Please help! I can't really believe this happened!

[CntryBoy]

Hello all. I'm new to this forum. I stumbled across this group while researching vaporization temps and characteristics of diesel burn rates. A recent acquaintance of mine was involved in a terrible accident last week in which he was badly burned. He, like many other folks in Louisiana were cleaning up after the recent storm. This gentleman used diesel, straight from the bulk tank he uses for his JD tractor. He put diesel into an open topped 5 gallon bucket and prepared to do some brush pile burning. He trickled some diesel onto the pile, he then placed the can safely out of the way, leaned over with a striker(plastic one that emits a small flame)and lit the diesel that was on some leaves. It exploded! Both of his legs were badly burned, his R arm and hand were terribly burned. He was and still is being treated at a local burn unit. This man is like most of us... Very much a farm boy, very capable, very much a common sense type, had done this hundreds of times, etc. No there was nothing else but diesel in the can. No, there was nothing else on the pile besides branches and leaves that had been raked and piled earlier that day. No there was no chance of anything else in the bucket. What I'm hoping for are concerned thoughts/opinions on what happened and how to keep this from happening to someone else. We have all done this countless times before. Could the diesel have vaporized due to the hot, humid 92% ,heat index day of 105 degrees so common in Louisiana? If so, what are the ideal parameters for such a situation? Thanks in advance for help with this very perplexing situation. Please do not say "There's no way..." I am not asking for insults, or directions on the proper way to use diesel, or the proper way to burn a brush pile. What I am looking for are good, scientific based ideas on why the diesel "exploded"? I know we all think this won't happen to us but it happened to him while doing what I have done many times. Thanks again for your help!

 

[MossRoad]

Maybe there was an unseen container, can, etc... in the pile.

 

[Thomas]

Welcome to TBN.

Wishing speedy recovery to gentleman.

"It exploded!"
Maybe diesel was mix with strong additive like non gel etc.

 

[BrkMstr]

Sounds like you already know what the temp has to be for Diesel to explode - those numbers do not change unless another chemical / element enters in, had the fuel been treated? If not had the vegetation been treated with some chemical? Methane / compost - You said the pile was wet, wet "hay" placed in a dry hot barn (compressed area works) ignites add fuel to it, it explodes - regardless wishing him a good recovery - sounds like he was doing the right thing, cleaning up after a storm sad to hear he got hurt.....

 

[bcp]

From
https://southeastpetro.com/wp-content/uploads/2015/12/Diesel-FlashPoint.pdf

Flash Point Properties - At elevated temperatures, diesel fuel will begin to vaporize and become ignitable with an open flame. The lowest temperature at which the vapor will ignite is the fuel's flash point. Diesel fuel #2 as specified by ASTM D975 has a minimum flash point of 125.6 F. For diesel fuel #1, the minimum flash point is 100 F. (Winter blends of #1 and #2 are allowed to be 100 F minimum as well). If the flash point falls below these values, the fuel becomes potentially unsafe to handle.

==============

If the fuel was in the sun on a 92 degree day, it could be over 100 degrees.

Bruce

 

[RalphVa]

Hope he recovers quickly.

I've never been able to ignite diesel with a match. Almost need a wick to get it going. Think there must have been some gasoline in the bottom of that diesel container when he put the diesel into it.

Diesel ignites just a bit better than lube oil, which is not flammable unless ignited by something else. Generally, this is the case for diesel, too.

Ralph

 

[MossRoad]

If it was a hot day, and the diesel was poured, it could have vaporized at as little as 100 degrees with #1 diesel fuel. #2 is 126 degrees.

Per this article...

https://southeastpetro.com/wp-content/uploads/2015/12/Diesel-FlashPoint.pdf

 

[Fuddy1952]

As a kid my friends and I were always blowing stuff up. We found out fumes were worse than liquid. We had a great burn pile with a nearby concrete "bunker" we could dive into.
A steel pail of gasoline we threw on a burn pile...then we tried just a small amount of gas sloshed around then went to throw that on. It knocked us both flat.
So sorry about your friend and hope he heals ok. The best bet would be a long pole like 10ft, burning rag on end. Most times I trail off with gasoline or lighter fluid maybe 20-30ft, light end like a fuse.

 

[JamesHW]

My way of starting burn piles is just to start up a pile of charcoal in one of those chimney starter things and then stick the burning coals under the pile on an old piece of metal. Never fails. I’ll do a second chimney’s worth if I’m in a hurry or it’s raining. Never fails to start brush or anything since it starts out as hot burning coals underneath the pile and anything over it drys out and eventually bursts into flames. I feed a little dry stuff to help it along Getting it started.

Hope your friend recovers fully.

 

[JDAOWNER]

THIS HAS HAPPENED TO ME, BUT NOT AS BAD. THE TIME IT TAKES TO MOVE BACK THE PAIL OF FUEL AND THEN RETURN TO LITE THE PILE IS ENOUGH TIME FOR FUEL TO VAPORIZE A LOT ON A HOT DAY. IT'S AMAZING HOW MUCH A PILE OF BRUSH WILL HOLD THE FUMES IN. AND LIKE IT WAS SAID, FUMES ARE MUCH MORE EXPLOSIVE THAN THE LIQUID. I POUR FUEL ON THE PILE NOW, THEN POUR A LINE OF FUEL ON THE GROUND ABOUT 12 TO 15 FEET AWAY AND LITE THE END OF THE LINE AND LET IT WORK IT'S WAY TO THE PILE. EVEN THEN THE HEAT WHEN IT REACHES THE BRUSH IS INTENSE.

 

[MHarryE]

I had a flash light off using diesel that had an additive.

 

[jjp8182]

Went looking on this (it's not all that far from some of the aspects of my job) and found these three sites discussing explosive atmospheres:

LCO-47: Diesel Fuel Vapor Hazards
Gasoline Safety - City of Bellingham
https://www.iecex.com/archive/dubai...5_IECEx_Dubai_Area_Classif_final_Leroux_P.pdf

So my guess would be that the diesel started to vaporize (was the container left in the sun? heat index *shouldn't* play a role as it's really more of "feels like" temperature used for personal safety rather than a measure of the energy/heat in the air*). Then since diesel vapor is also heavier than air the vapor (second link) it wouldn't have continued to rise. So along with being partially sheltered by the brush pile the vapor would have been localized to the brush pile. Then given the information in the first link regarding diesel vapors: "The vapors are explosive over a wide vapor-to-air mixture range. The lower explosive limit is less than 1%, and the upper explosive limit is about 10%."

If that's what happened it wouldn't surprising that it exploded as the difference between an explosive atmosphere and a fuel-air explosive (e.g. thermobaric bomb) effectively comes down to whether it was an unintended or intended creation of the conditions..

* Also note air temperatures (as provided by weather reports) *should* have been measured in the shade to eliminate measuring the influence of solar loading. So in a sunny area the local area air temperatures may very well be higher than reported.

..and I'll stop there before I go full redneck-nerd/geek mode and add I hope your friend has a full and speedy recovery.

 

[TractorGuy]

Hope your friend has a quick and complete recovery!

Fire is unpredictable. When I burn these days I get the cheap packs of toilet paper from the dollar tree and soak a few rolls in a mix of diesel and waste oil. The oil seems to lower the flash point an keeps it burning longer. I will place the rolls in the pile then I put one roll on the end of a stick that is long enough to keep it away from me and strong enough to support the roll. I will light that and go around lighting the other rolls then throw the one on the stick in the pile. Not saying it's the best practice but it has worked for me.

 

[4570Man]

I’m in the it didn’t happen crowd. Diesel barley even lights with a cigarette lighter. It won’t explode. I would believe gas accidentally getting mixed in a lot more plausible than anything else.

 

[fried1765]

I’m in the it didn’t happen crowd. Diesel barley even lights with a cigarette lighter. It won’t explode. I would believe gas accidentally getting mixed in a lot more plausible than anything else.

ME TOO !!!

 

[shooterdon]

Can you be 100% certain is was 100% diesel?

In any case, thanks for sharing and hoping that your friend recovers quickly.

 

[jonsstihl]

sure makes people think twice before doing it. I always use waste oil to start brush piles and most of the time I start a small pile then place more material on it as it burns. keeps the size of the fire more manageable.

 

[MossRoad]

Put some diesel fuel in a pump sprayer and spray it towards a flame and see what happens. WOOF!

 

[MossRoad]

If you can't light it like many of you mention (and I generally agree), then why do people get killed welding/cutting diesel fuel tanks and they explode?

Because of the vapors in a confined space.

All it would take is to put diesel fuel in a depression at an air temperatures above 100 degrees and it can form vapors that can ignite.

LCO-47: Diesel Fuel Vapor Hazards

 

[CobyRupert]

From
https://southeastpetro.com/wp-content/uploads/2015/12/Diesel-FlashPoint.pdf

Flash Point Properties - At elevated temperatures, diesel fuel will begin to vaporize and become ignitable with an open flame. The lowest temperature at which the vapor will ignite is the fuel's flash point. Diesel fuel #2 as specified by ASTM D975 has a minimum flash point of 125.6 F. For diesel fuel #1, the minimum flash point is 100 F. (Winter blends of #1 and #2 are allowed to be 100 F minimum as well). If the flash point falls below these values, the fuel becomes potentially unsafe to handle.

==============

If the fuel was in the sun on a 92 degree day, it could be over 100 degrees.

Bruce

Ding! Ding!
This.

In fact, diesel isn’t technically flammable. .....but get it above it’s flash point when it gives off enough vapor.....boom.