Edwards-Richardson correlation

Gas-solid fixed beds For axial dispersion in gas-solid fixed beds, the Edwards-Richardson correlation can be used (Wen and Fan, 1975 Andrigo et al., 1999). 

The Reynolds number is 4.56 and using the Edwards-Richardson correlation (eq. (3.317)) the particle Pec let number is found equal to 2.18 and thus, the bed Pec let number is 2179, which is fairly high and the plug-flow condition is assured. 

From Table 1-15 of Appendix I, we find that the diffusion coefficient of toluene in air is 8.7 X 10-6 m2/s. Then, using the properties of ah at 25 °C (Table 1-6, Appendix I), we find that Sc = 1.74 and Rep = 6.92, and using the Edwards-Richardson correlation (eq. (3.317)) the particle Peclet number is found to be 1.98 and thus, the bed Peclet number is 609.2, which is fairly high, and plug-flow condition can be assumed. 

In Figure 3.36, the Edwards-Richardson and Hiby correlations are compared for gas-solid systems, while in Figure 3.37, the Edwards-Richardson and Kubo conelations are compared for gas-solid and liquid-solid systems, respectively. 

Figure 3.36 Edwards-Richardson versus Hiby s correlation (for s = 0.45 and Sc= 1).

Figure 3.37 Comparison of Edwards-Richardson and Kubo correlations (for s = 0.45, for liquid Sc = 1000 and for gas Sc = 1).

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