A Unique Electric Pump.
The accompanying illustration shows the Aldrich, motor-driven vertical, triplex pump designed by and built at the Allentown, Pa., rolling mills. The pump was designed for the capacities up to 500 gal. and for lifts up to 300 ft. It will be noted that the crank-shaft is maintained in a rigid manner by a journal, which is entirely separated from the vertical standards, and held in positions by key-bolts, taking the work in shear. By means of a wedge underneath the journal the pump can be adjusted while in motion. A similar devce also permits the complete regulation of the bronze, adjustable bearings with which the connecting rods are fitted under the same conditions. The working barrels and guides are supported with a parabolic brace, the vertical standards being entirely separate. It is claimed that the fundamental condition of economy in pumping is a slow velocity of water. If the valve and water-areas are small, causing a high velocity, the loss is great, because the friction increases as the square of the velocity. The Aldrich triplex punr it is held, has been designed to meet these condition, the valveareas being built so that the speed of the water. as it passes through the m:mp. is about 3 ft. per second. It is maintained that there is approximately thirteen pcr cent, variation in the volume of water passing through a pump; consequently, the suction and discharge-pipes of these pumps are fitted with chambers which equalise the flow to a uirform speed. It will be seen that the suction-valve is located on one side of the working barrel, while the discharge-valve is on the other. These valves are so constructed that they are accessible through covers held in position by heavy stud-bolts. The interior of the working barrel is of circular or spherical section. The vibration in the gearng is reduced to a minimum, and the life of the pump lengthened. The bearings are supported bv a heavv bracket on the vertical standards, giving them a substantial support on the pinion-shaft. The induction-motors, showll in the illustration, used to drive this rumn where an alternating current is available, is of Allis-Chalmers construction. Electric pumps are now being utilised very extensively for auxiliary service, where steam pumps were heretofore almost universally employed.