A concentration capacitance sensor -- a helical shaped surface electrodes system--has been studied for the measurement of the volumetric concentration of ari/solid two-phase flow. Capactiance transducers have becoming increasingly used to determien concentrations of conveyed dispersed phase in two-phase flow. Until recnetly their use has been restricted to homogeneous mixtures due to their inherently non-uniform sensitivity distributions over the pipe cross sections and therefor having differnet responses to differnet flow regimes which can lead to significant measurement errors. It is, howeve,r possible to reduce the errors by using helical shaped surface plate electrodes so that the electrostatic field is twisted 180 deg from one end of the sensor to the other. A number of static experimetns has been carried out. As a result, the homogeneous error is less than 10
展开▼
