Investigating the feasibility of monitoring dynamic behavior of a fluidized bed using a piezoelectric accelerometer

Results obtained from the Geldart’s group B and D solids in a laboratory-scale fluidized bed indicate that significant information about the bed dynamics can be obtained from acoustic sensors. With simple pre-processing of acoustic signals with RMS filtering, the bed dynamics can be monitored by extracting the low-frequency acoustic-intensity modulation. Both linear and nonlinear analysis techniques show that pressure and acoustic signals share significant amount of information by characterizing various fluidization regimes associated with near minimum fluidization, developing slugs, slugging, and breaking slugs. Results demonstrate that piezoelectric accelerometer can be a useful tool for monitoring the dynamic behavior of fluidized bed, especially in hazardous systems where limited direct contact with the process is an advantage. Such monitoring capability shows great promise of becoming a valuable supplemental diagnostic tool for detecting anomalous or undesirable behavior such as defluidization and solid agglomeration in commercial fluidized bed reactors and combustors.