Evening Republican, Volume 23, Number 62, Rensselaer, Jasper County, 11 March 1920 — LIGHT AND POWER SITUATION [ARTICLE]

LIGHT AND POWER SITUATION

ENGINEER CHAMBERLAIN SUBMITS CAREFULLY PREPARED REPORT. The Republican undertakes the publishing of the report or Engineer Charles Chamberlain to the city council of Rensselaer relative to the needs of the city in added facility in the way of electric current. The report is of considerable length and will appear in installments. It will be of vital interest to every citizen and tax-payer of this city. > (Continued From Yesterday). Electric Current and Power Plant ob the Fano.’ Electricity for -power and light is being asked for by many farmers. This serviefe is 'being rendered by our present equipment in a small Some other electric utilities have this service connected to their lines under separate plans. The most popular one over the state where farm plants are connected with municipal ones seems to be: for the farmers to organize and erect and maintain their lines in the country, metering each farmer service. The city, to erect and maintain its lines to the appropriation limits, installing a meter at this (point, and selling its current to the farmers at a wholesale rate -at this point of connection to the farmers’ lines. Engine and Boiler Tost*. The tests on our engines and boilers in our present plant were conducted for 24 hours during December 17, 18 and 19, showing the following results under our varying loads which reduces the efficiency of this or any other central station. Our Corliss engines are noncondensing, operating on a steam pressure of 90 to 100 pounds. Carrying a varying load rs 80 to 284 killowats. Test showed steam consumption to be 48 pounds of steam per killowat hour for engine and auxiliaries. This showing is as good as could be expected of this type of Engine under our varying load conditions. Boiler Tee*. - Our boiler test shows under varying loads for 24 hours’ duration, operating on 90 to 100 pounds pressure, evaporating feed 'water from 210 to 212 degrees Fahrenheit to steam under a pressure of 90 to 100 pounds. , . . The amount of water evaporated is six pounds of water to one pound of Indiana screened egg coal, costing 84.62 in the plant bins. This means each killowat hour costs us on the switchboard 1 4-5 This is too much and is caused by the high price' of coal, and engines not efficient as condensing ? steam turbines - and not enough water evaporated in the amount of coal used. This can be remedied some in the present plant by adding more draft to furnace, either natural -or mechanical. Also by installing modern grates in furnaCThe efficiency of opr boilers or any other tubular boil® can not reach the efficiency of the modern water tube boiler for the varying loads that occur in central stations for the following reasons: Ist Steam pressure limited by thickness of the boiler shell ’required. If Ik tubular boiler -was designed to operate at 200 pounds steam pressure, it would require a /boiler shell about one-half inch thick. , .. . « 2nd. Thickness of boiler shell over thin tubes retard the heat units from being absorbed by the water in the boiler shell. . 3rd. Water circulation is not as good in tubular boilers, causing low steaming qualities. This is objectionable in a central station with varying loads and overloads continuously. . , . . • . 4th. With tubular boilers at 100 or 150 pounds steam pressure which is the limit and is in content danger of being reduced by the 'boiler insurance companies. Steam at the above pressure is not as dry as steam at 200 or 210 pounds pressure which is obtained and maintained by water tube boilers. Two hundred pound* .boiler pressure with 100 to 150 degrees of superheated steam is economical and is common boiler practice at this time. This reduces the latent heat losses as much (as possible. A modern steam turfnne plant if properly located, designed and installed should produce the following conservative economics over the present steato iplant with load conditions and number of day steam turbine plant running self with a condensei nitrating a 28-inch vacuum and oh steam 200 to 210 pounds boilei

pressure should show the following results in connection with water tube boilers equipped with stokers and modern chain grates. ‘ One 500 pound killowat steam turbine in plant in the reserve for One 500 killowat steaHn 1 - 1 turbine operating on the varying leads >as< given telwe would Sho# the following steam economies of 20.8 pounds of steam per killowat hour and 12 pounds of steam per killowat hour for boiler* feed pumps and auxiliaries, making a total of 32.5 pounds of stqam per killowat hour. Water tube 'boilers should at least evaporate 7 or 8 pounds of water per one pound of slack coal in the proper furnace. Figuring it at the low evaporation of seven pounds of water per one pound of slack coal at present prices of 813.57 coal in bins without drayage, we should generate and place current on the switchboard fbr 4-5 of one cent per killowat hour. This means a saving of one cent per killowat ‘ hour over our present plant, figuring both- plants at the test load conditions. The saving by installing modern machinery will amount to over seven or eight thousand dollars for the year if same test loads are maintained for the year. Assuming that the test load which would amount to 870,480 killowat hours for the year should fall off to the 1919 year load which consumed 514,208 worth of coal we still would show a saving of 86,986 after generating the test load at 4-5 of a cent per killowat hour by the turbine plant. The efficiency of the new machinery will increase as it becomes loaded to its full capacity, and reducing the coal consumption per killowat hour. The capacity of the new machines should be as large as good engineering practice will permit for present and anticipated-4oatter . If a new station is decided upon the building and smoke stack should be large enough for additional genefating units for future use. . (To Be Continued).