Author Topic: Undershot Ship Mill Hydro? (Read 6142 times)

jkeiling · « **on:** May 26, 2005, 05:39:29 AM »

I will attempt to attach a sketch of this sort of arrangement but just in case it does not work ..let me explain a bit. This would be an undershot paddle wheel which turns in river current and was normally mounted on a shaft protruding from the hull of a large boat anchored in midstream. It was used to drive mills for grinding ops etc. I plan to try to construct a similiar wheel and to mount between two pontoon type tubes. The river is medium sized average to slow moving river. It would be very slow I think, but very powerful so gearing up may be viable. I got this idea while trying to walk upstream (very hard) in a shallow section some years ago. Until I found this sketch on the net, I thought I had an original idea.hahaha. Anyone know of anyone who has tried this? Just an experiment to try at my river camp.

RobD · « **Reply #1 on:** May 26, 2005, 11:27:07 AM »

From what I've found the the undershoot is the least efficient but if you can do it easily low efficiency is better then no efficiency!

hobot · « **Reply #2 on:** May 26, 2005, 06:05:11 PM »

over or under - its the velocity that matters in these stream/river

wheels, trick is to concentrate via various funneling arrangements

then it can kick out some ummph for juice. Here's the master of it.

http://www.frank.germano.com/waterpower.htm

Got to figure a way to deflect debris in most waterways and for

flood conditions.

I've been pondering a chute affair with a windmill like fan turbine

in the way maybe two, but also if there's a reason we don't see

many or any of them done.

hobot

RobD · « **Reply #3 on:** May 27, 2005, 09:09:10 AM »

The problem with under wheels is not having water in a falling bucket like the over wheel so the under can never develope the same power unless you funnel it.
I thought about running pontoons with fins on them over a wide stream but then you pick up every twig that floats down. Winter ice is a problem too.
I like the Banki for low head but you need a good flow rate. You can just get power more easily with head no matter how you slice it.

Kwazai · « **Reply #4 on:** May 27, 2005, 01:27:45 PM »

not sure how deep your river is , but I'd thought a gorlov turbine made from a tin can (or 55 gallon drum) would be the way to go- much like a darrieus vawt except spiraled like a double helix so it could be on a cable/rope/belt to turn a generator on the pontoons.

anyway just a suggestion.

Nando · « **Reply #5 on:** May 28, 2005, 07:49:04 AM »

The right question is :

What is the use of your harvested energy, and what power level are you looking for ?.

There are several ways that one could use to get Run-in-river energy.

Let us know

Nando

RP · « **Reply #6 on:** May 28, 2005, 10:20:18 AM »

If you had an intake funnel affair with your pontoons or fins then you could have a skimmer type thing at the surface that would deflect incoming (floating) debri off to the sides while still allowing the under-surface current to come through unimpeeded.

I'd think you could have a bottom on the funnel also. Sort of like a three sided trough that narrows and gets shallower as it reaches the wheel.

jkeiling · « **Reply #7 on:** May 28, 2005, 12:22:22 PM »

Wow...alot of interesting replies here. As far as comparing this form of power to anything involving head pressure...well I realize that cannot be beat. Thing is...this is what I have to work with, and despite the aforementioned I know there is serious power to be harnessed here..problem is, I'm not sure how best to extract it. The reason I'm so confident about it's potential is because of the force (power) required to act against it (i.e. walking upstream). I'm not looking to produce meaningful power...just to have a little fun. The river varies widely in depth and flow rate (as most natural channeled rivers do). This time of year the depth at my dock is around 12' deep and tapers out as you go across to knee/waist deep. For specific data see USGS streamflow data South Branch of the Potomac River @ Springfield West Virginia. I thought about using a wooden cable reel (I'm an electrician) as the center hub of a large wooden paddle type wheel. I'd extend the wheel dia. using 2x2's to radiate out from the center on both sides and across these use approx. 30"x48" plywood paddles or whatever I could scrounge up. I can tell you that if you were to try to stand in midstream it would be absolutely impossible to hold one of these paddles in front of you...the force of the current would be far, far too much. Add to this great force the fact of leverage of the wheel acting upon the center axis (shaft). I also thought about using a 27" bicycle wheel and welding small pieces of angle radiating out and to that attaching paddles. I've considered all types of gensets and am thinking a DC PM motor would likely be best to begin experimenting. What could be used for a huge pulley? Would a bicycle wheel work...could I wrap a belt around that and then directly drive a very small sheave on the motor (generator)? I would like to stay away from multiple pulleys due to power loss. I want to build this as cost-free as possible because...well...it's cheaper and I think will add to the fun as well as the challenge. I'm a terrific scrounger! Any ideas?...let me here them please! P.S. I'm gonna attempt to post a sketch and photo of the river in another post right after this one.

jkeiling · « **Reply #8 on:** May 28, 2005, 12:34:34 PM »

A photo of the river:

Historical sketch of an undershot ship mill:

jkeiling · « **Reply #9 on:** May 28, 2005, 12:37:41 PM »

Photo of a huge undershot river water wheel: http://i3.photobucket.com/albums/y71/307/waterwheelriver.jpg

ghurd · « **Reply #10 on:** May 28, 2005, 11:58:28 PM »

One idea.

I have seen the 'chain link' type fan belts work well with bike wheels.

They are sometimes used with wood working equipment, but I can not find one on the internet right now.

A thought.

It is going to take some large surface area per paddle.

G-

nanotech · « **Reply #11 on:** May 29, 2005, 12:14:00 AM »

With the amount of torque you're going to be developing, I don't think using multiple gears/pulleys is going to be a problem.

I would definately go cogged belt versus V-belt. Timing belts for cars come to mind. They are able to handle large amounts of torque (ever tried to turn a camshaft by hand that hass all the valves in place?), are used to high RPM's, and generally last a fairly long time (how many revolutions would a normal engine make in 60,000 miles?).

One system you could use that would get you fairly high gear multiplication would be a transaxle from a riding lawn mower. That way you could also have a changeable setup for varying water levels. That way you could also have dual paddles for balanced setup. Either that or a drive system from a snowblower. Both of them are setup for high torque values. The advantage of the riding lawn mower is that quite a few of them have built-in brakes. Handy for servicing.

If I lived on the riverbank around here, you can BET I'd be tapping it for power!! The city already has with a small hydroelectric dam!!

jkeiling · « **Reply #12 on:** May 30, 2005, 09:09:42 AM »

I wish I knew what this "chain link" type belt looked like. I don't think I ever seen one before. Actually...I just sat here and thought about it and maybe I have seen what you are referring to...I wonder what they really call them? I agree on the large paddle surface area...I suggested 30x48 or somewhere in that neighborhood...do you think they should be bigger? All of that area will be submerged in the current. Click on the link I posted for the sketch...note how the paddles are arranged around the radius of the shaft..no 2 paddle arms are 90 degrees apart...I suspect this was done for a reason...I plan to replicate that arrangement...also note the enormous paddle area. Thanx for the comments and suggestions...this site is great!

jkeiling · « **Reply #13 on:** May 30, 2005, 09:56:48 AM »

WOW Nano...that lawnmower transaxle sounds like an idea with great promise. I could kick myself for not thinking of that. I also like the idea of having the first drive pulley already there once the transaxle arrangement is incorporated into the design. I'm gonna investigate this...I'm curious as to the drive pulley shaft size and length and especially curious about what the highest gearing is that I can acheive. I would guess that I'll still need to gear up one more time...that's why I'm considering this bicycle wheel as a sheave. If I went thru the transaxle and then thru a 27" bicycle wheel to a small (say 2 ") pulley on the generator I should be getting some pretty high RPM's. If this should turn out to be a bit too high and the whole thing starts to bog down maybe I would be able to remedy that with different gear delections in the transaxle. I also am thinking abot 2 transaxles...one driving the other. I need to decide on a final wheel diameter..then I think I can measure the current flow rate in feet per minute and divide that by the wheel circunference in feet and that should give me a pretty approximate wheel RPM minus a bit of loss (current flowing around the paddles). I can also easily tow this whole contraption with my motor boat to an area just a few hundred yards up river where the current is very swift although a bit shallower which is why I limited the paddle depth to 30". Sooo much to think about...the mad scientist is nearly ready to begin experimentation. Tell me...does this sound doable? Thanx again for all the input...this is a super-cool site.

ghurd · « **Reply #14 on:** May 30, 2005, 06:25:36 PM »

I think that sketch has 6 paddles, at 60 degrees.

Just 2 line up with the shaft for clarity.

I know what it looks like!

And I can't find it either!

This is close, but look more expensive,

having metal and all.

"T-Link Belt"

http://www.lathes.co.uk/page4.html

OK, I think this is it.

At least there is a name for it.

"Power Twist", but thats probably a brand.

http://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611768400&ccitem=

G-

nanotech · « **Reply #15 on:** May 30, 2005, 07:56:45 PM »

Um, not meaning to sound condescending here, but please try to remember how slowly a riding lawnmower's rear wheels spin and how fast that engine's spinning!!

On mine, the rear wheels MAYBE turn 100RPM in high gear while the engine is cranking out close to 4000RPM. Change into low gear and you're talking about the rear wheels coming down to about 10RPM to the same 4000RPM for the engine.

Just trying to figure out what you're trying to spin at more than 4000RPM!! :O

If you're talking about hooking up a Hugh Piggot style PM genny, even high gear with the paddles spinning at 10RPM is going to be pushing towards the upper limit of the genny (400+ RPM). If you're using a portable generator (like a Honda), then low gear will spin it up pretty good to about the right RPM's.......

jkeiling · « **Reply #16 on:** May 31, 2005, 09:31:55 AM »

Thanx for the link...yup that's the stuff I remember. I worked as a start-up tech at a coal-fired power station and worked around thousands of pieces of equipment. I do remember seeing this on something there, only it was black...not red in color. I suspect possibly the red color is indicative of this products wide temperature range. Unfortunately it is far too expensive for my blood; $226 for 25'...geesh, I've never paid that much for 25' of anything before. I sure would like to have about 15' of it though. Grainger is a great company and as an electrician we deal with them very often, they are however a bit pricey..maybe I can find it somewhere else. Do you think that 7/8" belt is what I'd need or could I get away with 3/8" or 1/2"? Again, thanx for the info. bro.

ghurd · « **Reply #17 on:** May 31, 2005, 09:58:34 AM »

I know its not that expensive around here.

I have no idea how wide.

Maybe depends on the wheel or specs of everything?

G-

jkeiling · « **Reply #18 on:** May 31, 2005, 09:59:34 AM »

Nano I'd guess your estimate of 10 RPM on the paddle wheel to be fairly accurate, depending of course on where I choose to locate it in the river. I actually thought perhaps the drive pulley on the transaxle turned a bit slower than 4000 RPM, so that threw me off a bit, however I was thinking I may have to use a small output auto alternator if that's all I can find. I think they do turn up around 4000 RPM at maximum. Around 2000 is idle I think. I realize between 12 and 48 watts is used in field current, but it might be worth checking out (I have one already laying around). I really want to find a low rpm dc pm motor, and for that I'm sure the transaxle would likely do it all. I really just never realized I'd get that much multiplication. I think you're right...I think that should be more than fast enough if I match it to the right genset. As an industrial electrician, I've had oppurtunities to grab dozens of these ideal dc motors, but at the time thought I had no use for them, and into the dumpster they went.Thanx again..it's nice to have your input, you've been a great help in planning this.

Dennis · « **Reply #19 on:** June 16, 2005, 04:42:20 PM »

Build a floating undershot wheel. Attach a spiral pump to it to convert the slow mechanical movement into pressure. Run that pressure into a small turbine.

Run the water from the turbine back into the spiral pump using a rotating scoop.

french town · « **Reply #20 on:** July 14, 2005, 09:06:10 AM »

Hi.

I have tried this.built a 7ft dia wheel 4ft wide. hooked to a mower trans. then pullied to a alt.

was able to light a bulb, but the tourque needed to do much more is unbleaveable.

I canned the idea. had fun trying though.

Good luck,have some fun.

Sam.

pyrocasto · « **Reply #21 on:** July 14, 2005, 10:00:57 AM »

That would be increadably inefficient compared to just hooking a genny to the undershot itself. ;-)

stcfarms · « **Reply #22 on:** December 09, 2007, 04:49:41 PM »

I have been looking in to using plastic barrel rafts (20' X 40') with

undershot water wheels to produce clean cheap energy. Since the rafts are

cheap to build and very safe they would make great 'off the grid'

homesteads. With a garden on the roof the homesteads would be self

sufficient.

I plan to hook the rafts together four wide and two deep making the island

an 80' square that will safely carry 192 tons. Since the locks on the

Mississippi are 110' wide and 600 feet long the island would not need to be

separated to go through the locks.

There are thousands of rivers that would produce enough energy to power the

water wheels. Anyone with even limited skills and hand tools can build the

rafts. Every time someone becomes self sufficient the 'powers that be' lose

some of their power. When everyone is self sufficient the 'powers that be'

will either have to work or starve.

You can visit our website at http://groups.yahoo.com/group/riverats/ and

download the plans and information.

spinningmagnets · « **Reply #23 on:** December 09, 2007, 11:09:09 PM »

Hi jkeiling, I recall reading that ancient Rome was surrounded and cut off from their regular mills, so they anchored boats in the closest river and used paddlewheels to grind grain into flour.

I noticed recently that the local electric and gas companies are getting their reels of wire and plastic gas tubing on metal reels instead of wood. With the cost of fuel, the old wood reels (5 foot dia, 5 foot wide) are heavier, and thus cost more to transport. Also, rather than pay to return the empties, the metal reels were crushed for scrap weight.

They appeared to be perfect for just this type of thing (if 5'X 5' works for you). Buying new steel and paying to have it cut and welded would cost 20X as much as scrap price. I had an idea about using 4WD front disc wheel bearings with the brake disc. Theres a central hole in the spindle for the front axle where a pipe shaft could pass through, but I haven't finished looking into if that would actually work. if you needed more torque, two could be mounted side by side on the same axle. Steel pipe comes in 10' lengths, and the ends can be cheaply threaded at Home Depot.

Flat paddles create a lot of turbulence, a "Poncelet" is an undershot wheel with curved paddles (looks like a circular saw blade from the side instead of wheel spokes) arranged so that water smoothly slides up the bucket towards the central axle, but stops halfway due to gravity, and then as it slides down and out, it imparts a little more energy to the wheel. The sides of the buckets should be enclosed, and the backs of the buckets could be rough as long as the faces are smooth.

http://www.waterwheelfactory.com/history.htm

How about motorcycle sprockets and chains? Bikers buy new ones all the time from a bike shop when the old chains and sprockets get worn. The old ones get tossed, can be bought for a 6-pack of beer.

Best of luck, have fun!

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Author Topic: Undershot Ship Mill Hydro? (Read 6142 times)