Physical Column Design

Actual physical design of a distillation column is a complicated process. Detailed descriptions of such designs can be found in references 39 42, 45.

Some items of interest will be discussed below.

For example, Figure 5-24 is a typical bubble cap column performance chart.

Figure 5-24: Bubble cap column performance (41).

Distribution of areas in a bubble cap column are given in Table 5-7 and Figure 5-25.

Figure 5-25: Tray area classification (41).

Table 5-7: Bubble Cap Column Distributions ^[*](41)
Tower Diam., ft	Downflow area	Liquid-distribution area	End Wastage
Crossflow	Double Pass	Crossflow	Double pass	Cascade double
3	10 20		10 25			10 30
4	10 20		8 20			7 22
6	10 20	20 30	5 12	15 20		5 18
8	10 20	18 27	4 10	12 16		4 15
10	10 20	16 24	3 8	9 13	20 30	3 12
12	10 20	14 21	3 6	8 11	15 25	3 10
15	10 20	12 18	2 5	6 9	12 20	2 8
20		10 15		5 7	9 15	2 6
^[*]Allocated cap area is determined by difference.

In Figure 5-26 the effect of liquid and vapor loads on sieve tray performance is shown.

Figure 5-26: Sieve tray performance (41).

Table 5-8 lists various recommendations for bubble cap columns.

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Chemical Engineers' Portable Handbook