Excerpt from Canadian Electrical News and Engineering Journal, Vol. 15: January, 1905
The controller is mounted on the engineer's platform and has seven steps; it acts by connecting different resistances, in series, with the rotating part of the motor. These resistances are entirely separate from the machine, being connected with it by means of three slip rings.
The mine incline varies from forty-five degrees to twenty degrees as depth is obtained. At present it has a depth of over 2,000 feet, and is equipped with double tracks of four feet gauge laid with 56 pound steel rails. The skips are self dumping and are not run in balance. These skips discharge into bins, the bottoms of which are about five feet above the tunnel track, which allows the cars running on the latter to be loaded through hoppers. The nominal speed of the hoist is five hundred feet a minute, but it has been found in actual practice that it only takes from five to six minutes for the skip to come from the bottom of the mine, discharge its load, and return again to the bottom. The total load hoisted (rope, skip and ore), is from 7 1/2 to 8 tons.
The crushing plant is situated by the side of the railroad track, about three-quarters of a mile from the mouth of the tunnel. This plant is supplied with power by a branch from the main line, and the machinery at present consists of a 20 inch by 6 inch Farrel crusher with a set of geared rolls used for reducing the hard ore to fines. This hard ore occurs in parts of the mine but not in all. The two machines (crusher and rolls), are driven by a 50-horse power, 200 volt, slow speed, type C, Westinghouse induction motor, supplied through two 25 k. w. transformers. Electrical measurements indicate that these machines take about 40 h.p. when crushing eight tons per hour. This plant is only a temporary one, to be used until the new mill, now under construction, is completed. The new mill will be driven throughout by 2,000 volt motors. It is designed to handle all the ore from the mine, and will both drass the rich ore for shipping and crush and concentrate those ores which are too lean to ship.
The hoist is so designed that, in case of accident, it may be operated by steam power by simply coupling an engine to each end of the countershaft of the new hoist, an operation which will require very little time. Steam will be supplied to the engines by old boilers, located about fifty feet away, the stacks from which consist of two tile pipes laid up the old shaft to the surface above.
The old compound steam, single stage air compressor, built by the Canadian Rand Drill Company, which is located just over the mouth of the adit tunnel, can be used in the case of low water, or, of accident to the electrically driven compressor. Steam is supplied to this old compressor by the two 125 h.p. boilers which formerly ran it.
In a recent test of the new plant it was found that, when double the full load was on the generators (a 100 per cent, overload test) the level of the water in the stand pipe was below its normal point, and that the water in the tail race was above the normal point; these water levels, both above and below, fluctuated rapidly and it was difficult to gauge them accurately with the means which were on hand at the time of the test. The actual head of water on the turbines is supposed to have been thirty-three feet, and if this assumption is correct the water wheels would have used, theoretically, 706 horse power of water, of which amount about 18 h.p. was consumed in the exciting generator. Allowing the main generator to have used 688 h. p. and on the assumption that it developed one hundred ampere per phase at a voltage of 2,160, and on the further assumption that the efficiency of the generator at this overload was 92 per cent., and that the power factor of the circuit (water rheostat) was unity, the brake horse power developed would have been about 543 h.p., which would give a. Это и многое другое вы найдете в книге Canadian Electrical News and Engineering Journal, Vol. 15