Liquid Piston stirling water pump

[windstuffnow]

  A few posts ago, about a stirling water pump I mentioned the Liquid piston stirling.  Here is a diagram of the device.

  As the hot side is heated the pressure will rise raising the water on the cold side and lowering the water on the hot side.  This creates a pressure which moves the water out the top one way valve.  Once the air has expanded to its maximum point a pressure drop takes place and the water on the hot side rises and the cold side lowers, also the bottom valve opens and replaces the water.   This is one cycle of the engine which, depending on how hot it gets can happen many many times per minute.  Basically it ossalates back and forth.  It will run on a fairly low temp but will pump alot of water the hotter it gets.   I built one several years back and its actually quite impressive and moves alot of water.   It was built from copper tubing and fittings soldered together, maybe all of 5 bux in parts.  The valves were simple ball bearings and a tapered aluminum insert pushed into the tube.   I've been trying to locate it with no luck so far.   When I find it I will post a pic of it.

   I believe the engine was called a Fluidyne engine pump.

Have  Fun

Windstuff Ed

[bob g]

pretty cool setup there Ed

you never cease to amaze me

might make for a clean simple pump system for a hot water heat system, not requireing any electrical power to operate.

cool

bob g

[JW]

Yes, these low delta-t stirling engines are at the least quite facinating. Nearest I can tell low delta-t means stirling engine designed to operate at max possible efficiency at low temperature differential, between hot and cold sides. Found many references to stirling engines that operate off of hand temperature. What confounds me most about these so-called low delta-t stirling engines, is that I have also heard of omega and sigma cycles for the stirling. Perhaps I am mistaken on these other cycles existance. Anyhow a PLC got the best of me today, off to fix that, grumble, grumble, it may take a couple of days...

JW

[Roamer195]

Hi Ed!

 If you have a flame as a heat source, you could make it even simpler by using a "putt putt" steam jet. These have been used in toy boats for more than 100 years. They make great pumps.

 You keep the dual ball-checkvalve and the horizontal tube. Except now the tube is longer and the very end of it is brazed into a block of solid metal.

Flame heat goes to the block until it causes the water inside to burst into steam. This pushes the column of water in the tube. As the steam expands down the tube, it hits a cool section and the steam condenses. This sucks water back in through the lower checkvalve and back into the block. Then the process repeats.

The only hitch is that you need peak temperatures high enough to boil water.

The better news is that the boiler never reaches explosive pressures and there's a long mechanical thrust to push the water through the pipes.

Here are a few sites describing the process better.

http://www.saturdayscience.org/page12.html

http://www.nmia.com/~vrbass/pop-pop/

http://www.buzzboats.com/how.htm

[Roamer195]

Payne, Peter R. "Heat engine in the form of a water pulse-jet"; US Patent 3,898,800, August 1975.

Payne, Peter R. "Pulse-jet Water Propulsor"; US Patent 4,057,961, November, 1977.

You can see the full patent image files here.

http://www.uspto.gov/patft/index.html

[stop4stuff]

hi Ed,

am i right in thinking the pump part is connected only to the hot side?

I was trying to make something similar about a year ago... from an idea in my head... and was told it couldn't work by someone i thought knew what they were talking about.

thanks for putting me straight )

paul

[windstuffnow]

  All that is meant by "Delta T" is the difference in temperature from the hot side to the cold side.  So a High Delta T would be where the temp on the hot side may be 1200 degrees where the cold side may be running at around 200 or a 1000 degree difference.  A Low Delta T would be like those models running from the heat of your hand where the ambient temp of say 70 degrees and an absorbed temp of around 80-90 degrees and your running on the difference of only 10-20 degrees.

  Stirling engines are interesting creatures to say the least.

Have Fun

Windstuff Ed

[windstuffnow]

  Hi paul,

    I don't think it really matters where the pump is connected as long as it's in a position where its always submerged in the displacer side of the water (fluid).  

Have Fun

Windstuff Ed

[windstuffnow]

   I've seen those ;o), I've never tried to make one.  Very similar to the Fluidyne but its closer to the modern day coffee makers.  The coffee makers use a single one way valve to pump the hot water in one direction.  As long as you had a heat source an old coffee maker would work well in pumping water also.

Pretty cool stuff...

Have Fun

Windstuff Ed

[nothing to lose]

People who say things can't work or can't be done seldom know what they are talking about!!

Examples,

1970's, at one time I wanted to make a device to convert 12VDC to 120VAC , it can't be done was the answers, we now call them Inverters!! It could have been done several ways though they would not be as good as what we have today and also would have been very expensive probably.

Early 1990's tech people trying to talk me into buying a CD rom Drive for several $100,

I said I would wait till I could make my own Cds, answer was it can never happen, it would take an entire building for the equipment. I now make my own DVD's!!

Last year,

Dual layer recordable DVDs will never happen, it can't be done. Now less than $80 for many daul layer burners, though the disks are still to expensive at nearly $10 each.

If it can't be done, it just takes longer to do it is all

[nothing to lose]

I am interested in building one also.

Could you make a sketch or parts list and assembly instructions? I think I have the basic idea, but is the U shaped tubbing caped at the top and Hot cold sides connected with smaller tubbing? Like 5/8 for the water tube and 3/8 for the top connecting tube?

Also is the tube connecting the side water tub running through the cold side or just past it. And is the tube open when it goes into the hot side, or is it capped and sealed?

[windstuffnow]

  I built mine using 1/2" copper tubing for the "U", a T fitting to connect the pump and 1/4" tubing for the connector at the top.   the connector at the top also had a T fitting to fill the device and capped with no air leaks.   For the valves I used some ball bearings and machined a tapered hole through a piece of aluminum that fit snugly in the 1/2" tube, both ends.   You need to make sure there is no air in the pump as well as the line going to the displacer "U" or it will end up with an air lock and wont pump although the engine itself may still run.   If I can find the old one I'll post pictures... I may build another one if I can't find it and post that one.

Have Fun

Windstuff Ed

[iFred]

http://www.geocities.com/hustierhof/index.html

Hi Ed. This is where I beleive it originated originally long ago.

[windstuffnow]

   I found the design in the "Stirling engine manual" volume 1.  I believe it was originally designed by Dr Colin West.   A large scale development of these low temp pumps was taken up by a company in Germany called Delta T Photon Energietecknik.  From what I understand they also can be used for cooling... not sure how.

   I built mine from a picture and some real bad diagrams thinking it probably wouldn't work... but it did.

   I've seen that page before and it is quite interesting what he's doing with simple parts.

Have Fun

Windstuff Ed

[drdongle]

Who ever told you in the 70's that inverters were not available didn't know what they were talking about, Tripp Lite has been making transistor inverters since the 60's and before that you could get vibrator driven inverters in the 40's and 50's.

Carpe Vigor

Dr.D

[nothing to lose]

"Who ever told you in the 70's that inverters were not available didn't know what they were talking about"

Ya, what I said

I don't think they were very common like now and alot of people had never heard of them at all. Kinda amazes me still how many people in the 90's or earlier were so dumbfounded about the 300watt ones I had then.

[Roamer195]

Just some history....

http://www.steve-w.dircon.co.uk/fleadh/mphil/history.htm

[iFred]

You might like these links also.. check out all the stirling stuff mid page..

http://www.redrok.com/engine.htm#brayton

I am almost sure you have seen this, the guy does awsome work..just updated too.

http://www.geocities.com/CapeCanaveral/Launchpad/5465/

[iFred]

Almost the same design here..

http://www.stirlingsouth.com/Roy/others/hubert/hubert.htm

[robotmaker]

Ed,

This is so far down on the list, I hope you get to see it.. if not, I guess I can email you...but I have a couple of questions on this pump.  I am making hot water with a waste oil stove and am pumping it thru pipes on my shop floor.  I was wondering if this sterling would do the same thing.  If I stick the hot end of that pump in the stove and have the cold end hanging out, think it will work?  Also, any height restrictions on this working?  If I scale it up, think it will pump gallons per minute? Maybe like 5 or so?

thanx

rj

[windstuffnow]

  Hi robotmaker,

    I can't really say what the potential of the machine might be.   I've only built a small model to date and never really rated it on its pumping ability. More of a curiosity at the time.  I would think it could be scaled up to produce the amount of gal/min you need but I'm not sure how to judge the size required.  The small one worked very well.  You couldn't run it at the boiling point, its basically a low temp type stirling.  If you ran it at say 200 deg on the hot side and around 65 or cooler on the cold side it will do a nice job of pumping ( about a 135 to 140 temp difference - the higher the difference the more efficient it is).  You could probably put the hot side on the outside of the wood burner and circulate cold air from the outside on the cold side making it quite efficient.   I'm working on some other ideas for a cheap and simple stirling ( no machine work or fancy cylinders) that I know would work for pumping alot of water as well as produce electric... and yes still machining parts for the hybrid stirling.  I'm in "stirling engine mode" for the next couple months...

Have Fun

Windstuff Ed

[nothing to lose]

While your in stirling mode

Would you be enterested in putting together the parts for small kits to be built?

 Once I get some other things done I'll be getting into casting aluminum. For now I been casting various things with lead free pewter. I also do some plating, chrome, silver, gold, brass, nickle...

Engine kits are on my to do "someday" list. Mini steam, compressed air, stirling.

I bet a solidly built working stirling engine kit, polished and plated,ready to assemble would sell well and bring alot more interest to the stirling engines also. I know if I could find one priced reasonably I would probably buy it myself. Best I have found is a built working stirling for around $100 or so. Like those hand helds. Didn't buy one.

 If I had a prototype to mold from I could probably make casting molds for most the parts like flywheel, rods, stands, cylinder ect.. anything that can be solid and a little heavy. Aluminum is hard to plate because oxidation occures so fast. Pewter is easier but a bit more expensive around $8lb (I think) last I bought it.

If you think you'd be interested I'll email you and we can talk about it.

[windstuffnow]

  Sounds interesting although I don't have anything in mind right now, at least nothing in the line of manufactured kits.   If I did design a kit, it would have to be of one that would actually do something.   Most of the ones you see in the range of 30-250 bux have about enough power to keep themselves going... fun to watch but pretty much useless in the power area.

  I'm going to start looking in my junk for parts to put together another liquid piston pump stirling, put the power maker on hold temporarily then design an alpha engine using common materials.  After toying with the idea of the liquid piston engine, I thought of a way to make liquid piston rings, this would enable the use of large pistons without the problems of machining pistons to fit a perfect cylinder bore and the piston can be any size.  The small test bed will have 2 - 6 inch pistons.  If it actually works then I may try a couple 22 1/2 inch pistons.  The low Delta engines operate at around 3 to 7 psi so large pistons are required to actually make any power.  I've calculated using a temp difference of around 140 degrees and using 2 55 gal drums as pistons with a 3 ft stroke would produce in the range of 2 to 4 hp.  A 55 gal drum is approx 22 inches in diameter and would have a area of about 380 sq inches.  At 3 psi should provide about 1100 lbs of push.  It will most likely run in the range of 60 rpm.  In any case... I'm not sure it will even work, its just a theory at this point...

Lots of Winter Fun

Windstuff Ed

[ghurd]

Has anyone considered pumping the water to a micro water wheel generator?

Like 2, 3, 5 watts?  

Seems like this could get good pressure peaks.

Maybe a pulsed Pelton wheel? Squirt, squirt, squirt...

I mean, the stove is going anyway. That would be a heck of a conversation piece.

G-

[nothing to lose]

I had never ran acrossed a low cost kit yet myself like $30-$60 even as a toy to just watch run. I don't get to many hobby shops or such, maybe I just missed them.

Kinda what I was thinking for putting together, if it actually did something even better. But, people like to build things and watch things run even if they don't actually serve a purpose. Look at model cars, train sets, ect.. so I figure a nice heavy chrome and brass plated engine and flywheel might go well.

Very interesting the idea of using 55gal drums for pistons. I do alot with those, never thought of using one for a piston though. I'll  have to keep a watch out for that

[nothing to lose]

Actually that was one of my first thoughts when I saw this.

Always looking for more things to do with my charcoal making system as I build it.

If I can build these pumps to work I'll have all the heat I need to run them anytime I am making charcoal. So if I run alot of these pumps around the furnace each pumping alittle water up hill that could provide alot of water running back down hill.

I think he said in another post the one he just built did about 7" lift around 1gal per hour (about). I think that was 1/2" or 5/8" copper tubbing.

 If I can get better lift and used 60 of these on my furnace I would have 1 gal per minute. Runing that back downhill into the same source bucket might run a small genie.

 Also I am looking at temps around 500-600F for a heat source so I may be able to run larger ones and more volume greater heights.

The heat leaving my charcoal maker is a useable waste product, always looking for more ways to use it as I build the system.

[Kwazai]

the links keep disappearing, but Geoff Egel had one of these posted on a site and it worked best when a resonant pumping frequency could be acheived. I built one out of 2 litre plastic bottles with cheap siphon pump one way valves and was able to pump a tsp. every 7 seconds with just a shop lite. This design actually works slower but more predictably if the hose/pipe at the top of the chambers is small enough that the air moves slower than the water. one of the things I did with the hot side was to put the tube down in the bottle part so that it was flush with the check valve. the water would fluctuate over the end of the tube and actually burp cooler air in -which when heated would pump water until uncovered-move to the other side-cool. it was a slightly different configuration than what is shown above.

   !----small hose---!

bottle(cold)       bottle(hot)

(      )                ( !  )       !-outlet-

(      )                (    )       !

checkvlv-------------checkvlv                    

inlet

  !

  !

with the plastic bottles it would pump up about 3", but trying to pull any suction pressure would collapse the bottle (8" was too much).

everytime I find the link it stays for a week or so and then disappears. The trick was a small hose at the top so the expansion pumps water before exhausting the air.

[Kwazai]

better picture

[Kwazai]