Inside a cylindrical cage of wire mesh a flame is burning. If the cage is set in rotation, an impressive fire column evolves.
How does it work?
The hot combustion gases rise upwards and drag air from outside into the cage. The further the air that goes in through the wire mesh gets to the axis of rotation, the faster it rotates. (pirouette effect) causing the tornado to spin really fast and the flame to reach a height of about 2,5 m.
Safety reference:
The fuel used is a safety fire gel on the basis of isopropanol which cannot bleed out. It remains safely on the metal plate in the middle of the cage. It produces no soot. The rotating plate is very stable and cannot tip over by itself. The flame cannot get out through the mesh.
The fire column only evolves if the cage is spun. In the unlikely case of something unforeseen happening, the cage that rotates by about 1 rpm can easily be stopped and the column instantly disappears. Overall, the fire will burn for 2-3 min during which time the fire column will be visible for about 1 min.
We have measured the heat which this experiment generates directly under the ceiling in a room measuring 30m2 and a ceiling height of 4,90 m: After 3 minutes the temperature does not exceed 45°C when the initial temperature is 18,5°C.
However, in case of doubt, we recommend having a firefighter present to supervise the experiment during the performance.
