Off-grid water pumping

[Woodsman]

While looking for some information today I ran across several links I thought might be interesting to some of you. This method is based on using the energy from pressure created by water-hammer. The same thing that makes your plumbing at home make noises if the water flow is suddenly stopped.

The first link offers some good basic information on how these work and how to make one at home.
Home-made Hydraulic Ram Pump

The second link here is from an American manufacturer of these pumps (they also have some other very interesting ideas and products also).
http://www.riferam.com/

Each link has some video's you can watch to help understand how these pumps work without requiring ANY electricity.

Something to consider, if you have the proper site conditions and need to pump water.

 

[shibumiseeker]

I've built two hydraulic ram pumps. The first was from plans from The Mother Earth News from I think 1978 or so. Cost about $45 in plumbing parts and took a little fabrication. It pretty much ran continuously for about 6 months. The next one I built from scratch just knowing the principles involved and it cost me about $50 and ran for two years with no maintenance.

Commercial ones can run for decades.

They are fun to play with building.

 

[ATOMonkey]

How much pressure can you generate?

 

[shibumiseeker]

How much pressure can you generate?

Depends on how much fall (head) you have in the drive pipe. Generally the ratio is about 10:1, but that ratio depends on the efficiency of your pump. I had a 2' fall on my first one and had no problems pumping the 18 vertical feet to the tank I was using to hold the water.

Since it takes 2.3 feet of fall to generate 1psi, every foot of fall is going to generate a little less than 4.4psi if the 10:1 ratio holds. Most rams need at least a foot and a half to two feet of fall to work.

 

[Woodsman]

Depending on the size of the feed line and how much water is wasted by the pumping process, the pump location might provide some beneficial water run-off also. That might be a stretch, but every video of these I've watvhed all have some water being dumped by the primary check valve.

It seems to me the inlet velocity in the feed line also contributes to the pumping action. I think the benefit of these would be to pump the water to a storage tank at a sufficient elevation to generate the pressure required. My take on these is that they are closest to solar pumping. The pump operates all the time when the potential is available. The water use available would be dependent on the installed storage volume.

 

[shibumiseeker]

Depending on the size of the feed line and how much water is wasted by the pumping process, the pump location might provide some beneficial water run-off also. That might be a stretch, but every video of these I've watvhed all have some water being dumped by the primary check valve.

Something like 90-99% of the water is being dumped out the waste valve (depends on how high you are pumping to). There's an optimal slope for the drive pipe, but off the top of my head I can't remember it. Mine was tuned to close the waste valve every 1.5-2 seconds.

 

[CopperWires]

I have been looking into micro hydro energy to use at our farm to power a few smaller items. I believe I have an ideal lay of land to make it work but I have also been thinking about using a water tower to create pressure. One of the problems is getting the water into the tower. Would something like this ram pump be able to push water to a tower? The tower would be about 15 to 20 ft off the ground.

 

[shibumiseeker]

I have been looking into micro hydro energy to use at our farm to power a few smaller items. I believe I have an ideal lay of land to make it work but I have also been thinking about using a water tower to create pressure. One of the problems is getting the water into the tower. Would something like this ram pump be able to push water to a tower? The tower would be about 15 to 20 ft off the ground.

Using a ram pump to pump water up to gain head is a horribly inefficient way to generate power. The ram pump is only a few percent efficient. You'd be better off using a low-head hydro system directly.

 

[Woodsman]

Another thought that might be worth consideration is the use of siphons, like the Romans used to lift water in their aqua-duct systems.