Manual Water Maker

You guys can pedal all you want, that's out of my league.

But I do like the idea of a longer lever arm that you can squish out ie a liter at a time.

 

The problem Fanie is that you need X amount of power to move Y amount of water past the membranes aT Z pressure for a water maker to make W amount of water. When you do the math tryin to operate the pump using arm strength will wear you out way to fast to really be practical. Though you could use it to make the given system easier to operate.

 

That is true Stumble, but if you use a lever with a 10:1 ratio and you weigh 80kg you have 800kg to apply on a certain surface area plunger to achieve forcing water through the membrane.

The smaller the plunger the higher the pressure per sq mm is going to be, the larger the plunger, the lower the pressure per sq mm. One will now have to calculate what size will move a bit of water without having to pump water as a main activity.

As soon as Richard comes up with his information data bank on the required pressures, then one can calculate the amount of water that can be moved with reasonable force. It may well turn out to be acceptable.

 

>>>>As soon as Richard comes up with his information data bank on the required pressures, then one can calculate the amount of water that can be moved with reasonable force.<<<<


Well Fanie that will not happen! And I made that pretty clear, I do´nt have such data, thats not my ballpark!


Stumble
<<<<You are right increasing the filter size would increase the desalination capacity>>>>

NOT filter! Membrane is the issue!

 

The hard part of building a watermaker is the RO membrane. Pumping water to a thousand PSI? That's easy. You can get a pump for under a hundred bucks at any auto parts store that will do it- they're used all the time for pressure washers. It's that darn membrane that's the engineering (and maintenance) nightmare.

If you want a manual watermaker, no electricity required, a pedal-driven pressure pump would certainly work. You wouldn't really save anything on the capital cost, though, because that motor is one of the cheapest, simplest parts of the thing. As bipeds, we humans can do much more work with our legs than with our arms; I frankly don't see much point in a hand-pumped watermaker except as an emergency backup or for a liferaft.