GB366695A - Improvements in pump priming mechanism - Google Patents

Abstract

366,695. Pumps. LEWIS, C. S., 2207, Pine Street, St. Louis, Missouri, U.S.A. Jan. 17, 1931, No. 1641. [Class 102 (i).] In priming apparatus for pumps two chambers are employed, the lower of which holds a charge of liquid for withdrawal by the pump, and means are also connected between the lower chamber and the pump intake so that liquid passes to the pump intake by gravity simultaneously with the withdrawal of a charge of liquid from the chamber. The intake C of the pump D communicates with the chamber B, which is also in communication with the sump L by pipes I, I<1>, I<2>. A small receptacle K open at its upper side is arranged in the chamber B and is connected by a downwardly sloping duct M to the intake C ; this duct M is connected by a pipe S to the horizontal portion I<1> of the suction pipe. The upper chamber A is connected by a pipe R to the intake C, and by a pipe N controlled by a valve N<1> to the lower chamber B. The pump outlet pipe E and suction pipe are joined by a pipe O with a controlling valve O<1>, and the discharge pipe F from the chamber A has a check valve G. Before the pump D is started, liquid is introduced through the pipe P to fill the pump, the chambers, and their associated pipes, including the vertical portion 1<2> of the suction pipe, up to the valve G. The expelled air passes upwards through the valve G. The pump is then set in motion and withdraws the charge of liquid from the chamber B ; this charge is forced through the pipe E into the chamber A, so that a quantity of liquid is forced from the chamber A into the discharge pipe F. Some liquid also passes into the chamber B through the pipe O, and through the pipe N. The liquid from the sump L rises in the pipe I to a height dependent on the reduced pressure in the chamber B. During this period of the working, liquid drains from the receptacle K' into the pump intake C, and any gas escapes from the chamber B through the parts K, M into the upper part of the intake C so that the pump is airbound. The connections M, C, E, O, I<2> permit the pressures in the two chambers A,B to be equalized and the chamber B will be filled by gravitational flow from the chamber A. During this filling action, gas is driven from the chamber B through the pipes M, S, to the chamber A, and also through the pipes I<2>, O. At this stage the pump is filled with liquid and acts to withdraw the second charge from the chamber B, so causing the liquid to rise higher in the pipe I from the sump L. The discharge of liquid from the pipe E into the chamber A compresses the gas in the chamber until the pressure is sufficient to cause the valve G to open for discharge. The action of the pump continues until the receptacle K is completely emptied of liquid ; the end of the pipe O in the discharge pipe E is then freed from liquid and the pressures in the chambers A, B are again equalized. The cycle of operations is then repeated until the remainder of the gas is expelled, and liquid is supplied continuously to the pump.