Equations for Flooding Rate in Packed Towers

(1) Lobo, W. E., Friend, L., Hashmall,. F., Zenz, F., Trans. Am. Inst. Chem. Engrs. 41, 693 (1945). Received for review August 9, 1960. Accepted Septe...
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NlNG HSING CHEN Solid Rocket Plant, Aerojet-General Corp., Sacramento, Calif.

Equations for Flooding Rate in Packed Towers

A

the original curve \vas shown in the illustration:

SUCCESSFUL CORRELATION of flooding data in gas-liquid packed towers has been given ( 7 ) as a curve by plotting on loglog coordinate paper,

a

Equation l agrees u i t h the values observed in the original curve ( 7 ) for the L range of from 0.02 to 3.00.

\vas plotted against

For 20 selected points, the mean deviation is -1.37Yc and the standard deviation is z t 4 2870. Because both coordinates have G terms. solution of this requires a trial and error method. To eliminate this tedious manipulation,

Similarly, the curve can be represented by the method of least squares as

log L G

t.1 pL

However, computers are now used widely for solving engineering problems, and they can solve a correlation equation much more easily than a correlation curve. For such computer solution. the correlation curve is transformed by the method of least squares to

modified

1'

Pb PI'

Equation 2 is valid for the ranqe of L G l j p/pc r . from 0.02 to 5.00. For 22 selected points, the mean deviation is +0.05670 and the standard deviation is 2~3.4470. The comparison is shown in the illustration.

/

Nomenclature

specific surface area of dr) packing sq. ft. cu. ft. packed kolume g, = Yewton's law conversion factor, 4.17 (108) lb. mass. (ft.) (Ib. force), (hr.) (hr.) G = superficial mass velocit) of gas flowing through packing, lb. 1 (hr.) (sq ft.) L = superficial liquid rate. lb. (hr.) .1,

=

E

= fraction of free void space within

isq.rt.)

the packing. cu. ft. cu. ft po = density of gas, lb. cu. f t . p~ = pL =

io:

poi

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oi

i

-

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ic

GIP,

To eliminate tedious trial and error method, the previous experimental curve for correlating flooding data in gas-liquid packed towers was modified

6

INDUSTRIAL AND ENGINEERINGCHEMISTRY

density of liquid, lb. cu. ft. viscosity of liquid. cp.

Literature Cited (1) Lobo, W. E., Friend, L., Hashmall, F., Zenz. F., T r a n s . -4m. Inst. Chem. Engrs. 41, 693 (1945). RECEIVED for review August 9, 1960 A C C E P T E D September 22, 1960