Capacitance based Tomography for Industrial Applications

AbstractThis paper discusses the applications of Electrical Capacitance Tomography systems in industries for studying the chemical processes taking place inside pipes and chemical vessels. It is a widely popular and nonintrusive technique for sensing and measuring the spatial distribution, voidage, and velocities of flow of the materials in a pipe. It helps the chemical process engineer in indirectly visualizing the chemical process taking place inside the vessel which until now was not possible. Capacitive sensors are employed to sense the change in permittivity of the materials inside the vessel. The acquired data is used to construct permittivity distribution images, which aid in understanding the nature of activities taking place inside the vessel, by calculating various key parameters related to the chemical process. The images can also help in deciding the future course of control actions needed to be taken if required. The advantages of the technique are non-intrusive nature for measuring the capacitances, simple transduction principle, fast response, simple and efficient algorithm used to generate images of reasonably good resolution. The sensors employed are capacitance sensors which are cost effective and easy to construct.