January 3, 1913. THE COLLIERY GUARDIAN. 33 SOME NEW TYPES OF CENTRIFUGAL AND TURBINE PUMPS. The Pulsometer Engineering Company Limited, whose works at Reading we recently visited, have just placed on the market some new types of centri- fugal pumps designed for various duties on land and water, of which we give a description below. Before doing so, it may be mentioned that the company’s works, which are situated on the outskirts of Reading, were laid out by the company in 1900, when they moved from Nine Elms, London, S.W. The site is upwards of 12 acres in extent, so that ample space is provided for the existing works to be extended as may be required. The works are of modern type, and the various shops are well equipped and lighted. Electric travelling cranes are fitted in the main shop, capable of dealing with loads up to 10 tons. The power station consists of three gas engines, which are supplied with gas from the company’s own producers. These gas engines drive dynamos which furnish the current to the motors driving the machine shops. There is a separate motor to each line of shafting. There is no type of pump better known to mining engineers than the “Pulsometer,” which, it is safe to say, is without a superior for rough work, and the makers, in introducing these new types of pumps, have been prompted rather by the appeals of a wider demand than Pulsometlp Engineering CP L’.° London &■ Reading. Fig. 1.—Low-lift Single-inlet Centrifugal Pump. engiRi NG igle: s tag! IMP - •so PULfeOMEjTERT LOljlDOr GALLONS PER MINUTE Fig. 4. by any necessity to supply a substitute for the old- fashioned “ Pulsometer.” Proof of this is afforded in the large stocks of Pulsometer steam pumps and boilers of all sizes constantly kept on hand at the works ready for immediate consignment to customers. The centrifugal type of pump itself is no new thing, and its evolution has been less rapid than that of some other forms of machinery. Its use, however, has been strikingly accelerated within recent years by the extended employment of electricity, which is especially adapted to machinery of the rotary character, and, at the same time, enables a much greater speed to be attained. In the past the limitation of head has seriously restricted the use of centrifugal pumps, but the quick-running electric motor, in conjunction with the development of the multi-stage turbine type, now enables lifts to be compassed over ten times as great as was possible in the past. It will be readily understood that one of the chief requirements in the case of an electrically-driven centri- fugal pump is accurate rating. Performances that exceed the guarantee will lead to electrical troubles, whilst those that fall below them are obviously unsatis- factory. This requirement can only be satisfied by the tank where the calibrated gunmetal v notches are fitted. After passing over the V notches the water finds its way back into the suction tank below the floor. The delivery head of the pump is produced by creating an artificial resistance in the delivery pipe by means of throttling. The suction lift and the head against the delivery are measured either by means of mercury columns or by means of pressure gauges with large dials, so that any possible error of observation is reduced to a minimum. The power absorbed by the pump is measured by an Amsler transmission dynamometer of the latest improved type, which measures the exact power transmitted from the coupling of the motor to the coupling of the pump, so that there are no uncertain allowances to be made for any frictional losses. In addition to the dynamometer readings, the electrical readings are also taken, and as very complete records exist of the mechanical and electrical losses in the motor, a very good check is obtained on the power absorbed at the time by having the two readings. Specially-made motors are used for the tests, these having a very considerable speed variation, so that any desired speed may be obtained. The results of the tests are plotted on curves, an implicit regard for detail and care in manufac- ture, and it is to this end that the Pulsometer Engineering Company have specially bent their efforts. The value of their experimental work has been greatly enhanced by a very comprehensive and accurate testing plant, the operation of which was a source of much interest to us. In addition to a complete steam plant for the testing of “ Pulsometer ” steam pumps, “ Deane ” direct-acting pumps, and other steam- driven pumping machinery, there is a very extensive and complete plant for the testing of electric-driven centrifugal and turbine pumps, which are always tested under the specified conditions prior to delivery. The water is obtained from a large reservoir below the floor, and after passing through the pump to be tested, is delivered into a measuring tank, fitted with V notches, and the quantity delivered is measured by a Lea recorder. The tank is capable of measuring up to 150,000 gallons of water per hour, and it is arranged to give a very steady level on the surface in that part of ilsofr .■'j 10 7070 THg PU LOUDON 500 PER, MINf ’UM’-SljZE / 700 )F 800 20 10 U u ! W- ETER| EN