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This is definitely the most detailed description of fire I've ever seen. Note - from an artistic perspective, and AFAIK, wood (and kerosene, and other sooty fu

This is definitely the most detailed description of fire I've ever seen. Note - from an artistic perspective, and AFAIK, wood (and kerosene, and other sooty fuels) produce a "deep"-looking flame, while propane (and other 'clean' fuels) produce a "shallow"-looking flame, due to the black colors introduced by the soot. Compare the look of the fire in these propane effects: http://www.effectspecialist.com/special_effects_Propane_flame_cannons.htm http://www.effectspecialist.com/special_effects_Propane_flam... to the look of the fire in this kerosene effect: http://mentalfloss.com/article/71663/watch-mesmerizing-fire-tornado-spin-slow-motion http://mentalfloss.com/article/71663/watch-mesmerizing-fire-... This is also (AFAIK) why you generally don't see "sooty" colored flame effects - the amount of the coloring agent that is needed to overcome the "darkening" of the soot is impractical, at least for large-scale effects. Source: That one time I got really excited the talked to people who'd made a (gigantic) flame tornado art piece.

JshWright 10y ago
The differences in the examples you provided have more to do with the exposure settings of the camera than the carbon (soot) content of the flame. It's actually the heated carbon particles that give flames their yellow color. The soot itself is what's glowing.
- RangerScience 10y ago
  Hmm. I mean, your first point is straight up wrong - I've spent far too much time looking at (and taking pictures of!) different kinds of fire to think the difference in appearance between propane and kerosene is just the camera settings. But your second point seems pretty reasonable; I'm still not sold. Can you go into more detail as to how the presence of glowing soot in one kind of fire - and absence in the other - would create the appearance of solidity (or lack thereof)? Edit: Sorry, that came out real aggressive. I mean, can you throw some more words at how the glowing soot changes the look of the fire - regardless of the artistic interpretation of the difference?
  - JshWright 10y ago
    Sorry, I was referring to the specific examples you provided. While those flames would indeed look different, those differences would be completely overshadowed by the differences in exposure. In one case you have flames that are _completely_ blown out (due to the dark surroundings), and in the Slow Mo Guys video the camera has been set to capture the details of the flame. There are absolutely differences between various flames burning in various conditions. When it comes to burning hydrocarbons (propane, methane, kerosene, gasoline, etc), that difference has more to do with the fuel/air mixture than it has to do with the specifics fuel. It is a lot easier to get a good fuel/air mixture when burning a gas like Propane. When a pool of liquid is burning, it is almost impossible to get a good mixture of fuel and air (even with a bunch of fans), so it is burning fuel rich, resulting in a lot of unburned fuel intermixed with the flame. I would suggest Periodic Videos recent video about the bunsen burner. They achieve both sorts of flames you're talking about with a single fuel source (methane). https://www.youtube.com/watch?v=in9BGz958jg https://www.youtube.com/watch?v=in9BGz958jg
  - mtreis86 10y ago
    If you want to provide visual evidence as an argument, you should really have the same camera and lens and exposure settings. Not some random images off a couple websites. Insisting that there is a difference doesn't reinforce your previous statements at all. The images here https://en.wikipedia.org/wiki/Colored_fire https://en.wikipedia.org/wiki/Colored_fire all have the same background and setup to them. To get back on topic: "Glowing soot" or Blackbody radiation emitted by solid particles in a flame, is by pyrotechnic standards, a washed out flame. Smoke as a background is best not burning. Pretty simple math - to get a red flame of 50 lumens to appear as red when background has gone up to 100 lumens requires a 150 lumen flame. This is why we don't use fireworks in the daylight. Source: Chapter 11 and 21 in fireworks practices and principals https://exploders.info/Files/Library/eng/pyrotechnics/firevorks_printsiples_and_pratstitse__ronald_lantsaster__-_1998_462s..pdf https://exploders.info/Files/Library/eng/pyrotechnics/firevo...
    - RangerScience 10y ago
      > same camera and lens and exposure settings Well, yeah, that would make a way more effective argument, but I'd have to obtain a a) manual camera, b) sizable propane fire c) sizable kerosene/etc fire, d) b & c having nearly identical brightness, and e) a place and time to do it. These are doable, but not on an internet-debate timeline. Think about the differences in your experience with propane and wood fired fireplaces. Most people have had at least one experience with both, and those are the only things I can think of where the flames in both are of comparable size/brightness. > Smoke as a background is best not burning I'm sorry, I don't understand. Are you missing a word, maybe? > [link] Amazeballs link, thank you! Do you know the name of the fireworks that produce large quantities of specifically fire? I know them as "gas bombs", but I have no idea if that's the correct technical term.
marcosdumay 10y ago
Next time you are playing with clean fires, try spreading¹ different kinds of salts above it (sodium, magnesium and iron salts will be easy to find, cooper is great). 1 - The easiest is to spread them over a metal mesh, try not too mix the salts too much.

JshWright 10y ago

The differences in the examples you provided have more to do with the exposure settings of the camera than the carbon (soot) content of the flame. It's actually the heated carbon particles that give flames their yellow color. The soot itself is what's glowing.

RangerScience 10y ago
Hmm. I mean, your first point is straight up wrong - I've spent far too much time looking at (and taking pictures of!) different kinds of fire to think the difference in appearance between propane and kerosene is just the camera settings. But your second point seems pretty reasonable; I'm still not sold. Can you go into more detail as to how the presence of glowing soot in one kind of fire - and absence in the other - would create the appearance of solidity (or lack thereof)? Edit: Sorry, that came out real aggressive. I mean, can you throw some more words at how the glowing soot changes the look of the fire - regardless of the artistic interpretation of the difference?
- JshWright 10y ago
  Sorry, I was referring to the specific examples you provided. While those flames would indeed look different, those differences would be completely overshadowed by the differences in exposure. In one case you have flames that are _completely_ blown out (due to the dark surroundings), and in the Slow Mo Guys video the camera has been set to capture the details of the flame. There are absolutely differences between various flames burning in various conditions. When it comes to burning hydrocarbons (propane, methane, kerosene, gasoline, etc), that difference has more to do with the fuel/air mixture than it has to do with the specifics fuel. It is a lot easier to get a good fuel/air mixture when burning a gas like Propane. When a pool of liquid is burning, it is almost impossible to get a good mixture of fuel and air (even with a bunch of fans), so it is burning fuel rich, resulting in a lot of unburned fuel intermixed with the flame. I would suggest Periodic Videos recent video about the bunsen burner. They achieve both sorts of flames you're talking about with a single fuel source (methane). https://www.youtube.com/watch?v=in9BGz958jg https://www.youtube.com/watch?v=in9BGz958jg
- mtreis86 10y ago
  If you want to provide visual evidence as an argument, you should really have the same camera and lens and exposure settings. Not some random images off a couple websites. Insisting that there is a difference doesn't reinforce your previous statements at all. The images here https://en.wikipedia.org/wiki/Colored_fire https://en.wikipedia.org/wiki/Colored_fire all have the same background and setup to them. To get back on topic: "Glowing soot" or Blackbody radiation emitted by solid particles in a flame, is by pyrotechnic standards, a washed out flame. Smoke as a background is best not burning. Pretty simple math - to get a red flame of 50 lumens to appear as red when background has gone up to 100 lumens requires a 150 lumen flame. This is why we don't use fireworks in the daylight. Source: Chapter 11 and 21 in fireworks practices and principals https://exploders.info/Files/Library/eng/pyrotechnics/firevorks_printsiples_and_pratstitse__ronald_lantsaster__-_1998_462s..pdf https://exploders.info/Files/Library/eng/pyrotechnics/firevo...
  - RangerScience 10y ago
    > same camera and lens and exposure settings Well, yeah, that would make a way more effective argument, but I'd have to obtain a a) manual camera, b) sizable propane fire c) sizable kerosene/etc fire, d) b & c having nearly identical brightness, and e) a place and time to do it. These are doable, but not on an internet-debate timeline. Think about the differences in your experience with propane and wood fired fireplaces. Most people have had at least one experience with both, and those are the only things I can think of where the flames in both are of comparable size/brightness. > Smoke as a background is best not burning I'm sorry, I don't understand. Are you missing a word, maybe? > [link] Amazeballs link, thank you! Do you know the name of the fireworks that produce large quantities of specifically fire? I know them as "gas bombs", but I have no idea if that's the correct technical term.

marcosdumay 10y ago

Next time you are playing with clean fires, try spreading¹ different kinds of salts above it (sodium, magnesium and iron salts will be easy to find, cooper is great). 1 - The easiest is to spread them over a metal mesh, try not too mix the salts too much.