1

yj+u

F Xf' Feed Tank

Figure 4.15. Schematic Diagram of the Feed Plate and Feed Tank for

MVC Column

4.3.3, Middle Vessel Batch Distillation Column (MVC)

Referring to Figure 2.2 for MVC column configuration, the model equations for the rectifying section are the same (except the reboiler equations) as those presented for conventional batch distillation column (Type III, IV, V in section 4.2). The model equations for the stripping section are the same (except the condenser equations) as those presented for inverted batch distillation column (Type III, IV, V in section 4.3.2). However, note that the vapour and liquid flow rates in the rectifying and stripping sections will not be same because of the introduction of the feed plate.

Here, the model equations for the feed plate (Figure 4.15) will be presented for model type III, IV and V.

Feed Tank and Feed Plate: i = Nr. i = 1 to nc a) Feed Tank Total mass balance:

dHf dt

Component balance:

b) Feed Plate Total mass balance:

Component mass balance: dxn

Hj-^ = Lxj_li-L'xji +V(yj+u-yji) + Fxfl-LfXji (III.m4)

Note that liquid and vapour flow rates vary throughout the column (unlike that is shown in Figure 4.15)

Feed Tank and Feed Plate: j - Nf: i = 1 to nc a) Feed Tank Total mass balance:

dt J

Component balance:

dt b) Feed Plate Total mass balance:

Component mass balance:

d(HjXji) dt

Energy balance:

Lj-lxj-u +vj+\yj+U + Fxfi ~vjyß ~Ljxji -LfXji (IV.m4)

diH£} 1h'n +Vj+1 hVj+] + Fhp-Ljhj -V¡h] -Lfh) (IV.m5)

4.3.3.3. Rigorous Model with Chemical Reaction- Type V Feed Tank and Feed Plate: i = NE: i=ltonc a) Feed Tank Total mass balance:

dH f

Component balance:

d(Hfxfi)

b) Feed Plate

Total mass balance:

-Lf+AnjHj

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