Posted by Bob F on February 25, 2009, 1:31 am
The concept of the jet valocity being 1/2 the wheel bucket velocity would
certainly help in determining the ideal RPM for the generator/winding
combination. Thinking about it, I believe "z" said earlier that the generator
provider said the operating RPM should be 1/2 the freewheel RPM.
Posted by z on February 28, 2009, 4:34 am
Uploaded Some updated pics of the screen under higher water conditions.
It does the job -- i'd be using it but I've had some car trouble so can't
make it to the hardware store for some fittings I need. Very annoying,
bearing went south in my transmission grr.
Posted by Neon John on February 28, 2009, 5:43 am
What does Coanda say about cleaning out the small debris? Do they
sell a comb or something similar that can be used to clean the slots
of those twigs and stuff?
I know you said that it's hard to get materials up there but that spot
looks like it's just begging for a real dam. A 10 or 15 ft high one
would store a great deal of water and energy.
Do I recall you saying that this stream is fed from a pond or was that
someone else doing microhydro? Could you go on up to the pond and tap
the water there?
Posted by z on February 28, 2009, 5:28 pm
It'd be a job !
Thats me. This line feeds a pond that I use to draw from for micro-
hydro. The pond is about 40-50 feet lower than this intake and holds
around 15k gals. There is another spring near the pond that feeds it as
well, so during low water times I can keep hydro-ing for longer into the
dry season. But if I didn't have that pond I'd seriously consider
putting a real dam on the stream.
But now i'm thinking about linking the new intake directly into the line
that feeds the hydro since it looks like its getting enough water. Then
maybe when the water gets lower I could switch back to the pond and lose
some head but keep the water supply going.
Thus the need for some good variable needle nozzles that I can dial in
for whatever conditions are current, rather than having different sets of
nozzles you have to switch all the time.
I sent an email to canyon hydro asking about the needle nozzles they use,
maybe they can set me up
I think the one shown in that page are waaay to huge for what I need.
Even when I move to two inch I am maxing out at a little under 60 gpm, so
using two nozzles i'll need nozzles that max at 30gpm or so and go down
from there. But maybe those guys will know where to send me.
So far i've not found a supplier from just standard googling.
So anyone who's ever run across variable needle nozzles that aren't $00
each please let me know!
Posted by z on February 28, 2009, 5:48 pm
oh i missed this part
Well the coanda guys mostly sell big water treament applications or
municipal sized projects. They were nice enough to run me that chunk at
the end of a larger order, so they're not geared to the consumer. I
suppose the big applications have some need for regular maintenance
So I expect a wire brush once in a while will do the job -- but i'm going
to let it run .. the force of water on those little leaves may well move
them off eventually.
Another thing is one of the guys here was saying he had a similar setup
and it ended up growing moss between the gaps over time, so I expect to
have to wire brush it once in a while to keep the moss down.
But thats not a huge deal