Identification of the state of a fluidized bed by pressure fluctuations

A novel approach was used for the on-line characterization of the stare of a fluidized bed. The treatment technique wing the Fast Fourier Transform of measured pressure fluctuations was developed to create plots describing th e evolution of bed behavior from fixed bed to pneumatic transport. A new tr iad of quantities proposed are: divide ratio (degree of dominancy) of ampli tude spectrum, square root of spectrum power of pressure sure fluctuations, and gas velocity. The technique was demonstrated on gas fluidization of so lids having a wide size distribution composed of irregularly shaped solids.