It's quite a lift

A hydraulic system using a small plastic pipe?

A mining engineer would know

Being that we commonly power our whole households with solar panels these days here in Australia, that would seem to be the obvious solution for a similarly sunny climate. Would power a small pump no problem. Security? Well whatever your friend puts in will face the same problem. Three kilometres of plastic pipe is likely to go walkabout too. They may have to hire an askari or two (guards).
Tis quite a lift at 500 metres. Depending on what types of pumps are available down there, it may have to be done in stages with small tanks along the way.

I used to use a bore pump that dropped down the hole and ran on compressed air from a compressor mounted topside. Just a piston going up and down forced by air on one side and pushing the water up the pipe on the other. Worked very well. No idea of the possible lift with it though. And compressor is more high maintenance than a simple electric pump unit, which is a big consideration in Africa.

There must be other water supply systems in use in Tanzania they can model from?

As Ady1 says it's quite a lift and would need pressures in excess of something in the order of 50 bar or 700 psi to lift water to this level. This would require secure fittings and some very high pressure plastic/pvc pipe.

Tables give the following pressures for 1/2 in plastic pipe:

a) Schedule 40; Min burst 1910 psi, Working 358 psi.

b) Schedule 80; Min burst 2720 psi, Working 509 psi.

This is at an ambient temp of 23C however the above ratings are REDUCED TO 20% of the above figure when the pipe is operated at 60C. An uncovered/exposed pipe running for 3km with a low flow rate could show a significant rise in temperature. The problem will be alleviated as the pipe rises and the head diminishes.

Martin

Edited By Martin W on 23/10/2018 01:37:33

Ever thought about windmills , they work in outback Australia , don't need a lot of wind to power them

and they work at night. They are a piston pump and do not require a lot of maintanance.

An 8 foot windmill will lift 185 ft about 150 gallons per hour when using 13/4 pump .

Depends hugely on the geology, but a group our Scouts have worked with in Zambia have drilled more than 50 wells by hand, with the cost coming out about £5k including the India mkII Pump. They are mostly drilling through sand gravel and clay to a depth of 30 to 50 metres.

They use 2" black screwed pipe, with a home made drilling head (mostly weld and bits of hss) and a cheap non-return valve… which they suspend using a convenient tree or tripod….

They dig a small hole and fill it with water, then lift the "drill" up and drop it in the hole…. The head loosens the ground and the waste is carried upwards inside the screwed pipe and fountains out of the top. More pipe is screwed on the top and the hole gets deeper. It can need a lot of local labour to lift the drill pipe but that yields a benefit that everyone in the village helped and has some ownership of the project… at the end they pull the drill pipe up, push plastic pipe down the hole, and concrete the top over and mount the pump…. They add bleach to kill any contaminents pushed down during the "drilling process" and after a week start to pump the trick is to make sure the water comes from deep enough to be clean

It sounds (and looks) totally Heath Robinson, but it's done with local people, money raised here and in the US and makes a real difference. They've now dug/refurbished more than 50 wells and established a maintenance team for the next 10 years,,,, 60,000 people have clean,sustainable, water that they produce themselves

The charities Water Aid and drop4drop are very knowledgeable in this field.

Anything is possible of course if you have the money and materials.

However, given the lift of 500m pumping pressures in excess of 50 bar are probably not feasible for your situation, so stage pumping would be required, as a minimum 5 stages with tanks and associated control gear. Even in the developed world, pressures above 15 bar for public water distribution systems are avoided if possible primarily on grounds of cost and safety (cost of fittings doubles if you have use NP16 or higher).

You haven't stated volumetric requirements, but assuming that you can maintain a flow of 10 ls, the power requirements even to lift 100m are quite significant HQg/e1000 would be approximated to 110 10 10/800 just shy of 15kW for each stage of pumping (because water is heavy – if you don't believe me fill a couple of 20 litre jerries and carry them up a 500m hill!).

so unless significant resources are available or there is a convenient perched aquifer on top of the hill a donkey cart is probably your best option

.

Volumetric requirement was effectively stated by:

"How can a regular (no matter how small) supply be arranged ..."

but I doubt we can take that literally.

MichaelG.

Is it off the wall to suggest powering the thing with a stirling engine heat side from solar reflectors and cool side with some of the water?

According to one of the old locals (here in rural wales) some folk used to get their water via a simple overhead cable with tiny buckets powered by the remote stream they got the water from. I can't remember what the syetem was called but reported to be quite efficient.

pgk

How about some lateral thinking from 'Stub 'Blue Eyes' Mandrel…

Could PV powered dehumidifier be used to extract potable water from the atmosphere at the top of the hill?

A dessicant based dehumidification might work best (depending on the temperature/humidity profile) but is unlikely to generate drinkable water unless you re-distill it (solar still)?

You would have to take precautions against legionella.

Neil'

Is there much humidity in Tanzania, just asking?

Tony