A Treatise on Practical and Theoretical Mine VentilationJ. Wiley & sons, 1900 - 141 sivua |
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Tulokset 1 - 5 kokonaismäärästä 18
Sivu 24
... upcast , and circu- lation will be from C to A , on account of the heavier column of air CD . This is the principle upon which furnaces are em- ployed to ventilate mines . They are placed at the bottom , or near the bottom , of the upcast ...
... upcast , and circu- lation will be from C to A , on account of the heavier column of air CD . This is the principle upon which furnaces are em- ployed to ventilate mines . They are placed at the bottom , or near the bottom , of the upcast ...
Sivu 25
... upcast 72 ° . From the table on p . 21 , we find that 100 cubic feet of air at 42 ° weigh 7.67 pounds : therefore ... upcast columns of air . Let M = the motive - column , or head of air , D = the depth of the upcast in feet , t ...
... upcast 72 ° . From the table on p . 21 , we find that 100 cubic feet of air at 42 ° weigh 7.67 pounds : therefore ... upcast columns of air . Let M = the motive - column , or head of air , D = the depth of the upcast in feet , t ...
Sivu 26
... upcast of ten square feet , the pressure on each square foot of upcast will be the same as on the one square foot of the down- cast , provided there is no friction . When calculating the weight of the motive - column , 26 § 11 MINE ...
... upcast of ten square feet , the pressure on each square foot of upcast will be the same as on the one square foot of the down- cast , provided there is no friction . When calculating the weight of the motive - column , 26 § 11 MINE ...
Sivu 27
... upcast 202 ° , the barometer being 30 " on an average in the two shafts , which are equal in length ? Pounds . 900 cubic feet of air at 42 ° F. 71.406 900 cubic feet of air at 2020 F. = = 54.126 Difference in weight • • 17.280 Suppose ...
... upcast 202 ° , the barometer being 30 " on an average in the two shafts , which are equal in length ? Pounds . 900 cubic feet of air at 42 ° F. 71.406 900 cubic feet of air at 2020 F. = = 54.126 Difference in weight • • 17.280 Suppose ...
Sivu 28
... upcast , the better ; as the longer upright column of light air gives rise to a brisker ventilation . For this reason , furnaces should not be used in shallow pits . When coal is worked at a dip , the effect of natural ventilation is ...
... upcast , the better ; as the longer upright column of light air gives rise to a brisker ventilation . For this reason , furnaces should not be used in shallow pits . When coal is worked at a dip , the effect of natural ventilation is ...
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air circulating air gave air in mines air passing air-column air-course air-current amount anemometer asphyxia atmosphere barometer brattice carbonic acid coal coal-dust Colliery column cubic feet cubic foot cubic inches Davy lamp diameter discharge districts double downcast drifts employed engine equal explosion fan-drift feet of air feet per minute feet square fire-damp flame formula furnace gallery gases gauze height hence horse-power inches of mercurial inches water-gauge increased ksv2 lamp length marsh-gas measured mechanical ventilators mercury method miners morocco motive-column Mueseler lamp multiplied number of revolutions oxygen perimeter piston pounds per square pressure per square pressure required Problem proportional quan quantity of air regulators required to overcome resistance revolutions per minute rubbing-surface safety-lamp sectional area shaft shutter smaller airway splitting square feet square foot Suppose temperature tion tity total pressure tube upcast velocity ventilating pressure volume of air