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Examination questions for certificates of competency as mine inspector, mine foreman, mine manager, fireboss, hoisting engineer, etc. as given by the state examining boards; together with answers
Anonymous
Paperback. RareBooksClub.com 2013-09-13.
ISBN 9781230153810
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Publisher description
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...60 feet apart. The airways are very large and are kept up and in good condition. The volume of air is nearly three times the quantity required by law, and yet complaints are made of the ventilation, and it is a long time after a shot is fired before the smoke gets cleared out. What do you think is the matter? M.--///. Ans.--There should be no trouble on the entries of the mine under these conditions. The air may not, however, be properly deflected into the rooms or chambers and made to sweep the working faces as it should. It may be necessary to put up curtains on the airways to deflect the air into the rooms. Again, the sectional area of the airways, which are very large, may be such that the velocity of the air is too small to remove the gases and smoke rapidly when a shot is fired, although a large quantity of air may be passing; this is often the case in thick seams, where the airways are very large. Ques. 1314.--In a mine employing 250 persons, each person being allowed 200 cubic feet of air per minute, give the total volume of air required in a day of 10 hours, in cubic feet and its weight in tons, the temperature being 62 F., and the barometer 30 inches. F.--Pa. (B) Ans.--The number of cubic feet of air circulating through the mine in the given time should be 250X200X60X 10 = 30, 000, 000 cu. ft. The weight of 1 cu. ft. of air at the temperature and pressure given is 1.3273X30----=.07624 lb. 460+62 The weight of air that should circulate through the mine in 10 hr. is, therefore, .07624X30, 000, 000 = 1, 143.6 T. Ques. 1315.--What is the smallest quantity of air required to be circulated per minute to make safe a section of a mine, under the following conditions: In the section, there are two entries and fifty-five rooms. The entries are
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Examination questions for certificates of competency as mine inspector, mine foreman, mine manager, fireboss, hoisting engineer, etc. as given by the state examining boards; together with answers
Book reviews » Examination questions for certificates of competency as mine inspector, mine foreman, mine manager, fireboss, hoisting engineer, etc. as given by the state examining boards; together with answers
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