| 摘要 |
PURPOSE:To take accurate measurement continuously for a long time by generating a Karman vortex street in a multiphase flow, measuring the period of vortex generation through an optical fiber and a photodetector, and calculating the flow rate of the multiphase flow. CONSTITUTION:When a Karman vortex steet generating body 1 is arranged at right angles to a flow, a right and a left vortex are generated alternately behind the generation body 1 to form a Karman vortex steet 9. Left and right granules and liquid drops vary alternately in density at optical fiber fixing holes 3 and 3' of the Karman vortex steet generating body 1, so the density variations are irradiated with light through a right and a left optical fiber 4. Its reflected light is guided to a photodetector 6 through the optical fibers 4 and converted photoelectrically to input the phase difference between output terminals of a right and a left photodetector 6 to a signal process 7. The period of the density variation coincides with the generation period of the Karman vortexes, so the flow rate is calculated from the reciprocal number of the period, i.e. frequency of the Karman vortexes 9. |
