Equations for Flooding Rate in Packed Towers

I

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

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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