Some simplified equation for evaluating the minimum fluidization

velocity is given below:

Richardson et al$.[11,16]$

Doichev and Akhmakov

$17$

$U_{mf}=\frac{{}_g}{{}_g{d}_p}(\sqrt[\phantom{2}]{{25\mathrm{.}7}^2+0\mathrm{.}0365Ar}-25\mathrm{.}7)$

$U_{mf}=\frac{{}_g}{{}_g{d}_p}(1\mathrm{.}08{10}^{-3}A{r}^{0\mathrm{.}947})$

Barbosa et al$.[18]$

$R{e}_{mf}=1\mathrm{.}9{10}^{-3}A{r}^{0\mathrm{.}87}{U}_{mf}=\frac{R{e}_{mf}}{{}_g{d}_p}$

Ar is the aspect ratio defined as$,Ar=\frac{d_p^3{}_g({}_p-{}_g)g}{{}_g^2}$

$($a$)$ Catalyst pellet is to be fluidized by $CH4$ flow at $1$ atm in a vertical

cylindrical vessel. The density of the catalyst particles is $3000k\frac{g}{m}3,$

calculate the minimum fluidization velocity for the following operation

conditions:

Pellet diameter $dp=500$ um

$CH4$ temperature fixed at $T=800C.$

$($b$)$ Using Geldart chart to classify the type of pellet.

$($c$)$ Using general fluidization regime diagram to identify the possible

fluidization regimes