This work focuses on the development of a novel linear stability criterion for the state of homogeneous fluidization regime, based on a new mathematical model for gas-fluidized beds. The model is developed starting from the well-known particle bed model. A mono-dimensional momentum balance is derived leading to a set of equations which explicitly include voidage-gradient dependent terms (elastic force) for both solid and fluid phases. A fully predictive criterion for the stability of homogeneous fluidization state is here proposed, based on the well-known Wallis’ linear stability analysis. The criterion requires the choice of an appropriate averaging distance, which in the present development is found to be bed-voidage dependent. The linear stability criterion resulted in turn in a simple, yet fully predictive, relationship for incipient bubbling voidage. Validation was carried out analyzing the influence of all physical properties and sensitivity to closure relations, showing substantial agreement with literature data.
Busciglio, A., Micale, G., Vella, G., Rizzuti, L. (2010). Linear stability analysis of gas-fluidized beds for the prediction of incipient bubbling conditions. CHEMICAL ENGINEERING JOURNAL, 157, 489-500 [http://dx.doi.org/10.1016/j.cej.2009.12.040].
Linear stability analysis of gas-fluidized beds for the prediction of incipient bubbling conditions
BUSCIGLIO, Antonio;MICALE, Giorgio Domenico Maria;VELLA, Giuseppa;RIZZUTI, Lucio
2010-01-01
Abstract
This work focuses on the development of a novel linear stability criterion for the state of homogeneous fluidization regime, based on a new mathematical model for gas-fluidized beds. The model is developed starting from the well-known particle bed model. A mono-dimensional momentum balance is derived leading to a set of equations which explicitly include voidage-gradient dependent terms (elastic force) for both solid and fluid phases. A fully predictive criterion for the stability of homogeneous fluidization state is here proposed, based on the well-known Wallis’ linear stability analysis. The criterion requires the choice of an appropriate averaging distance, which in the present development is found to be bed-voidage dependent. The linear stability criterion resulted in turn in a simple, yet fully predictive, relationship for incipient bubbling voidage. Validation was carried out analyzing the influence of all physical properties and sensitivity to closure relations, showing substantial agreement with literature data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.