Hydrodynamics of dilute suspension drying in fluidized bed using the Gaussian spectral and wavelet transform analyses.

Signals of pressure fluctuations can be evaluated by using different ways such as chaos, spectral, time domain and wavelet transform analyses. We have studied a fluidized bed drying process of dilute supension by the Gaussian spectral and wavelet transform techniques. This study was performed in order to identify the defluidization phenomenon. During the drying process the temperature profile, relative humidity, absolute humidity, and drying force were analysed using glass beads as the inert material (particle mean diameter of 1.55 mm). A suspension of calcium carbonate (15% concentration) was atomized at flow rates of 11 and 15 mL/min. Results from the hydrodynamics analysis showed that the fluidization regime transition can be successfully monitored by applying the Gaussian spectral and wavelet transform techniques because changes in the value of the central frequency, energies and scale structure were verified for the bubbling and fixed bed condition. Psychometric parameters have shown the lower potential energy in the drying process. [ABSTRACT FROM AUTHOR]