BBC’s Science Focus imagines a brighter future … brighter from the blazing fire-tornadoes used to clean plastics and oil from our over-polluted oceans:
Taking inspiration from a freak 2003 incident in Kentucky – where a bourbon spill sent 800,000 gallons up in flames, twisting into a 30m (100ft) fire whirl on a lake – Prof Elaine Oran and her team began to wonder whether the same process could be harnessed for good.
“We were joking about how it must have smelled,” she told BBC Science Focus. “Then we looked carefully at what was happening. Larger fire whirls were pulling in and eating up smaller fire whirls, actually pulling them in and absorbing them.”
So the team constructed a 4.8m-tall (16ft), three-walled triangular structure at a fire training facility in Texas, with a pool of crude oil floating on water at its centre. When ignited, it produced a roaring, nearly 5.2m (17ft) fire whirl.
Compared to conventional fire pools, it burned through oil 40 per cent faster, cut soot emissions by 40 per cent, and consumed up to 95 per cent of the fuel.
The secret is in the spin. Rather than spreading outward, the vortex sucks in oxygen from all sides – burning hotter and more completely, like a giant incinerator rather than a bonfire.
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You can read more about the fire-whirl method here, in Fuel.