Page 324 - Applied Process Design For Chemical And Petrochemical Plants Volume II

Packed Towers 31 3

-A :Wire Screen, also Weir- ,Type(Steell
--- B :Plain Melai Plate
Wire Screen Plate ~92% Fres Space
with 3/8"Square Openings

L: Water Rate, Ib./Hr.(sq.ft.)
Air Mass Velocity, Ib../Hr.(sq.ft.)
Figure 957. Comparison effect of pressure drop across support u
plate and bed of 1% in. lntalox@ saddles. Used by permission of
Leva, M., Lucas, J. M., and Frahme, H. H., Ind, Eng Chem. V. 46, No. 500 1,000
6 (1 954); all rights reserved.
Gas Mass Velocity, Ib./Hr.(sq. f t.)
Pressure Drop Through Fused Raschig
Ring Plate,wi!h Plate Covered with
One inch of I Size lntalox Saddles
(L:Liquid Mass Rate Parameter)

Plate = 58 % Free Area

Figure 9-39. Pressure drop through fused ceramic Raschig ring plate
with plate covered with 1 in. of 1 -in.-size Intalox@ saddles. Used by
permission of Leva, M., Lucas, J. M., and Frahme, H. H., Ind. Eng.
Chem., V. 46, No. 6 (1 954); all rights reserved.

Pocked 40" High with
I" lntolox Saddles

2 4 6 8 10 12
Ratio of Liquid Mass Velocity -Air Mass Velocity through Tower 5.0
L 3,570

Figure 9-38. Effect of choice of support plate on flooding rate. Used
by permission of U.S. Stoneware Co. (now, Norton Chemical Process
Equipment Corp.).

In general the dumped saddle type packing should give less
blocking to support openings than ring type.
500 1,000
Example 9-2: Evaluation of Tower Gas Mass Velocity> I b./Hr.(sq.f t.)
Condition and Pressure Drop Pressure Drop through Plain Ceramic
Plate
Check the design of a 4ft, Gin. I.D. tower packed with (LE Liquid Mass Rate Parameter)
43 ft of 1-in. x Xiin. thick steel Raschig rings if the service Curve A also Represents Weir-Type
requires a liquid rate of 2,250 lb/hr (ft2) of 10% caustic Plate Covered With One inch of I"
solution (sp. gr. = 1.22) and 4,540 Ib/hr (ft2) of 110°F air lntalox Saddles
containing C02 to be scrubbed at 363 psia. Plate-20 O/O Free Area Plain Ceramic
~60 ?h Free Area Weir- Type
1. Determine the operating range for the tower by ref- Figure 9-40. Pressure drop through plain ceramic plate. Used by per-
erencing to Figure 9-21B or 9-21C. Use 9-21C for this mission of Leva, M., Lucas, J. M., and Frahme, H. H., Ind. Eng.
example. Chem., V. 46, No. 6 (1 954); all rights reserved.