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Forum Index : Other Stuff : Building a hydraulic ram
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| MOBI Guru  Joined: 02/12/2012 Location: AustraliaPosts: 819 |
[quote=glenn]Not quite. If the flow is slow, the bubbles will rise faster than the water flow, and end up accumulating in the high points, effectively becoming a blockage in the pipe. It gets to a point where flow can be reduced to a near stop. [/quote] I've had that many times with windmill pumps and cattle troughs over slightly undulating ground. Yes, bleed points do work. David M. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Automatic air purge valves like that are commercially available. I remember seeing a whole bunch of them fitted to a pumped solar water heating project I was once responsible for a very long time ago. As water in the collectors heated, dissolved air was released and tended to form air traps at the high points in the pipework. As the collectors were on the roof, and the hot water storage tank at ground level, there was nowhere for the air to go. These worked like a carburettor float bowl in reverse, with a brass float and a needle and seat at the very top. These were a sturdy brass casting, very well made, but looked expensive. They would spontaneously burp and fart, bubble and dribble away merrily on a hot day. As I remember, the manufacturer's name was Spirex Sarco. Cheers, Tony. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Found it !! This is the Spirex Sarco automatic air vent mentioned in the previous post. http://www.spiraxsarco.com/pdfs/SB/s31_06.pdf And here is some more Sirex Sarco info... http://www.spiraxsarco.com/products-services/products/pipeli ne-ancillaries/air-vents-and-air-eliminators.asp#ti Cheers, Tony. |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
The creek stopped flowing a month ago, very dry here, lots of thunder storms but they all seam to round my place  . So I used the dry spell to improve on the pump.
One problem with my set up is the storage tank fills up with water, as the compressed air is absorbed into the water. This affects the pumps efficiency and I need to drain the tank every couple of days. There are a couple of ways to fix this, either use a bladder, or add a snifter(sniffer) valve. I decided to go with the snifter valve, simply because I had the bits already. For a snifter to work, the air it introduces needs to rise through the check valve and into the pressure tank, so it needs to be mounted vertically. I used a iron elbow, drilled a 3mm hole and fitted a screw and nyloc nut to act as the snifter valve. Under pressure it seals, and under vacuum it lets a little air in. The vacuum occurs just after the "hammer", when the water column bounces back up the feed pipe. Its only short, but its more than enough to suck in a little air. We finally had a few mm of rain on Boxing day, and a day later the creek started flowing again, so I had a chance to test the new pump. 
And here you can see the little bubbles rising in the pressure tank. 
The modifications worked well, but unfortunately the creek dried up after a day so I'll have to wait for more rain. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
An update on the ram. Its been running now constantly for several months. The snifter valve works perfectly and the coke bottle never fills with water. I've had to machine the check valve flap a couple of times, its wearing down with all the hammering and I'll have to replace it in a few months. I get a few air bubbles in the feed pipe ever week or so, just means I need to shut off the pump for a few seconds to give the bubbles a chance to rise up out of the inlet. Up at the house I've dedicated a 5000l water tank to the pump, it took about 10 days to fill it. This "creek" water tank has its own 240v pressure pump and I use it to wash cloths ( via a 20 micron filter ), wash the car, water the garden etc. Its all working well. At a guess I would say the pump has moved 120,000 litres ( or 120 tons ) of water over the last 10 months. Not bad for a few bits of PVC, brass and a coke bottle. 
Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
My Onga air tank just went west so I had to buy a new Davey 8 liter one for $100. Filled the rubber bladder with water and can't see a leak. Do they get porous after a while (14 years?) and then leak under pressure? After opening the air valve air and water came out. Anyway, I will not throw this old tank away and try my hand with building such a ram with this tank and see how it goes. Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Nice picture of the blue yabbies (Cherax destructor!). Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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Cornelius Newbie  Joined: 26/12/2008 Location: NorwayPosts: 27 |
Really nice work! 
It's good to hear that your ram pump does something useful. It has been a while i dropped by here, so i haven't read your thread until now, and i who just finished making a similar ram pump myself...  It's really great fun, building something so simple that does such good work, i think...
Here's a picture of my build; 
I've modified the waste valve to be able to add weights to the valve; that way, i can optimize the performance of the pump to the fall and flow i have on my site. |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Well the creek didn't flow for about 5 months. Apparently we had our driest summer in 120 years, figures  . Fortunately the soak fed "pond" maintained its level, so happy little fish and my solar pump could keep my tank filled with creek water.
A few weeks ago mother nature decided to send down all the rain it was supposed to last summer, in a week. So the creek was flooded. 
About 3 meters deep over where the pump was. At the time I wasn't to worried, I had dyna-bolted the pump to several boulders in the bed of the creek. The boulders were about the size of a bar fridge, or large suit case. Unfortunately, the water was so strong it dislodged the boulders, along with the pump, and just about everything else in the creek. After a few days the water had resided, and the creek bed looked very different to how it looked a week before. Amazingly, many of the fish were still there. Walked down the creek for several km and only found a couple of the PVC pipe lengths. Pump was gone  I also found a lot of old tires, farm machinery, a drowned cow and fencing wire, and a couple of nasty brown snakes, one who chased me for a few feet, little bugger.
So bought the bits to make a new pump. A few improvements over the old design, including a purpose made clapper valve. So far its working well, more flow than the other pump, and I havn't optimised it yet. 
This pump will also be easier to drag up the bank if theres any chance of flooding. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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