GB882478A - Process and apparatus for measuring flow of fluids - Google Patents

Abstract

882,478. Liquid meters; fluid-pressure servomotor control systems. CANADIAN INDUSTRIES Ltd. Sept. 7, 1960 [Sept. 10, 1959], No. 30804/60. Classes 69 (1) and 135. Apparatus for measuring the flow of liquid in which large fluctuations in temperature and viscosity occur comprises a flow divider to the downstream arms of which are connected a pair of constrictions, a constant volume pump controlling the flow in one stream and means for determining the pressure drop across each constriction. In the apparatus shown for measuring the flow of fluid taken from a conduit 1 the fluid is passed through a flow divider 3 to the limbs of which are connected two preferably identical constrictions 4, 5. These may be capillary tubes, nozzles, orifice plates or Venturi tubes. The first stream passes through a constant volume pump 6 and back to the conduit 1. If the pump is placed before the constriction 4, the streams are passed through coils in a temperature equalizing bath before passing through the constrictions. The pressure drops across the constrictions are measured either by manometers when the flow in the second stream is calculated manually or by pneumatic or electrical pressure differential cells 7, 8 from which signals are sent to a divider 13 and the flow rate is shown and recorded by recorder 14. A pneumatic signal from divider 13 may be transmitted through tube 15 to a pneumatically-controlled diaphragm valve 16 to control the flow of fluid to its point of use.