thinking three, but I'm not sure.  Four would be easy enough to build with spars jointed as they cross each other, and might work better with a four bolt hub. The tower will be made of scavenged pipe, braced by two struts to leeward.  I'll have to find a way to weight the bottoms of the tower and struts, but I don't see that as a huge problem.  I'd like to be able to take the whole thing down in the winter and store it in the barn.  I'd probably also need to go up to hub height to grease things once a week or so. All right then.  Just how cracked am I? Dan

Water pumping windmill | 24 comments (24 topical)

Re: Water pumping windmill (3.00 / 0) (#1) by TomW on Sat Jan 14, 2006 at 11:13:27 AM MST

Dan; You might want to look at something called a "bojon" I think its called for ideas. Basically an air pump that raises water with bubbles. Could be pretty simple just an old gas motor used as an air pump on a wind machine. I don't think they take much air pressure and seem quite simple. Inject air at the bottom of a tube deep in the pond and rising air lifts water. gravity feed from there. Then there is the old style "sucker rod" pumps you see in farm country. An Archimedes screw might work too but coupling it to a wind machine might be problematic. Cheers. TomW The Truth is the Truth, even if no one believes it; and a lie is a lie even if everyone believes it

Re: Water pumping windmill (3.00 / 0) (#9) by finnsawyer on Sun Jan 15, 2006 at 09:01:44 AM MST

That 'Archimedes Screw' would make a real point of interest for visitors to the farm.  Coupling it to the wind mill shouldn't be too hard.  Just use a screw drive, which has a 90 degree change of direction built in plus a large drop in speed.  Add one or more U-joints and you've got the Archimedes Screw at the desired angle to the water. GeoM [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#10) by TomW on Sun Jan 15, 2006 at 09:23:15 AM MST

GeoM; Good point! Cheers. TomW The Truth is the Truth, even if no one believes it; and a lie is a lie even if everyone believes it [ Parent ]

old stuff (3.00 / 0) (#2) by wdyasq on Sat Jan 14, 2006 at 12:07:44 PM MST

Personally, I would be looking at one of the old waterpumper style mills.  You are already planning on storing the water before use.  With "only" 20' of lift and a relatively short 300' run it won't take too much of a mill to pump a great amount of water. But, if you are determined to reinvent things, try new methods of building blades and venture into unknown areas with little or no advice and support, it is your choice. I left my mind reading glsses in my other shirt.  I do not know what application the "Gaviotas" airfoil was used.  But, one of the theories of very efficient airplanes is to lower drag by using an efficient, low drag airfiol inverted on the elevator. Ron Adventure is just bad planning." -- Roald Amundsen

Re: old stuff (3.00 / 0) (#14) by redeyecow on Sun Jan 15, 2006 at 08:57:07 PM MST

Been using an old farm pumper for years and it's a marvel by by today's throw-away standards. It's basically a great big pump jack about as heavy as an engine block with a crankcase for changing oil. It has 4 inch roller bearings in each end of the main shaft. Built to run forever if maintained. The rotor is an 8 ft. multi-blade which develops scary tork if your trying to hold it in a bit of a breeze. That's up the 38 ft tower. With no load on the pump rod (wood), it winds up to about 1 rev/sec or 60rpm. Not too speedy but loads of tork.       The windmill is offset from the well pump, so I have a walking beam with a heavy weight under the windmill. The windmill lifts the weight. When the weight drops it lifts the pump rod at the other end of the beam. I am changing this to a chain and pully system so the windmill doesn't have to lift the weight from a dead stop. ie. there won't be a weight so no "cogging effect".      Seems like any pumpjack could be modified to work on a tower with a big rotor directly attached. The pumpjacks are geared way down so you'd have loads of power to run any kind of reciprocating pump.  I think these metal multi-blades tend to wash the wind away from the blades at higher rpm. They're designed to pump water in almost no wind. They actually tend to pump too much water in continuous winds.       Good luck, keith     Barn's burnt down--now--I can see the moon. [ Parent ]

Re: old stuff (3.00 / 0) (#15) by ghurd on Mon Jan 16, 2006 at 06:19:23 AM MST

I know of an smaller(5~6' dia) old farm mill, hooked to a hand pump, in a poor spot for good wind.  Old parts cobbled together. Works great. G- Ghurd.info [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#3) by kell on Sat Jan 14, 2006 at 01:48:22 PM MST

Pumper mills like you used to see on farms all over the midwest didn't have airfoils, just a whole bunch of flat boards.  Surely you know the kind I'm talking about.  Slow moving.  Chunk chunk tickety tick.  Why make a high-speed, high power mill and gear it down?

Re: Water pumping windmill (3.00 / 0) (#4) by willib on Sat Jan 14, 2006 at 04:04:55 PM MST

i was going to suggest an automobile differential for the 90 degree hawt to vawt convertion , but no. how about using a vawt to start with.. If you want to go high tech, use a half of a 55gal drum as a template and make your Vawt out of fiberglass.. you can stack them on top of each other for more power. and they have plenty of torque to begin with.. Carpe Ventum (seize the wind) One needs faith in the future

Re: Water pumping windmill (3.00 / 0) (#5) by Dan 04617 on Sat Jan 14, 2006 at 07:25:07 PM MST

Tom, thanks for your idea.  I've seen ads for compressor windmills, and maybe I need to think in terms of finding a good small compressor with a bad motor and putting it to work. I'm not interested in the old clunker farm mills because they are very expensive, not known for being very efficient, and you really don't know what you're going to get.  And I want people to see the blades spinning for marketing reasons.  I know just enough about S-rotors not to want one of them either.  I've been looking for both torque and efficiency, but if a compressor design can be made up cheaply then I may go for that.   Anyone know what the underwater arrangement looks like in the compressor type pumps? Dan

Re: Water pumping windmill (3.00 / 0) (#6) by elvin1949 on Sat Jan 14, 2006 at 09:01:16 PM MST

mine is a 2 in. casing with 1/2 in. air line inside. NO OTHER PARTS but the compressor and storage tank. later elvin [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#7) by Flux on Sun Jan 15, 2006 at 02:08:55 AM MST

For air lift you need a certain ratio of pipe immersed to the lift, not sure off hand but I think you need twice as much submerged as the lift, that could be a problem as I doubt that a pond would be deep enough. Do a google on air lift pump, there is lots of information. Flux [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#11) by Dan 04617 on Sun Jan 15, 2006 at 09:45:32 AM MST

Okay, I googled.  It looks like if you want to pump water up X', you need the pipe submerged X+2'.  I need 25' of lift, more or less, and the pond is 3' deep.  So that's not going to work. Here's a thought:  I have a couple piston pumps from the dump, and occasionally see more.  Adapting a compressor sounds like it might be easier than gearing down an efficient set of blades, and may also make a pivoting, furling mill easier to engineer.  Maybe I should be thinking about pneumatic motors to drive the piston pump. Back to google... Dan [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#12) by willib on Sun Jan 15, 2006 at 10:23:12 AM MST

thats getting a bit complicated.. Personally i dont think that a piston pump will work with water.dont you need some sort of a rotating impeller to pump water? also , you said your mill will be located 300' horizontally and 20' vertically from the pond ? i would suggest, not pumping 20' all at once but pumping the water a little at a time . http://www.otherpower.com/images/scimages/2965/water.GIF this will make you pumping needs considerably less. Carpe Ventum (seize the wind) One needs faith in the future [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#13) by Dan 04617 on Sun Jan 15, 2006 at 10:58:23 AM MST

The piston pumps I have on hand are designed to pump water.  They are generally belt driven.  The original electric motor would have a 1 1/2" v-belt pulley, and the pump has a 12" pulley.  There's an enclosed gearbox with a crank shaft and lube.  The piston is double acting, with about a 3" throw and maybe a 1 1/2" or 2" diameter.   Dan [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#21) by Don Cackleberrycreations on Thu Jan 26, 2006 at 11:09:36 AM MST

Old hand pumps for wells are a version of a piston pump they are also pretty simple to make requiring an oring to seal the "piston" and a pair of flapper valves . Ive seen them made from 1' pvc to 8" steel pipe a three inch would work fine and a 6 ft farm style mill would turn it depending on the stroke you chose  for higher lift you can use a multi stage . a single pipe with a series of pistons and valves such pumps are used in some deep wells. a rotary pump is not very efficient a piston or diaphram pump is a better bet.   The old pump jack mills were made to last forever  they were more worried about them being functional then efficient. poor unedekated redneck with attitude [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#8) by hvirtane on Sun Jan 15, 2006 at 04:40:04 AM MST

I would like to suggest triangular sail wing blades for a hawt, if you don't like savonius vertical axis wind machines. - Hannu

Re: Water pumping windmill (3.00 / 0) (#16) by scottsAI on Mon Jan 16, 2006 at 11:55:16 AM MST

Dan 04617, The more blades the slower the speed, benefit is more torque. Second benefit, works with slower wind speeds. When dealing with wind turbines why are you so worried about efficiency? I could understand, cost, time to build... efficiency.... make it bigger!! How much water do you need to pump per day? 20' lift is not much. That seems to be the real question, and the problem that needs to be solved. How is another question. Other power has a solar panel running a pump, fast answer with a rather low price. What is your time worth? Solar should take little of your time to build it up. No barn on the other side of the road? Nice to have some electric lighting? Maybe going electric will be the ultimate answer. Just some thoughts. Have fun with what ever you decide to build! Scott.

Re: Water pumping windmill (3.00 / 0) (#17) by Dan 04617 on Tue Jan 17, 2006 at 05:50:24 AM MST

I need to pump an average of 4000 gallons a day to keep an acre of garden properly watered.  I'm worried about efficiency because that's a lot of water and because I may eventually want to use this for other air powered tools.  I like the idea of storing compressed air a lot more than I like lead-acid batteries, and I know where there's an old propane truck in a junk yard. I located my copy of Hugh Piggott's "Windpower Workshop".  It has relevent information. Pumps should have a tip speed ratio of 1 or 2.  With a 4 meter, four blade design, this translates to something in the neighborhood of a 5"-6" chord.  Tip angle is about 20°.  Midpoint angle is more like 48°. Inboard of that, I won't worry.  Lots of twist, but with that size, I'm thinking of laminating some things together to make my blanks. I'm keeping an eye out for a very small compressor to fit.  5HP models seem a bit large.  Maybe a one or two horse will come up.

Re: Water pumping windmill (3.00 / 0) (#18) by Gary D on Tue Jan 17, 2006 at 12:58:31 PM MST

Depending on the water resupply ie. stream, springs, or rain runnoff, you could possibly use a ram pump. You need about a 2.75 gallon per second resupply plus any evaporation for your actual use (to keep the pond full). If you have a good ammount going thru the overflow pipe most of the day (when not pumping) this method "may work". No electric or gas or wind needed, just water pressure.... ps. don't use the overflow itself to drive it, if feasible. Probably not worth 2 cents... Gary D. [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#19) by Gary D on Tue Jan 17, 2006 at 01:41:23 PM MST

I forgot the most important info... you'd need 5 to 10 times the water flow to pump the 2.75 gps you'd need in a 24 hour period. If you have that during your gardening period, it would be possible.  Gary D. [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#20) by Julio on Thu Jan 26, 2006 at 10:23:45 AM MST

A homemade water pumping piston encased in a 3-inch (76.2mm) diameter high pressure pvc pipe traveling say 10 inches (254mm) (I made one and plans are at your resquest. It will have to be lathed.) will deliver 60805 cubic millimeters in one trip. If it were to travel 40 times per minute then it would do 2400 trips in one hour, thus equalling 1459.32 cubic meters. These equal about 390 gallons per hour. At that rate per hour times hours traveling you develop a table thus: hours = 6240 gallons hours = 6647 gallons hours = 7020 gallons. This piston can be powered with a 16-blade galvanized sheet (Dimensions at your request. The large sheet provides for 17 blades so you are left with one to spare). You can form the blades at home and build your own wheel (It is about 12 feet in diameter. I also have the plans). This arrangement has lift capabilities of no less than 30 feet provided the piston is close to the water and preferably IN it. You need no multiplication since it will probably lift you. Maintenance: Change piston gaskets once every year or so. Grease every 3 months or so. I built one for myself and it has been working for about three years. If you are further interested, let me know. Julio.

Re: Water pumping windmill (3.00 / 0) (#22) by Dan 04617 on Sun Jan 29, 2006 at 07:11:30 AM MST

Thanks Julio.  I got the plans you emailed.  That would certainly do the trick, but I'm hopeing I can find a way that involves less work to construct.  I'll keep you posted if I try anything along those lines. [ Parent ]

Re: Water pumping windmill (3.00 / 0) (#23) by econologica on Thu Apr 13, 2006 at 08:29:08 PM MST

Dan,  Perhaps my floating windpump www.econologica.com/flopump.html would fit your pond and the wind there. Simon Farthing

Re: Water pumping windmill (3.00 / 0) (#24) by econologica on Fri Apr 14, 2006 at 09:36:52 AM MST

Dear Dan,     Perhaps my floating windpump www.econologica.com/flo-pump.html would fit your pond and the wind there. Simon Farthing Simon Farthing

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