Alternative Power sources - Re: OT and theory. Limit on siphons

Author

Re: OT and theory. Limit on siphons

metalmorphosis@caverock.net.nz

2005-09-20, 9:21 pm

harry k wrote:
> Is there a height limitation on a water siphon, i.e., spring on one
> side of ridge, house on other, how high can the ridge be before a
> siphon won't work?
>
> I think it can exceed the normal straight suction limit of aprox 34 ft
> (sea level) provided you can fill the pipe first but can't find it in
> google and can't figure a reasonable experiment.
>
> 2nd part: Buddy claims a siphon won't pass through a dip over 34 ft.
> That I maintain is BS but again I can find no google info.
>
> Harry K

For gas free water the limit is aprox 34 ft, yes

However water from a spring will have disolved gas and at noticably
less than 34 ft the gas will come out, and if the flowrate in the pipe
is too low a gas pocket will accumulate at the high point of the siphon
and eventually stop it working.

As far as the dip bit goes, I presume the situation could be likened to
a pipe starting at say 100 ft altitude, climbing to 120 ft, then going
into a vally with a base at 1 ft then back up the other side to 90 ft.
This system would flow ( as long as a gas pocket did not form ). There
is no limit on how low the low point is beyond the point that the head
would burst the pipe.

If you put a boost pump at the start of the line, the poster will
increase the max hight of the line to 34 ft + ( head capacity of pump
)ft, ie a pump that ill pump that has a 30 ft head would anable you to
get the line over a 64 ft ridge and back down the other side

zenboom

2005-09-21, 8:21 am

<metalmorphosis@caverock.net.nz> wrote in message
news:1127260452.304935.297500@g49g2000cwa.googlegroups.com...
>
> harry k wrote:
>
> For gas free water the limit is aprox 34 ft, yes
>
> However water from a spring will have disolved gas and at noticably
> less than 34 ft the gas will come out, and if the flowrate in the pipe
> is too low a gas pocket will accumulate at the high point of the siphon
> and eventually stop it working.
>
> As far as the dip bit goes, I presume the situation could be likened to
> a pipe starting at say 100 ft altitude, climbing to 120 ft, then going
> into a vally with a base at 1 ft then back up the other side to 90 ft.
> This system would flow ( as long as a gas pocket did not form ). There
> is no limit on how low the low point is beyond the point that the head
> would burst the pipe.
>
> If you put a boost pump at the start of the line, the poster will
> increase the max hight of the line to 34 ft + ( head capacity of pump
> )ft, ie a pump that ill pump that has a 30 ft head would anable you to
> get the line over a 64 ft ridge and back down the other side
>

bear in mind that atmos. pressure decreases with elevation + height.... I
forget the rate.

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