On Wed, 02 Jun 2010 18:31:51 +1000, FarmI wrote:
"Billy" wrote in message
Harry K wrote:
On Jun 1, 8:29 pm, "FarmI" ask@itshall be given wrote:
"Billy" wrote in message
In article
,
Harry K wrote:
On May 31, 7:44 pm, "FarmI" ask@itshall be given wrote:
"John Gilmer" wrote in message
"FarmI" ask@itshall be given wrote in message
. au...
"John Gilmer" wrote in message
"Bob Noble" wrote in message
.. .
It looks more to me like that is a bridge used to support
a big
pump
for some kind of irrigation. Note the pump in the middle
with the
overhead to rise the pump.
I suspect that the "bridge" served to hold a "hydralic ram"
which
uses
the velocity of the water to pump a small portion of the
water to
the
level of the surrounding fields.
Nope. Hydraulic rams need a head of water above the pump so
that the
water drops into the ram. - its the action of the water
falling into
the
ram that makes the pumping happen.
Nope, yourself.
You just don't understand how a hydralic ram operates.
I do but I'd love to see a cite that would prove me wrong. I
have a use
for
such a beast.
It uses the kinetic energy of a stream to raise a small
portion of
water
well above the level of the stream.
A stream can certainly be used to do that with a hydraulic ram
but the
stream must allow the water to drop into the ram not just flow
past it
gently like the water does in a slow moving irrigation channel.
I'd certainly be very interested to see a pic of any hydraulic
ram that
works as you say it will. I can't see how a slow moving stream
can make
use of the water hammer effect that gives the 'ram' its name
but I'd
certainly like to know more details. Can you post a cite
please.- Hide
quoted text -
- Show quoted text -
The system I referred to sat right on the edge of the stream. The
stream was a 'gentle one'. The input pipe ran a distance up the
stream so I guess you could say 'dropping into the ram'. Yes,
there has to be an elevation difference but there is no "dropping
into the ram' in any sense the normal person would use.
You could look it up on the 'net.
Harry K
Sorry Harry K but I'm tagging onto a response from Billy. (Thanks
Billy for
responding as otherwise I wouldn't have seen this) I have not ever
seen any
post from you Harry on this subject but your comment suggests that
you have
written something on this before. I have seen no other post from you
other
than this reply from Billy.
As I mentioned earlier, a stream can indeed be used to operate a
ram. And
indeed it can be used in just the way you describe. But as I also
wrote there MUST be a drop. That drop does not have to be like a
mini waterfall
immediatley above the ram. It can as you mention come from a
considerable
distance upstream (usually by pipe) to allow for the drop into the
ram. Any 'normal person' with half a brain cell should be able to
figure out that
water flowing to a ram downstream from an intake pipe forms a
'drop'. And a
'drop' there must be (at least there must be a drop unless they have
inveneted something new that no longer operate using water hammer
principles)- Hide quoted text -
- Show quoted text -
Aha. The post I was replying to read like you were saying there had
to be something like a mini waterfall.
I never said any such thing!!!! But in an odd way, you have hit the
nail on the head as to why the bridge could never have been used for a
hydraulic ram (more below).
A 'head' of water can be provided by a pipe bring the water some
distance as we've both already agreed. It CAN also be provided by a
waterfall or even a header tank (not that I mentioned any means of how
the drop was achieved to the ram despite what you erroneously thought).
But to go back to that bridge which is high above an irrigation channel.
As you probably know, irrigation channels are a body of slow moving
water and they are on very gently slope. Just how far upstream do you
think the inlet pipe would need to be to provide a head for a hydraulic
ram situated that high above the water on that particular bridge? That
bridge never held any ram because as we both know, there needs to be
that 'drop'. How many miles would a pipe have been run back up that
irrigation channel to allow a drop to run a ram sitting up on that
bridge?
Referring to the photo, I disagree with "high above".
http://personal.morris.umn.edu/~webb...ndeBridge2.jpg
One of the puzzling things about the possibility of it having been used
as a conventional bridge is that it was set down into cuts in the banks.
Also, the previous exchange in context was:
John Gilmer wrote:
"I suspect that the "bridge" served to hold a "hydralic ram" which uses
the velocity of the water to pump a small portion of the water to the
level of the surrounding fields."
Farm1 replied:
"Nope. Hydraulic rams need a head of water above the pump so that the
water drops into the ram. - its the action of the water falling into
the ram that makes the pumping happen."
Part of the reason I interpreted your "drops" and "falling" literally was
that you were explicitly disagreeing ("Nope") with what John G wrote.
I dunno why you can't see my post. Perhaps you have me kill filed?
I don't know if I have you kfed or not. I tend to killfile habitual
drongos or loonies. Sometimes posts just go missing. It seems to be
happening more as time goes on and ISPs are getting funny about usenet.