Mass Balances According to Ideal Models

In this section, we will investigate three kinds of mass balances for a fluidized bed the plug flow, the CSTR, and the hydrodynamical Kunii-Levenspiel models [18]. The ideal models can be utilized only for rather crude, approximate calculations only the design of a fluidized bed should comprise a hydrodynamical model coupled with experiments on a pilot scale. 

If the one-dimensional plug flow model is applied to a fluidized bed, all equations derived in Section 5.2.1 are applicable. The balance Equations 5.16 through 5.20 are therefore used to describe a fluidized bed. Although the balance equations are nonrealistic from the physical point of view, they can, however, provide an interesting comparison by delivering the extreme performance of the fluidized bed in question. For the sake of a comparison, even the CSTR model for a fluidized bed is described below. The mass balance for component i encompasses, in the case of a backmix model, the entire reactor volume and is given, at the steady state, by the following equation  

For a system with a single chemical reaction, the balance Equation 5.221 can be expressed using the reaction rate, R  

In case of multiple chemical reactions. Equation 5.222 is transformed to 

As the space time (t = Vr/Vo) is inserted. Equations 5.224 and 5.225 assume newforms  

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