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The calcium carbide industry
4IO
CURRENT TOPICS.
2o,ooo-Kilowatt Turbo-generator at New York F_.dison Company's Station. (Elect. Rev. and West. Electn., lix, 967.) The turbine is of the vertical type built by the General Electric Company. The base dimensions are 17 feet 6 inches by 17 feet; height above floor, 35 feet 7 inches; height of foundation above basement floor, IO feet; area occupied, 279 square feet; nominal rating of turbine, 30,000 horsepower; diameter of wheels, 13 feet; total number of wheel buckets, 7,200; approximate bucket velocity, 6 miles per minute. The generator is of 4-pole, 3-phase, 25-cycle type, operating at 6,6o0 volts, 75 ° revolutions per minute. Capacity, 2o,ooo kilowatts. Steam consumption, guaranteed, at 175 pounds pressure by gauge, 28.5 inches vacuum, superheat 100 ° F., is as follows : Load in K . W . io,ooo I5,ooo 2o,ooo
Steam, pounds per K . W . an hour. I5 I4.4 I5
Total steam p e r hour, pounds. I5o,Ooo --2i 6 , o o o 300, ° 0 0
Each turbine requires 400 tons of coal per day; 86,000,000 gallons water for condensing, and 80,000 cubic feet per minute of air for cooling the generator windings. Three turbine units occupy a space formerly taken up by four 3,5oo-kilowatt engine-driven units. The Waterside stations of the New York Edison Company have a capacity of 500,000 horsepower. They have a total of I,II4 miles of mains, feeders, and cables in their underground system, and supply electric energy over twenty-one square miles of Manhattan and about forty square miles of the Borough of Bronx. The Calcium Carbide Industry. (Times, Eng. Suppl., Dec. 27, I 9 I I . ) - - I n the choice of a site for a carbide factory the chief factors which have to be considered are cheap supplies of raw materials, lime or limestone and coke or anthracite, and of power. Most of the large works have been established in places where a practically unlimited supply of water power is available, especially in Norway, where there are also large deposits of limestone. The limestone must be free from magnesia, and especially from phosphorus compounds. Rather more than the theoretical amount of lime is used, v/z., 2,000 pounds of lime to 1.2oo pounds of anthracite per ton of carbide. The manufacture is conducted in electric furnaces provided with two inclined electrodes capable of maintaining a temperature of about 3,038 ° C. (5,500 ° F.). In a modern works a furnace takes about 1,5oo kilowatts, and produces 50 to 60 tons of carbide per week. On a moderate scale the power consumption is estimated at about one electric horsepower per year per ton of carbide, but in very large installations the power consumption is much lower. For example, at Odda more than 30,000 tons of carbide are produced per year by six turbo-alternators of about 4,000 horsepower each, and one of these serves as a stand-by.
CURRENT TOPICS.
2o,ooo-Kilowatt Turbo-generator at New York F_.dison Company's Station. (Elect. Rev. and West. Electn., lix, 967.) The turbine is of the vertical type built by the General Electric Company. The base dimensions are 17 feet 6 inches by 17 feet; height above floor, 35 feet 7 inches; height of foundation above basement floor, IO feet; area occupied, 279 square feet; nominal rating of turbine, 30,000 horsepower; diameter of wheels, 13 feet; total number of wheel buckets, 7,200; approximate bucket velocity, 6 miles per minute. The generator is of 4-pole, 3-phase, 25-cycle type, operating at 6,6o0 volts, 75 ° revolutions per minute. Capacity, 2o,ooo kilowatts. Steam consumption, guaranteed, at 175 pounds pressure by gauge, 28.5 inches vacuum, superheat 100 ° F., is as follows : Load in K . W . io,ooo I5,ooo 2o,ooo
Steam, pounds per K . W . an hour. I5 I4.4 I5
Total steam p e r hour, pounds. I5o,Ooo --2i 6 , o o o 300, ° 0 0
Each turbine requires 400 tons of coal per day; 86,000,000 gallons water for condensing, and 80,000 cubic feet per minute of air for cooling the generator windings. Three turbine units occupy a space formerly taken up by four 3,5oo-kilowatt engine-driven units. The Waterside stations of the New York Edison Company have a capacity of 500,000 horsepower. They have a total of I,II4 miles of mains, feeders, and cables in their underground system, and supply electric energy over twenty-one square miles of Manhattan and about forty square miles of the Borough of Bronx. The Calcium Carbide Industry. (Times, Eng. Suppl., Dec. 27, I 9 I I . ) - - I n the choice of a site for a carbide factory the chief factors which have to be considered are cheap supplies of raw materials, lime or limestone and coke or anthracite, and of power. Most of the large works have been established in places where a practically unlimited supply of water power is available, especially in Norway, where there are also large deposits of limestone. The limestone must be free from magnesia, and especially from phosphorus compounds. Rather more than the theoretical amount of lime is used, v/z., 2,000 pounds of lime to 1.2oo pounds of anthracite per ton of carbide. The manufacture is conducted in electric furnaces provided with two inclined electrodes capable of maintaining a temperature of about 3,038 ° C. (5,500 ° F.). In a modern works a furnace takes about 1,5oo kilowatts, and produces 50 to 60 tons of carbide per week. On a moderate scale the power consumption is estimated at about one electric horsepower per year per ton of carbide, but in very large installations the power consumption is much lower. For example, at Odda more than 30,000 tons of carbide are produced per year by six turbo-alternators of about 4,000 horsepower each, and one of these serves as a stand-by.