3 edition of Frictional Ignition of Gas During A Roof Fall. found in the catalog.
Frictional Ignition of Gas During A Roof Fall.
United States. Bureau of Mines.
|Series||Report of investigations (United States. Bureau of Mines) -- 5548|
|Contributions||Nagy, J., Kawenski, E.M.|
A kg brick and a 1-kg book are dropped in a vacuum. the force of gravity on the 10kg brick is.. 10 times as much as the force on the 1 kg book When a women stands with two feet on a scale the scale reads N. when she lifts one foot the scale reads. "It’s also important to note that MSHA did not conclusively rule out a roof fall or other frictional activity as the cause of the ignition, which the UMWA believes is the most likely ignition.
"Legal" gas checks are required by 30 CFR before a bolter is taken into or operated in a working place. Testing is also required every 20 minutes while in the working place. All tests must be taken while under supported roof, which in the case of a roof bolter requires the use of an extendable. 1) Fall in production from effected areas 2) Fall of productivity and increase of cost and usually higher than the direct losses. For breakout of a mine fire 3 conditions must be fulfilled. 1) Sufficient quantity of combustible material must be available. 3) Sufficient supply of oxygen must be available. 4) A source of ignition must be present.
A simulated frictional ignition on Longwall led to a gas explosion, which opened and damaged the doors in the tailgate and blew out the pressure release panels at the upcast shaft. The ignition injured three coalmine workers on a longwall face. Two coalmine workers in the main gate were knocked over, but remained conscious. Longwall shearer frictional ignition hazard. Look after electrical protection back-up batteries. Two men fall 2 metres after charge up basket boom assembly fails. Uncontrolled release of well bore fluids from pressurised shallow aquifers formation during coal seam gas drilling operations. Uncontrolled upward movement of drill string.
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Frictional ignition of gas during a roof fall (OCoLC) Material Type: Government publication, National government publication: Document Type: Book: All Authors / Contributors: John Nagy; Edward M Kawenski; United States. Bureau of Mines. Frictional ignition of gas during a roof fall / By John.
Nagy and Edward M. Kawenski. Abstract. Includes bibliographic of access: Internet Topics: Mine roof Author: John. Nagy and Edward M. Kawenski. Details of 23 incidents involving frictional ignition of methane in the coal mines of New South Wales (Australia) between and are discussed by the New South Wales Department of Mineral Resources ().A summary of these incidents, outlining the circumstances and type of rock material involved, is given in Table the 23 incidents reported, 16 (or 70%) involved picks on Cited by: Another possible ignition source is the frictional impact of rock on rock during a roof fall.
In addition to flammable methane gas, some underground coal mines encounter heavier molecular weight liquid hydrocarbons that can generate flammable vapors.
Energy released in a roof fall that creates a spark and ignites a methane mixture would be considered a frictional ignition. A frictional ignition occurred at the longwall shear.
An explosion of an accumulation of methane gas occurred at the longwall shear. An explosion of floating coal dust occurred throughout the mine. A roof fall resulting from a lack of ceiling supports restricted air flow through the mine resulting in an explosive float dust atmosphere.
of methane-air and an ignition source. This source is usually the hot streak caused by the frictional impact of the mining bit on hard rock, and the frequency of occurrence increases with increased bit wear.
Another possible ignition source is the fric-tional impact of rock on rock during a roof fall. A frictional ignition occurred at the longwall shear. An explosion of an accumulation of methane gas occurred at the longwall shear.
An explosion of floating coal dust occurred throughout the mine. A roof fall resulting from a lack of ceiling supports restricted air flow through the mine resulting in an explosive float dust atmosphere.
The causes of methane ignitions are summarized, and data demonstrates that frictional ignition sources, not electrical arcs, are the root causes of most methane ignitions at the face. The special case of roof bolters is also reviewed, and frictional ignitions are. Frictional ignition of gas during a roof fall / ([Washington, D.C.]: U.S.
Dept. of the Interior, Bureau of Mines, ), by John Nagy and Edward M. Kawenski (page images at HathiTrust) Mine Safety Board decision prevention of coal-dust explosions by rock dusting / (Washington, D.C.: U.S. Dept. of the Interior, Bureau of Mines, ), by United States.
Smacker's Knob Mine - Fall At some time between 3rd and 13th JunePeter Carl Daniel, who was working alone in a shallow opencut at the Smacker's Knob opal mine some 33 km south of Kynuna, sustained fatal injuries when buried under a fall of ground. A frictional ignition occurs when the friction between the cutting pick and the rock being cut reaches a critical temperature at which the resulting “smear” will ignite methane.
Jason Blee, aged 33 years, died on Monday 9 April (Easter Monday) while employed in an underground coal mine. He died from a pelvic crush injury when he was trapped between a.
The Inquiry found that a roof fall had occurred in the goaf Other recommendations following the Moura No. 4 mine disaster included: research into frictional ignition, research into methane ignitions by mine equipment, formalization of training standards in the industry, the establishment of emergency procedures surrounding: explosion open.
In the flammable and explosive zone, gas combustion or explosion is likely to be triggered when high-temperature sparks are generated by an impact occurring during the caving of the hard roof. Auto ignition takes place at approximately º to ºC (º to ºF),depending on the type of oil, the amount of impurities in it and usage.
New “high-temperature” fryers are designed to maintain the heat of the oil longer and cook at higher temperatures (much closer to auto-ignition), making these units a more significant fire risk. A frictional ignition of methane occurred at an underground coal mine when a continuous miner intersected a projected structure during production in a development panel.
Workers on the machine attempted to extinguish the fire using water hoses, however this was unsuccessful. This is due to friction between rocks caused by fall or caving of sandstone roof rock. The rocks containing hard surfaces such as siliceous or quartz, bearing sand stones can produce ignition.
Mainly Frictional ignition hazard depends on the mixture of the contacting materials. The composition of. The roof fall in the gob area caused a sudden outrush of air containing methane gas in the immediate vicinity where the shear machine was operating and.
The Queensland Mines Inspectorate has issued an alert regarding recent frictional ignition events at a Queensland mine. A roof fall incident at the Moranbah North underground operation has reportedly resulted in suspension of operations.
The NSW Resources Regulator will lead a causal investigation into a mine gas incident at. The explosion began after gas, mostly methane, was ignited by frictional impact as the shearer was cutting sandstone roof or by the rock colliding with steel supports or other rock while falling from the sandstone roof behind the longwall shields.
It is deemed more likely that the longwall mining machine (shearer) ignited the methane.(). Application of CFD Techniques to Assess Spontaneous Heating/Fire during Extraction of Thick Coal Seam Using Blasting Gallery (BG) Method.
Combustion Science and Technology: Vol.No. 9. except during actual recording, these troubles may be reduced, but likely to be replaced by others due to surges of the gas pressure in the connecting passages, and even when these are short the time taken for a change of pressure in the cylinder to reach and deflect the diaphragm, may introduce a phase lag which is serious at high engine speeds.