Calculating the Tower Vapor and Liquid Loading
These loadings at the critical trays are calculated from a series of heat balances
starting at the bottom stripping section and continuing up the tower to the top
Units are in BTU/h. °F. Ft
2
Fluid being cooled
Naphtha pumparound
Kero
Debutanizer bottom
Gas oil (inc. BPA)
Reduced crude
Light end bottoms
Vacuum distillates
Bitumen
Cat oil slurry
CDU overheads
Crude
Crude
Debutanizer feed
Crude
Crude
Light end feed
Crude
Crude
FCCU feed
Crude
70–80
70–75
75
40–50
20–30
70–75
30–40
20
40
80–90
75
80
40
110
30
38
38
50
65
85
100
90
65
23
30
40
CDU overheads
Splitter overheads
Amine stripper overheads
Debutanizer overheads
Reformer effluent
CT water
CT water
CT water
CT water
CT water
CT water
CT water
CT water
CT water
Water
Naphtha feed
Recycle gas
Crude oil feed
Naphtha coolers
Debutanizer bottoms
Light end overhead
Reformer effluent
Reformer effluent
Crude tower overheads
18 in. dia. bundles
30 in. bundles
> 30 in. bundles
Hydrocarbon
20 000
17 500
15 000
Water
30 000
26 500
~23 000
Debutanizer bottoms
Light naphtha
Gas oils
DEA or MEA
Reduced crude
Fluid being heated U a
Exchangers
Coolers
Vapour heat exchangers
Condensers
Air coolers
Reboilers (use heat flux in BTU/h/ft 2 )
Fig. 12 Overall heat transfer coefficients in oil refining
Atmospheric and Vacuum Crude Distillation Units in Petroleum Refineries
151