IMAGING PHARMACEUTICAL FLUIDIZED BED PROCESSING BY ELECTRICAL CAPACITANCE TOMOGRAPHY

摘要

An electrical capacitance tomography (ECT) sensor with 8 electrodes was used to measurefluidized bed processes with different operating conditions. Key process parameters are analyzed,including process moisture, cross-sectional solids concentration, time-averaged raw capacitance,averaged solids concentration in the chamber, the effect of a Wurster tube on hydrodynamic behaviorand the frequency spectra. The test results show that the change in the process moisture can be measuredfrom the raw capacitance of adjacent electrode pairs combined with a calibration model. It is also shownthat ECT could provide information on the fluidized bed process state and simultaneously could be usedas a process monitoring and fault diagnostics tool. Future work is discussed in the end of the paper.