Twentieth century hand-book for steam engineers and electricians, with questions and answers (1905)
RFFWJ18ETwentieth century hand-book for steam engineers and electricians, with questions and answers (1905)
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . *::tf%. ENGINE OPERATION 2G9 In a non-condensing engine the pressure of theatmosphere, amounting to 14.7 lbs. per square inch atsea level, is constantly in resistance to the motion of EXHAUSTINLET
RM2AXHTC1Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . *::tf%. ENGINE OPERATION 2G9 In a non-condensing engine the pressure of theatmosphere, amounting to 14.7 lbs. per square inch atsea level, is constantly in resistance to the motion of EXHAUSTINLET
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . figure 95 170 ELECTRICITY FOR ENGINEERS dirt as may accumulate therein to fall out rather thanin the clash pot. The three cuts show the manner of suspending thespools and their accessibility, it being possible toremove any spool by simply taking out the two screws.
RM2AXG00RTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . figure 95 170 ELECTRICITY FOR ENGINEERS dirt as may accumulate therein to fall out rather thanin the clash pot. The three cuts show the manner of suspending thespools and their accessibility, it being possible toremove any spool by simply taking out the two screws.
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . figure 74. tages over them. In the two phase system two cur-rents displaced 90 degrees from each other andotherwise exactly similar to the single phase currentsare used. In the three phase system three currentsseparated 120 degrees are used. These currents areshown in Fig. 74.
RM2AXG8WGTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . figure 74. tages over them. In the two phase system two cur-rents displaced 90 degrees from each other andotherwise exactly similar to the single phase currentsare used. In the three phase system three currentsseparated 120 degrees are used. These currents areshown in Fig. 74.
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . distributed amongfour valves, each valve performing its own particularfunction in controlling the distribution of the steamfor the end of the cylinder to which it is attached.Also each valve may be adjusted to a certain degreeindependently of the others, and this fact goes fartowards explaining why engines of this type, with thedisengaging valve gear, are so much more economicalin the use of steam than are those with the ordinaryfixed cut off. Thus, for instance, the steam valves of 158 ENGINEERIN
RM2AXJYFTTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . distributed amongfour valves, each valve performing its own particularfunction in controlling the distribution of the steamfor the end of the cylinder to which it is attached.Also each valve may be adjusted to a certain degreeindependently of the others, and this fact goes fartowards explaining why engines of this type, with thedisengaging valve gear, are so much more economicalin the use of steam than are those with the ordinaryfixed cut off. Thus, for instance, the steam valves of 158 ENGINEERIN
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . it leaves much room forimprovement; not because of any variation in theinduced electromotive force, but because of the lossesoccurring in the armature and wires conveying current.The loss of voltage in the armature and line equals thecurrent multiplied by the resistance; consequently, asthe current increases more and more volts are lost andthe pressure goes down. If we would have the pressureremain at its normal value, we must find some way toincrease the field magnetism as the current deliveredby
RM2AXGTA4Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . it leaves much room forimprovement; not because of any variation in theinduced electromotive force, but because of the lossesoccurring in the armature and wires conveying current.The loss of voltage in the armature and line equals thecurrent multiplied by the resistance; consequently, asthe current increases more and more volts are lost andthe pressure goes down. If we would have the pressureremain at its normal value, we must find some way toincrease the field magnetism as the current deliveredby
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . the constant current and the voltagevaries with the resistance, in order to keep the currentconstant. This is accomplished by a regulator on thedynamo, which is designed to compensate for thechanges of resistance in the circuit and to increase ordecrease the pressure as required. In estimating the size of wire for a series system youconsider the total length of the loop. There is noaverage distance as the total current travels over theentire circuit. We will assume that you have an arclight circui
RM2AXGY7TTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . the constant current and the voltagevaries with the resistance, in order to keep the currentconstant. This is accomplished by a regulator on thedynamo, which is designed to compensate for thechanges of resistance in the circuit and to increase ordecrease the pressure as required. In estimating the size of wire for a series system youconsider the total length of the loop. There is noaverage distance as the total current travels over theentire circuit. We will assume that you have an arclight circui
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . ning constant, the voltage is pro-portional to the current, so that the amount of currentsent through the milli-voltmeter or ammeter is exactlyproportional to the current flowing through the shunt.Fig. 79 shows connections for ammeters which carrythe entire current and those used with a shunt. The object of such a construction is apparent. Inthe installation of the switchboard, where eachammeter registers several thousand amperes, it is notnecessary to construct the large conductors in such amanne
RM2AXG6YNTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . ning constant, the voltage is pro-portional to the current, so that the amount of currentsent through the milli-voltmeter or ammeter is exactlyproportional to the current flowing through the shunt.Fig. 79 shows connections for ammeters which carrythe entire current and those used with a shunt. The object of such a construction is apparent. Inthe installation of the switchboard, where eachammeter registers several thousand amperes, it is notnecessary to construct the large conductors in such amanne
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . figure 40. steam, and it is subject only to the temperature of thesurrounding atmosphere. It is claimed that as a resultof this the accuracy of the spring is insured and thatno allowance need to be made in its manufacture forexpansion caused by the high temperature to which itis subject when located within the cylinder. Anothergood feature of this design is, that the spring can beeasily removed without disconnecting any one part ofthe instrument in case it is desired to change springs. THE INDICAT
RM2AXJT5MTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . figure 40. steam, and it is subject only to the temperature of thesurrounding atmosphere. It is claimed that as a resultof this the accuracy of the spring is insured and thatno allowance need to be made in its manufacture forexpansion caused by the high temperature to which itis subject when located within the cylinder. Anothergood feature of this design is, that the spring can beeasily removed without disconnecting any one part ofthe instrument in case it is desired to change springs. THE INDICAT
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . ged, the system is said to be balanced. Itis also very important to arrange so that the neutralwire cannot readily be broken. Should the neutral *4 ELECTRICITY FOR ENGINEERS wire be opened while, for instance, fifty lamps wereburning on one side and say ten or twenty on theother, the ten or twenty would be broken by the excessvoltage. Grounded wires ordinarily cause moretrouble than anything else on electric light or powercircuits, but with the three wire system, the neutralwire is often grounded.
RM2AXGYMRTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . ged, the system is said to be balanced. Itis also very important to arrange so that the neutralwire cannot readily be broken. Should the neutral *4 ELECTRICITY FOR ENGINEERS wire be opened while, for instance, fifty lamps wereburning on one side and say ten or twenty on theother, the ten or twenty would be broken by the excessvoltage. Grounded wires ordinarily cause moretrouble than anything else on electric light or powercircuits, but with the three wire system, the neutralwire is often grounded.
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . FIGURE 48. with the pivoted end of the pendulum (Fig. 48), butwith this arrangement, owing to the curved travel ofthe pendulum, there is greater liability to distortion ofthe diagram than in the first method. In case it isdesired to use the Brumbo pulley, the radius of thesegment can be found by the same process as thatused for finding the point for connecting the corddirectly to the pendulum. One of the neatest and most easily applied devices 182 ENGINEERING for reducing the motion of the crosshe
RM2AXJG4ATwentieth century hand-book for steam engineers and electricians, with questions and answers .. . FIGURE 48. with the pivoted end of the pendulum (Fig. 48), butwith this arrangement, owing to the curved travel ofthe pendulum, there is greater liability to distortion ofthe diagram than in the first method. In case it isdesired to use the Brumbo pulley, the radius of thesegment can be found by the same process as thatused for finding the point for connecting the corddirectly to the pendulum. One of the neatest and most easily applied devices 182 ENGINEERING for reducing the motion of the crosshe
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . to handle notonly the boilers successfully, but is at times requiredto run the engine in the absence of the engineer. Hethus acquires the ability to operate that particularengine, while at the same time he may be compar-atively ignorant of the peculiarities of other types.Or an engineer may have had years of experience withsimple non-condensing engines, but if called upon tooperate a compound condensing engine, he would findthat he had a great deal to learn. TANDEM COMPOUND ENGINE, BUCKEYE ENGINE
RM2AXHTNRTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . to handle notonly the boilers successfully, but is at times requiredto run the engine in the absence of the engineer. Hethus acquires the ability to operate that particularengine, while at the same time he may be compar-atively ignorant of the peculiarities of other types.Or an engineer may have had years of experience withsimple non-condensing engines, but if called upon tooperate a compound condensing engine, he would findthat he had a great deal to learn. TANDEM COMPOUND ENGINE, BUCKEYE ENGINE
Twentieth century hand-book for steam engineers and electricians, with questions and answers .. . FIGURE 71. current or by means of a resistance box connected inthe fields of the exciting dynamo. This latter regula-tion is of course the more economical, as there wouldbe considerable energy wasted were a resistance usedin the main exciting circuit. Alternating currents aregenerally used where currents are to be transmittedlong distances, as for instance, where power is derivedfrom a water fall situated some distance from the 128 ELECTRICITY FOR ENGINEERS point of use Its adaptability for such w
RM2AXG9ETTwentieth century hand-book for steam engineers and electricians, with questions and answers .. . FIGURE 71. current or by means of a resistance box connected inthe fields of the exciting dynamo. This latter regula-tion is of course the more economical, as there wouldbe considerable energy wasted were a resistance usedin the main exciting circuit. Alternating currents aregenerally used where currents are to be transmittedlong distances, as for instance, where power is derivedfrom a water fall situated some distance from the 128 ELECTRICITY FOR ENGINEERS point of use Its adaptability for such w