Pharmaceutical Manufacturing Handbook: Production and

154 EFFECT OF SCALE-UP ON OPERATION OF JACKETED REACTORS
mCp/UA, min
30
28
26
24
22
20
18
200 250 300 350
Mass of water, kg
FIGURE 10 Linear regression to estimate thermal mass and UA . ( From ref. 19 .)
perature of 60 ° C (based on a total of eight experiments at fi ve different reactor
fl uid volumes).
3.1.5
TC1
TC2
FIGURE 11 Characteristic pilot plant vessel control strategy. Slave (secondary) controller
based on jacket outlet temperature is shown. The control valve is on the outlet stream to
minimize temperature gradients (when switching from hot to cold fl uids) that would be
imposed if the valve was on the inlet. ( From ref. 18 , with permission .)
DYNAMIC SIMULATION STUDIES
To cold HT
fluid system
To hot HT
fluid system
From cold HT
fluid system
From hot HT
fluid system
Older pilot plant and manufacturing processes often used steam for heating and
water for cooling, with a switch - and - purge strategy between the two modes. Recent
process designs have two heat transfer fl uid systems (hot and cold heat transfer
fl uids) that are used for most of the heating and cooling needs. In addition, some
vessels may have nitrogen coolers for cryogenic operation.
A simplifi ed schematic for a jacket heat transfer service is shown in Figure 11
[18] . Here, two separate heat transfer fl uid headers are used, and the control valve
is on the outlet stream to reduce the temperature shocks that might occur if a single