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Flame Tornado

Public summary: 

Watch a tornado form under the effects of moving air.

Demo of a flame tornado
Useful information
Kit List: 

- Rotating turntable with attached mesh thingy
- Cotton wool & petroleum jelly
- Lighter


Old explanation:
Demo of a flame tornado - a small fire is made at the centre of a rotating mesh tube. The tube is rotated giving incoming air angular momentum, so it gets dragged in and makes a cool tornado effect.

To set up place a crucible at the centre of the tray. Let people give it a spin to show a tornado isn't formed like that. Place mesh around and spin again. This messes with incoming air and leads to vorticies and tornadoes through scientific magic someone should explain here!

New explanation
Ensure the turntable is placed on a flat surface outside. Cover cotton wool with petroleum jelly ahead of demonstrating because a) it's not nice to do and b) it will make demonstrating easier. Place some in the centre of the turntable and (very carefully) light it using the lighter (aim for the cotton wool as the jelly itself isn't flammable and will melt). Make sure people are standing out of the way when you do this! Then, spin the turntable and you should see a flame tornado.

I have no idea how this works, so [insert science here].

Risk Assessment
Date risk assesment last checked: 
Wed, 05/02/2020
Risk assesment checked by: 
Conor Cafolla
Date risk assesment double checked: 
Wed, 05/02/2020
Risk assesment double-checked by: 
Beatrix Huissoon
Risk Assessment: 

A metal jar lid of cotton wool & petroleum jelly is burnt within a mesh cylinder that will rotate on a turntable. As it rotates the flame gets drawn into a tornado, due to conservation of angular momentum.

Hazard Risk Affected Person(s) Likelihood Severity Overall Mitigation Likelihood Severity Overall
Hot surfaces People, and especially fingers, could get burned if they get into the fire or touch hot surfaces. All 3 3 9 Only touch insulated surfaces (i.e. the turntable edge and not the mesh). Keep crowds back to make easier to control. Only to be done by an experienced demonstrator who has practised ahead of time. Audience to be told not to touch the experiment, and demonstrator to avoid continuously running the experiment to minimise contact with the hot jar lid/mesh.

The mesh cylinder is held onto the turntable very well and acts as a shield to stop people touching the flame itself, and stops the it from escaping.

The demonstrator should exercise caution when touching the lid especially, as it will be very hot when you come back to it. Keep trough of water nearby to submerge the lid and cool completely.

In case of accident, run burned areas under cold water for 10 mins or until it stops hurting - whichever is longer. Summon a first aider to assist the casualty.

2 3 6
Burning liquid The burning liquid could escape, and cause a fire/burns. All 3 4 12 Be very careful about where it is set up so there is nothing flammable nearby - to be done on a clear piece of flat ground only. The audience should be made to stand well back, and the demonstrator should maintain a safe distance while demonstrating, keeping long hair tied back and skin covered.

There should be a fire blanket close at hand (safety box).

Petroleum jelly is used because it is viscous so will not fly out too easily

The jar lid is constrained so it remains central.

Smother any flames with the fire blanket. If fire spreads call 999. In case of burns follow actions for burns above.

2 3 6
Publicity photo: