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HE enormous growth of the electrical industry throughout the world during the past decade has entirely revolutionized methods of power development. Especially is this true west of the Rocky Mountains, where gigantic natural waterpowers have been put to a useful purpose. Owing to the fact, however, that most of the western streams show a great variation in flow in the different seasons of the year, it is not always possible to depend solely upon waterpower for the supply of electrical energy. In recent years the advent of crude petroleum upon the Pacific Coast, representing a total annual production of over one hundred million barrels, has made it possible when rainfall or water supply is lacking to economically supply the needed power. During certain hours of the day, too, when the so-called peak load conditions are to be met by a central station, additional electrical energy over that possible to supply from the hydro-electric station. is found to be necessary. Hence, the steam power plant, consisting of large concentrated units, is now recognized as an indispensable auxiliary to continuity of service.

FIG. 1.-A 20,000 h.p. Curtis turbine installed in San Francisco.

In order that there should be no excessive loss in distribution, these concentrated steam power units are usually found in the


FIG. 2.-Exterior view Long Beach Plant, Southern California Edison Company. This plant is noted for its use of meters, for various sorts of economy studies and for records obtained in daily operating practice. Note the finish and aesthetic beauty of the exterior.

heart of the great distribution centers. Especially is this true where abundance of circulating or cooling water may be obtained. Thus we find in Central California, Station A and Station C of the Pacific Gas & Electric Company, and the Fruitvale Station of the Southern Pacific Company, all situated in the distributing centers of San Francisco and its immediate vicinity. In the Los Angeles district we find that the Redondo and Long Beach plants of the Southern California Edison Company, owing to the lack of abundant cooling water near the distribution center are situated at a distance from it of some fifteen or twenty miles. It will now be interesting and instructive to examine the details of a typical power installation of the sort just hinted at.

First, we shall describe the so-called steam cycle or the journey of the steam-making water from the time it enters the steam boiler until it has passed through the turbine, or power unit, and returned again to the boiler; secondly, we shall consider the circulating water which is necessary in large quantities to convert the exhaust steam back again into water; and thirdly, we shall also touch briefly upon the journey of the oil from the time it leaves the cars at the sidetrack until it disappears from the chimney as a flue gas. We shall also touch briefly upon the general size and functions of apparatus employed to accomplish these results.


The Storage Tank.-The supply of water for steaming purposes is usually brought to a make-up or storage tank from supply wells either on the immediate premises or nearby property. If these are not found, it is brought from rivers, lakes, or other bodies in the vicinity, or in many cases is purchased from some water company supplying the municipality. The storage tanks are varied in size, shape and capacity from a small tank, used as a receiver and hot-well, to a number of tanks, large and small, used for storage purpose only.

The use of storage tanks depends upon the source and quantity of water supplied and the load carried by the plant. Where there is a steady and positive source of supply, the tank may be of small capacity. In some cases where the supply is small and the storage at different periods is unfit for use, larger storage and settling tanks are required, and at times even filtration and cleaning tanks also are employed.

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