A NEW RECONSTRUCTION ALGORITHM FOR PROCESS TOMOGRAPHY

In this work a new reconstruction algorithm for use with oil/gas pipe flow imaging has been developed. Accurate images of representative oil/gas distributions (that is, flow regimes) occurring in flow pipes has been obtained. A capacitance sensor system has been used. In the algorithm the oil/gas distribution has been represented by a set of parameters describing the oil/gas interface. A finite-element-based mathematical simulator of the multi-electrode capacitance sensor system has been developed. The simulator is capable of calculating the capacitances for a set of input parameters (namely for a given oil/gas distribution). The reconstruction algorithm calculates the image by finding the parameters that give fewest discrepancies between calculated and measured capacitances, using an optimization routine. All regimes tested in this work have been successfully reconstructed with the new algorithm, and the reconstructions are compared with images produced by the well-known linear back projection algorithm. The new algorithm has been tested using data from a capacitance imaging system; however, it can in principle be used with other imaging techniques.