A STEAM ENGINE OF EXCIPTIONAL ECONOMY.

A STEAM ENGINE OF EXCIPTIONAL ECONOMY.

针对目前manifes强烈的兴趣ted in the steam economy of prime movers, both of the reciprocating and turbine types, it is impossible to pass without remark some results lately obtained in an official pumping engine test at the Park avenue pumping station, Chicago. The engine is of the Worthington, duplex, reciprocating, tripleexpansion type, having semi-rotary steam valves, but no flywheel. The latter is replaced by compensating cylinders so arranged that their pistons retard the motion of the main piston during the first part of the stroke, but assist it towards the close, giving a uniform resultant thrust. The pistons of these auxiliary cylinders work against air under pressure from a tank. The engines are vertical, and the weight of the pistons, plungers and rods is counter-balanced by another auxiliary balancing plunger, also working through the medium of water against air under pressure. The capacity of the engine is about 22,000,000 gallons per day against a total head of slightly over 121 feet, and 660.9-horsepower was indicated in the test. The duty obtained was 174,735,801 foot-pounds per 1,000 pounds of steam used, corresponding to an economy of 11.32 pounds of steam per net horsepower delivered in water lifted, or 10.01 pounds of steam per I. H. P. The steam pressure was 144.45 pounds per square inch, with 154° Fahr. superheat at the throttle, the steam cylinders being provided with jackets and re-heaters. Two other engines of the same design in the Central Park avenue station and three more in the Springfield avenue pumping station have all shown under test an economy of steam less than eleven pounds, although the economy per delivered horsepower was not as high in the test quoted. These tests were carried out under the supervision of the bureau of engineering of the city of Chicago and. together with the engines and the power station, are fully described in a pamphlet distributed by Henry R. Worthington. of New York city.

At Chicago, where Superintendent Nourse of the water department has employed ten inspectors to canvass the city and discover who is wasting the water, the plan works well, and the inspectors have no difficulty in reporting something like fifty people a day who are wasting the water.