Nomographs for the Absorption Factor Equation SHERWIN CHASE Illinois Institute of Technology, Chicago, 111.
N CERTAIN methods for the design of multicomponent absorbers and column stills (g,9), the following type of equation appears:
I
where E
= “efficiency” of the o eration A = L / K A V ,absorption factor N = number of theoretical plates required
The nomographs for this equation (Figures 1 and 2) were developed by the use of determinants and transformations as described by Allcock and Jones (1). The use of the charts is made clear by the three operations: (1) Make the simple calculation of A - E; ( 2 ) extend a line from A - E through A ; (3) find N on the network a t the intersection of this line with the proper value of E. For a given case the choice of chart may depend on a trial, but in general the higher range chart (Figure 2 ) will be found to serve for the higher values of E .
-2.5
1.4
1.3
FIGURE 1 1499
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INDUSTRIAL AND ENGINEERING CHEMISTRY
1500
"! B
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FIGURE 2
Vol. 34, No. 12
INDUSTRIAL AND ENGINEERING CHEMISTRY
December, 1942
Because of a mathematical quirk, these charts give an infilinityOf when A = 1* in this case the equation simplifies to: N=- E
or E = - N N f l
When either A Or E is the straight edge be pivoted around the known point On the chart intersects the remaining scales in complementary values.
it
1501
Literature Cited (1) Allcock and Jones, “The NomogramtP, London, Sir Isaac pi& man & Sons, 1941. (2) Brown, G , G.,et al., Trans. Am. Inst. Chem. Engra., 30, 438-546 (1933-34). (3) Souders, M.,and Brown, G . G.. IND.ENG.CRIM... 24. . 519-22 (1932). NOTE. Reproductions of these nomographs, approximately 16 b y 20 inches, may be obtained from the Department of Chemical Engineering, Illinois Institute of Technology, for 50 cents per set.
Equilibria in Ethanol-Water Svstem at Pressures Less Than Atmospheric J
A. H. BEEBE, JR., I
