Over the ages, a lot of human activity has been concerned about getting water from where we find it to where we want it. If you want to move water to a lower elevation, there’s no problem. But if you want to move water up, you need a pump. The ancients used what we call Archimedes’ screw to raise water. But a Wirtz pump as [Steve Mould] shows in the video below, is another kind of spiral pump that is also very old and uses the same basic principle as the screw pump.
In a way, the Wirtz is just an Archimedes’ screw in cross-section. Part of what makes it work, however, is air-locking. [Steve] made a small model but found it didn’t work exactly as he expected. Of course, investigating that led to some interesting observations.
To solve the problem, a field trip to see a huge working Wirtz pump was in order. As it turns out, the size of the water channel is a balance. It can’t be too small or too large. Surface tension plays a part, as does the transport of trapped air through the system.
[Steve] learned some lessons and made another pump that — while not as stylish — worked much better. We couldn’t help but think this would be easy to put together post-apocalypse, so probably a good thing to have in your bag of tricks.
If you have electricity and motors, of course, it is easy. You can even 3D print a centrifugal pump.