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 Effecient Operation of MinesMcGraw-Hill, 1920 - 433 páginas |
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Resultados 1-5 de 40
Página 128
... intake haulage roads and shaft or slope bottom of a mine worked on safety lamps , provided there are lamp stations beyond which these men may not pass . The use of mixed lights is a dangerous practice . The danger does not consist ...
... intake haulage roads and shaft or slope bottom of a mine worked on safety lamps , provided there are lamp stations beyond which these men may not pass . The use of mixed lights is a dangerous practice . The danger does not consist ...
Página 147
... intake of the cir- culatory system . This device regulates the supply of oxygen and proportions it to the rate of consumption , which varies with the work performed by the wearer . Also , a pressure slightly in excess of 1 cm . of water ...
... intake of the cir- culatory system . This device regulates the supply of oxygen and proportions it to the rate of consumption , which varies with the work performed by the wearer . Also , a pressure slightly in excess of 1 cm . of water ...
Página 161
... intake opening , ' and the other for it to leave the mine , called the " return " or " discharge opening . " Two distinct air passages or airways are also required , leading from these openings into the mine , in order to conduct the ...
... intake opening , ' and the other for it to leave the mine , called the " return " or " discharge opening . " Two distinct air passages or airways are also required , leading from these openings into the mine , in order to conduct the ...
Página 162
... intake " and " re- turn " airways . These openings and airways form a part of the circulating system in the mine , similar to the arteries and veins of the human body . Kinds of Ventilation . - There are three different kinds of ...
... intake " and " re- turn " airways . These openings and airways form a part of the circulating system in the mine , similar to the arteries and veins of the human body . Kinds of Ventilation . - There are three different kinds of ...
Página 163
... intake air ; and the difference in weight of these two air col- umns destroys the equilibrium of the mine air and creates a current in the airways throughout the mine . A considerable difference of temperature is often observed between ...
... intake air ; and the difference in weight of these two air col- umns destroys the equilibrium of the mine air and creates a current in the airways throughout the mine . A considerable difference of temperature is often observed between ...
Otras ediciones - Ver todas
Mine Gases and Ventilation: Textbook for Students of Mining, Mining ... James Thom Beard Sin vista previa disponible - 2018 |
Términos y frases comunes
absorbed acetylene air column air current airway antilog atmosphere atoms battery breathing bag bulb Bureau of Mines burning calculated carbide carbide lamp carbon dioxide carbon monoxide cent chemical chimney circulation coal combustion constant corresponding Cosine Sine Cosine Cotang Tang Cotang cubic cylinder Davy lamp density downcast dust equal explosive firedamp formula gaseous gases gauze given horsepower hydrogen ignition inches increase inflammable intake liquid logarithm long ton mantissa mercury methane minute mixture molecular molecules nitrogen oxygen passing percentage of gas potential values pounds power potential pressure potential produced quantity of air ratio reaction rubbing surface safety lamps saturated saturated vapor pressure seam sectional area shaft shown Sine Cosine Sine specific gravity square substance Tang Cotang Tang temperature tion tube unit pressure upcast valve vapor pressure varies velocity ventilating pressure volume of air water gage water vapor wearer weight
Pasajes populares
Página 401 - Minutes = 1 Hour 24 Hours = 1 Day 7 Days = 1 Week 28 Days = 1 Lunar Month...
Página 29 - Al . . . .Sb ....A ....As ....Ba . ...Bi . ...B . ...Br . . . .Cd . . . .Cs . . . .Ca ....C . . . .Ce . . . .Cl . ...Cr ....Co . ...Cb . . . .Cu...
Página 399 - Apothecaries' weight 20 grains = 1 scruple 3 scruples = 1 dram = 60 grains 8 drams = 1 ounce = 24 scruples...
Página 152 - ... skilled in such work, and all parts that require sterilizing shall be readily accessible for this purpose. (c) All parts of the apparatus subject to or liable to be subjected to pressures in excess of 5 pounds per square inch shall be...
Página 42 - Law states that the rates of diffusion of gases are inversely proportional to the square roots of their densities. Or...
Página 156 - Test 15 is made to determine the maximum length of time that the apparatus will supply the needs of the wearer when in a quiescent state. The wearer will remain as far as possible in a sitting posture throughout the test and perform no work. He will be allowed to manipulate the devices controlling the compressed-oxygen or compressedair supply to conserve such compressedoxygen or compressed-air supply to the greatest advantage.
Página 102 - AC, it follows, ex cequali, that as AM is to AC so is the time along AM to the time along AC. THEOREM IV, PROPOSITION IV The times of descent along planes of the same length but of different inclinations are to each other in the inverse ratio of the square roots of their heights From a single point B draw the planes BA and BC, having the same length but different inclinations; let AE and CD be horizontal lines drawn to meet the perpendicular BD; and...
Página 55 - ... the weight of an equal volume of air at the same temperature and pressure.
Página 150 - Permissibility tests will not be made unless the unit has been completely developed and is a form that can be marketed. (f ) The results of the tests shall be regarded as confidential by all present at the tests and shall not be made public in any way before the shot-firing unit is formally approved by the Bureau of Mines.
Página 152 - A self-contained breathing apparatus in which the expired atmosphere is recirculated shall be provided with a release valve that is operated manually or automatically and is placed at some point in the circulatory system of the apparatus. The function of this valve shall be...