COMPOSITION MONITOR AND MONITORING PROCESS USING IMPEDANCE MEASUREMENTS

摘要

Radio frequency bridge techniques are used to parameterize the complex dielectric properties of solids, liquids, gasses and mixtures thereof. This parameterization is performed in an electrically isolated, physically open structure which allows continuous or batch monitoring of the materials and their mixtures. A method and apparatus are provided for measuring the composition of mutlicomponent process streams flowing in pipes or ducts. The method uses the pipe in which the mixture flows as a waveguide in which propagating radio frequency electromagnetic energy is induced through dielectric loaded apertures. The dielectric measurement is performed in an electrically isolated, flow through test section which induces constructive or destructive interference patterns at characteristics frequencies. The characteristic frequency determines the dielectric constant of the mixture. The dielectric properties are used in turn to determine mixture composition. A density measurement is also provided for three comiponent strams such as oil, water, and gas. Temperature and pressure measurements are made to correct for temperature and pressure induced variations in calibrated component impedance and density values.