A process for recovering starch particles from a slurry of starch and gluten uses gravitational

settling on a "starch table." Here the slurry is fed to one end of a table where the starch

particles settle and remain on the table, and starch$-$free liquid is discharged from the opposite

end of the table. A starch table that is $2\mathrm{.}0ft$ wide and $120ft$ long can handle a maximum

slurry feed rate of $2\mathrm{.}0ga\frac{l}{m}in$ while still providing a starch$-$free slurry at the exit of the table.

The slurry has the following physical properties: $=1{10}^{-3}k\frac{g}{m}-sec$;$-{}_0=100k\frac{g}{m^3}$

You have been asked to evaluate a process improvement involving the use of a continuous

centrifuge with a $$ value of $31,500m^2.$

Note that: $g=9\mathrm{.}81\frac{m}{se{c}^2}=32\mathrm{.}174f\frac{t}{se{c}^2\text{;}1f{t}^3}=7\mathrm{.}48$gal

a$.$ Using the information from the starch table determine the size of the starch particles. Hint: the

sedimentation time is equal to the residence time when Qmax is reached.

b$.$ What is the maximum slurry feed rate $(Qmax)$ that the centrifuge can handle $($and still give a

starch$-$free slurry at the exit$)?$ You may use assume the diameter of the starch particles is $10$

um if you could not solve part $($a$).$

c$.$ How much would Qmax increase if the rotation rate of the centrifuge was doubled?