How to make sure your dust collection system complies with. The directory is focused solely on safe handling of powders and fire, flashfire, and explosion safety. With this device, miners, regulators and mine operators will have the information necessary to take immediate action to eliminate an explosion hazard. As will be demonstrated in the further descriptions. Firedamp explosions can trigger the much more dangerous coal dust. Disasters videos you can use in your safety training programs. Initiation of coal dust explosions by gas explosions. He has over 40 years of experience in bulk material handling industries, 25 of which were spent in dust explosion protection through thorwesten vent based in germany. Classical textbooks nonenglish dust explosions coal dust explosions and their suppression. Basics about dust explosion mitigation cv technology.
Hartmann is chief of the dust explosions and coal mine experiments branch. Both the cdem and the new msha rule represent the significant impact that the niosh mining program has on. A centennial of mine explosion prevention research cdc. Prevention of coal dust explosions 2 introduction continuous increases in coal production rates have been achieved in south african coal mines. Awareness training, good housekeeping, reference to safety data sheets, and adopting best practice should, in combination, minimize the potential for. Oxygen and fuel cannot be avoided in a prb coal fired power plant, but the heat source can originate from several different sources. Demonstration by msha at the sunrise coal llc, carlisle mine. Grinding coal to dust before combusting it improves the speed and efficiency of burning and makes the coal easier to handle. Managing dust in a power plant begins with good housekeeping, followed by retrofits using properly designed equipment. Although methane explosions are dangerous, those that involve coal dust are even more so. A dust explosion can be catastrophic and cause employee deaths, injuries, and destruction of entire buildings. This is a vintage video of a coal dust explosion at the experimental mine in.
In many combustible dust incidents, employers and employees were unaware that. Mine safety and health admininstration pittsburgh, pennsylvania abstract there are a large number of facilities throughout the world which handle coal, such as preparation plants. Coal dust ignition leeds to serious fire at yallourn power. Thus, combustible dust poses a serious safety hazard. A freak release of natural gas triggered the april 5, 2010, explosion that killed 29 workers at the upper big branch mine, according to a documentary commissioned by former massey energy co. That explosion was fueled by massive accumulations of combustible sugar dust throughout the packaging building. Many other facilities use coal as a fuel, such as cement and lime factories. Still, the former massey ceo insists that the purpose of the film is to start a. The dust must be combustible and release enough heat when it burns to sustain the fire.
This explosion came 15 years after the previous coal dust explosion, and complacency was thought to be a factor. The dust must be capable of being suspended in air. As the conveyor moves, any friction that occurs can be enough of a heat source to cause an explosion. These days, the construction of explosion proof equipment goes far beyond the fi eld of electrical engineering. Mine safety, and later, the safety of coal pulverizing systems, have received much detailed attention. An explosion happens when two other elements are added to the equation dispersion of dust and confinement of dust, as shown in diagram a. A freak release of natural gas triggered the april 5, 2010, explosion that. A combustible dust explosion hazard may exist in your workplace, especially if you are in the food, plastics, wood, rubber, furniture, textiles, pesticides, pharmaceuticals, dyes, coal, metals, fossil fuel power generation or one of many other industries that processes, handles, stores or transports materials or byproducts in fine, powdery form. Basics about dust explosions globally, the amount of devastation incurred by a factory explosion is staggering. The new mine safety and health administration msha rule requires a minimum of 80% rock dust in all mined areas outside the return airway to prevent explosion propagation. Previous publications described the llem coal dust explosion test.
The us chemical safety board recently reported that they have identified 281 combustible dust incidents between 1980 and 2005 that killed 119 workers and injured 718, and extensively damaged industrial facilities. Cdc mining feature coal mine explosion prevention niosh. Combustible dust explosions combustible dusts are fine particles that present an explosion hazard when suspended in air in certain conditions. In most cases, dust explosions are first initiated by methane explosions. The national institute for occupational safety and health niosh, as part of its continuing research program for evaluating coal dust explosion hazards, has investigated several areas in which current practices may need to be updated in order to adequately protect mines against coal dust propagated explosions. Fire extinguishing and preventive and preparatory measures electrostatic hazards in powder handling. Coal dust explosions and their prevention scholars mine. Coal dust only needs to accumulate to a footprint size and already it is a fire hazard. Explosions in underground mines and surface processing facilities are caused by accumulations of flammable gas andor combustible dust mixed with air in the presence of an ignition source. Dust explosions can occur where any dispersed powdered combustible material is present in highenough concentrations in the atmosphere or other oxidizing gaseous medium, such as pure oxygen.
These explosions resulted in 199 fatalities and 718 injuries. Safety and health niosh and the mine safety and health administration msha conducted. Solid coal is not readily combustible but can be ignited through sustained contact with an open flame. On february 4, 2018 a power plant coal dust fire was reported at the yallourn power station in victoria, australia. Overton said that this thinking was helpful to prevent and control dust explosion. When a conveyor belt collects coal dust, it becomes a fire hazard. Dont repeat a history of combustible dust explosions. Preventing coal dust explosions in underground coal mines. Dustsafetyscience improving combustible dust safety in. Coal dust cloud explosion in silo combustible dust.
Finelydivided coal dust is a moderate fire and explosion hazard, particularly when dispersed in the air at high concentrations in an enclosed space and exposed to flame or other ignition sources. Such methanedust explosions are prevented by inerting the coal dust in a way that prevents the exploding methane from igniting it. Float coal dust is a serious explosion hazard if it accumulates on top of the rock dust and the area is not inerted by the application of additional rock dust. Fire and explosion prevention in coal pulverizing systems. Plants can no longer sweep coal dust under the rug and ignore the health and safety hazard it presents, because a single spark can cause a dust explosion that could put a plant out of service, perhaps permanently. Technology for realtime monitoring of coal dust explosion. Preventing ignitions and explosions mine safety and. The pressure wave or wind forces created by a small methane explosion can scour the mine entry, blowing coal dust up into the air. Combustible dust prevent combustible dust explosions. Settled dust on horizontal surfaces may also be dispersed into the air by an initial explosion, resulting in a much more serious secondary explosion. Pdf coal dust explosion prevention and protection based on. Controlling coal dust is vital to worker safety because of the risk of coal dust explosions.
Observations on manifestations of coked coal dust in mine explosions. Preventing coal dust explosions hazardex for safety. For a fire to occur, the fire triangle needs to be present oxygen, fuel, and heat. In addition to creating safety and environmental hazards, coal dust increases the cost of maintaining. Postexplosion observations of experimental mine and laboratory. A dust explosion is the rapid combustion of fine particles suspended in the air within an enclosed location. Therefore, it is very significant to prevent and mitigate dust explosion intrinsically with the thinking of inherent safety. Pdf in order of dust explosion prevention and protection, a dust explosion control framework was proposed based on four basic principles of inherent. Coal dust fires and explosions the pioneering effort to establish the relative ignition sensitivity and explosibility of air and various flam mable dust mixtures was carried out by the u. Visit the dust safety directory to explore available prevention and protection providers.
Dust explosions occur when combustible dusts build up in the air and combust rapidly, causing a strong pressure wave to form. General stonedusting to the required standard and the correct siting of barriers erected to the approved specification have prevented coal dust explosions in the uk since the 1934 gresford colliery disaster in which 265 men were killed. If exploding methane disperses and ignites the coal dust that has accumulated on the mine ribs and floor, the burning coal dust immeasurably increases the strength of the explosion. A total area of 800 square feet was damaged as the result of the accident. The basic requirements for a dust explosion to occur is that combustible dusts are suspended in air and are ignited. In such cases protection and safety are provided by equipment which is reliably explosion proof. In this episode of the dustsafetyscience podcast, we interview vincent grosskopf, founder of coal mill safety. Explosion hazards of coal dust in the presence of methane. For example, coal dust was one of the causes of the westray mine explosions. Blankenship documentary blames msha for upper big branch mine disaster. This explosion led to changes in safety systems, including the use of confinement systems and no smoking policies. This film, 12 points of safety, produced in 1926 by the us bureau of. In these exciting times, i look forward to seeing what we can achieve together as we move into the second half of 2018 and beyond.
In an article written by the chemical safety board, they documented 50 separate incidents of combustible dust explosions. They are a deadly hazard in a variety of workplaces, from grain silos to plastics factories. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. Combustible dust explosions over the past decade in u. If the roof, floor, and sides of any entry are covered with a film of water of sufficient. While much progress has been made in preventing explosion disasters in coal mines, explosions still occur, sometimes producing multiple fatalities. February, 2008 coal dust silo explosion injures 6 workers stonehouse process safety commentary. The novel and film describe the deadliest industrial disaster in americas history and its coverup. In multiple combustible dust accidents between 2008 and 2012, employees and employers alike were often ignorant of the fact that combustible dust was a hazard. Types of dusts involved in dust explosions unknown 11,5%. In practice, for a dust explosion to occur, a number of conditions must be met including.
Preventing coal dust explosions in underground coal mines office of mine safety and health research. And in 2008, a huge explosion and fire at a sugar refinery in georgia killed 14 and seriously injured 38. Hes been semiretired since 2011 and now does tactical consulting, specifically working with cement production. Blankenship documentary blames msha for upper big branch. The explosion hazards of float coal dust have been studied over many decades by the former u. Thanks to msha and the great personnel at the mine. Combustible dusts and explosion safety what is a dust explosion. Often the finer particles dust remain in suspension in the silo. These technical safety data have been determined under standard conditions in. Finelydivided coal dust is a moderate fire and explosion hazard, particularly when dispersed in the air at high concentrations in an enclosed space. Frames from a highspeed movie during an oil shale face blast showing the.
Other ma1or preventive measures which can be adopted include rock dust barriers, concrete stoppihgs, and pressure relief vents in their various forms and modifications. Coal dust explosion prevention and protection based on. Finer coal dust is more explosible and requires more rock dust to inert. This instrument, the coal dust explosibility meter cdem, is a simpletouse handheld device that provides a passfail assessment of coal mine dust samples.
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