Scienceshow/Cryogenics/The Fountain

• Status for this guide: Not yet finished
• Scienceshow/Physics, Scienceshow/Cryogenics

Safety

Safety Class

• Very dangerous (Should only be attempted after careful training)

Required Safety Equipment

• The show performer: Glasses / Cryogenic gloves

• Audience/participants: None.

Materials

• One brass tube, 5cm across, 40 cm high. This brass tube is closed on one end and open on the other.
• One cork with two holes in it which fits on the brass tube
• Two glass tubes which fit into the holes in the cork, 40cm long
• Liquid nitrogen
• Water
• A stable table

Procedure

Preparation: Stick the glass tubes into the cork. Make sure the glass tubes stick out about 5 cm above the cork.

Put on safety goggles and cryogenic gloves.

Put some water onto the table, and put the tube in this - with the closed side down. Pour the liquid nitrogen into the tube. Now put the cork with the glass tubes down into the brass tube. This will cause a massive fountain of liquid nitrogen to squirt out of the glass tubes.

The waste product (liquid nitrogen) will evaporate into the air.

Dangers

• Be sure to always wear gloves and glasses when doing this experiment
• Be sure to NEVER do this experiment twice in a row, while the equipment is still cold. If the equipment is still cold, the lower temperature difference will cause the liquid nitrogen to evaporate slower. This means that you get liquid nitrogen sprayed all over you!
• Keep your head below the tube when doing this experiment. Liquid nitrogen which lands in your neck is less dangerous than liquid nitrogen which lands in your face

Other Factors

As said above, the higher the temperature difference between the equipment and the liquid nitrogen, the larger the effect. Therefore, it is possible to increase the effect of this experiment by heating the equipment with a blow drier beforehand.

Show notes

It is very important that you need two people to do this experiment; one pours the liquid nitrogen into the fountain tube, the other one puts the cork on. If you try to do both by yourself, so much liquid nitrogen will have evaporated that the effect will be much less.

Explanation

What's taking place

The liquid nitrogen evaporates, creating more pressure in the tube. Because the glass tubes are below the waterline of the liquid nitrogen, the liquid nitrogen is pushed out instead of the gas.

In the real world

Espresso machines work like this; steam is built up in a chamber, and the boiling liquid is pushed through coffee powder.

More Information

• Websites with more info the end.

Acknowledgements

Experiment developed by Stichting Rino Page made possible by EuroPhysicsFun

References

See Wikipedia:Footnotes for an explanation of how to generate footnotes using the <ref> and </ref> tags .

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