Science

New "blue whirl" fire tornados spin up a cleaner burn

New "blue whirl" fire tornados...
Researchers have discovered a new type of fire tornado they call a "blue whirl", which burns cleaner and more efficiently than its yellow counterparts
Researchers have discovered a new type of fire tornado they call a "blue whirl", which burns cleaner and more efficiently than its yellow counterparts
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Blue whirls could find applications in cleaning up oil spills by burning the fuel away more completely, with less pollutants released into the water and air
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Blue whirls could find applications in cleaning up oil spills by burning the fuel away more completely, with less pollutants released into the water and air
Researchers have discovered a new type of fire tornado they call a "blue whirl", which burns cleaner and more efficiently than its yellow counterparts
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Researchers have discovered a new type of fire tornado they call a "blue whirl", which burns cleaner and more efficiently than its yellow counterparts

Harnessing the power of fire has served humanity well for thousands of years, but fire tornadoes are harder to tame. Now a team at the University of Maryland has discovered a new type of fire tornado they've dubbed "blue whirls", which produce a cleaner burn and could be harnessed to reduce carbon emissions and burn away oil spills with fewer airborne pollutants.

"A fire tornado has long been seen as this incredibly scary, destructive thing," says Michael Gollner, co-author of the study. "But, like electricity, can you harness it for good? If we can understand it, then maybe we can control and use it. This is the first time fire whirls have been studied for their practical applications."

Looking at the well-known yellow fire whirls, the team's goal was to investigate how the these burn fuel on the surface of water. In the process, they discovered blue whirls, a previously unobserved type of fire tornado that burns more efficiently and more stably while producing much lower emissions than their turbulent yellow counterparts.

"Blue whirls evolve from traditional yellow fire whirls," says Elaine Oran, co-author of the paper. "The yellow color is due to radiating soot particles, which form when there is not enough oxygen to burn the fuel completely. Blue in the whirl indicates there is enough oxygen for complete combustion, which means less or no soot, and is therefore a cleaner burn."

Blue whirls could find applications in cleaning up oil spills by burning the fuel away more completely, with less pollutants released into the water and air
Blue whirls could find applications in cleaning up oil spills by burning the fuel away more completely, with less pollutants released into the water and air

This efficiency could see blue whirls being employed on the site of ocean oil spills, where cleanup efforts sometimes involve corralling the crude oil into a thick layer that is then burned, producing clouds of toxic smoke. With the ability of the blue whirls to burn the oil more completely, the amount of pollutants that are released into the air and water would be reduced. The main hurdle to that process, the team says, is scaling up the blue whirl from the small lab-made versions.

"Fire whirls are more efficient than other forms of combustion because they produce drastically increased heating to the surface of fuels, allowing them to burn faster and more completely," says Gollner. "In our experiments over water, we've seen how the circulation fire whirls generate also helps to pull in fuels. If we can achieve a state akin to the blue whirl at larger scale, we can further reduce airborne emissions for a much cleaner means of spill cleanup."

In addition to improving fuel efficiency and environmental cleanup, blue whirls may also find use as a platform for studying vortices in the lab, and how a vortex can break down in fluid mechanics.

"A fire whirl is usually turbulent, but this blue whirl is very quiet and stable without visible or audible signs of turbulence," said Huahua Xiao, assistant research scientist in the Clark School's Department of Aerospace Engineering and corresponding author of the paper. "It's really a very exciting discovery that offers important possibilities both within and outside of the research lab."

The research appeared in the journal Proceedings of the National Academy of Sciences (PNAS) and the new blue whirls can be seen in action in the video below.

Source: University of Maryland

UMD Discovers the Blue Whirl

8 comments
DarwinG
enjoyed the article and video clip, then I realized what I was watching!!! It took me a minute, but I have done a form of this hundreds of times (shock)! As a young man & apprentice Mechanic, on uncounted times I remember "Lighting up" a Oxy-Acetylene cutting torch!! Same principle different equip.. 1) step 1 open the valves of both "tanks" ! 2)from a closed position, open (slightly) first the Acetylene line valve @ the base of the torch handle. 3) Carefully light the gas being released. this will give you a dark yellow an sooty flame. 4) now carefully (and slowly) open the Oxygen control valve @ the base of torch handle, slowly increase the Oxygen flow until the flame turns a light Blue color!!! I have been using this kind of apparatus since I was a young man, and I and thousands if not millions others have been "heating" and Cutting Steel & iron products for decades! My point is not to Criticize but to point out the Tech. is already "out there" although in a different application. Don't reinvent just re-purpose what is already there working!!!!!
Eric the Red
I think this is more of a "lets try and see if nature can burn better". Lighting Oxy-Acetylene requires pure oxygen, this looks like it uses drafts to make the fire swirl and suck in 'air' to add the extra oxygen. Probably a formed metal grill could induce cleaner burning swirling flames. This experiment looks like a forced draft is use to start and reinforce the swirl.
windykites
Corredt me if I am wrong, but a yellow flame contains glowing soot(carbon) particles. A more 'efficient' blue flame has combined the carbon with oxygen, creating carbon dioxide. What is worse: soot or carbon dioxide?
Veronica Roach
Have to say - blue flame technology is common in oil heating apparatus - you have to burn with a blue flame or the whole thing goes all sooty on you (just as they describe here) - so I really do not see this as anything they have just 'discovered' - obviously if you have never met actually flaming appliances because you have been surrounded only with invisible heating systems and never had to think about getting warm, you may think you have discovered something new - no - like others responding here, this is nothing new at all !
Bob Flint
How do you expect to control a burn on a undulating open ocean. The winds cannot be controlled or commanded, we cannot even transport fuel without making a mess...and the best we can come up with is to burn it, not only wasteful, but deadly in so many ways...
Don Duncan
Observing and evaluating the "blue whirl flame" as 100% efficient is a good start, but just the beginning. We already knew it was the optimum configuration. How do we induce and maintain it in all situations? That's the question. That's why I read the piece. I was expecting to find that answer, or at least an indication.
Imran Sheikh
this is more like Focused Fire like Focused Light, i feel the color of light will change with pressure.
Future3000
Is this a late April fool of the University of Maryland? DarwinG and Eric the Red said it: to increase Oxygen / fuel ratio for better burning by increasing airspeed is nothing new! I think it's average knowledge of mankind since bronze age!