Air Lifting

"SteveB" wrote: (clip) Anyone else ever done this? (clip) ^^^^^^^^^^^^^^^^^^^ I use city water pressure and a small jet pump to empty my water bed. I doubt that it would lift the water 20 ft, through. However, if you used a small electric pump to drive a jet, you could probably pump a large volume of water up into your storage tank.

If you have a pressure washer, it will do the job, although it would be relatively energy inefficient. It transfers a few gallons per minute.

i

When you use the pressure washer, remove the spray nozzle and leave a easy big opening.

i

Huh? A pressure washer delivers 1500+ PSI! To lift water 20', you only need about 10 PSI. A pump with a 25' head would do real well in this situation.

Jon

It can deliver a lot less PSI if you remove the pressure nozzle:)

And, delivering less pressure, it will deliver more water, to any practically possible head. Its flow is not bad with the nozzle removed.

I have a bad ass but 20 year old military surplus pressure washer, so I know...

If the OP already owns a pressure washer, like I do (with a 50 ft hose), he already can do some pumping.

i

"Jon Elson" wrote: Huh? A pressure washer delivers 1500+ PSI! To lift water 20', you only need about 10 PSI. (clip) ^^^^^^^^^^^^^^^^^^^^^^ If you combine Ignoramus idea with mine, I think you will have a god working system. Use the pressure washer to drive a jet pump (like used on a waterbed.) The washer would send out a thin, high velocity stream, which should easily lift a large volume of water 20 ft.

Removing a nozzle would also make the pressure washer into a decent pump. Not the most efficient, but quite doable.

i

If I recall correctly , the air lift method works by adding air to the column of water in the pipe. With the added air, the column weighs less and the water/air column will rise to the height where its weight is the same as the weight of the pure water.

Not a great explanation, but anyway the lift of such a system is limited. In short I don't think it will work for your application.

What would probably work well is the Harbor Freight 12 volt marine utility pump. 240 gallons per hour, 23 foot lift. It is currently on sale at $25. LOT NO 9576

Dan

I think that a regular pump is the right way to go. However, if I had to pump water uphill 20 vertical feet, I would not use a pump with 25 foot of lift. Even if it worked, it would be very slow. You probably would want a pump with 40 or 80 vertical feet of lift (about 20 to 40 psi).

RV's use 12 volt pumps for potable water, they have good pressure, around 35 psi, cost around $50 US. However, they only deliver around 3 gallons per minute.

Open the yellow pages and look for "pumps". A pump designed for a shallow well would be a good choice, it would have enough pressure to pump water uphill and still deliver good pressure/flow to a faucet. Sump pumps generally would not have enough pressure to provide good delivery with 20 feet of head. Also, sump pumps may not be designed for potable water, while well pumps probably are intended for use with potable water.

Richard

snipped-for-privacy@krl.org wrote:

Yeah. After some thought, I think I am overthinking this. Will go to the pump store where I can probably pick up one someone didn't pay for and get a decent price, AND a pump that I know will do the work. All I have to pump is 55 gallons at a time, but I don't want to be there half an hour.

Steve

20 feet of lift is only about 10 PSI. If your truck's water tank can take 10 to 20 PSI, just pressurize the tank with the small compressor.

Nearly any thin cylindrical shell can take 20 PSI with no problem. Plastic soda bottles and beer cans can take over 100 PSI. If the tank has flat ends, they might need to be braced with plywood discs. and tierods.

The venturi effect may have a very slight effect on the air lift tube, but mostly it is the water pressure itself that lifts the column. By putting air in the column you're reducing the pressure inside, causing the water to rise. You need depth to make it work.

I'd look for a cheap water pump. You don't need much pressure for a 20 foot head, which is just about 10 psi. Garden hose connections should do it, although they're probably in violation of some health or building code.

John Martin

Yes, when I testet my vacuum pump. It sucked about 8m. Here is a plan:

HTH, Nick

Even good 'marine' pumps tend to be rated for head at ZERO flow and flow at ZERO head. Also they do not often maintain their ratings when they age a bit. It also may have been rated at 13.8 V or even 14.4 V and if run at 12V will underperform. Rough rule of thumb for boat pumps, buy twice the pump you think you need.

Hey Steve,

Well, I see lots of advice has been given already, so I'll leave any suggestions about your actual "question". I would ask for a clarification though. What's this "water" used for? If it is to be potable, them any use of air injection should be well thought out, as air is a carrier and nutrient of many forms of undesirable bacteria, and any compressed air that is not of a surgical grade will no doubt have contaminants from the compressor/tank itself. I know I wouldn't want to drink what comes out of the air-line on mine for sure!! And besides, as has been discussed here on RCM before, using compressed air you've generated is not very economical of energy. It is an expensive method of transferring energy.

As to the reason you are contemplating doing this...is it just for the "off-season" use and need for water in the cabin? If so, why not a marine/RV diaphragm type pump in line with a "55 gallon" ground level tank (the 55 gallons was what I think you describe as having already). They are readily available in 12VDC or 115VAC with a pressure switch to provide a relatively constant pressure in the lines. Assuming that the "seasonal" water supply is due to the freezing hazard, this would seem to make it more convenient in my estimation.

Take care.

Brian Laws>I want to lift water about 20 feet from my truck to the storage tank on the

What you described was frequently used in mining to generate large amounts of mechanical and pumping power. It is called a Pelton Wheel where you have a large, but very efficient water wheel driven by a hi pressure jet. You can create this by aiming the pressure washer at the impeller of almost any pump. You could probably make a swimming pool pump work if you got access to the impeller. The ultimate result is to use the power produced by a pelton wheel to drive another pump.

It is used for bathing and washing dishes. In both cases, it is heated first.

steve

Looking over all the answers is very enlightening, but 20 feet to a pump is a lot for average pumps. Why not put two pumps in line, one at the bottom and one halfway up? Sure, one might push or pull a little more than the other, but you'll get your water where it needs to be with the least amount of hassle. Then again, you could just roll the barrels out onto the manlift you recently acquired to get stuff up and down your little cliff house. Lessee,

55 gallons of water is well over 400 pounds, so that might be pushing the limits of the machine.

Right. In other words, it works great in an environment already filled with water, like a swimming pool, or the ocean. But, it won't work well, or at all, where the density outside is 100 times lower, like the air. You don't have the equivalent head of water at the inlet side in that case.

Jon