Patent ID: 7609368
Filing Date: 2009-10-27
Classification: G01F

Abstract:
1. A method for measuring the velocity of a multiphase fluid flowing in a pipe having transparent portions, the multiphase fluid comprising a liquid phase and a gaseous or solid phase, the method comprising the steps of: directing a pair of collimated beams of light from an illuminator through the multiphase fluid by said transparent portions of the pipe, said pair of collimated beams spaced apart in a direction of flow of the multiphase fluid by a predetermined distance; detecting scattered, deflected and attenuated light with a pair of photodetectors to produce a pair of signals, each of said pair of photodetectors associated with one of said pair of collimated beams; calculating a cross-correlation function between said pair of signals to determine a time delay between the signals; calculating the average velocity of the multiphase fluid by taking the ratio of the predetermined distance to the time delay between the signals; and passing the pair of signals through a plurality of band-pass filters to isolate a plurality of pairs of corresponding frequency components, each of the plurality of pairs of corresponding frequency components corresponding to one of a plurality of flow components.