Show ROTARY converters FOR MINING SERVICE WRITTEN FOR THE MINING REVIEW rotary converters are being used in many coal and metal mines direct current is necessary for the operation of mining locomotives because alternating current motors cannot satisfy the speed and space requirements alternating current is used for the transmission of the energy from the steam or hydroelectric hydro electric generating stations to the mines and the rotary converter is the logical machine for efficiently converting the alternating to direct current at the point where the energy is to be used several public service companies in both pennsylvania and in colorado are making a specialty of supplying mines with alternating current energy and are developing excellent mining loads the larger mining companies find it economical to establish steam or hydraulic generating stations at points where energy can be generated cheaply and to transmit it a aa high tension alternating current to the mine or group of mines where it is utilized whether alternating energy is generated by a public service company or by the mining company experience shows the rotary converter to be an efficient reliable machine for converting the alternating to direct current A nominal voltage of either or is adopted for the direct current distribution systems within the mines A good example of a mining plant ro tary converter installation is shown in figure 1 which is a view of the substation at mine aline no 22 of the consolidated coal company of pennsylvania this station receives energy as alternating curren current fat at 2300 volts three phase 60 cycles the pressure is stepped to volts for the alternating side of the westinghouse kw rotary and is delivered as direct cur car rent at volts A standard westinghouse black marine finished switchboard carrying the usual switch gear and instruments controls the incoming alternating current line the rotary converter and the outgoing direct current feeders which radiate to different parts of the property in large mines it is sometimes expedient to locate rotary converter substations sub stations underground near the center of the area they serve such an underground substation of the consolidated coal company is is shown in figure 2 the room forming the station is lined with brick which is waterproofed on the outside and the roof is arched so that it will drain and that dripping water cannot damage the apparatus the incoming lines to this station are alternating terna ting current 2300 volts three phase 60 cycles and the kw rotary converter 7 7 M r A 0 figure 1 figure 2 delivers direct current at volts tile the transformers stepping down from the alternating transmission voltage of 2300 to the alternating rotary voltage of are located lo 10 in the substation see figure 2 A pipe frame work arranged over the high tension transformers supports the high tension bus bars A two panel black marine finished switchboard carries the equipment for motoring and controlling the incoming and outgoing lines the transformers ant and the rosaries rotaries rot aries arles armored lead covered cables are generally used to convey the high voltage energy to an underground substation in a mine the cable is usually carried down a borehole rather than through the workings so io that the chances of injury from falling rock and from interference will be minimized |