Thursday started out as a normal day at many workplaces across the nation. After the lunchtime break, things would begin to change and heat up real quick in a span of two hours across three states. Prior to the clock striking 2:00 P.M. CST, a combustible dust fire consisting of titanium dust flared up in the dust collector at a dental equipment manufacturing facility in Pennsylvania.
In the Midwest, at approximately 2:30 P.M, as firefighters were responding to the titanium combustible dust fire at the Den-Tal-Ez Inc dental facility in Lancaster, Pa, a combustible dust explosion rocked the Farmer's Co-op Society grain elevator in Sanborn, Iowa.
An hour and a half later as events were just getting heated up, the afternoon turned into a leapfrog event as Baldwin Feed and Seed grain elevator in Baldwin, Wisconsin became engulfed in flames. This is very unusual for so many combustible dust related explosions and fires to occur with a span of two hours on the same day. Luckily there were no injuries only heavy economic damage to the businesses.
It's All the Same
Combustible dust is combustible dust. It doesn't matter if it's grain , metal, rubber, plastic, wood, coal, etc. All this dust is generated from a raw product of combustible particulate solids. The only difference in the dusts is the heat of combustion (oxidation), which is a measure of the rate of combustion. Which could range from 1200 KJ/mole O2 for magnesium all the way down to 470 KJ/mole O2 for starch. Proper preventive and costly mitigative measures needs to be instituted with all classes of organic, synthetic, coal, and metals. Until a comprehensive combustible dust standard is instituted more events will occur on a daily and weekly basis.
Since the OSHA grain facility combustible standard was instituted in 1988, occurrences of grain dust explosions have been reduced 30 %, with an average of 14 events annually. Have we reached an acceptable level now with the grain facility standard ? Or should a review of current procedures be in order?
Dust Explosion Research Institute
A Dust Explosion Research Institute (DERI) facility in the United States would be a good move. The time has arrived for all stakeholders in industry, academia, and cooperation with governmental agencies in facilitating the planning stages for a combustible dust research institute. This is not a novel idea, as Norway has done so decades ago at it's CMI facility in close collaboration with the University of Norway.
The results have led to the exciting field of combustible dust computational fluid dynamic (CFD) studies in conjunction with computer aided design. GEXCON, a leading Norwegian research and consultancy in explosion scenarios took over the work of CMI in 2000 and now provides a revolutionary FLame ACceleration Simulator (FLACS) in modeling the dust explosion process.
Combining physical properties of minimum explosive concentrations, minimum ignition temperatures, minimum ignition energy, and deflagration index's into the computer application of CFD will provide a cross spectrum of industries the intricate nature of combustible dusts. Much more research needs to be done as this is only the tip of the iceberg. Question is, will, the industrial powers of our nation be up to the challenge?
For others who are up to the challenge be sure to stop by the GEXCOM booth at the 2008 AIChE Spring National Meeting April 6-10, 2008 Ernest N. Morial Convention Center
New Orleans, La. . Olav Roald Hansen and Kees van Wingerden will be there with demo programs of FLACS and the Dust Explosion Simulation Code, which is the awesome CFD code for simulating the course of industrial dust explosions in complex geometries such as we experience here in the U.S. . Click here for brochure
Click here for FLACS video
Thursday, April 3, 2008
After 14 combustible related dust incidents last month which included 6 explosions, the month of April will be starting out in the same dismal form. On Tuesday, April Fool's Day, a combustible dust fire started in the silo that contained sawdust generated from the wooden flooring manufacturing process at Appalachian Wood Floors in Portsmouth, Ohio bordering Kentucky on the northern banks of the industrious Ohio river.
Ohio is no stranger to combustible dust fires and explosions. Less than two months earlier and hundred miles west, further up the Ohio River in Cincinnati, a wooden products plant vanished off the face of the earth as the owner watched nearly three decades of memories burn to the ground. Toughest part was the mentally anguishing dilemma of the nearly two dozen employees who no longer had a place to go to work the next day on Monday morning. Luckily no injuries in this incident either.
Just over three years ago, about an hours drive south from Lake Erie in Leipsic, Ohio at a pet food manufacturer, a combustible dust explosion occurred in the silo injuring one firefighter. The day before the incident, firefighters worked to clear smoldering cellulose in the silo. It is believed that an ember remained in the machinery overnight and caused the flash dust explosion the following afternoon.
Preventive and mitigative measures is very expensive for business with the installation of detection, isolation, ventilation and suppression fire equipment. Should this fire and explosion equipment be required at all business's that handle combustible particulate solids that generate combustilbe dust? Thats a tough question to answer especially with the many small companies that barely are getting by with other overhead costs.
A cost benefit analysis would best be able to determine an equitable solution. In the meantime the clock is ticking for the next combustible dust explosion in the magnitude of the tragic preventable and predictable Imperial Sugar Refinery explosion two months ago on the western banks of the Savannah River in Port Wentworth , Georgia.