flashdamp
Jump to navigation
Jump to search
English[edit]
Etymology[edit]
flash + damp, with 'damp' having the meaning of 'gas', as in old German, modern Dutch, and Danish.
Noun[edit]
flashdamp (uncountable)
- (mining) A mixture of methane, carbon dioxide, and nitrogen that is found in mines, and ignited quickly within a safety lamp, but that is then extinguished quickly due to the exhaust products of the flame. Flashdamp can be heavier than air (called heavy flashdamp) or lighter than air (called light flashdamp), depending on the proportion of carbon dioxide.
- 1908, J. T. Beard, C.E., E.M., Mine Gases and Explosions: Text-book for Schools and Colleges and for General Reference[1], 1st edition, John Wiley & Sons, page 127:
- Flashdamp is a more dangerous mixture than firedamp: first, because it is difficult of detection and often escapes the notice of the fire boss, who mistakes it for blackdamp, and has various ways of accounting for its position at the roof; second, because of the popular fallacy that this mixture, which extinguishes the flame of a lamp, is not explosive, whereas at certain stages of dilution it becomes highly explosive.
- 1917, Coal Age: With Which is Consolidated The Colliery Engineer: Devoted to Coal Mining and Coke Manufacture[2], volume 11, McGraw-Hill, page 886:
- A flashdamp mixture is often lighter than air and presents the peculiarity strange to mines, of extinguishing a light at the roof.
- 1920, James T. Beard, C.E., E.M., Mine Gases and Ventilation: Textbook for Students of Mining, Mining engineers and Candidates Preparing for Mining Examinations: Designed for Working Out the Various Problems That Arise in the Practice of Coal Mining, as They Relate to the Safe and Efficient Operation of Mines[3], 2nd revised and enlarged edition, McGraw Hill Book Company, Inc., page 41:
- For illustration, let it be required to calculate the specific gravity of flashdamp (undiluted mixture of methane and carbon dioxide) directly from the specific gravities of these gases […]
- 1947, Alberta Dept of Lands and Mines. Mines Branch, Annual Report of the Mines Branch of the Department of Lands and Mines of the Province of Alberta[4], page 121:
- [An exam question under the Coal Mines Regulation Act on the topic of Gases, Shot-Firing and Safety Lamps] What is Flashdamp? How is it formed? Where found, and what action has it on the flame of safety lamps? An area contains 2658 cubic feet of this gas. What volume would there be of the two gases forming this flashdamp? Show how you would find the Specific Gravity of flashdamp from the Specific Gravities of the two gases forming flashdamp.