GB1145332A - Radiation-type interface detector - Google Patents

Abstract

1,145,332. Photo-electric level indicators. UNIVERSAL OIL PRODUCTS CO. May 9, 1966 [May 10, 1965], No.20418/66. Heading G1A. The level of liquids or fluent solids or the boundary between liquid, or gaseous phases in a container is located by investigating absorption of radiation passing through the medium or mediums in the container by means of a source vertically travelling inside a conduit in the container and a detector vertically travelling in synchronism with the source outside the container. In Fig. 1 a separator is shown for separating a mixture of hydrocarbon and hydrofluoric acid which enters at 11 and whose components leave at 12 and 13: inside the separator there are three distinct phases, hydrocarbon at 36, the mixture at 38 and the acid at 40. To detect the boundaries of the phases 37 and 39 a radio-active source enclosed in a lead block 16 having an outlet slit is moved up and down the conduit 14, either by the pulley system as shown or a piston and rod system, and which transmits radiation through the liquids to a detector 18 suspended outside the container and travelling in synchronism with the source along guide tracks 20. Instead of the track a vertical shield may stop the detector swinging about. At the base of the conduit is a lead shield 15 incorporating a condensation drain 15a and at the base of the track is another source 42 for calibrating the recorder 23. Signals from the detector may be used to control the operation of the separator. The conduit 14, instead of passing completely through the separator, may extend only part of the way, either from the top or the bottom or may include a right-angled bend to leave via a side wall. Suggested sources are radium, cesium europium and thorium and suggested detectors are geiger counters, proportional counters, scintillation counters and ionization chambers.