FIVE MILLION-GALLON DEANE PUMP.
BANGOR, ME., has just installed a 5 000,000gallon duplex power pump, the largest ever made in the United States, and built expressly by the Deane Steam Pump Company, of Holyoke, Mass., for the water works of that city.A similar pump, with a capacity of 3,000,000 gallons (fully described in FIRE AND WATER of May 22,1897, p. 163). was built by the samecompany in 1894, for Lewiston, Me. It has been in successful operation ever since its erection, and its success leads the builders to look for similar good results at Bangor, where its capacity is sufficient to supply the water wants of a city of 60,000, instead of only 22,000 inhabitants—as at present. The pump in question is a power pump—i. e., not operated by steam, but deriving its motive power from water. Such a motive power—or, in some cases, electricity—is usually employed in hilly parts of the country because the water power may be utilized there to good advantage and at less cost. In Michigan and Wisconsin these pumps are as popular as in some parts of the East.
In the power pump all the requirements as a pump that are demanded of a steam plant must be met with, and several other exacting ones in addition. The fluid to be handled is non-elrstic, and, while this is met in the direct-acting type of steam pump by the elastic steam cushion, the load in the power pump is received fully on the crank-pin as it passes the centre. Therefore, in the power pump the bedplate must be so constructed as to withstand this excessive strain and vibration. The foundations must also be of the most substantial character; all working parts must be of unusual stiength; and suitable means of adjustment to compensate for wear must be provided. Strength, smooth running, and durability of the gearing must be insured by proper materials, correct proportions, and such rigid support for the bearings that they will retain accurately their true positions, maintain the exact centres, and insure the running together of the pitch circles. The recoil due to the momentum of the water column and the varying velocity of the pump plungers must be considered. Every detail must be studied with reference to convenience of operation and freedom from delay or stoppage on any account.
The Bangor pump is a duplex, and its capacity of 5,000,000 gallons is attained when its crank shaft is run at the rate of seventeen revolutions to the minute, and against a total head of 375 feet. The intake pipe is thirty inches in diameter, and the discharge pipe is sixteen inches in diameter. The power that operates the pump is received by way of a large pinion shaft, which is connected to a turbine water wheel, which has a capacity of 400 horse power. The water wheel supplies the power through the large pinion-shaft to a pinion, which, in turn, connects with a monster gear, with inserted wooden teeth seventeen inches in diameter and thirty-inch width of face. This large gear is secured to a crank-shaft, which is held in bearings fourteen and one-half inches in diameter and thirty-two inches long—one of these being placed at eacl end of the gear. To the end of the crank-shaft disLs four feet six inches in diameter are secured, and into these are fitted large steel pins having a diameter of eight inches. These crank-pins were put in place by means of hydraulic pressure, and are secured in position by very large keys. The connecting rods are made of hammered wrought iron scrap, and to each end of these are fitted bronze boxes, in which the crankpin and cross-head pin run. The cross-head, in turn, is connected to a large plunger, which is seventeen inches in diameter. When this machine is set in motion a stream of water is conveyed through 8,000 feet of six-inch pipe at a velocity of 200 feet. This pump, if connected to a fire system, will throw twenty large fire streams 100 feet high—equaling ten of the largest fire engines working at their maximum capacity. It will throw 4,500 gallons of water every minute 100 feet high. The pump was made, from drawings to final finishing, at the works of the company, and. when it was ready for delivery, it weighed 200,000 pounds, and took eight cars to transpoit it to its destination. It will be erected in a space fifty feet long and forty feet wide.