Figure4. Out-put of model in terms of (a) concentration of
ethanol and diethyl ether as a function of time, (b) time interval of
27000 s for concentration of ethanol and diethyl ether as a function of
adsorbent length and (c) temperature profile variation versus time at
different length of bed for feed flow rate of 333 kmol/h
One of effective parameters in design of adsorption bed is gas
superficial velocity. For constant feed flow rate, one can easily
calculate diameter of adsorption bed based on gas velocity and feed flow
rate. In adsorption processes, it is evident that gas superficial
velocity greatly enhances energy and mass transfer by decreasing the
external film around the adsorbent. 19Increase in
superficial velocity is favored till meeting maximum permissible
pressure drop, near to the criterion of 7.50kPa/m. 17,
20Figure 5 shows variation of Reynolds number, the Peclet number and
velocities with time.