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314 Chapter 6

COMPONENT SEPARATORS

The most frequently used component separators are absorbers, strippers, fractona-
tors, and extractors. According to Humphrey [74], fractionators are used in 90 to
95% of the separations in the US. The principles of component separators are cov-
ered extensively in several texts such as Treybal [29], King [30] and Henley and
Seader [31, 65]. We will only consider short cut sizing methods. These methods
are useful for preliminary design estimates and for first guesses for more exact
calculations, requiring iterative calculation procedures.
A fractionator or absorber consists of a cylindrical shell containing internals,
either trays or packing, as shown in Figures 6.12. By creating surface area trays
and packing promote mass transfer between liquid and gas. A liquid film forms on
the packing and vapor bubbles through the liquids on the trays. Packed separators
are usually used for diameters less than 2.5 ft (0.762 m). In both separator types,
the liquid enters at the top of the column and at the feed tray for fractionators and
flows downward by gravity. Gas enters the separator at the bottom and then flows
upward countercurrent to the liquid flow.

Sieve Tray

Dcyuncomer

Weir

Sieve Tray Column Packed Column
Source: Reference 6.37 Source: Reference 6.77

Figure 6.12 A fractionator or absorber design, with permission.

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