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Патент USA US2405593

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Aug. 23, 1946'. ~
F. L. MELVILL
_
2,405,593
PACKING FOR VAPOR AND LIQUID CONTACTINGAPPARATQS
Filed Feb; 4, 1944
o0wow.
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ATTORNEY
Patented Aug. 13, 1946
‘
~ 2,405,593
UNITED STATES‘ PATENT OFFICE
PACKING FOR VAPOR AND LIQUID
CONTACTING APPARATUS
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Francis L. MeIvilI, New York, N. Y.
Application: February 4, 1944, Serial No. 521,049
‘Z Claims.
1,
(01. 261—94')
2
This invention. relates to- packing for gas or
or cries-crossed to form a. series oiintersections
or points of. contact which are regularly and
vapor and liquid contacting, apparatus. Although
the invention has a wide range of utility, it- is
particularly useful in connection with contact
symmetrically‘ arranged in vertical staggered
rows; and which de?ne.- liquid mixing and dis
tributing zones. The streams of. liquid ?owing
ing apparatus employed for the absorption,
cooling, drying, cleansing or-h-umidifying of. gases,
for the evaporation, cooling or heating of liq
uids, or for reaction purposes. Such'apparatus
may, for example, take the form of fractionating
towers, scrubbers, cooling towers and the like.
In such apparatus, a. packing is usually employed
for e?ecting intimate contactv between the .de
scending liquid and the ascending gas or vapor.
As used herein and in the claims, the term
“gas” includes vapor within its scope.
The invention provides» a novel. packing for
gas and liquid contacting apparatus which; avoids
the presence of unequal. gas or liquid passages
along. ‘the downwardly converging packing. eleé
ments- respectively merge and intermix at the
intersections of these elements, and. then subdi
vide into corresponding streams as they ?ow
, along the elements. diverging from saidiinter
sections. The liquid. ?owing down a singleel'e
ment of the. packing isregularly mixed. with liq.
uid ?owing down an adjacent element. ofv the
packing, and the resulting mixtureis thenre
distributed among elements diverging from. ‘the
mixing zone. each; of these. redistributed streams
carrying substantially the same aliquot part of
the liquid reaching. the mixing. zone.- from. above.
and prevents channeling or segregation of the
The nature of the invention.
be. apparent
?owing gas in open spaces and of the liquid 20' ‘from the. following description when considered
along surface areas, with the result that at
in connection with the accompanying drawing
any cross-section of the packing at right angles
forming. a part thereof,.and inwhich: '
to the general direction of countercurrent ?ow
Fig. 1- is a fragmentary axial vertical section,
of the liquid. and gas, the. composition of. the
somewhat diagrammatic, oi a‘ gas and liquid; con
liquid. and gas .are- substantially uniform.
28 tacting' device containing a packing embodying
The invention also provides a new and im
the invention;
'
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proved packing of the general character de
scribed; which feeds: andv spreads out the liquid
Fig. 2 is a transverse section, somewhat dia
grammatic, of. the contacting device, taken. on
evenly in a thin ?lm- and in av regular predeter
mined symmetrical manner as it descends. in a
treating chamber, so that even. distribution of
the liquid throughout the ?ow area of the cham
her is aiiorded, which provides the- maximum of
effective (i. e., wetted) surface area per unitv
line 2-2 of. Fig. .1;
30
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Fig. 3' is a view in elevation of one of. the pack
ing elements: prior to assembly;
'
Fig. 4. is: a view in elevation. showmg a pair
of packing elements assembled to fijrman. inter
secting liquid mixing and. distributing zone; '
of packing space, o?ers aminimumof: resistance - 1
Fig. .5; is a. view in. elevation of. a portion of
to the passage of the ascending gas, andv a?ords
the packing of Figs. .1‘. and 2. but. shown. on a.
a maximum of intimacy of contact and interlarger scale; and
action between liquid and gas, so that equilibrium
Fig. 6 is a'horizontal section 'of- the packing.
between the ?uid in either phase immediately
taken on line. 6—6‘ oi Fig. 5.
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adjacent to the inter-face and the main bulk
Referringtoz Figs. 1 and 2 of theadrawi'ng. the
of the ?uid comprising the phase is rapidly
gas. and liquid: contacting device is shown com.
attained.
prising a- vertical cylindrical. column or tower
The invention further provides apackingoi the
l0. containing the packing ll of the invention.
general character described, which comprises a
The. gas to be: contacted is delivered tothe lower
series of simple, comparatively inexpensive. ele 45 portion‘. or the’ tower l0 below the packing U,
ments requiring little or noshaping, and which
and flows upwardly through’ the packing, while
can be easily and expeditiously assembled.
liquid. is; fed. to“ the uppenportio-n of the tower
In carrying out. the features of the invention,
above the packing, and ?ows downwardlythrough
packing elements of small cross-section. and de
the packing in thin. streamsandin intimatecon
sirably in the form of rods, wires or tubes, are 59 tact with the ascending gas in. a manner'to- be
arranged to form a network of. predetermined.
described. The liquid is desirably delivered. to
pattern, and to de?ne courses along which the
liquid. is directed in. the form of thinv exposed
the upper portion of the tower Ill and. over the
streams encircling the elements. The packing.
substantially evenly over the top of the packing
ll, so that the liquid is. distributed substane
elements arevdesirably straight and are. latticed
packing H insuchscattered form asto be. spread
2,405,593
tially uniformly throughout the packing at its
cal. The two layers 20 of elements 16 of each
upper end. For that purpose, the liquid may
be delivered over the packing H in spray form,
or may be delivered by a liquid feed device simi
lar to that shown and described in my copending
packing sheet H are interconnected to form a
sheet unit, as will be more fully set forth, and
are latticed as described to de?ne a series of
quadrilateral staggered meshes 22 large enough
to prevent capillary ?lming of the down ?owing
liquid across the meshes, but preferably as small
as possible having regard for the liquid gas load.
application Serial No. 536,306, ?led May 19, 1944,
to feed the liquid in predetermined equally
spaced tlunmstreams over the packing.
\
The packih
The adjoiningsections of-Zthe elements I16 form
‘51:5 shown occupying the‘centralj
‘ '
ing ‘the two upper; sides of each ineshi? are of
portion of "the towerlil,"'while the‘ diametrically
opposite side chordal sections 12 of the tower are m ,_ . equal length, and the adjoining sections of the
elements forming the two lower sides of each
left vacant or unpacked. A pair of partition '
.mesh are also of equal length, and are desirably
plates 13 on the straight or chordalsides respec-_
tively of the packing I !, prevent ?ow-into or out. _' of the same length as the two upper element
sections. The meshes 22 are advantageously in
of the packing through the sides. The unpacked.
the form of equilateral parallelograms, and are
spaces l2 of the tower I!) may be sealed either at ‘
‘speci?cally shown as square in shape. The
the bottom or the top in any .‘manner wellriknown ,
in the art to prevent by-pass ?ow through these
meshes 22_of each packing sheet I‘! are arranged
spaces. The clearance between the arcuate pe~
in vertical rows with the vertices l8 of the meshes
20 of each row in vertical alignment, and the meshes
of adjoining vertical rows medially staggered.
ripheral portions of the packing H and the cor
respondingjwall of the tower l0 may be sealed
bya'ny suitable means,‘ asi'for example by means
o’flaye'rs Hof glass wool. -
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.
f'As a feature of the invention, the packing ll
This construction lends symmetry to the arrange
ment, and serves-to assure a more uniform mix
ing and distribution of the liquid in its-downward
cot prises alseries of ‘slender elements l6 which 25 ?ow through the packing l l
The elements H5 in the two criss-crossed layers
may be in'the form of wires,‘ tubes,‘ ?at strips or.
20 of each packing sheet ll desirably are inter
the/like, and which are shown specifically, as solid
cylindrical. rods. These'packing elements 16 are
identical in transverse cross-sectional size and
shape,‘ ,and their surfaces are of such material
andj?ni‘shjasto be substantially-wetted by ithev
liquid undernorinal'operating conditions. For
connected at the intersections l8 ofv said ele
ment preferably by welds 23.
These welds 23
Y preferably are on the upper sides of the intersec
tions l8 to prevent irregularities at the bottom
of- each intersection l8 which would vbe undesir
able, since they might cause the liquid to flow
therefrom in the form of droplets or to be dis
sirably of material having the necessary finish‘
t'oaff'ord the required wetting properties... These 35 tributed unequally. This would adversely affect
the desired regularity in the distribution and flow
packing’ elements - 1Bv are" of ‘sufficient diameter
of the liquid as will be more apparent hereinafter.
so‘ that they will have ‘substantial rigidity.‘ For
that purpose, ‘the-packing elements 16 are de
example, packing" elements one-tenth of an ‘inch
inr'ydiameter will ‘be satisfactory, although'larger
It will be understood that any number of these
Welds 23 maybe-formed according to the overall
size of the packing sheets I‘! or the size of the‘
or?tsmaller sizes may "be desirable depending upon
packing elements.‘ For example, the welds 23 may
the circumstances of'use ofthe packing.
.
be formed at each intersection 18, or at spaced
Although the packing elements l6 are shown in
cylindrical'form, as far ascertain aspects of the
The lengths of the packing elements l6 vary
invention a'reiconcerne'd, they may be of any suit
ablelzsymmetrical cross-sectional shape. .For ex-. 45 according to the overall size of the packing sheets
I1, or the cross-sectional size‘ of the elements.
ample, the surface of‘ the elements'?i may be
For example, in the smaller packing sheets, the
nod-Yea; ?uted or l'otherwisetreat‘ed to form a
intervals.‘
regular pattern ‘thereon: ‘The grooves may ex
tend parallel to the longitudinaliaxis of the ele
ments l6,’ or may extend helically‘or in theform
of a thread. Such'surfac'e grooving of the ele-:
ments" it maybe provided to increase the liquid
carryingca'pacity of; the rods. Also, instead, of
using single ‘rods-Wires or‘the like, as far as cer
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elements 16 may be made to extend integrally
from edge to’ edge of the sheet, while in the larger
packing ‘sheets, theelements, and especially the
longer ones, may consist of di?erent sections po
sitioned in axial abutting alignment. These axi
ally _aligned elements 16 may be'butt-welded to‘
gethenif desired.‘-
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tain aspectsof the ‘invention are concerned each 55 rl‘he packing sheets I‘! as described are sub
stantially identical as far as the size'and shape
of the packing elements It may consist of mul
tiple wires braided or helically twisted together,
or laid side by side;
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Y’
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of their meshes 22 and the diameter of their ele
ments 16 are concerned, and are arranged verti—
cally in lateral face to face contact with the ‘ele
The packing elements‘ iii are arranged to form
aplurality of-vertical units‘ or sheets IT in face 60 ments of alternate layers 20 running in the same‘
oblique direction, to form the composite packing
to‘falce contact, each comprising a series of ele
H. Thesepacking sheets I‘! desirably are so ar
inents criss-crossed-‘to'de?ne a plurality of liquid
ranged that the meshes 22 of one sheet are in
mixing and distri uting junction zones 18; In
horizontal registry with the meshes of the other
the speci?c‘ form'of the‘irivention shown, each
vertical packing sheet 11 comprises two inter» 65 sheets, ‘as shown in Figs.- 5 and'6. ', However, as
far as certain aspects ‘of, the invention‘ are con‘~
facing layers 2B of packing elements arranged in
cerned, the packing sheets H may be relatively
'c'rissicross fashion. ; The elements it‘ of one layer
2B-in'a5p'acking sheet I‘! are equally spaced and
displaced vertically, so that the meshes 22 of one
packing sheetv I‘! ‘are out of phase with the'meshes
arranged‘obliquely'in parallel-in one‘ vertical
plane, and the elements of‘ the other layer of the 70 of adjoining sheets. :For example, the meshes 22
of‘ alternate packing sheets rll' may be in hori-'
"sense sheetare spaced the same distance ‘apart
zontal registry, while‘the meshes of intervening
and ‘are similarly arranged obliquely’ in parallel
packing sheets maybe ‘in horizontal‘ registry but
displaced with'respect tofth‘e' ‘meshes ‘of
tionsireverseyto those ‘of the elements of, the ?rst 76 medially
the other sheets.‘ TInrthis‘latt‘er' arrangement‘, the
laye‘rs'but atthesame’inclination with the verti
iii-a vertic'aliplaneebiitj extend in oblique direc
5
vertices of the. meshes 22 of one packing sheet I‘!
would be disposed centrally with respect to the.
meshesof adjoining sheets.
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The packing sheets l1 may be interconnected
together, or may be relatively displaceable verti
cally. This latter arrangement may be preferred,
where for example, it is desirable to vibrate some
or the: sheets I]: edgewise with. respect to others
to promote turbulence‘ in the ?uid. ?ow or to pre»
vent-clogging of‘ the packing.
Inthe use of‘. the packing H, the liquid with.
which it is. desired to contact the ascending gases
is delivered to the top section of the packing as
described, and is: divided into; a number of pre
6
at any point in any plane at right- angles to the
general directi'onof ?ow. Maximum intimacy of‘
contact and maximum interaction.between-‘liquid
andgas is obtained, and; equilibrium is rapidly es
tablished between the material in either vapor
or liquid phase immediately adjacent to'theilnter
face: and the main bulk of the: material compris
ing‘the phase.
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Orr any cross-section of the packing H at right
10 angles to the, general direction of ?ow-oi the liq-r
uid and gasv the composition of‘ the gas; is sub
stantially the samev and the composition of the
liquid in its constituent streams- is substantially
thesame. The pressure drop of‘ the liquid pass
determined exposed. streams which flow obliquely 15 ing- through the packing Ill and the amount of
downwardly along the elements It in regular zig-r
liquid retained by the packing under normal op
zagcourses. The liquid ?owssubstantially evenly
erating conditions is comparatively low. A com
in: av series. of thin films over the. surfaces of the
paratively long path of travel of the liquid pass
packing elements: in a direction generally counter
ing through the packing H is provided so that
to the direction of flow of the gas. The maxi 20 retention of the liquid for a- period long enough
mum-of liquid? surface thereby is exposed to. the
to assure the necessary saturation or interaction
action of‘ the ascending gas. The liquid stream
with the gas is assured.
flowing down along a single element i=6 of the
Inasmuch as each of the elements extends in
packing ll merges‘ at a juncture l8. with the liq
a downwardly inclined: direction from the inner
uid stream ?owing down ‘an adjoining element.
, wall. of the tower l0, liquid which reaches the wall
At this. juncture t8’, the two streams are thor
by way of some of the elements will ?ow away
oughly intermixed, and the resulting mixture is
from the wall by way of other elements andIIthu-s
then subdivided and redistributed equally between
will. tend to retain the liquid. in the packing and
the elements diverging downwardly from the
prevent short circuiting. ?ow down the wall of
juncture. Each of these diverging elements con
thetower.
stitutes part of another pair of elements con
The velocity of the vapor v?owing upwardly
verging towards a juncture it, so that. the two.
through the packing: will‘ cause or tend tov cause
diverging distributed streams merge and inter
the liquid on the elements to assume a stream
mix with other adjoining streams, and then again
lined or tear drop. shape suchas would present
become subdivided. This process is repeated; so 35 the minimum resistance; to the ?ow of' vapors
that uniform mixing and distribution of the liq
and this, together with the surface effects which
uid in thin ?lms throughout the width oi'each
become pronouncedv with‘ thin films of liquid, will
packing sheet IT is assured. Also, since the pack
have the e?ect of distributing: the liquid over the
ing sheets I‘! are in lateral face to face contact,
surfaces. of the elements with a tendency for a
the liquid in one sheet is not only distributed and
major part ofthe liquid to flow down» the upper .
mixed substantially uniformly throughout the
paits of the-elements, the amount of‘ liquid so
width of‘ the sheet, but is also distributed and
?owing. increasing with. increased vapor ‘velocity.
intermixed with the liquid_ of adjoining packing
The effect of this is to insure the maximum ex
sheets. in this manner, substantially uniform
posure of the liquid to the' vapor and to facili
mixing and. distribution of the; liquid throughout
tate the mixing of the streams of liquid ‘at the
the entire horizontal. section of the packing “ is
juncture points 18:.
assured.
'
Since many- changes can be made in the apé
If the flow along the various elements It is
paratus disclosed, and many apparently widely
not. equal, the degree of inequality will tend to
different embodiments: of the invention can be
become‘prog-ressively reduced due to the fact that ,, made without departing from the‘ scope of the
each element will divide, or will tend to divide,
claims, it is intended that all matter contained
the whole of the liquid reaching a given mixing
in the above description or shown in’ the accom
zone [8 equally with‘ its element partner in that
panying drawing shall be interpreted as illus
zone. This is. particularly important in the up
trative-and notin a limiting sense.
per section of the packing I I, where the liquid
What is claimed is:
feed may not be deposited uniformly over the top
11. In gas and liquid contacting apparatus com
of the packing. By the equalizing process de
prising a column with a liquid inlet and a gas
scribed, the distribution of the liquid under these
outlet in the upper part thereof and a gas inlet
conditions will become uniform in the upper sec
and liquid outlet in the lower part thereof, said
tion of the packing H. Uniform distribution of
column being adapted for countercurrent ?ow, a
the liquid when once attained near the top of the
packing for the column comprising a plurality
packing I I will persist to-thebottom thereof. The
of vertically extending sheets disposed in the path
gas ?ows generally upwardly and tortuously
of flow of said‘ gas through the column, each sheet
through the meshes 22‘ countercurrent to the liq
comprising straight slender elements which are
uid and contacts the exposed thin liquid ?lms
vertically inclined and in contact, the elements
on the packing elements IS. The disposition of
being arranged to form a plurality of mixing zones
the meshes 2-2‘ insures the necessary turbulence ' comprising a series of intersections in spaced
to secure thorough mixing, thus avoiding the loss
horizontal and spaced vertical rows, said rows
of efhciency which results when gas at the liquid
and‘ said intersections being closely spaced; the
gas interface is not mixed as rapidly as possible ' distance therebetween being sui?cient' to form
with the main bulk of the gas, and when other
spaces between the intersections large enough to
purely local conditions within the packing ll
prevent capillary ?lming of the liquid there
tend to vary the composition of the gas across
across.
any section of the tower Ill. The velocity of
2. In gas and liquid contacting apparatus com
the gas upwardly will be substantially the same 75 prising a column with a liquid inlet and a gas
2,405,593.
outlet‘ in the upper part thereof and a gas inlet
and‘ liquid outlet in the lower part thereof, said
column being adapted for countercurrent ?ow, a
packing for the column comprising a plurality of
vertically extending sheets disposed in face to
face contact and in the path of flow of said ‘gas
through the column, each sheet comprising
straight slender elements which are vertically’
inclined and in contact, the elements being ar
ranged to form a plurality of mixing zones com
prising a series of intersections in spaced hori
zontal and spaced vertical rows, said rows and
said intersections being closely spaced, the dis
tance therebetween being su?icient to form spaces
between the intersections large enough to prevent
capillary ?lming of the liquid thereacross.
V
3. In gas and liquid contacting apparatus com
prising a column with a liquid inlet and a gas out
let-in the upper part thereof and a gas inlet and
liquid outlet in the lower partthereof, said col
umn being adapted for countercurrent ?ow, a
packing for the column comprising a plurality of
‘ 5. In gas and liquid contacting apparatus com~~
prising a column with a liquid inlet and ages
outlet in the upper part thereof and ages inlet
and liquid outlet in the lower part thereof, said
column being adapted for countercurrent ?ow, a
packing for the column comprising a plurality of .
vertically extending sheets disposed in face to"
face contact and in the path of ?ow of said gas
through the column, each sheet comprising a
fabric of straight slender packing elements which
are vertically inclined and are regularly arranged
in accordance with a predetermined pattern to
form a network provided with a plurality of ver-i
tically extending zig-zag sections having uniform
alternate turns, and de?ning regular predeter
mined flow paths along which the liquid is adapt
ed to ?ow in de?nite streams respectively, these‘
sections being joined at staggered intervals to‘.
de?ne mixing zones where the streams merge and;
then subdivide as they descend, said elements be
ing so arranged that the mixing zones are closely:
spaced, the vdistance therebetween being suf?-.
cient to form meshes of a size to-prevent capil
vertically extending sheets disposed in face to
lary ?lming of the liquid thereacross.
face contact and in the path of flow of saidgas
through the column, each sheet comprising a net 25 6. In gas and liquid contacting apparatus com-.
work of straight slender elements which are ver
prising a column with a liquid inlet and a gas.
outlet in the upper part thereof and a gas inlet
and liquid outlet in the lower part thereof, said
column being adapted for countercurrent flow, a
meshes, each having diagonally opposed junction
corners substantially vertically aligned and de 30 packing for the column comprising a plurality
of vertically extending sheets disposed in face to
?ning liquid mixing and distributing zones re
face contact and in the. path of ?ow of said gas
spectively, the elements bounding each of said
through the column, each sheet comprising two
meshes diverging obliquely downwardly in pairs
or more criss-cross layers of slender packing ele-_
from the upper junction corner of said latter
mesh at substantially equal angles with the ver 85 ments of predetermined shape which are vertical-r
1y inclined, the elements of each layer extend
tical, and converging towards the lower junction
ing obliquely in the same general direction, and
corner of said last-mentioned‘ mesh at substan
. the elements of adjoininglayers extending ob
tially the-same angle with respect to the verti
liquely in transverse directions to form a series
cal, said elements being so arranged that the mix
ing and distributing zones are closely spaced, the 40 of liquid mixing and distributing intersection
zones, at least some of said elements being in
distance therebetween being su?icient to form
contact at said zones, said elements beingso ar
meshes of a size to prevent capillary ?lming of
ranged that the liquid mixing and distributing
the liquid thereacross.
V
intersection zones are closely spaced, the distance
4. In gas and liquid contacting apparatus com
prising a column with a liquid inlet and a gas 45 therebetween being sufficient to form meshes of
a size to prevent capillary ?lming of the liquid
outlet in the upper part thereof and a gas in-v
let and liquid outlet in the lower part thereof,
7. In gas and liquid contacting apparatus com
said column being adapted for countercurrent
prising a column with a liquid inlet‘ and a gas
flow, a packing for the column comprising a plu
outlet in the upper part thereof and a gas inlet
rality of vertically extending sheets disposed in
and liquid outlet in the lower part thereof, said
face vvto face contact and in the path of flow of
column being adapted for countercurrent ?ow,
said gas through the colunm, each sheet com—
a packing for the column comprising a plurality,
prising a network of obliquely extending slender
of vertically extending sheets disposed in face
elements which are vertically. inclined and are
to face contact and in the path of flow of said
regularly shaped and regularly criss-crossed to
gas through the column, each sheet comprising a
form de?nite vertical rows of equilateral quad
plurality of straight elements which are verti
rilateral, meshes of substantially the same size
cally inclined and are regularly arranged to form
and ‘shape, having diagonally opposite vertices
a series of intersections de?ning liquid mixing
in substantially vertical alignment, the meshes
‘ and distributing zones, at least some of the inter-_
of one vertical row being staggered with re
secting elements being interconnected by welds
spect to the meshes of the adjoining vertical
formed on the upper portions of the intersec-~
row, and arranged in lattice relationship there
tions, while the lower, portionsof the intersections‘
with to de?ne a series of junction zones towards
are‘ free of welds, said elements being so arranged
which the elements converge in pairs obliquely
downwardly and from which the elements diverge ,- that the intersections are closely spaced, the dis
tance therebetween being su?icient to form
in pairs obliquely downwardly, at least some of
tically inclined and are regularly arranged and
in contact to form de?nite rows of quadrilateral
thereacross.
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meshes of a size to prevent?capillary ?lming of
said elements being in contact at the junction
the liquid thereacross.
zones, said elements being so arranged that the
junction zones are closely spaced, the distance
FRANCIS L. MsLvnL.
therebetween being sufficient to form meshes of a 70
size to prevent capillary ?lming of the liquid
thereacross.
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