Only the heat balance over envelope 3 is given in Table 12. The others follow in
a similar fashion, but the summaries of the calculated loads are given for all three
sections (see Table 13):
Solving for x 3 ¼
2, 391, 000
111
¼ 21, 540 lb=h:
Checking fractionation:
Between HGO and LGO
Reflux ratio ¼
22, 809
24, 675
¼ 0:92
Number of trays = 11 (2 PA trays = 1 Frac tray).
Factor = 10.2.
Fig. 21 Overall tower heat balance diagram
Atmospheric and Vacuum Crude Distillation Units in Petroleum Refineries
173