What size water wheel?

[Sprucegum]

I finally got my little spring cleaned out and running at about one(1) gallon per minute. The spring is 30 feet above camp and 600 feet away horizontally. I like the idea of a water wheel better than a turbine just because  :
Question is ; how big a wheel should I build? how fast will the water turn it? and what ratio will I need to run a 12 volt generator( or alternator ) ?

I am open to any and all suggestions

[johnjbc]

This is the power in the entire 30 foot of fall. You will need either a lot higher fall or a bigger flow to think about generating power

Weight of water       power / min      Power/ sec
8                                  20                     4             


4   /   550   =   Horse Power
            0.007272727

[Ianab]

How big can you make it?

Bigger it is, the more torque (and therefore power) it can produce.

But is 1gal per minute enough to generate any usefull power?

This table shows 100gal/min over a 10 foot wheel giving .215hp (~100 watts).

http://www.waterwheelfactory.com/HP%20Table.htm

Ian

Edit - John bet me too it.  :

[Sprucegum]

  :( Thanks for the education Guys. That is a good link on waterwheels, do you have a similar one for turbines?

I'm not giving up yet  ;)   

[crtreedude]

Hmmm, been thinking of a waterwheel too. I have a aguaponics system and I want a pump that doesn't need water. I need to move between 1 to 2 cubic meters of water per hour. The water flow is a 6 inch pipe full, and the fall is about 2 meters.

I am thinking, which is always a problem, of hooking up some Rube Goldberg contraption salvaged from a bike to move buckets from below to above. It should work just fine. But, since some of you are a lot more inventive than I am, I thought I might just see if there is something easier.

[Don P]

If the wheel is turning a crankshaft then it can drive a pump. With even a small stream I've seen work done. A trip hammer type of arrangement could run off of low flow. Water could fill a container, lifting a weight to "cock" a mechanism. When it is cocked a trip drops the weight and there is alot of useful energy available, whether to spin an alternator hooked to a battery, or pump a squirt of water up a tube. Then the empty container returns to be filled again. It's not constant but it is 24/7 and can lift quite a drive weight.

[Ianab]

Hmmm, been thinking of a waterwheel too. I have a aguaponics system and I want a pump that doesn't need water. I need to move between 1 to 2 cubic meters of water per hour. The water flow is a 6 inch pipe full, and the fall is about 2 meters.

I am thinking, which is always a problem, of hooking up some Rube Goldberg contraption salvaged from a bike to move buckets from below to above. It should work just fine. But, since some of you are a lot more inventive than I am, I thought I might just see if there is something easier.

Not sure exactly what flow your 6" pipe will have, but it sounds like you have a usefull amount of water to either drive a wheel and just attach a pump to the shaft.

Alternatively a Water Ram will work with a head down to about 3ft. How much flow you can get depends on how high you want to pump it, but it may be a solution for you.

DIY plans here.

http://www.clemson.edu/irrig/Equip/ram.htm

Ian

[Sawyerfortyish]

I seen this someplace where someone used a low geared rearend from a truck. Hooked the water wheel up to where the rim bolted and fixed the other axle so it wouldn't turn then hooked up whatever they wanted to drive (a generator,shaft pully) to where the driveshaft was bolted to. Now you have a low cost low speed input and high speed output gearbox.

[slowzuki]

1 gpm is very small to do work with with only that head as others have noted.  Could you make a pond up top and a self priming siphon to save up a bunch to blast through in a short spurt every hour or two?

[Sprucegum]

Storing it up for a gusher every couple hours - good idea  8)

I like the truck gear box idea too   8)   8)

No matter how old I get I still have more time than money     ;)

[splitter]

Guys, I studied water flow, head etc. Have a creek next to my house, one gal. a min. isn't much at all, sorry. You get the most from your water source with a pelton wheel.  Splitter

[Saki]

Hey There , Sprucegum. It is funny you ask, because I have been studying this very type of thing. From the research I have found so far, conventioal wisdom is saying these three things:

Need at least 20 feet of fall ( you have )
Need at least 2 GPM ( which you can get )
Best setup for a particular site is, site dependant - make the most of your site

One of my best resources, and I am sure your local library or bookstore can get itis titles:

Microhydro - Clean power from water - By Scott ????

Goes through basic examples, site particulars, etc

Odds are, you will need a pond or holding tank of some type to be really successful

But lets run some numbers. If we assume a 2 GPM requirement for your generator ( will vary depending on your needs ) and say you could find an old 1000 gallon stock tank to capture and hold your water. That would give you 500 minutes of generating time, or about 8 hours per day, actually more than that because as you are drawing 2     out, the spring is putting 1 back in. I don't know exactly what you are hoping to do with your generator, but it seems that it would not take much( as far as holding capactity to let you generate most of the day every day, most of the time.

Also, look at the other possibilities - fresh fish in this holding tank there for the eating, run a line and a soaker hose for your garden, or other stuff, throw in a dry hydrant fitting, and you can have an emergency reservoir for your local fire dept - may save your house or your neighbors someday. Lots of possibilities.

Check out the book, I think it will be a great starting spot for you. Best of luck- I think if a lot more people would look at these little marginal things, we may be able to take a big chunk out of our own energy problems ourselves. Best of luck.

[marc_b]

I everybody

I make a experimentation in the small hydro kit

If is posible to you ti find a small dc 90 or 180v dc brush permant magnet

type motor this motor make a 12v in very low rpm and you place a diode

and one 12v batery just a direct drive water wheel for low gear and transfert

lost.

just put them together and a lot of experimentation.


marc_b

[Sprucegum]

  8) Thanks for the encouragement.

I have lots of room for storage tanks and I just happen to have a 90V DC variable speed motor.

I also have winter coming soon  :(  so I won't get a chance to try anything this year. Hopefully I can get everything in place for a trial as soon as spring thaws.

My entire camp runs on 12 volt batteries so all I am aiming for is a reliable tricklie charge.

[slowzuki]

The reason we are sugguesting the holding tank is the minimum parasitic loss of all the components you will need to overcome.  The trickle you have may get absorbed by all the losses unless you save up a bunch to send through.

With some creative dips of the pipe you can make a siphon that self primes then unloads your tank every time it gets full.  They use this technique in dousing systems for septic beds.