float valves

[MayR]

Hi all,

I am working on a project for a boarding school in a developing country in the Pacific. I am trying to install a simple washboard type aerator above a tank (to try to reduce H2S smell). The water will be pumped into the aerator, flow through the aerator as through a waterfall, then enter the tank. I want to put a float valve in the tank to stop the pump when the tank is full. However the inflow will be into the aerator, which will be about 1.2m above the tank and will be a separate unit. I do not have any power available (the pump is about a km away so I cannot use its power source). Any suggestions you may have as to the float situation will be most gratefully received!!

 

[Charnwood]

Float switch:
http://www.floatswitch-shop.co.uk/

 

[Burnerman]

No power available sounds like a real issue, on the face of it.....
You'll need a float switch in the tank, controlling a remote valve for the water feed.
A couple of points to ponder.....Would you be able to use a car battery for a power source, charged by solar?
Next, would the existing pump be upset if its outlet was suddenly shut off?
John

 

[hazetimesfive]

what is a washboard aerator..

 

[Burnerman]

As far as i know, hydrogen sulphide gas can be bubbled through water as a sterilising agent.....obviously this makes the water pong so the water is made to tumble down a small waterfall to aerate it.
If we get a post back, it could be an interesting project!
John

 

[Charnwood]

Won't, on second thoughts, work so deleted.

 

[MayR]

Thanks people for your thoughts. I am attaching a drawing of the existing tank set up

Untitled

• MayR
• 5 Dec 2012
• 1

and a VERY rough sketch of the proposed set-up

Untitled

• MayR
• 5 Dec 2012
• 1

The aerator will just be a small tank or similar, with water being sprayed into it and being splashed as much as possible (eg off washboard-type arrangements) so as to release the H2S which is entrained as a gas in the water (it is naturally occurring in this instance due to vegetation that is grown near the well).

I really would prefer not to try and put a power source at the tank, because it is just an additional source of maintenance and expense simply for a float. We have a solar pump at the well, but that is about 1km from the tank.

 

[Burnerman]

There's still the question of stopping the pump by shutting its outlet off - certainly most electric pumps wouldn't like this, so you need a pressure sensitive device to shut it off in the delivery line.
At the tank, the float switch or whatever needs to close a valve on the incoming pipe......this would be reasonably achievable using a power source I think but bloomin' difficult without one.
Presumably wasting water is unacceptable.
John

 

[MayR]

Thanks Burnerman - I know nothing about pumps and I thought that floats simply cut off the outlet - or actually I did not think about it at all . I am still somewhat confused - the set-up we have in place currently (see drawings above) works.
I was hoping that I would not have to make a call between having power and wasting water!!!

 

[Burnerman]

The system you have so far is fine - nothing wrong with that.
One question though, at the moment when the tank is full, what happens to the excess water......does it just splash over the side to waste?
A float switch could be fitted to the side of the tank, but there's nothing to control there....even if a valve was installed in the pipe from aerator to tank, then there would just be an overflow at the top of the aerator.
So - if you want to avoid wasting water, somehow the pump has to be switched off or surplus water diverted away.
Points to ponder!
John