So that's where we left off on Page 1 of this project. So far we've got about 3 days into it all! It's lot of fun doing this sort of thing.. even if it doesn't work!
It's amazing how we can fit a hydro project, a big wind turbine project, lots of tools, and 17 folks with instruments including a standup bass in half of my 10 X 50 trailer!
Back to work. We spent about 2 hours grinding rust off it, sprayed primer and paint over it. Probably not necessary, but it makes it look nice, which is especially important if it doesn't work!
Here it is all painted up! We'd intended to put a shroud over the alternator that would rotate with it, to keep water out of the bearing and off the electric components. We never found the right piece and ran out of patience with that, but we will add that later if it works well enough to warrent the effort.
Another shot of it assembled. We've not put the nozzel on it yet, it's in the back of the truck.
Pictured above you can see where we plan to put it. The 4" pipe comes from the bottom of the dam, again.. about 3' of head. Its a thoughtful arrangement. We're only taking a small portion of the water from the creek here. Up above the dam there is a bit of an island which splits the creek. Some of it feeds the dam, the rest of it flows round the side so as not to interrupt the creek.. fish can still go back and fourth, and if the creek is high, it won't have much affect on things.
This is Scott's old machine, which ran for 2 years even through the winter. Again, it was good for about 1 amp (12 watts) or so. It's a squirrel cage blower, belted up to an Ametek computer tape drive motor. To get an amp from it, the belt tension was very critical and required frequent adjustment. It was a good machine though! Hopefully what were doing here will be an improvement...
Here we've got the machine at the site, and are making adjustments. Again, just about everything is adjustable here! In the end, we got best results by feeding the water in at about 10 O'clock on the wheel, most of the water seems to exit at about 5 O'clock.
Here it is running along making about 2 amps (1.9 amps to be precise). We were hoping for at least 2.. but after lots of adjustments we simply couldn't beat 1.9! It's tricky to adjust! Every change we made to the alternator changed the best nozzel position. We could adust the airgap on the alternator, and we could change the wiring from Star to Delta. I definitley noticed higher efficiency in Star... it always produced slightly more power at the same rpm in Star with a wide airgap than it did in Delta with a narrower airgap. (the airgap is the distance between the magnet rotors and widening it reduces the flux through the coils allowing it to run faster) We left it in Star, with an airgap of about 1.25" (pretty wide!). So, it could be made at lower cost with smaller magnets, and a narrower airgap, or... it could be slightly more efficient with the same magnets, a narrower airgap, and coils made up of fewer windings and thicker wire. We may make this change at some point. As it is, it runs without a load at about 160 rpm, and loaded at about 110, producing 1.9 amps @ 12 volts.
Well, it was lots of fun and it seems to work reasonably well. We need a shroud over the alternator to keep the water off and a screen over the intake. One problem that I never thought of... the creek is full of magnetite sand! Even after a couple hours I could see a little building up on the magnets. It might payoff to have a screen, and lots of magnets at the intake to collect some of that before it gets to the wheel. A shroud over the alternator would also serve well to keep almost all the water out.
Click Here for page 1 about this fun experiment!
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©2003 by FORCEFIELD
