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How to get liquid with bubbles running through surgical tubing? Answered

Hello all,

I may just not be searching the right terms, but I can't for the life of me find a way to have colored liquid with bubbles in it run through surgical tubing. (Basically, the bubbles show that the liquid is flowing.) I've seen this effect in movies using smaller diameter tubing and also in larger tubing in the frame work of old style juke boxes.

For halloween, I'm thinking about a throwing a mad scientist party and using a black light lit  fluorescing liquid In the tubing. Bonus points if it's portable for the costume!

And yes, I haven't really played with pumps before, so if most do this out of box, please be kind. :)

many thanks!



Best Answer 6 years ago

There's a pretty simple solution to your problem. Use gravity. In those old juke boxes, the fluid isn't moving, it's the bubbles rising. All you have to do is have an upper and lower reservoir connected by a tube. Fill it with oil, and then put a small bubble of air in the lower reservoir and watch it rise. Do this at an even rate and you've got the effect.

A pretty easy way to do it it make an upside down dripping funnel. Make the hole at the top small you get slow bubbles, make the hole big you get a fast stream of them. All you have to do is make a valve at the bottom and refill the funnel with air every once in a while. Note, the funnel has to be open to the fluid on both sides. (Imagine air surrounding a funnel dripping out water. It's open to the air at the top and bottom. Now, flip it upside down in a pool and put air in it... Same effect, different direction.)



Many thanks to everyone! I think I'll probably use multiple answers for multiple props. (really like the idea of using the bubbler for a mad scientist backpack tank and the oil for a table top one.) If it works out well, I'll post an instructable on it.

One simple tip is to use a high-viscosity liquid like oil, the bubbles can be much easier to manipulate nicely than water.


If you are sucking the water (pump after the tube) rather than pushing it (pump before the tube) then you could probably get away with a pin prick hole at the beginning of the tube (you may have to experiment to get the right hole size). If you are pushing the liquid and try this you pretty much will just get a jet of water on the outside.. Just make sure that when placing the pump in a sucking position you don't have too much length or height difference to overcome or you risk cavitation.

Otherwise do as frollard said: Use an air pump. Maybe even add one of those aquarium diffusion blocks to get lots of small bubbles.

air pump.

Usually aquarium - you can get them that run on line voltage or battery powered - if you want to run wireless then battery is the way to go. Search battery air pump.

To get the bubbling effect there are a couple options -- one is to insert bubbles in one end of a filled tube letting the air out the other side -- so long as the bubbles don't push the liquid out of the tube you're okay (need a larger diameter pipe)

also an option is to build a peristaltic pump to move the liquid and bubbles through the pipe together.