Application of electrical capacitance tomography in pharmaceutical manufacturing processes

While fluidized beds are commonly used in the pharmaceutical industry, the understanding of the fluidization processes is limited because no efficient tool is available for real-time online monitoring and measurement. In recent years, electrical capacitance tomography (ECT) has been used to investigate granulation, drying and coating processes in pharmaceutical fluidized beds. For measuring drying and granulation processes, a novel online calibration method was proposed and implemented to deal with continuous change in the moisture content of solids. Experiments were carried out using various fluidized beds of different scale, and good results were obtained. For monitoring the coating process in a Wurster fluidized bed, a unique ECT sensor is designed with three sets of electrodes. By this electrode combination, all regions of the Wurster fluidized bed can be monitored. Based on the work done so far, it is concluded that ECT is a very useful tool for monitoring and measurement of pharmaceutical fluidized beds.