Steam Boilers for Electric Power Stations

Abstract

CONSIDEBABLE progress has recently been made in developing the type of boiler used in electric power stations. It is now generally recognized that considerable economies can be effected by the use of larger steam-generating units, higher steam pressures and higher temperatures. The average capacity of boilers now being installed in power stations has risen to nearly 200,000 lb. of steam per hour. These work in conjunction with alternating current generators giving 30,000–50,000 kilowatts. In the Electrical Times of November 24 a description is given by Mr. V. Walker of a number of the latest types of boilers recently installed. Attention is also directed to the alterations made necessary when pulverized fuel is used. Messrs. Babcock and Wilcox have developed some of their boilers so as to take advantage of the economies inherent in the use of high rates of heat release per square foot of furnace now obtainable. They have designed a boiler for the Brighton Corporation so as to have a normal evaporation of 175,000 Ib. per hour at 675 Ib. pressure per square inch and 875° F. To overcome the difficulties of natural circulation, forced circulation has been developed. Two other types of boiler, the La Monte and the Loeffler, are also being installed in Great Britain.