Grain Elevator Explosion
Grain Elevator Explosion
(OP)
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
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RE: Grain Elevator Explosion
A reference for those needing to deal with the matter:
Dust Explosions in the Process Industries
Second Edition
Rolf K. Eckhoff
Butterworth-Heinemann
Linacre House, Jordan Hill, Oxford OX2 8DP
225 Wildwood Avenue, Woburn, MA 01801-2041
A division of the Reed Educational and Professional Publishing Ltd
RE: Grain Elevator Explosion
I used to work for a company that sold explosion suppression systems. It literally sensed the beginning of an explosion and flooded the area with Halon - a cousin to Freon. IT WORKED. I saw a number of films that showed it. Even talked to a guy that was in a propane filling room when an explosion was averted by the system we had installed. Other than soiling his pants - he was fine.
System wasn't cheap - back then in the $25,000 range. But a lot cheaper than 3 lives.
FENWAL made the system - not sure if they are still in business but Halon has kind of been banned - I think - or it is very expensive. I think race cars still use them. Not sure why airlines don't??
You can breathe the stuff as the concentration is only in the 5-7% range and just displaces a fraction of the oxygen content whereas nitrogen need to be in the 30%+ range - which can suffocate you.
RE: Grain Elevator Explosion
I suspect that the lack of implimentation is due to the cost... The three deaths may not be a significant cost saving to the company.
Dik
RE: Grain Elevator Explosion
During cleaning, even small sparks can result in big booms.
RE: Grain Elevator Explosion
RE: Grain Elevator Explosion
RE: Grain Elevator Explosion
RE: Grain Elevator Explosion
Be interesting to see the new report... doesn't seem like they've learned very much...
Dik
RE: Grain Elevator Explosion
On a smaller scale in a past career, I designed high speed explosion detection-suppression systems using UV/IR detectors and high speed water as well as CO2 suppression. The challenge with this size of a vessel is the rapid detection-suppression sequence required over a very large area. Some grain silo facilities will be a quarter to half mile long, and then each silo is quite tall. Water cannot be used effectively since the silo will not be maintained above freezing temperature as all times. Halon is not an option - very expensive (if you can get it, hundreds of thousand of dollars per silo and deadly once you get the discharge required for an empty silo into a partially filled one.) There is probably a suppression system one could design, but prevention is far less expensive, however that requires the rather undependable human element.
RE: Grain Elevator Explosion
I sort of agree... but, proper housekeeping is essential and employee training is also imperative...
I've worked on projects in chemical plants where even the flash from a digital camera will detonate stuff... powder that can ignite by friction, as well as the potential for toxic gas release... and these firms have a significant training program as well and the trained employees are also up with the program... every action is almost safety related.
It would be interesting to know what part of their program is dedicated to safety and housekeeping. I'm not making any comment on what this firm did or didn't do for safety, but, in my experience it can be done... There are far more dangerous environments. There is also a cost associated with this... staying alive is 'non-productive'.
I don't know... six lives have been forfeit in the process.
RE: Grain Elevator Explosion
RE: Grain Elevator Explosion
I.e.. suppose OSHA said, "There are no rules for equipment, procedures, or documentation. The only rule is this: Each worker death results in a fine, due immediately, in cash, of 1,000,000 USD, (inflation adjusted)."
I suppose it would need a "whichever is greater" clause to cover the case where $1E6 is petty cash, but you get the idea.
Mike Halloran
Pembroke Pines, FL, USA
RE: Grain Elevator Explosion
OSHA regulations actually never include the "it's just too darn expensive" option. And I certainly agree that housekeeping is paramount, but the safety profession and the insurance industry recognize that relying upon the human element is seldom satisfactory for high-risk systems and situations. Some events remind us how unreliable methods requiring human intervention can be.
Engineered controls are always preferred because of their reliability. But the grain industry has very few workable engineering methods for dust control. Some methods include suppressing dust with sprayed oils (causes significant fire, storage, and processing problems of its own), dust extraction (which doesn't work very close to where the grain is handled), or inerting the entire silo (expensive and creates a lethal environment inside the silo.)
I'm not excusing poor practices, only emphasizing that the issue is not so simple as some would make it out to be.