Document zzGgzwGm91v74eB5EZ8RGM7rm

AUTUMN POWERFAX . 1 9 3 3 production, but not so with the industrial. In the latter, at least in certain seasons, some of the steam is used for space heating and process requirements. There fore, some charge only for the B.t.u. value of the heat removed in making power; if non-condensing, this amounts to from 3600 to 4500 B.t.u. per kwh. generated plus the heat lost through exhaust heads; if condensing, the same figures plus heat rejected to the condens er are used; in bleed units the com putation is a little more involved. Others charge any arbitrarily de termined percentage of the steam passing through the turbine they may choose, with some regard to bleed, exhaust or condensing pres sures. And there are still other methods and variations. Attempts are also being made by the Ameri can Society of Mechanical Engi neers to standardize these costs. In any event, once the method is known, comparisons may be re duced to the same basis. Plants Purchasing Electric Power In plants purchasing or selling all or part of their power, certain instruments are always provided by the utility on which to base its billing. These instruments are usually relied on by both the pow er purchaser and seller, but in some of the larger plants separate check instruments are installed. The usual instruments consist of a recording or integrating kwh. meter or kva.-hr. meter or both, with a demand recorder in either kw. or kva. or both. A power fac tor indicator and sometimes an ammeter and a voltmeter are also provided. The records from all of these should be tabulated in a suitable record file or book in any plant from the smallest to the largest. It is indispensable for proper control to .have these rec ords from month to month and year to year and to include at least total kwh., total kva.-hr., peak kw. and peak kva. and the average power factor. Records of this sort in the hands of one cap able of making the proper anal ysis may be used for revising op erating methods or installing cor rective equipment to the financial advantage of the owner of the records. The unit cost of purchased pow er per kwh. may be easily com puted from the bill or readings if all power is purchased. If only part is purchased, the quantities and costs should be added in with the corresponding generated pow er items. A method sometimes fol lowed, and one oftentimes leading to erroneous and costly conclu sions, is to figure the cost sepa rately for each of the two. But this overlooks the points that either the purchased or generated power would be more expensive without the other; and that some of the distribution expense within the plant should be borne by pur chased power. The second end lest pert ot this erticle by Lewis J. Sforsini will appear in the Winter Issue of POWERFAX. ELLIOTT EMPLOYEE BUILDS TOY POWER PLANTS brother-in-law, has been manufac turing, for the past couple ofyears, toysteam engine outfits, suchas the one illustrated at the left. These units have been sold by the two men to department stores from New York to Chicago. They have sold 110 outfits just a little smaller than the one pictured here, with out a generator, in addition to ELLIOTT Company at itsRidg- quite a few-of the complete out way works, builds a complete fits shown. line of steam engine - generator The men recently had a letter units. But J. D. Pedersen, experi from an enthusiast at Springfield, mental engineer at Elliott Com Illinois, in which the statement pany's Jeannette works, is in the was made that these units were the steam engine business also -- on first example he had ever seen of the side. Mr. Pedersen, with his a truly representative mechanical toy steam engine made in the U. S. The unit pictured at the left has a boiler 3' in diameter by 6" long. It may be fired with an electric heating element or by an alcohol burner. The boiler is equipped with safety pop valve, whistle, gauge glass and drain cock. The engine has a cylinder diameter of bore by stroke. Current from the generator lights the light shown. The entire unit is finished pleasingly in nickel plate with a mahogany base 10' x 15'. The smaller engine without gen erator has a J' bore by stroke and the boiler is 2j^' in diameter by 5' long. . * * * 15 CRIMDEBN00000177