Flooding Velocities in Liquid-Liquid Extraction Towers

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PU R D U E UNIVERSITY

THIS IS T O CERTEFT T H A T T H E THESIS P R E P A R E D U N D E R M T SUPERVISION

JOHN FRANCIS ROORDA, JR.

BY

ENTITLED

FLOODING VELOCITIES IN LIQUID-LIQUID EXTRACTION TONERS

C OMPLIES W I T H T H E UNIVERSITY R E G U L A T I O N S O N G R A D U A T I O N T H E S E S

A N D IS A P P R O V E D B Y M E A S FULFILLING THIS P A R T O F T H E R E Q U I R E M E N T S

FOR THE DEGREE OF

DOCTOR OF PHILOSOPHY

P R O if ^ S S O R I N C H A H G E O F T H E S IS

çead o f

August

S

chool or

D

epartm ent

19

T O T H E LIBRARIAN;-THIS THESIS IS N O T T O B E R E G A R D E D A S CONFIDENTIAL.

F K O F E S S O R IN ’ O B A B G B

G K A D . S C H O O L F O B M S—3 - 4 9 —I M

FLOODING VELOCITIES IN LIQUID-LIQUID EXTRACTION TOYUERS

A Thesis

Submitted to the Faculty of Purdue University

by

John Francis Roorda, Jr,

In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

August, 19i|-9

ProQuest Number: 27712197

All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is d e p e n d e n t upon the quality of the copy subm itted. In the unlikely e v e n t that the a u thor did not send a c o m p le te m anuscript and there are missing pages, these will be noted. Also, if m aterial had to be rem oved, a n o te will ind ica te the deletion.

uest ProQuest 27712197 Published by ProQuest LLO (2019). C opyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C o d e M icroform Edition © ProQuest LLO. ProQuest LLO. 789 East Eisenhower Parkway P.Q. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346

ACKNOWLEDGMENTS

The author wishes to express his grateful ap­ preciation to Professor Dysart E. Holcomb, director of this research, for constant assistance and suggestion of a most helpful kind.

Thanks are due also to the many

others who contributed to the success of this project by discussion and by technical assistance; and to the Shell Oil Company who contributed the oil employed in the course of the research. This study was made possible by a grant by the Shell Fellowship Committee, through the Purdue Research Foundation, and the author particularly wishes to thank the Committee and the participating companies of the Shell group for this fellowship.

TABLE OP CONTENTS Page

I. II.

A B S T R A C T ......................................

i

I N T R O DUCTION...................

1

REVIEYiT OPTHE L I T E R A T U R E .......................

3

III.

.................................. A.

Statement of theP r o b l e m

B.

Method of Investigation

6

.........

6

..............

6

C * Equipment................................... ..........

7

1.

Extraction Columns

2.

Interface C o n t r o l

3*

Distributors

4 .

Packing Supports

5*

Manometer

6.

Plow M e a s u r e m e n t

........

l5

7#

Temperature Measurement .............

l5

8•

Water Supply

16

9.

Oil S u p p l y ....................

16

10 •

Plow Control

17

11.

Packing Materials .............

17

12.

Density Measurement

17

13.

Interfacial Tension Measurement ......

.......

........................ ....

7 13 13 ll{.

.........................

...............

......

...........

D • Fluid Materials

15

I8 I8

1.

Oil ...................................

18

2.

W a t e r .............

19

3.

Manometer Fluid

I9

.................

TABLE OP CONTENTS (Continued) Pag© E.

P.

G.

Experimental Procedure ............

19

1#

Calibration of Rotameters ............

19

2.

Flooding R u n s .................

20

3*

Droplet Rise Rate Measurements ......

25

i|.. Measurement of Packing Characteristics

25

Preliminary Findings

26

1.

Column Construction

.................

26

2#

Distributor Construction . . . . . . . . . . .

27

3.

Droplet Characteristics in Packed C o l u m n s .......

28

I4.. Heat Transfer in the Column Between the Two Fluids ....................

26

D a t a .......................................

29

H.. Results

IV.

.....................

.......................

1{.6

1.

Packing and Wall Effect Factors.......

$0

2.

Theory of Flooding

65

3•

Manometer Plots

....... ................

SUMMARY AND CONCLUSIONS ................... .......................

72 9I

APPENDIX A.

GLOSSARY

APPENDIX B.

N O M E N C L A T U R E.....................

9 i|.

APPENDIX C.

PHYSICAL DBÎENSIONS .............

95

APPEimiX D.

FLUID PROPERTIES ................

96

APPENDIX E.

ROTAMETER CALIBRATIONS ..........

99

LITERATURE C I T E D ..............................

101

93

V I T A ........................................... 1 0 2

LISTS OF TABLES AND FIGURES

List of Tables Table 1*

Liquid-Liquid Extraction Flooding Data

•••*

2.

Rat© of Ascent Data

.................

k-7

3.

Calculation of Packing Factor .............

^6

Calculation of Wall Effect F a c t o r ........ 5*

30

6l

Correlation of Packing Factors with Packing Characteristics ....................

65

6.

Physical Dimensions ..............

95

7.

Specifications of Shell l50-Turbo-Raffinate

^6

8.

Properties of Fluids ..............

97

9# 10.

Rotameter Calibration Rotameter Calibration

.

99

.................... 100

List of Figures Figure 1*

Schematic Diagram of Equipment

2.

View of Main Part of Apparatus . . ... . ..

9

3#

Six Inch Liquid-Liquid Extraction Tower (Without Weir or Distributor) . . . . . . .

10

Distributors Employed in Flooding Velocity Studies ..... «

11

5»

Flooding Velocities

..................

1^9

6.

Transformed Flooding Velocity D a t a ........

51

ij-.

.........

8

List of Figures (Continued) Page

Figure

7-

8

.

9.

. 11. 10

.

12

Effect of Relative Packing Size on Flooding ...................

53

Relation of Packing Factor to Packing Diameter .................. ...... .

58

Relation of Wall Effect Factor to Relative Packing Size ....................

59

General Correlation of All Flooding Data •

62

Relation Between Combined Flooding Factors and Packing Characteri sti c s . . . . . .

64

................. .

68

Droplet Ascent Rate

13.

Loss of Droplet Ascent Rate by Hindering .

70

34.

Spray Flooding Curve from Droplet Ascent Rates ........................ .

73

15 .

Manometer Differential, Ij. Column, Spray Operation ........

75

Manometer Differential, Raschig Rings .......

76

16. 17.

18

.

19 . 20

.

21 22

. .

Column, 2"

Manometer Differential, ij. Column, 1 l/2*^ Raschig Rings ......

77

Manometer Differential, i}. Column, 1" R a s c M g Rings ....

78

Manometer Differential, !{. Column, 3/Ij-” Raschig Rings ......

79

Manometer Differential, Ij. Column, 1/2” Raschig Rings ....

80

Manometer Differential, 6 Operation ..........

Column, Spray

81

Manometer Differential, 6 Raschig Rings ......

Column, 2”

82

List of Figures (Continued) Pag©

Figure

23 .

Manometer Differential, 6 ” Column, Raschig Rings .....

1 1 /2"

24.

Manometer Differential, 6 " Column, Raschig Rings ....

1"

83 84

25.

Manometer Differential, 6 ” Column, 3 /4 " Raschig Rings .....

85

26.

Manometer Differential, 6 ” Column, 1/2" Raschig Rings .....

86

27.

Manometer Differential, 2 ” Column, 1" Raschig Rings .....

87

28.

Manometer Differential, 2 ” Column, 3/4 " Raschig Rings ....

88

Manometer Differential, 2 ” Column, 1/2" Raschig Rings ....

89

Manometer Differential, 2 ” Column, Spray Operation ........

90

Effect of Temperature on Physical Proper­ ......... ties Correction Factor

98

29.

30 . 31.

FLOODING VELOCITIES IN LIQUID-LIQUID EXTRACTION TOYffiRS

ABSTRACT

Simiraary Flooding rims were made in two, four, and six inch dlamieter columns v;ith two, one and one-half, one, threequarters, and one-half inch stoneware Raschig rings as well as with the columns unpacked.

The data were manip­

ulated, and a packing factor, independent of column size, was extracted from it.

This factor was related to the

packing diameter by means of a plot using special coordin­ ates.

A wall effect factor was calculated and reported

on a plot as a function of the tube to particle diameter ratio.

A general correlation of all flooding runs was made

by use of the packing and wall effect factors, and it was shown that this correlation will reproduce the data with a probable error of nine percent.

The combined packing and

wall effect factors were shown to be related by a factor to the quotient of the surface area per unit volume and the square of the fraction void. A manometer connected across the column was used to determine the flooding points. Two methods were developed for duplicating the spray curve by use of data on the velocity of ascent of droplets

11

In a coluim of still fluid as a function of the droplet population density.

Introduction Although there has been much interest in recent years in the study of liquid-liquid extraction, relatively little data have been published on the factors involved in column design.

The greater part of the writing has been concerned

with specific commercial applications and with investigations of extraction capacity and other topics involved in the con­ tacting of the phases. The maximum volumetric capacity of an extraction tower is of particular interest as this throughput deter­ mines the column diameter.

It was a purpose of this study

to determine the influence of tower packing upon limiting flow.

Both the absolute size of the packing material and

its size relative to the size of the tower were of interest, the former as it affects flooding rates, the latter not only for this reason but because oversize packing permits an anomalous flow condition at the wall of the tube which adversely affects the capabilities of the tower for extrac­ tion.

The mechanism of flooding in liquid-liquid extrac­

tion columns is, as yet, little understood, and it was a purpose of this study to enlarge and clarify the knowledge of this phenomenon.

ill

Several of the aspects of flooding have been inves­ tigated; researches have been carried out and reported on as regards efficient column design (2 ), the influence of the physical properties of the solvents (2 , 3 ), and to a limited extent the effects of packing size (2, 3)#

The

effect of the presence of solute on flooding has also been noted (4).

Improvements in liquid-liquid extraction dis­

tributors have also been made (4)*

These are discussed

under appropriate headings.

Experimental Apparatus Column Design The three columns were cylindrical tubes (a) about four feet long fitted on each end (see Figures 1 and 2) with a disengagement section (b, c) whose function was to prevent, by slowing the continuous stream, turbulence at the ends of the column which would cause local flooding (2).

The two larger columns, whose diameters were 3*79

and 5*59 inches, were constructed of Lucite with steel end plates (g), and the small column, of diameter 1 .8 ? inches, was made of pyrex tubing with Lucite end sections. The transition from the column diameter to the header diameter was accomplished at the distributor end by use of a conical section (e) whose sides formed a 3 0 degree angle. At the end admitting the continuous fluid, the column was

iv

-Ch

-c

rO-

SCH EMAT IC

DIAGRAM FIG. I

OF EQUIPMENT

m

m

PIG. 2.

LiqniD-LiqUID e x t r a c t i o n e q , uipment

VI

extended into the disengagement section about four inches to form a weir (d) over which the continuous fluid was forced to flow in its entrance into the column.

The header

to column diameter ratio was 1 * 7 3 in the case of the two larger columns and 5 «23 for the small column. The maintenance of the interface (h) at a definite place within the continuous fluid entrance header was ac­ complished by the means of a valve (!) in the light fluid exit line and a vented inverted U-tube (j) in the heavy fluid exit line. The distributors (f) used nozzles to disperse the discontinuous fluid rather than a perforated plate in order to insure maximum uniformity of bubble size (ij.).

The two

and six inch distributors had tubes set into a plate; the four inch distributor plate was a piece of metal milled in such a way as to form a number of truncated hexagonal pyramids.

The diameter of the holes drilled in the nozzles,

which produced bubbles of about five-sixteenths inch diameter, was 0 . 1 1 6 inches, and the tube spacing, on equilateral cen­ ters, was three-eighths inches for the two smaller distribu­ tors and seven-sixteenths for the six inch distributor.

The

number^of tubes employed was I9 , I0 6 , and 1 6 3 for the three distributors in ascending order of size. The packing supports were constructed of one-quarter inch mesh screening and were mounted in the columns at the

vil

distributor heads in such a way that the discontinuous fluid droplets did not strike them in passage t h r o u ^ the column (2), Measurement of Variables The manometer, used to detect the inception of flood­ ing, was a 3 0 inch glass U-tube filled with water-saturated nitrobenzene and connected across the column with quarterinch pipe* The flow to the columns of the two solvents was mea­ sured by two rotameters with scales 375 and ij.00 millimeters long.

Three sets of floats were used so that best advantage

could be taken of the long scales. Temperature was measured by ordinary mercury thermom­ eters having two degree scale divisions.

In the early runs

the temperatures of both entrance and both exit streams were taken.

It was noted that the temperature of the dis­

continuous fluid, which had been elevated as much as 3 0 degrees Fahrenheit by recirculation to take care of excess pump capacity, was reduced to the temperature of the con­ tinuous fluid in passing through the column. This was true even at continuous rates which were quite low. Tap water was used throughout the runs as the con­ tinuous fluid, and the single discontinuous fluid employed was "Shell 1 5 0 Turbo-Raffinate," a hydrocarbon oil of

viii

density about 54 poi^ds per cubic foot, and viscosity about 30

centipoise at 100 degrees Fahrenheit.

Measurements of

the density and Interfacial tension with the tap water were made and are reported in Table 1.

Table 1 Physical Properties of Fluids Tej^ip. op

Interfacial Tension (S ; dyne/cm.

60 68 71 76 80

3 8 .1

.

Oil Density ./» 1 #/ft3 f 51)-.11 5 3 .9 1

37.1 5 3 .7 7 3 6 .1 5 3 .7 2

Chemical stoneware Raschig rings of diameters two, one and one-half, one, three-quarters, and one-half inches were used as packing material in this study.

Experimental Procedure To begin a run, a zero reading of the manometer was taken with the interface valve closed, the U-tube in mid­ traverse, the interface at the position maintained during the run, and the continuous rate set at the rate held throughout the run.

The discontinuous control valve was

cracked and the rate set at a point estimated to be about one-half that at flooding.

After a few minutes the manometer

Ix

reading was noted, and the discontinuous rate was advanced an amount corresponding to 1 0 millimeters on the rotameter scale.

These stepwise advances were continued until it was

suspected that flooding was near; whereupon, they were re­ duced to five millimeters.

fJhexi the column began flooding

after an advance in rate, it was allowed to continue in operation until the column was about one-half flooded.

The

rate was then reduced to a point just above the last rate which did not result in flooding, and the process of flood­ ing in the column was allowed to reverse for a time.

The

rate of discontinuous fluid was advanced again to a point below that which had first caused flooding and the column was allowed to continue to flood.

This bracketing process

was continued until a rate was found wliich would just main­ tain the flooding. The interface was maintained at the same point through­ out the run by manipulation of the two controls at low con­ tinuous rates and by the valve alone at h i ^ continuous rates.

The final stages of a run took a period of from one

and one-half to three hours to complete because the inter­ face at flooding is sensitive to any change of flow condi­ tion within the column and is most difficult to control manually.

The position of the interface is relatively un­

important, within limits; migration of the interface is of major consequence since it results in a change in the

continuous rate to the column*

Tills is the source of the

greatest experimental error in measurement*

It can be

minimized by making the disengagement section the smallest diameter possible consistent with the removal of turbu­ lence effects at the end of the column*

The small diameter

makes volumetric change of level more easily detected by increasing the linear effect. Flooding took place as has been described by Blanding and Elgin (2), with the effect being most noticeable at smaller column diameter, higher continuous flow rates, and larger sizes of packing.

VJhen either flow rate is increased

above the flooding point the holdup increases sharply at the interface end of the column, creating two distinct regions of holdup in the column.

The increased holdup re­

gion enlarges slowly at the expense of the low holdup sec­ tion, producing the effect of a sort of "holdup interface" moving along the column toward the distributor.

Lowering

one of the flow rates below the flooding rate results in reversal of direction of movement of this special interface. If the increased holdup region of the column is allowed to progress through the column, it will reach the entrance to the conical section; whereupon, bubbles will commence to fill the disengagement section, ultimately being carried out with the continuous exit stream.

There is a rate, some­

what below that whose effects have Just been described, which

XI

will maintain the termination of the massed column of drop­ lets just at the distributor end of the tower*

Such a rate

was taken as flooding. During a run the manometer differential increases in a near linear way with the incremental increases in discon­ tinuous rate.

When the column begins to flood the manometer

differential increases a much greater amount and reaches a value, when the column is fully flooded, several times that exhibited just before flooding began.

Since the manometer

reading changed in a way nearly proportional to the visual phenomenon, it was used to determine the flooding point which was taken to be the rate barely allowing the increase of manometer differential characteristic to flooding.

Use of

the manometer in this way furnishes a more reliable means of detecting the achievement of limiting flow than do visual techniques vjhich become indefinite as the packing size is decreased. Before a set of flooding runs on a packed column was begun a preliminary run was made to obtain assurance of the randomness of the packing.

If the column tended to flood

at a single point, it was repacked until the tendency to flood occurred at several points or generally throughout the column. The droplet ascent rate measurements were made by shutting off the discontinuous rate suddenly and noting the

xii

time required for the end of the column of droplets to pass between two marks on the column.

Experimental Results When the four inch column, the first to be constructed, was being tested prior to making flooding runs considerable difficulty was experienced with a turbulent, eddying flood­ ing just above the distributor at rates well below those to be expected.

It was finally discovered that, despite rea­

sonable care, the column proper was eccentric about onethirtysecond of an inch with respect to the conical section. Correcting this fault removed the anamolous flooding condi­ tion. The function of the lower disengagement section is to prevent turbulence at that end of the column resulting from the water velocity increasing as it approaches and goes past the distributor.

The annular area around the distributor

in the four inch column was less than $0 percent greater than the area of the column.

This annulus could probably

be made still smaller without forfeiture of proper opera­ tion, a factor of importance in the design of large columns. The upper disengagement section should be about the same diameter as the lower; a small size favors sensitivity of detection of movement of the interface.

As long as it is

an inch or so above the weir the position of the interface

Xili

will not affect flooding.

Sufficient space above the inter­

face should be allowed, however, for the bubbles to break to avoid carrying the continuous fluid out of the column with the discontinuous.

For the oil and water system em­

ployed here two to three inches was ordinarily sufficient. One sieve plate distributor was tried and found use­ less because the oil had such a strong tendency to wet metal.

The distributors that were used were designed to

have a gap between distributor points that the oil would not easily bridge and were manufactured according to two schemes, each of which worked equally well (see above).

The chamfer

on the ends of the tubes of the six inch distributor added nothing. As the rate through the distributor tubes was in­ creased, a point was reached where the bubbles no longer farmed at the tip of the tube but broke off the end of a stream of oil extending out from the tube.

This resulted

in lack of uniformity of bubble size which was undesirable because at flooding some classification of the bubbles would then take place, with the smaller bubbles collecting in the conical section and, occasionally, causing a chaotic condi­ tion at that place.

For this reason tubes were spaced as

closely as possible on equilateral centers, and a distribu­ tor slightly larger than the column diameter was employed. The bubbles formed were about five-sixteenths of an inch in diameter, and the spacing between tubes three-eighths

xiv

of an inch on two distributors and seven-sixteenths on the third* In the spray columns and with packing sizes down to about an inch, the oil bubbles did not coalesce and reform as they did with smaller sizes*

Because of the small

crevices between packing particles of sizes one-half inch or smaller, reforming of the bubbles was extensive.

These

reformed bubbles varied in diameter severalfold a l t h o u ^ there were few bubbles formed larger than the original diameter.

Runs on three-eighth rings were attempted, but

flooding rates could not be measured because they were well below the minimum accurate rates obtainable with the rota­ meters* During early runs temperatures of the exit streams were taken, but this practice was discontinued when it was discovered that the discontinuous fluid temperature always came down to that of the continuous fluid.

Because this

was true, even at low water rates, the temperature of the fluid system within the column was taken to be that of the water.

Data All data taken in the course of the investigation are summarized in Tables 2 and 3.

XV

Table 2 Liquid-Liquid Extraction Flooding Data Oil Temp. Run Uo. tp;OF

Water Temp. tg;OF

Series AA AB AC AD AE AF AG AH AI

62 II

i

I I?

i

I 80

25600 37600 ilj.600 50600 314.00 20000 44200 9250 0

5750 3190 9920 1125 4280 7930 1560 124.30 19570

1.65 0.75 2.2 ÎI15 l i

lt.25

I4.’* Column, 2 " Raschig Rings

:

6g 64

I

Series ”C” CD CE CF CG CH Cl CJ CK CM

Break Point in. FbU 02

ij.” Column, Spray Operation

86

Series BE BP BG BH BI BJ BE BL BM

Water Rate Oil Rate C;#/hr.ft.^ D;#/hr.ftr

66

I i

88

62 62

14600 17300 12070

20000 9220 22600 6150 25600

0

5860 4240 7490 2920

4.25

ill

i.-r 1585 11790 ,990 16210

2.35 6.3

2.0

4 " Column, 1 l/ 2 “ Raschig Rings 7950 5600 14600 16730 18900 21000 12620 10380 0

Continued

6540 8300 3810 2600 2210 1500

S o 12860

it:r

4..1 2.9

ill 4-45

3.4.

xvi

Table 2 (Continued) Run No.

tD

t c

Series itgn ED EE EE EG EH El EJ EE

87 88 96 96 100 98 96 96

73

100 82

79 79 76 94 94 Series

GA GB GC

73 74 73 Series

HE HC HE HP H G H H

HI

82

75 77 73 75 75 89

10920

74

72 70 70

6960 5830 4710 34.60 194.0

75 73

74

74 74 75 74 72 69 70 71 f fQ .fl

71 71 72

ftH » »

66 61 66

64 64 67 —

D

Break foint

4 " Column, 1 " Raschig Rings 9480 §170

Series fipfi PA PB PC FD PE PP PG PH

c

798 1035 1330 1586 2240 2520 3050 4800

1 .6 1.9

2 .0 2 .3

2.25 1.9 2.0 2.6

4 " Column, 3/ 4 " Raschig Rings 3460 4710

9480 194-0

1795 1025 725 513 263 142 2320

1230

2 8 0 0

5830 6960 8170

1.0 1.2 0.4 1.0 0.45

0 .4 5 1.6 1.5

4» Column, 1/2" Raschig Rings IQkO

3460 615

41s 118 655

0.4 1.0

1.65

6" Column, Spray Operation 30800 25700 21000 164.60 11950 7500 0

Continued

4610 6040 68 d O 8260 10160 11940 16100

2.0

2 .65 3 .85 2.50 2.95

4 .5 6.95

xvii

Table 2 (Continued) Run No.

tD

tc

Series ifjii JA JB JC JD JE JP JG JH JI

99

89 84 80 80 80

74 72 81

70 60 60 60

65 66 63 62 ——

Series *E" KB EC ED EE EP EG EH El EJ

95 94 91 06 81

77 75 78 92

60

64 59 $9 60 63 63 65

Series "L"

LB LC LD LE LP LG LH

92

I

89

68 66 69

71 70 70

99 99 99 96

b

Break Point

6” Column, 2 ” Raschig Rings 25700 22800 19900 17020 14200 11380 8620 5860 0

1140 1925 2360 3150

1 .5 1 .7

4410

3.2 3.5 3.5

5460 6820 8300 13500

2.0

2.45

3 .9 5.ë

6" Column, 1 1/2” Raschig Rings 21000 18730 16450 14200 11950 9720 7520 5300

0

1025

3.1

985 1780

2280 3060 3960

5080 6100 9820

3.3 3 .4 3 .8

4.9 4.25 5.0 6.4

6” Column, 1 " Raschig Rings 10650 9100 7650 6190 4750 3100

0

93

610

1.2

845 1175 1618 2040 2640 6200

I f

2.7 1.5

2.3

6" Column, 3/^-” Raschig Rings

Series MA MB MC m ME MP

C

72 70 70 70 70

7900

6680 5450 4220 2830

0 Continued

1% 1080 1445

1 .5 1.65

2010

1.65

4790

3.75

xvili

Table 2 (Continued) Run No*

tD

tc

Series "N" NA NB NC ND NE NG

85

10k

94 89 81 100

75 77 75 75 75

Series ftpir PB PC PD PE PP PG PH

86

87 95 91 94

80 81

79

80

82

100

mm ■»

90

78

Series "4" QA QB QC QD QE QP QG

86 86 86 86

78 78 78 80

89

81

89

79

101 Series "R"

RB RC RD RE

88 85 87 87

85 85 85

Series *‘s ” SA SB SC 8D SE SP SG

94 99 103 103 102

99 97

81

79 79 79 79 77 76

C

D

Break Point

6» Column, 1/2” Raschig Rings 1590 890

2160 2680 3200 0

455 998 280 125 86 1766

1.2 — — — — — —' —

2» Column, 1 " Raschig Rings 14250 11100 8000 5050 3250 0 16920

1350 1820 2580 4540 5360 10280 600

2.2 1.7

2.35 2.55 3.25

5 .0

0.8

2» Column, 3/ 4 ” Raschig Rings 14300 11100 8000 5050 3250 0 16920

1.7

880 1550 2720 3760

2 .7 3 .0

4790

5.0

9830 480

1.55

1.9

2« Column, 1/2” Raschig Rings 3250 2100 5050 0

640

2.2

935

1.05

300 2000

1.0 1.05

2” Column, Spray Operation 8000 14300 19400 24100 28700 33700 39100

11440 10240 9170 5590 3970 2840 1710

4.0 3.35 3.75 2.2

2.85 1.25 0.55

xlx

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