Modern Gasworks Practice

CHAPTER X ELECTRICAL PLANT IN GASWORKS The growing use of electricity as a source of power for operating gasworks plant has rendered a knowledge of this form of energy of increasing importance. A close acquaintance with the details of technical electricity is by no means necessary, for the practical construction of the apparatus is in the hånds of specialists. Every gas engineer should, liowever, aspire to a working knowledge of the subject, and he should be in touch with the applications in practice of the more important theories. The importance of electricity has recently been emphasized by instances where gas concerns have, in addition, obtained powers for a public supply of current. If electrically driven charging machinery is in use it is obviously economical in the majority of cases to operate other coal- and coke-handling plant by the same means. As a general rule it may be said that th.e ideal conditions for all power consumers is the continuous use of a set of plant working at something approaching its normal maximum capacity. To this end, it can usually be arranged to work the coal-handling plant together with charging machinery for ten or twelve Louis out of the twenty-four, and the charging machinery during the night only. In small works it is possible to make use of the coal-handling and charging machinery alternately with the same power installation, and in this way the necessary electrical plant is considerably reduced. If coke conveyors are also installed it can be arranged to use two out of the three pieces of plant at one time. Those who contemplate the introduction of electrical plant must bear in mind that if energy in this form is to be obtained at its cheapest it is essential that a good plant' load should be maintained upon the generating sets. Electricity when generated by means of town gas is an extremely cheap form of power, particularly when it is used on gasworks, for in such cases the gas consumed should be reckoned on “ cost into holder ” figures. In comparing costs with those of steam-driven generating plant the expense entailed in the provision of boilers should be included. If, however, existing excess boiler power is available, then generation by steam has its attractions. Steam, moreover, may be produced by means of materials which may frequently be almost unsaleable. In general, however, preference should always be given to generation by gas, unless other methods present indisputable advantages. GENERATING PLANT A point which has to be decided in each individual case is whether it is advisable to generate the current at the gasworks or to take advantage of the local supply. 342