here is how it happened...

I build a biodiesel processor here in Nairobi Kenya and am developing a small project for some of the Kenyan and Rwandan people.

I hired a welder to fabricate some pipe fittings on a 55 gal or 208 liter barrel. I told him that there must be no leaks. Well, it leaked! After demething my first batch and watching methanol pool on the top of the barrel, I decided to call him back to honor his guarantee. I sent a truck and by the time he got here i realized that even though I drained out all the bio, there were fumes of methanol in the barrel... so what did I do to not waste time???

Lets open the 2 inch bung fitting and the half inch breather fitting on top of the barrel and hold a match to the 2 inch opening and burn off the fumes!!! Then the welder can get to work!!

I did it! The flame that came out of the opening sounded like a jet engine and was about two feet high! My initial thought at this amazing sight was fear of explosion and death to all those who were near.... So what did I do???

In a split second, I tried to cap the flame with my hand! stopping the fire and avoiding potential explosion. Well, the flame one, blowing my hand back and burning the skin off. The flame came to rest, burning off all the fumes and there was no explosion.

Close Call!!! A mix of trying to be a hero and a fool all at the same time!

its been 2 and a half weeks and I can almost use my hand! It is healing well and will be fine.

I keep wondering what would of happened if I didn't open the vent hole... less air so less flame? or the flame looking for more air and explosion resulting?

Who knows, and I rather hypothesize than find out!

I have heard that when welding a fuel tank that it should be filled up with water first, to push the fumes out. I have never done it. I am sorry to read about your accident.

water works, it pushes the air out of the drum, car exhaust also works, and steam for 30 minutes is also a good way to play safe.

Tofir Mira,

Good to hear your hand is getting better.

OK to your question, about what would happen if you hadn't opened the vent hole. Those drums are not designed to contain pressure. If you had used the small bung instead of the big one, it would have still burned. Not to mention that the drum would have likely come apart at the seams, violently. The flat ends of the drum are not welded on the edges of the sides and top are folded together into a water tight seam. Before the welded seam on the side ruptures, the metal fold holding the lid on unrolls. When that happens the lid is launched into the air like a razor edged Frisbee of death. I have been told of these launched drum lids cutting through roofs clean. I heard of one that when half way through a brick wall. If you check out this link to closed head drum processors you will see a picture of a drum that launched it's drum lid several thousand feet away, never to be found again. There was a time when we made processors out of closed head drums, and during that time there were more than a few that caught fire and launched their lids.

Again, I am relieved that things didn't turn out worse.

Your lucky it didn't explode and your lucky you still have a hand.... WOW, that story made me shudder...
http://biodiesel.infopop.cc/ev...3106871/m/2227001633
Play safe!
Jon

Hey thanks Rick da tec, Biotom, WesleyB, and John!

Means a lot to me that you have replied! Thanks Rick for the barrel info... I wish I did the proper research before I build the processor. Our project is so underfunded that we went with the most economical. We are over budget all ready due to optimistic idealism by other organizers who know nothing of the bio realm..

Oh ya and the day I got off the medication for my hand I contracted Malaria! That was another 5 days of suffering with a hand I couldn't use!

But all is better now! I am totally grateful for the experience and do not regret it. The lessons i have learned are invaluable! After all that suffering I was so grateful to he alive! I feel like we take life for granted; as if everyday we expect to live, and when something like this happens, it really puts it all into prospective.

Thanks All!!