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TRANSCRIPT
Combustible Dust
A Panel Presentation and ConversationEEI Fall Occupational Safety & Health Committee
Conference – September 28, 2010
What do the Titanic, USS Maine
and Burnsville (Coal Fired Power
Plants) have in common?
Titanic – Coal bunker fire
USS Maine – Coal bunker explosion
Initiated war with Spain
Recent Black Dog Power Plant - Coal silo
fire/explosion
American Electric Power
Combustible Dust Management
Gathering information – “How do you
know?”
The Story Musgrave lesson – “Put an eye
on it.”
“If the generator is running then everything
must be fine in the coal yard – right?”
Continue improvement
Reclaim tunnel reviews
Holes left in the chutes, should have been patched or install
an inspection, maintenance door to make a complete
installation.
Identify and Act on Simple Fix
It’s okay…Replace the cover and
patch the hole!
Coal samplers are a big dust generator…Doors should be
easy open with simple durable hinges and latches.
After an event, there should be a punch list
made to be sure lessons learned are addressed
Others Required Planning
NFPA 850
Recommended
Practice, not a
Standard
2010 Edition
Three Chapters
General
Hazard Specific
Annex
NFPA 850 General:
Administration
Referenced Publications
Definitions
Fire Protection Design Process
General Plant Design
General Fire Protection System & Equipment
Construction Sites
Fire Risk Control Program
NFPA Standards
NFPA 654 - Standard for the Prevention
of Fire and Dust Explosions from the
Manufacturing, Processing, and Handling of
Combustible Particulate Solids
Current Status Update
Definitions
Explosion Controls
NFPA 68 - Standard on Explosion Protection by
Deflagration Venting
NFPA 69 - Standard on Explosion Prevention
Systems
New Definitions
Combustible Dust – removed particle size
A combustible solid that presents a fire or deflagration
hazard when suspended in air or some other
oxidizing medium over a range of concentrations,
regardless of particle size or shape.
Dust Explosion Hazard Area
Flash Fire Hazard Area
Dust Accumulations - Housekeeping
Proposed Changes to NFPA
Standards Related to Dust
(Definition) Flash Fire – A fire that spreads rapidly
through a diffuse fuel, such as dust, gas, or the vapors of
an ignitible liquid, without the production of damaging
pressure.
(NFPA 654, Section 3.3.x – Proposed)
Proposed Changes to NFPA
Standards Related to Dust Dust Explosion Hazard Area – A room or building
volume where an unvented deflagration of the entrainable dust mass can result in a pressure exceeding the strength of the weakest structural element not intended to fail.
Dust Flash Fire Hazard Area - An area where combustible dust accumulations on exposed or concealed surfaces, outside of equipment or containers, can result in personal injury from thermal dose during a dust deflagration, as well as any areas where dust clouds of a hazardous concentration exist during normal operation. A propagating deflagration yields a flash firethrough a hazard area.
(NFPA 654, Section 3.3.x.1 and 2 – New and Proposed)
Proposed Changes to NFPA
Standards Related to Dust
Dust accumulations amounts shall reflect
the conditions that exist just prior to
routinely scheduled cleaning, and shall
not include short term accumulations
cleaned…
Pressure relief devices shall not be vented
to an area where a dust explosion hazard
or dust flash fire hazard exists.