A Treatise on Practical and Theoretical Mine VentilationJ. Wiley & sons, 1900 - 141 sivua |
Kirjan sisältä
Tulokset 1 - 5 kokonaismäärästä 18
Sivu 23
... pressure or head of air - column required being from ten to twenty times as much in order to overcome the friction and resist- ance of airways , etc. , in underground workings ; and , were it not for these resistances , very small pressure ...
... pressure or head of air - column required being from ten to twenty times as much in order to overcome the friction and resist- ance of airways , etc. , in underground workings ; and , were it not for these resistances , very small pressure ...
Sivu 28
... required during the summer months in order to keep the venti- lation uniform during the year . 5.283 pounds of the total pressure From the above , it may be seen that natural ventila- tion may be more during the winter than during ...
... required during the summer months in order to keep the venti- lation uniform during the year . 5.283 pounds of the total pressure From the above , it may be seen that natural ventila- tion may be more during the winter than during ...
Sivu 47
... pressure in pounds per square foot , and the theoretical velocity of air due to this pressure . This table , it must be remembered , is only theoretically true , on account of the enormous power required to overcome friction to the ...
... pressure in pounds per square foot , and the theoretical velocity of air due to this pressure . This table , it must be remembered , is only theoretically true , on account of the enormous power required to overcome friction to the ...
Sivu 51
... pressure required to overcome the friction , and produce circulation . Taking the air at 62 ° F. , one cubic foot , with the barometer at 30 inches , would weigh 0.0763 of a pound . If we now multiply this motive - column by the weight ...
... pressure required to overcome the friction , and produce circulation . Taking the air at 62 ° F. , one cubic foot , with the barometer at 30 inches , would weigh 0.0763 of a pound . If we now multiply this motive - column by the weight ...
Sivu 54
... pressure or head of air - column required for its pro- pulsion is proportional to the square of the velocity ; so that to double this velocity there must be four times the head ; to treble it , nine times the head ; etc. ( a ) ...
... pressure or head of air - column required for its pro- pulsion is proportional to the square of the velocity ; so that to double this velocity there must be four times the head ; to treble it , nine times the head ; etc. ( a ) ...
Muita painoksia - Näytä kaikki
Yleiset termit ja lausekkeet
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