Burning Liquid Fuel in a 9 Foot Vortex

About 100 cc of burning petroleum ether (a mixture of heptane and pentane) was poured on the floor when the vortex was already established. The high air speed across the surface of the pool picks up and atomizes the fuel and carries the burning droplets up the vortex. The burning droplets, and the incandescent particles of soot created, tend to sit at a constant distance from the center, producing a hollow tube of fire. Note the relative transparency of the tube.

The horizontal band at the top of the image is a fluorescent light in the background. The fog or smoke at the bottom is just that, glycol smoke introduced to make it possible to find the bottom of the vortex core when dumping in the fuel.