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

[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.