Coal particles with size of $0\mathrm{.}14$mm$,$ shape factor

$$s

of $0\mathrm{.}92$ and a particle density of $1200$kg$/$m$3$

are to be fluidized with air at $200000$ Pa $($abs$)$ and $300$C$.$ The bulk density of the coal material

is $1000$kg$/$m$3$

$.$ The voidage at minimum fluidizing velocity is $0\mathrm{.}38.$ The bed is charged with

$350$kg of solid material and the diameter of the empty bed is $0\mathrm{.}60$m$.$ The viscosity of air is

$52$

$1\mathrm{.}845$x$10$ Ns$/$ m

$$

$.$ The gas constant R can be taken as $8\mathrm{.}314$ J$.$ mol$-1$

$.$ K$-1$

$.$

$()$

$2$

$2233$

$311\mathrm{.}75150$

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$+$

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$=$

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$$ u d

e

u d

e

gd e mf

s mf

mf

s mf

mf s

Calculate:

a$)$ Height of packed bed $[8$marks$]$

b$)$ The minimum height of fluidized bed $[4$marks$]$

c$)$ The pressure drop at minimum fluidizing velocity $[8$marks$]$

d$)$ The minimum fluidizing velocity $[10$marks$]$