Ergun Software for Bubbling Beds

Bubbling and Bed Expansion

This module provides a number of information on the bubbling aspects of the fluidized bed:

- Presentation of fluidization state on the Reh's modified diagram.

- Calculation of bubbles size variation along the bed, as well as the mean and maxi bubble diameters. The user can choose among a number of available methods (Wether's method, Darton's method, Mori and Wen's method…).

- Variation of voidage along the bed, average bed voidage, bubble void fraction

- Bubble rise velocity, bubble mean residence time in the fluidized bed.

- The mean values are calculated from integration over the bed height as shown in the figure beside.

Here is an example of how Ergun Software calculates the "mean bubble volume fraction":

In the example above, Darton's equation is used to estimate the local bubble size. Then Davidson's equation is used to calculate the bubble rise velocity (Ub). The combination of these equations with those of "continuity" makes possible to calculate the bubble volume fraction in the bed. Other "Bed Expansion and Bubbling" models especially adapted to diverse class of particles are also available. Werther's model is one of the most performant:

All data and results are saved in a text file saved by the program. The "Virtual Expert" analyses and makes some comments on the results obtained.

Ergun Design Technology

Example of Grace's diagram for fluidization regime

example of results obtained from bed expansion and bubbling calculations

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