Thread: Airlifts - pumping water around a gravity system using only air

I came across this interesting piece - submergence and also sizing of air pumps:

B2.jpg
Source: https://www.plantservices.com/articles/2002/12/


Improving airlift performance

There's also an interesting paper on the use of vortices on improving airlift performance: https://digitalcommons.bucknell.edu/...=honors_theses this uses a back flow through the air injection nozzle at 45 degrees to make the airlift water rotate - including the air.

So by having an combined water + air injection at the bottom at 45 degrees the vortex created helps improve performance. Now they are using gallons per minute flow rates, so it would be interesting to see how much of an improvement it would make for a lower flow rate.

Thanks for the info Nick. Although the conclusions of the paper on making a vortex/ swirl of injected water suggests that it made little improvement to flow in most configurations.

Although others reading this may not want to go into that much detail, it does show that airlifts are backed up by science, and not just a bunch of people on a forum who claim they work.

I must admit the main reason why i was initially hesitant about using air lifts, rather than a conventional pump, was in case it didn't work, as it seems to good to be true.

But built in the right way, boy do they work.

Sent from my SM-A520F using Tapatalk

Originally Posted by Twhitenosugar

Thanks for the info Nick. Although the conclusions of the paper on making a vortex/ swirl of injected water suggests that it made little improvement to flow in most configurations.

Although others reading this may not want to go into that much detail, it does show that airlifts are backed up by science, and not just a bunch of people on a forum who claim they work.

I must admit the main reason why i was initially hesitant about using air lifts, rather than a conventional pump, was in case it didn't work, as it seems to good to be true.

But built in the right way, boy do they work.

Sent from my SM-A520F using Tapatalk

Oh yes - there's a massive amount of academic research into airlifts as they are used extensively in industries such as agriculture etc. I was looking at the efficiency of using slugs (bubbles the width of the pipe) rather than a small bubble flow at the side.

I worked out the lpm air for my 1.75m submerged airlift for 10,000lgh flow rate = 48.69 lpm of air according to the diagram..

However I'm concerned that it doesn't take into account pipe diameter..