GB1329161A - Apparatus for supplying brine to a dialysis device - Google Patents

Abstract

1329161 Electric retroactive control of physical variables T E EATON 19 May 1971 [25 May 1970] 15808/71 Heading G3R [Also in Divisions B1 F2] Brine is supplied to a haemo-dialysis device K at predetermined temperature, salinity, rate of flow and pressure by apparatus including devices 41, 25, 27 and 28 for measuring temperature, salinity, flow and pressure respectively. These devices produce electric signals which, after amplification at 42, 63, 49 and 54, are compared with signals from hand-set potentiometers 43, 64, 50 and 56. The error signals, after amplification at 44, 65, 51 and 57 are respectively applied to a heater 40, a valve 33 associated with a tank 62 of brine, a valve 31 in a by-pass fluid circuit associated with a pump P and a valve 26 (see Division F2). A constant head of water is maintained in a supply tank 23 by a valve 22 in the supply conduit controlled by a level-detector 35 through a time-delay 39. Signal lamps 80 indicate when any of the variables fall below or rise above the predetermined values. When all the variables are within predetermined tolerances, a switch 77 can be operated to control a valve 29 to direct the brine through the dialysis device K. If any of the variables subsequently deviates from the desired range, or if a photo-electric detector 30 detects blood in the brine passing from the dialysis device, the switch 77 is opened. The salinity-measuring device 25 is a conductivity cell and the flowmeasuring device 27 comprises a reed, Fig.4 (not shown) arranged at right-angles to the flow and carrying strain gauges.