METHOD AND APPARATUS FOR DETECTING FOREIGN MATTER IN LIQUID FLOW CONTAINING BUBBLE

摘要

PURPOSE: To provide a method and apparatus for detecting the presence of foreign matter in liquid flow containing bubble. CONSTITUTION: An acoustic horn 14 or pump 20 is provided to mechanically generate a hydraulic state alternately changing in liquid flow to monitor the response of the bubble for such alternating hydraulic pressure. When the alternating hydraulic pressure state is mechanically generated in the flow, the pressure change of large amplitude is generated, and the bubble is substantially deformed. The bubble monitor detects the light scattered by the bubble at the optical beam 6 from a light emitting unit 4 and emitted to a photodetector 8. When the bubble is thus substantially deformed, the amplitude of the light scattered by the bubble is largely changed in response to it, and discriminated from the light scattered by the sold particle in the flow not such changed.