Sciencemadness Discussion Board

Could a thermal lance with Aluminium fuel be operated with compressed air?

Merryp - 27-8-2019 at 15:36

Given the fact that Al can maintain thermite reactions with weak oxidizers, like Fe2O3 or CaSO4, I was wondering if a thermal lance made of Aluminium could be operated in an "oxygen-assisted", but not pure oxygen atmosphere.

Any ideas?

Herr Haber - 28-8-2019 at 03:56

I thought about giving it a go with Al tubes and Oxygen then realized the tubes would burn way too fast.

Then... looking at some professional equipment I saw iron / steel tubes with inner wires (looks like a high voltage cable) that ressembled Al or Mg.

Interested in your findings.

Ubya - 28-8-2019 at 06:58

Quote: Originally posted by Merryp  
Given the fact that Al can maintain thermite reactions with weak oxidizers, like Fe2O3 or CaSO4, I was wondering if a thermal lance made of Aluminium could be operated in an "oxygen-assisted", but not pure oxygen atmosphere.

Any ideas?


yea but in thermite the aluminium is in a powder form, the finer the better. to burn a tube even if only 1mm thick you need oxygen, pure oxygen, compressed air is not enough

Merryp - 28-8-2019 at 10:15

Quote: Originally posted by Ubya  
Quote: Originally posted by Merryp  
to burn a tube even if only 1mm thick you need oxygen, pure oxygen, compressed air is not enough


Yeah, I guess so. Would've been neat to make a thermal lance with just a compressor, but that's probably not going to happen.

Twospoons - 28-8-2019 at 14:44

Given that industry is always looking for the cheapest way to do everything, if compressed air worked you would expect it would be in general use for thermic lances. Its not.

wg48temp9 - 28-8-2019 at 15:34

Quote: Originally posted by Twospoons  
Given that industry is always looking for the cheapest way to do everything, if compressed air worked you would expect it would be in general use for thermic lances. Its not.


DiIY plasma cutters work with air and yes there is the extra power from the plasma. I think most of the heat is from the oxidation of the steel because if you use the plasma supply for TIG welding it can only just weld 1mm steel but you can plasma cut 5mm easily. Thinking about that, the air blast may increase the voltage across the arc significantly and hence increase the power relative to the TIG but i still think oxidation is significant if not the primary source of power.



Twospoons - 28-8-2019 at 17:37

Sure, but if you turn off the arc, does the steel keep burning in a stream of cold air? AFAIK you need the arc to heat the air (and the steel) hot enough to get it to react with the steel.

[Edited on 29-8-2019 by Twospoons]

Antiswat - 2-9-2019 at 23:33

seeing how Al works with water after a bit of gallium, gallium could maybe help with your idea? maybe steam could be blasted through it to act as oxidizer? they did make aluminium-water rockets, frozen solid. but that was nano aluminium. at the very least gallium-treated Al should be very doable to powder