Bisbee daily review., 1922-07-30

zines, direct connected to 60 cycle, 3 phase, 15OO Xiv. generators. 2 5-cyl., 1250 H. P. engines. direct con- nected to 60 cycle, 3 phase, $50 Kw. generators. <~
 GLOBE-2 5-cyl., 125O H. P. en- zines. direct connected to 60 cycle, phase, $50 Xiv. generators.
 The above ratings are for sea level conditions, and the actual power is l slightly reduced at the elevations ; where the engines are used which vary from $500 to 5000 feet.
 The engines are all of the vertical type, equipped with cross-heads, and ! not trunk pistons; all bearings are ! easily accessible and all main bear ings, cross-head slides and crank-pin bearings have continuous oiling sys- i tenn with proper equipment of oil fil- ] ters and circulating pumps.
 i The pistons, cross-head slides, cylin- i der barrels, heads and exhaust pipes above floor line are water cooled. The i scavenging air is admitted to the cyl ! finders through four valves in each cylinder head. These valves, as well ] as the fuel injection valve and the fuel pumps, are operated from one shaft located alongside the cylinder heads. The fuel is fed to- each cylin- der by a pump under control of the i governor, and the quantity of oil reg ulated according to the load on the ! engine. A double system of fuel oil | piping is connecte dto each pump; i one for starting oil. which has to re- main fluid at the lowest temperature liable to be reached in the power i plant, and the other for running oil , which can be any oil that will be fluid i at the temperature that it is practical 1 to heat it. The piping for both oil ! systems is arranged with an external l heating pipe through which hot water ! is circulated to heat the fuel oil, and 1 by bringing the discharge water from one of the exhaust pipe cooling jack cts, there is no difficulty to keep the | fuel oil at 140 degrees F., when the i engine is operating at one-half load or over. and the piping is properly insulated.
 Each engine is equipped with three . oil fuel tanks; one for light oil and ! two for running oil. Each of these | two tanks is of sufficient capacity in | the latter plants to run the engine at full load for at least eight hours. |
 ! Each engine drives it's scavenging pump and a high-pressure air com- 1 pressor for fuel injection, and is a complete plant in itself except that the cooling water goes to a common stump and is repumped, to a cooling ' tower by one or more pumps inde- | pendent from the engine.
 The 25O H. P cylinders have 20 3-4 T O rrn i at 1S0 R. P. M. The 500 H. P. cylin- ders have 2S in. bore and A in. stroke. They run at 12O R. P. M.
 Oil Usage
 Since the plants were put in oper- ation we have used California IA de grees B. fuel oil or Mexican IA de | grees B. oil for running oil except for
 a short period when Mexican oil de- ! lievries were stopped The Mexican ! oil contains as much as 4 1-2 per cent
 sulphur and averages about 3-4 per cent This increases the difficulties I of cylinder fabrication and the main i tenance cost of the cylinders and pis- ton rings. It makes it necessary to carry the exhaust gases away from
 steel buildings and cooling towers as ! sulphuric acid is found when the tenn I perature of the gases is lowered. It is
 also troublesome to handle when cold. It is the same oil which we use in our
 boiler plants, and the bad effects of
 the sulphur are present in these plants as is shown by the destruction
 of steel stacks, and quicker deteriora-
 tion of economizers.
 The cooling water has an import
 ant bearing on the running costs of T the engines. If the water carries
 scale-forming impurities, the scale
 formed in the cylinder heads and pis- tons increases considerably the crack ] ing of these parts, not only through
 the heat insulating properties of the T scale, but also by the loose scale plug ging water passages and stopping the circulation of water.
 The fuel consumption of the en. zines is good: including the exciter
 losses for the generator, the 125O H P. engine delivers a K. W. H. at the switchboard for .69 lb. of fuel oil at } loads between 600 and 700 K w. The
 20OO H. P. engine delivers K. w. H. for .67 lb. of fuel oil at loads between
 1900 and 1500 K w.
 The power required to operate the l circulating pumps. fuel oil handling
 pumps, lighting, etc., is from 2 per ! cent to per cent of the total output according to the local conditions.
 Fuel Consumption
 In practice, according to load fac tor on the engines and on the plant,
 the number of times engines are
 stopped and started. the fuel consump
 tion is from per cent to 20 per cent higher than shown on test runs for
 the load corresponding to average
 load on the engines. For example, at Globe, during the first five months of
 this year the average load per engine
 running was 5S7 K. w., the peak load carried exceeded 900 K. w per engine and the fuel consumption was 763 lbs. per K. w. H. generated; the test
 curve showing .695 lbs. for 5S7 K. w. I At Morenci, making proper allowance
 for excitation of generators. the fuel | consumption in the same period was .795 lbs. per K. w. H. generated with an aVpra Vp load Of XII k w npr an-