Will Atomized Kerosene Ignite with a Spark in Controlled Conditions?

[guss]

Will atomized kerosene (that is, kerosene as mist in air), with a proper stoichiometric ratio in an environment of 1-2 atm and 15-45º C, ignite via a spark/plasma arc?

I know kerosene generally has to be in a warm environment to ignite, but I am trying to figure out a way to get around that (if you have any ideas, please let me know).

Thanks a lot!

 

[Pkruse]

Yep. Blew up a house that way when I was a kid. Made a great fuel air bomb, but I was too young to understand what one of those was at the time.

You do not need a stoichiometric ratio because burning happens on the surface of each atomized droplet. This is why you can run a diesel engine with fuel/air mixtures far less than stoichiometric, since diesel fuel and kerosene are exactly the same thing for the purposes of this discussion. (Not the same thing for other discussions.)

Since gasoline burns as a vapor and not as an atomized mist, that must be near stoichiometric.

 

[Jobrag]

Sounds as if your trying to start a jet engine.

 

[Averagesupernova]

My thoughts were similar to Jobrag. When I saw the title of the thread I said to myself: Let's hope so, otherwise there are a lot of jet airplanes in trouble. An electric arc is a very very common way to ignite fuel oil.

 

[guss]

Yep. Blew up a house that way when I was a kid. Made a great fuel air bomb, but I was too young to understand what one of those was at the time.

You do not need a stoichiometric ratio because burning happens on the surface of each atomized droplet. This is why you can run a diesel engine with fuel/air mixtures far less than stoichiometric, since diesel fuel and kerosene are exactly the same thing for the purposes of this discussion. (Not the same thing for other discussions.)

Since gasoline burns as a vapor and not as an atomized mist, that must be near stoichiometric.

That's interesting, thanks.

Sounds as if your trying to start a jet engine.

Yeah. In model jet turbine engines, fuel is, as far as I can tell, always vaporized through tubes inside the combustion chamber. This makes it so that the engine must be hot to run on kerosene (so it's usually started on propane then switched to kerosene), and I believe it's also less efficient. I'm hoping to use 2 or 3 micro atomizers to get the job done, and hopefully I can get it to work.

 

[darrinburr]

i read a post here,

i'm trying to get to the guy that asked a question how to ignite kerosene 40 deg. c .

i'am neither a chemist nor physicist.. i am an ad-hock professor..

the solution is simple, and you don't even need a "spark" the apollo missions did it all the time, insertion into lunar orbit and lunar exit.. but it has to be done without nitrogen (which we breathe 75% +15% oxygen + the others) so we need the vacuum and cold of space to get it done... that's why it works out there.. and it's very cold.

it's LOX(super cold liquid oxygen) and kerosene... mix it correctly, it just works! no spark needed!
we used LOX plus near frozen Hydrogen on the space shuttle missions..
[RIP challenger 86' and Columbia 03']

the great physicist, Michio Kaku once said "..we cannot get off this planet without being a tier 1 hydrogen, society.."

i say lets get it done already!!

 

[jrmichler]

Will atomized kerosene (that is, kerosene as mist in air), with a proper stoichiometric ratio in an environment of 1-2 atm and 15-45º C, ignite via a spark/plasma arc?

This is an old farmer cost reduction scheme. Kerosene was cheaper than gasoline, so they had an incentive to run tractors on kerosene. The technique was to put a blanket over the radiator, run the tractor hard until the water started to boil, then switch to kerosene. It worked on the low compression engines of early tractors, and as long as the water kept boiling.

This is from my father, who left the farm as soon as he was old enough, and never looked back.

 

[Flyboy]

i read a post here,

i'm trying to get to the guy that asked a question how to ignite kerosene 40 deg. c .

i'am neither a chemist nor physicist.. i am an ad-hock professor..

the solution is simple, and you don't even need a "spark" the apollo missions did it all the time, insertion into lunar orbit and lunar exit.. but it has to be done without nitrogen (which we breathe 75% +15% oxygen + the others) so we need the vacuum and cold of space to get it done... that's why it works out there.. and it's very cold.

it's LOX(super cold liquid oxygen) and kerosene... mix it correctly, it just works! no spark needed!
we used LOX plus near frozen Hydrogen on the space shuttle missions..
[RIP challenger 86' and Columbia 03']

the great physicist, Michio Kaku once said "..we cannot get off this planet without being a tier 1 hydrogen, society.."

i say lets get it done already!!

… okay, wait…

Are you suggesting that kerosene is hypergolic with liquid oxygen?

That is completely incorrect. You can get it to be hypergolic with high-test hydrogen peroxide, but HTP is hypergolic with pretty much anything even remotely flammable.

At cryogenic temperatures, even spark ignition will not light off kerosene/LOX. That’s why they use tetra ethyl aluminum/tetraethylborane (TEAL/TEB) for ignition on the Merlin engines on the Falcon 9.

At ambient temperatures in a gas turbine engine, the spark required to ignite kerosene during startup is… powerful. The spark plug on your car will not cut it. You need a lot hotter spark than a traditional spark plug can provide. Usually you need a capacitive discharge igniter, and even the small ones run in the single digit joule range. The ones on airliners are easily 20+ joules and will straight up kill you on the spot if you accidentally discharge it through you.

Once you’re lit, though, whether on a gas turbine or a rocket engine, you no longer need an ignition source to maintain combustion. The constant flow nature of the engines means that there is always combustion occurring in the combustion chamber and you’re just adding fresh reactants. Piston engines running on kerosene get around the ignition source requirement by running high enough compression, and by extension high enough temperature, to cause autoignition of the fuel as it gets sprayed into the cylinder.

 

[Borek]

This thread has run its course and will be closed.