Gaining Fluid Bed Process Understanding by In-Line Particle Size Analysis

Different process phenomena and process failure modes could be monitored using the in-line particle size data measured by spatial filtering technique (SFT). In addition to the real-time granule growth monitoring, other events, such as the blocking of filter bags and the distributor plate, could be observed. SFT was used off-line, at-line and in-line in 14 differently manufactured granulation batches. No significant fouling occurred during the manufacturing due to the appropriate positioning of the probe. The off-line SFT results correlated well (R2 = 0.97) with the sieve analysis results. It was also found that size segregation influenced both the in-line and at-line particle size results during the fluidization: in-line method underestimated and at-line method overestimated the final particle size.