GB338580A - Improvements in or relating to liquid flow regulating apparatus - Google Patents

Abstract

338,580. Bailey Meter Co., (Assignees of Barrett, J. M.). Jan. 24, 1929, [Convention date]. Regulating or controlling.-A system for controlling a series of centrifugal pumps supplying a common header comprises means for the maintaining definite proportional relations between the deliveries of the several pumps and for causing the flow through the header to vary the deliveries of all pumps in step with each other. In the system shown in the Figure the header 1 is supplied through pipe 2<a>, 2<b>, 2<c> the pipe 2<a> being supplied by a centrifugal pump 3 driven by a constant speed electric motor and having its output adjusted by a balanced valve 6 in the outlet pipe, the pipe 2b is supplied by a centrifugal pump 3 driven by avariable speed electric motor 7 controlled by a variable rheostat 9, while the branch 2c is supplied by a centrifugal pump 10 driven by a steam turbine 11 controlled by a balanced valve 13. An apertured plate, flow nozzle or Venturi tube is inserted in the delivery pipe from each pump and pipe connections 14, 15 made to the high and low pressure zones, lead to the two sides of an adjustably loaded bellows actuating an auxiliary valve 21. The valve 21 has two faces and works between two seats either or both of which may be adjustable and controls the supply and exhaust to and from a power cylinder coupled to the controlling valve or rheostat of the pump unit. The loading on all the regulators is adjusted simultaneously by cams 39 on a shaft 38 engaging rollers 40 carried by the spindles 19. The shaft 38 is rotated against the action of a spring 35 by a piston 34 coupled by a cord 36 to a pulley 37 on the shaft and subject to the pressures derived from a pair of Pitot tubes 32, 33 arranged in the header 1 so as to vary the load in accordance with the rate of flow in the header.