| The main objective of the thesis was to develop new, automatic and reliable methods to analyze time series to identify flow regimes in multiphase reactors.;Time series from multiphase reactors exhibited cyclic behavior. The V statistic, previously only used to study economics, successfully provided cycle times for many of the multiphase systems. A new statistic, the P statistic, was developed to calculate cycle times for the systems for which the V statistic failed. Statistics to characterize the regularity of the cycle time, the regularity of the cycle amplitude and the cyclic strength were also developed.;The correlation dimension is a parameter of a chaotic system. There were no general, well defined and proven rules for selecting its calculation parameters. Therefore the effects of these parameters were examined and a method for their selection was developed. Automatic and reliable calculations of the correlation dimension thus became possible and adaptable for process control purposes.;Three hydrodynamic flow regimes were identified in gas-liquid-solid systems with the standard glass beads and also with low density polypropylene particles as the solid phase: a fixed bed with a uniform close-packed structure and little particle movement, an agitated bed wherein the particles move intermittently, and a fluidized bed wherein particles flow continuously. Correlations and models cannot be used to predict the minimum liquid fluidization velocity. Standard measurements provide the minimum agitation velocity. New techniques were developed to obtain the minimum liquid fluidization velocity.;A method to detect channelling in a liquid fluidized bed of angular Biobone particles, a unique immobilization substrate, was developed. Jet mixing to reduce channelling was also examined.;Analysis of time series from measurements in a pilot plant and an industrial riser reactor allowed a solids radial flow structure to be proposed: the core consists of a dilute suspension of solids, an intermediate region consists of a wavy layer of a dense solids suspension, and the annulus consists of a dense solids layer.;A method to identify defluidized zones in gas-solid fluidized beds within 200 ms was developed. This allows corrective action to be taken to prevent production problems. |
