# eeked out another 8 volts on the hydro - Page 6

Posted by Bob F on October 20, 2008, 1:01 am

I suspect that there is an advantage in having the speed with which the water is
moving down the pentstock be part of the speed which the nozzle increases before
the wheel. The reservoir would eliminate this possibility, likely causing
efficiency losses.

Posted by Ken Maltby on October 20, 2008, 5:07 am

One of the differences between a water wheel and a water
turbine.  The flow of water in the feed pipes is hopefully not
an issue, because when it becomes one, it's a problem.   It's
head/pressure that you trying to extract from the pipes and
the fewer GPMs you can use to accomplish what you need,
the better.  A water wheel is very much dependent on the
rate of flow, an impulse turbine like the Pelton depends on
the a high pressure jet of water that comes from kinetic
diferential and a little from the weight of the water, pratically
nothing from the flow.  (In fact a large flow/GPM would
indicate some waste/inefficiency.)

Luck;
Ken

Luck;
Ken

Posted by Neon John on October 20, 2008, 5:39 pm
On Sun, 19 Oct 2008 23:58:37 +0000 (UTC), "Malcolm \"Mal\" Reynolds"

The first problem to overcome is that the reservoir must be a pressure vessel
capable of withstanding the full head pressure.  If memory serves, he has 40
or so PSI of head.  That rules out a 55 gal drum.  A section of pressure-rated
large diameter (NOT that foam-cored sewer-rated stuff) PVC pipe might do the
job.

That would help only if his flow balancing problem is because of differing
dynamic pressures at the entrance of each nozzle.  That is, flow to one is
affecting the flow to the other.  If the pressure vessel were large enough,
the velocity would drop to a very low value except at the entrance of each
nozzle.

One architecture that I've seen on commercially made turbines that might work
well here is a ring manifold surrounding the wheel with several nozzles
drawing directly from the ring.  The ring was probably stamped in halves and
brazed or welded together but one could make a pretty good one with a little
practice using dead-soft copper tubing filled with sand and a conduit hickey.

John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com  <-- best little blog on the net!
Tellico Plains, Occupied TN
Be in the world but not of it -Bhuddist proverb

Posted by Vaughn Simon on October 20, 2008, 6:14 pm

A circle made from PVC electrical 45 degree or 90 degree sweeps would also
work, and would give plenty of opportunities to install Tee fittings for inlets
and outlets.

Vaughn

Posted by Ulysses on October 19, 2008, 9:31 pm

This is making my Honda BJ look good.  At 10 amps it was at about 12.5 volts
so that would be 125 watts.  If only it would sustain that.  BTW so far I
have spent \$ on it.  This is why I never throw anything away.

•
• Subject
• Author
• Date
 Re: eeked out another 8 volts on the hydro Vaughn Simon 10-18-2008
 Re: eeked out another 8 volts on the hydro Vaughn Simon 10-20-2008
 Re: eeked out another 8 volts on the hydro Vaughn Simon 10-18-2008