Combustible dust related fires and explosions occurring amongst wood pellet manufacturers in the United States is a problem plaguing facilities on a global basis. Last month a fire occurred at the Wood Fibre Products facility in British Columbia, Canada, where several conveyor belts were ablaze.with product. The local fire chief acknowledge that fires of this nature are not uncommon.

This common thread of combustible dust related fires on a regular basis is a troubling issue. Especially when the likelihood and severity of these incidents can be reduced if best engineering practices are applied when handling combustible particulate solids that generate combustible dust. Such standards can be found in the NFPA 664: Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities, which can be viewed for free on their website.

Combustible dust related explosions and fires are a global problem that occurs on a daily basis across a wide spectrum of industry where the dragon does not differentiate between borders. In conjunction with combustible dust events, many facilities in the manufacturing sector are restructuring in conjunction with plant shutdowns and ensuing layoffs.

This economic condition in a majority of instances is unpreventable especially due to current global energy supply and demand considerations. Yet the occurrence of combustible dust explosions and fires which will totally destroy a facility can be minimized through proactive preventative administrative and engineering “best practices” mitigative measures.

Several weeks ago the Dongwha Patinna fibreboard plant in Tutura, New Zealand experienced a combustible dust explosion in the duct work leading to the dust collector in which a worker was severely burned from the rapidly expanding fireball exiting an open access door.

Had an interesting phone call from Steve today inquiring if I knew of any resources here in the United States that could assist in obtaining ATEX/CE certification so his company could market their coal mining equipment in the EU under the ATEX directive. I really didn’t know anyone here in the USA in an ATEX consultant capacity that could help. But that did get the wheels turning and I did find some valuable resources on the web.

The ISA, which was founded in 1945 and located in North Carolina hosts the ISA12, Electrical Equipment for Hazardous Locations Committee. Currently the committee is developing standards for electrical equipment in hazardous locations with the close cooperation of the Underwriters Laboratories standards technical panel (UL STP 60079).

Welcome to the debut of the Combustible Dust-ATEX topic page on the Bulk-Blog. The complex issue of combustible dust related explosions and fires generated from combustible particulate solids in the manufacturing process is a global problem that can be minimized through administrative preventive measures in addition to mitigative engineering best practices. Global trading partners spanning the globe have their own unique regulatory framework in the prevention and mitigation of combustible dust incidents.

The Combustible Dust Policy Institute located in Santa Fe, Texas is actively seeking solutions through in-depth research of incidents and interviews with stakeholders where combustible dust explosions and fires have recently occurred in the process technology and manufacturing sectors. Locally in the United States a comprehensive combustible dust regulatory framework is absent in the protection of the workforce or workplace.

I am happy to submit a guest blog for Joe Dos Santos. This is to lighten things up from the technical stuff engineers like so well and frankly…I just don’t understand. Until now!

Spending most of my college life in public relations and marketing classes, engineers and engineering seemed a world away…even though I could walk to the engineering building on my campus in under five minutes. That’s actually strolling. Still, the dynamics of what they did, the math, the figures, the equations! It was way over my head. After all, it was all I could do to get through my remedial math courses much less pursue a higher level of math. Now don’t think I didn’t feel the pressure. My father, a Cornell graduate said he learned to love the thing that really challenged him. Yep….math! And of course, we can’t forget my brother the MIT graduate. Of course I felt the pressure. After all…they are both…you guessed it, Engineers!!!

Dear Bulkaholics,
I am a new member of your community. My business is Coal to Liquids plants. Is there anyone with experience in feeder technology for coal gasifiers? The problem is to feed dried coal (especially in the case of lignite) into the pressurized (Siemens or Shell) gasifiers. The train: Coal Crushing, Coal Pulverizing, Coal Drying, Coal Bunkering, Coal Feeding has to be optimized and a save handling is required (preventing coal dust explosion). I am interested to hear from someone.     

Do you have money to burn?  Of course not, yet chances are that you are doing just that within your pneumatic conveying system.  Have you ever noticed the hissing sound of such valves when you tour your plant?  If so, you are wasting electric energy and maybe risking future maintenance issues.  I cannot tell you how many cement and food processing facilities I have been to, where not at least some valves leaked severely.   You may think the cause is the valve itself – think again:  Most likely it is your system that does not need all the air and hence is blowing it off through the valve.  The fix is not necessarily a new valve, but either a new belt drive or motor speed slow-down by means of a variable speed drive. 

Through study analysis and experience the writer will attempt to continuously rationalize and expand the conventional conveyor technology revealing the link between theory and practical issues and in the process, through a deeper understanding, take the technology beyond its presently perceived limits. This approach has, in the past 20 years, yielded a greater understanding, a broader application of the principles, and even new technologies to the market place.

This Post:
Experiences/Frustrations with Conveyor Belt Specs:

Why don’t Belt Manufacturers understand what they publish?

At Dos Santos International we are experts in the Sandwich Belt High-Angle Conveyor Technology. The Sandwich belt system works on the principle of hugging bulk material continuously in a sandwich between two smooth surfaced rubber belts. Hugging pressure on the bulk material develops its internal friction, which resists any back sliding tendencies, allowing the material to convey at any high angle up to vertical. The writer rationalized this technology as an expansion of the conventional conveyor technology during the period 1979 thru 1982. This work culminated in the landmark article “The Evolution of Sandwich Belt High-Angle Conveyors” by Dos Santos and Frizzell.

Dear Sir,

I read much of the Powder/Bulk Portal and the Bulk On-line is on my computer desktops. I commend your site as one of the best sites to gain contacts and information.

I do not have an engineering degree but was for many years the senior conveyor technologist supervisor with Ace Conveyor Services (Australian Conveyor Engineering), later (Continental Ace Services) (Continental Conveyor & Equipment) [Australia] and have worked in the mining industry since 1950s.

I have quite a number of conveyor and other mechanical innovations in my repertoire with the latest “patent application” throughout the PCT and remaining major countries of the world. The innovation is viewable on the company’s website, which is the company in which I hold a 25% shareholding.

The first two things to consider about bulk density are the nature of the bulk material and establish the purpose for which the measurement is to be made. This is because the bulk density of a powder is strongly dependent upon both the nature of the particles and the manner is which the sample is prepared and measured. This is considerably more important for some powders compared to others. The density of fine powders is very sensitive to the amount of gas that is trapped in the voids and to the stresses acting on the bed of material. On the other hand, the density attained by firm, coarse particles depends much more on the conditions of formation of the bulk and to the geometry of the measuring container. This is because air can escape from the coarse bulk easily, the contact structure of large grains can sustain relatively large forces before yielding and a wall contact surface constrains the way in which the large particles can nest together.