GB770736A - Average flow indicating system - Google Patents

Abstract

770,736. Electric measuring systems. PANELLIT, Inc. June 8, 1955 [June 15, 1954], No. 16477/55. Class 40 (1). [Also in Group XIX] A recording system comprises flow responsive apparatus for finding the average rate of flow of material in a number of different time intervals in units based on a common period comprising computing means responsive both to means for measuring the quantity of material flowing during an interval and to means for measuring the interval. A sensing device in a recording system 12 is fed repeatedly and sequentially from a stepping switch 46 with voltages proportional to the average rate of flow of material through pipes 2, 2<SP>1</SP> . . . taken over the interval elapsed from the beginning of the last of a succession of hourly periods and the averages are printed automatically at the end of each hourly period and at any instant during the period, as desired, by operation of a manual read out switch. To derive the voltage corresponding to the pipe 2 the instantaneous rate of flow is derived from the difference of pressure either side of a restriction 14 by extracting its square root and is fed to an integrator to drive a shaft 16 in accordance with the quantity that has flowed through the pipe 2. The shaft 16 then acts through a clutch 18 linearly to displace the moving contact of a potentiometer in proportion to the quantity that has flowed since the beginning of the hourly period when it was returned to zero potential position by a spring 32 released by a solenoid 30 when briefly energized upon a synchronous motor 24 acting through a cam 26 on contacts 28. The input to the potentiometer 20 is derived from the moving contact of a potentiometer 22 which is linearly displaced by the motor 24 through a clutch 29 so that it taps a voltage inversely proportional to the interval of time since it was set to maximum potential by a spring 28 under control of the same time cam 26. Thus the output of the potentiometer 22 is directly proportional to the quantity and inversely proportional to the time and so represents the average rate of flow since the beginning of the hourly period. If the static pressure in the system is liable to fluctuate compensation may be introduced through a further potentiometer 36 and where averages are derived from a number of pipes 2, 2<SP>1</SP> and the maximum ranges of the corresponding apparatus vary, scale compensating factors are introduced through potentiometers 44, 44<SP>1</SP>. In an alternative embodiment the inverse time factor may be introduced in the sensing device of the recording system, Fig. 4, not shown.