Pressure fluctuations as a diagnostic tool for fluidized beds. Technical progress report, April 1--June 30, 1996

The pressure fluctuations in the transition regime between bubbling fluidization and fast fluidization were investigated using system identification techniques. The results show that the voidage waves and surface eruption effects seen in bubbling fluidized beds are also observed in the transition regime fluctuations. In addition, a third frequency phenomenon is observed in the spectrum which is hypothesized to be a surface wave phenomenon analogous to surface waves in water. The validity of previously derived similitude parameters for bubbling fluidized beds (BFB) was investigated using spectral analysis of pressure fluctuations. When BFB similitude parameters are matched in two different beds, the pressure dynamics are similar under most conditions, suggesting that the correct similitude parameters have been defined for BFBs