Minimum extinguishant and maximum oxygen concentrations for extinguishing coal dust-air explosions. [Ca. 10 refs]

Technical Report · Mon Jan 01 04:00:00 EST 1973

OSTI ID:7266289

Grumer, J; Miller, L F; Bruszak, A E; Dalverny, L E

In addition to nine powder and gaseous extinguishants of propagating Pittsburgh seam coal dust-air explosions earlier evaluated, 10 other powders have similarly been evaluated under like conditions such that wall quenching of the coal dust-air flames was virtually absent and the dust concentration was temporally and spatially uniform to within about +-5 percent. None of the newly examined extinguishants was better than Purple-K (potassium bicarbonate); the 10 of this report are anhydrite (calcium sulfate), monobasic (4 types) and dibasic ammonium phosphate, natural and synthetic cryolite (sodium fluoaluminate), sodium sulfate, and tricalcium phosphate. Except for anhydrite, sodium sulfate, tricalcium phosphate, and the cryolites, these materials were about equally effective, when present in relatively low concentrations (weight-percent of the coal dust-extinguishant mixture). The maximum oxygen concentration for the extinguishment of otherwise uninhibited coal dust explosions and the influence of coal dust particle size and the volatile content of the coal were also explored. For the present, the choice of the inhibitor among the good ones evaluated is not so critical as the system to be used to deploy the extinguishant against a coal dust explosion.

• Research Organization: Bureau of Mines, Pittsburgh, Pa. (USA). Pittsburgh Mining and Safety Research Center
• OSTI ID: 7266289
• Report Number(s): BM-RI-7782
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000 -- Coal
Lignite
& Peat-- Mining
014000* -- Coal
Lignite
& Peat-- Combustion
016000 -- Coal
Lignite
& Peat-- Health & Safety
AIR
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
AMMONIUM COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM PHOSPHATES
CALCIUM SULFATES
CHEMICAL EXPLOSIONS
COAL FINES
EXPLOSIONS
FLAMES
FLUIDS
GASES
INHIBITION
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
SODIUM COMPOUNDS
SODIUM SULFATES
SULFATES
SULFUR COMPOUNDS