- Joined
- Jul 24, 2001
- Posts
- 19,993
In case you were wondering where I have been during the past two months, here are some details for you...
A while ago I started working for a friend of mine who runs a small firework production plant near Nuremberg. Making fireworks always was one of my passions next to video games and music so I was very happy about the offer to join his team.
One day we made a test mix of a new 70/30 flash of potassium perchlorate and fine-powdered aluminium that we got from an Indian factory, we wanted to test its effectiveness for our ground salutes. Sadly, the potassium perchlorate really was low-quality potassium chlorate which is a lot more sensitive to impact, friction and static electricity and we were using a new laminate for the tumbler barrel in which the mixing took place...
...so we filled the barrel with said chemicals, switched it on and then went to the room next door where we continued loading tubes with flash mixture. Right at the moment when I was on my way to the mixing room to get another batch, the machine went boom (the bang was incredibly loud) and sent me flying down the stairs. My friend Alex who was working with me in the filling room and I miraculously escaped with just a few minor brushes. We were quite lucky under the circumstances, we only had a test-batch running with about 100 grams of flash mixture instead of the usual 3 kg's...
Later on it turned out that the guys at the Indian factory mixed up chlorate with perchlorate. We also made some chromatographic tests and found that it was contaminated by bromine, this is what caused most of the deadly accidents in China and India in the past. What's more, the new laminate of the mixing barrel is not ESD-safe (ESD = electrostatic discharge)... this is what we found out the hard way.
The explosion occured when the lid of the mixing barrel opened automatically after the programmed mixing time. This caused a small electrostatic discharge of only a few joule which would not have been enough if we had used perchlorate, but it was powerful enough to ignite the sensitive chlorate-aluminium mixture.
One thing is for sure, we'll never buy Indian (per)chlorate again. Had this accident occured under normal production conditions, half of our factory (including us) would have been blown to space.
As I mentioned before, we escaped with a few bruises, broken fingers, temporarily impaired hearing and monstrous headaches for a few days. The overpressure of the explosion bursted several small blood vessels in my eyes, I looked like a zombie for three days. When the explosion blew me down the stairs, I fell on my right arm which went numb for a while, I couldn't type and using the toilet was a real challenge as well.
Needless to say we spent several days with investigating the accident and introduced a number of new security measures. Pushing your luck is not a good idea, eh. We installed a new mixer which is belt-driven, the barrel is made of reinforced cardboard and thus 100% ESD-safe. We also reduced the maximum barrel load to 1 kg at a time.
Well... making fireworks is a dangerous job, that's for sure. Sometimes you're lucky, sometimes you aren't... I'm just glad I'm still here.
A while ago I started working for a friend of mine who runs a small firework production plant near Nuremberg. Making fireworks always was one of my passions next to video games and music so I was very happy about the offer to join his team.
One day we made a test mix of a new 70/30 flash of potassium perchlorate and fine-powdered aluminium that we got from an Indian factory, we wanted to test its effectiveness for our ground salutes. Sadly, the potassium perchlorate really was low-quality potassium chlorate which is a lot more sensitive to impact, friction and static electricity and we were using a new laminate for the tumbler barrel in which the mixing took place...
...so we filled the barrel with said chemicals, switched it on and then went to the room next door where we continued loading tubes with flash mixture. Right at the moment when I was on my way to the mixing room to get another batch, the machine went boom (the bang was incredibly loud) and sent me flying down the stairs. My friend Alex who was working with me in the filling room and I miraculously escaped with just a few minor brushes. We were quite lucky under the circumstances, we only had a test-batch running with about 100 grams of flash mixture instead of the usual 3 kg's...
Later on it turned out that the guys at the Indian factory mixed up chlorate with perchlorate. We also made some chromatographic tests and found that it was contaminated by bromine, this is what caused most of the deadly accidents in China and India in the past. What's more, the new laminate of the mixing barrel is not ESD-safe (ESD = electrostatic discharge)... this is what we found out the hard way.
The explosion occured when the lid of the mixing barrel opened automatically after the programmed mixing time. This caused a small electrostatic discharge of only a few joule which would not have been enough if we had used perchlorate, but it was powerful enough to ignite the sensitive chlorate-aluminium mixture.
One thing is for sure, we'll never buy Indian (per)chlorate again. Had this accident occured under normal production conditions, half of our factory (including us) would have been blown to space.
As I mentioned before, we escaped with a few bruises, broken fingers, temporarily impaired hearing and monstrous headaches for a few days. The overpressure of the explosion bursted several small blood vessels in my eyes, I looked like a zombie for three days. When the explosion blew me down the stairs, I fell on my right arm which went numb for a while, I couldn't type and using the toilet was a real challenge as well.
Needless to say we spent several days with investigating the accident and introduced a number of new security measures. Pushing your luck is not a good idea, eh. We installed a new mixer which is belt-driven, the barrel is made of reinforced cardboard and thus 100% ESD-safe. We also reduced the maximum barrel load to 1 kg at a time.
Well... making fireworks is a dangerous job, that's for sure. Sometimes you're lucky, sometimes you aren't... I'm just glad I'm still here.
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