St. Louis Pumping Engines Tested.
At St. Louis, pumping engines Nos. 1, 2, 3 have been installed and tested at Bissell’s Point pumping station. They are of the Allis-Chalmers type and have a capacity of 3,000,000 gal. each. They have replaced two 18,000,000-gal pumps of the bucket-and-plunger, single-cylinder, condensing, beam and flywheel type and one 20,000,000-gal. pump of the bucket-and-plunger, double, compound condensing, beam and flywheel type. These were erected in 1870 and 1874. and were supported by masonry piers on solid rock foundations, which were removed to make way for the new engines. These are of the vertical, triple-expansion type, with three single-acting, outside-packed plungers,
each located directly under one of the cylinders. The bedplates rest on solid rock foundations, the main pillow-blocks and the cylinders are supported by columns of the A frame pattern. The cylinders are 34 in. 62 in. and 94 in. in diameter by 6 ft. 0 in. stroke; the water-plungers are 33⅞in. in diameter by 6 ft. 0 in. stroke. All the eccentrics of the valve-motion are run by a layshaft located immediately above the second gallery floor. There are two eccentrics operating the valves of each cylinder, one for the admission, and one for the exhause. The cut-off of the highpressure cylinder is controled by a centrifugal governor; the cut-off of the intermediate cylinder is adjusted by hand. The low-pressure cylinder is provided with a fixed cut-off. The admission and the exhaust-valves of the high-pressure cylinder and the admission and exhaust-valves of the low-pressure cylinder are all of the poppetvalve type, with single seats. These valves are operated by cams or curved levers. The pumpvalves are of rubber outside diameter.
There are seven valve-cages in each of the suction and discharge-diaphragms. Each cage is provided with 28 valves. The aggregate free area of 196 valves is 7.76 sq. ft., and the area of one plunger is 6.26 sq. ft. The suction and dischargepipes are 36 in. in diameter. The air-pump, feedpump, and the air-compressors are permanently attached to the plunger of the low-pressure cylinder. The circulating water of the condensers is taken from the suction-pipe, and, after having passed through the tubes of the condensers, returns to the suction-pipe again. 1 he.se engines in construction are practically duplicates of highservice engines Nos. 9, 10, 11 and 12 at the Baden pumping station, except that the low-pressure cylinder is 94 in., instead of 92 in. diameter, and the water end 20,000,000, instead of 15,(XX),000-gal. capacity. The engine-pit is 55 ft.x81 ft. and 28 ft. deep; the total height from foundation to top of steam cylinders is 64 ft.