Cryogenic Grinding Facility Ablaze

Yesterday evening a Brimfield, Ohio cryogenic grinding toll processing plant caught fire, several hours after the employees clocked out. According to the facility website, crumb rubber is ground up in from discarded tires, assisting in the nation's recycling efforts. In the cryogenic milling operation particles are micronized in a range from 595-105 microns.

Non-Friable Feedstock
The cryogenic process is more efficient than ambient temperature milling where heat generation is not an issue, which minimizes potential ignition sources for combustible dust. Additionally, non-friable inputs like rubber and elastomer's (SBR, EDPM, Viton) do not grind efficiently in an ambient temperature environment. Adding liquid nitrogen to the feedstock transforms scrap rubber into a brittle property that is easily milled at the reduced temperatures (cryogenic grinding).

Prior Fires
News accounts stated that nearly one-hundred residents were ordered to evacuate while ten fire departments responded from surrounding towns. A manager from a adjacent commercial building, recollected that he witnessed five to seven fires at the plant over the last eight months. Hopefully fire officials will be able to find the root cause of the incident in addition to determining the fuel load that propagated the fire so rapidly. It seems after nearly a half a dozen fires earlier in the year that warning signals preempting the current event would of been sufficient in lessening the likelihood and reducing the severity of the Saturday evening plant fire in Ohio.

NAICS: 326299/All Other Rubber Product Manufacturing OSHA NEP D-2

Video Credit: hollieolesky

Wood Pellet Dust Fire Non-Issue?

A New England wood pellet manufacturer experiences a second dust related fire in two weeks. In the prior fire, an ignition source from the pellet mill caught pellets on fire and subsequently the conveyor feeding wood pellets to the outside silo also caught fire. The fire in the silo smoldered for over a day.

Last month a similar combustible dust related fire at a wood pellet plant occurred at Westwood Fibre Products in Kelowna, British Columbia in which the conveyors were ablaze with wood pellets. The fire chief who responded to the Westwood fire seems to concur regarding a non-issue with such fires when he stated to the news reporter that, 'of course being a wood fibre plant with dust and sawdust it's not uncommon to have small fires in these types of operations."

From viewing the above picture, it wasn’t much of a non-issue, when last year in Monticello, WI, Risley Pellet Solutions exploded, injuring two workers. Over the last six weeks in Marion, PA., AJ Stoves and Pellets, has experienced hopper explosions twice due to combustible dust. Since there were no fatalities or three or more injuries, it's like the tree fell in the forest, yet no one heard it. So did the tree fall?

It's highly advisable that all wood pellet manufacturers install spark detection and extinguishment systems adjacent to their conveyors. If that is to expensive, then at least shutdown the conveyor at the first sign of fire so burning pellets will not enter the adjacent bulk storage unit.

As a matter of any fire occurring where combustible particulate solids are handled, you be the judge of whether it is a non-issue or not. Hopefully the prior examples will add light to the subject in whether preventative and mitigative measures should be implemented according the the NFPA combustible dust standards.

Recent Wood Pellet Mfg. Explosions and Fires

8/22/08-AJ Stoves & Pellets- dust explosion/hopper
8/15/08 Corinth Wood Pellets- fire/sawdust dryer
8/10/08 New England Wood Pellets- fire/pellet mill
7/15/08-AJ Stoves & Pellets- dust explosion/hopper
5/20/08 Corinth Wood Pellets- fire/exterior burner

Photo Credit: Monticello Fire & Rescue

Chemical Preparations Dryer Fire

Yesterday a spray dryer fire at chemical preparations and toll manufacturing plant for pet food, agricultural, personal care and industrial markets. Example of dryers utilized at the facility.

Spray Drying: Rogers Box Dryer 3,000 lbs./hr. Liquid evaporation rate

Fluid Bed Dryer/Agglomeration 200 lbs. / 400 lbs./hr. Liquid evaporation rate

Rotary Drum Dryer 700 lbs./hr. capacity

An excellent text concerning prevention and mitigation of dryer fires can be found in the Institute of Chemical Engineers text, "Prevention of fires and explosions in Dryers-A User Guide."

Atomized Aluminum Powder Explosion/Fire

An investigation is continuing concerning the fire that occurred on the atomizing line at the Toyal America Lockport, Illinois facility two days ago. News Video, explosion aftermath.

Aluminum Dust Incidents:
Catalina Cylinders 8/21/08-dust-collecting hopper
Commercial Alloys 7/26/08-aluminum grinding machine
DWA Aluminum Composites 4/28/08-explosion

Aluminum Powder Mfg. Process: Nova Bimet Technologies Pvt. Ltd
Working Safely with Aluminum Powder CCOHS
ALUMINIUM POWDER – HAZARDOUS OR NOT? ALPOCO

From: Aluminum powder applications. by Gurganus, Thomas B.
Source: Advanced Materials & Processes, 8/1/1995.
Via: HighBeam™ Research

Coal Dust Fire India Thermal Plant

Third combustible coal dust fire in the past three months in India, at a coal-fired electric generating plant. Maybe a strict housekeeping program would lessen the likelihood of the next fire. NFPA 120 Standard for Coal Preparation Plants, is an excellent resource in preventative and mitigative measures here in the United States.

Additionally, the PRB Coal Users Group works proactively with their membership in sharing "best engineering practices" in the handling of coal at energy plants. Also, Hazard Control Technologies, a supplier of industrial firefighting equipment offers a wide array of products and training that assists firefighters in responding to coal dust fires at power plants.

Dust Collector Fire New Jersey

http://www.packetonline.com/articles/2008/08/29/cranbury_press/news/doc48b815ae1c279401755058.txt

Fire in an exterior cyclone sawdust collector where officials believe that a mechanical problem caused a spark, igniting the sawdust. Would spark detection and extinguishment system lessened the severity and likelihood of this incident? Additionally, a proactive inspection and maintenance program as outlined in NPFA 664 will provide added protection to all manufacturing facilities that process combustible particulate solids.