Note: Descriptions are shown in the official language in which they were submitted.
1~2~3395
The present invention relates to a process for direct
mass o~ heat exchange~ The present invention also relates to
a device for use in the Process~
Various types of i-nternal column structures, that
operate according to different principles or are constructed as
a result of production considerations, are used for direct mass
or heat exchange. For reasons of improved classification, these
internal column structures are divided into groups. Thus, a
distinction is made between the plate and packed columns as well
as between spray and sprin~ler columns, and mechanically powered
rotating and pulsing columns. Recently, column packings have
grown more numerous. Unavoidably, all internal column structures
have certain disadvantages in addition to their particular
advantages so that their use is governed by the type of applica-
tion. Thus, the objective must be to find a universally usable
internal column structure that takes scientific knowledge of
material, heat and pulse exchange into consideration, as well as
the economic production of all the column sizes and materials
re~uired by industry.
In order to be able to use this internal column structure
for all column sizes, it must consist of individual elements of
identical dimensions, that can be combined according to each parti-
cular column diameter iand height. In addition, the design must
be self-supporting to permit the use of the device with any desired
material. Economical series production and storage will be ensured
by the above-described design features. ~owever, the division of
the total column volume must be such as to ensure that areas of
equal size are formed, the configuration of which ensures the
maximum mass, heat and ~ulse exchan~e,
-- 1 --
llZ~)395
In order to achieve a minimum specific column volume,
B during ma~ r~ /or heat exchange the gases or vapours, or
liquid or solid material particles must be passed through the
column at different concentrations and/or temperatures as fast
as possible, counter to the flow and be brought into contact with
each other so that the maximum material, heat or pulse exchange
results. In actual practice, in the case of most internal column
structures the counterflow cannot be assured in the area of each
individual column cross-section, and is disrupted to an ever-
increasing degree as the column diameter increases. In addition,as the speeds of the material streams that are moving in counter-
flow increase, remixing can easily occur throughout the whole
height of the column, thereby reducing throughput capacity. In
the case of plate columns, when the liquid is passed across the
plates, only a cross flow is possible, so that plate divisions
with additional drain-off possibilities are necessary in the
event of large column diameters. Each size of column thus
requires a different design. Not all materials are suitable for
plate columns and so, for example, the most corrosion resistant
and favourably priced ceramic materials and various plastics
cannot be used for them.
~ lthough packed columns entail the advantages of econ-
omical production and the possibility of using all materials, as
well as the fact that columns of all diameters can be used, the
liquid distribution within the column is disrupted so badly
because of the random filling and the concomitant various spaces
that remain that not only are the localized quantity ratios of
the material streams different, but counterflow cannot be main-
tained across the whole cross-section of the column (maldistri-
bution). For this reason very large exchange columns cannot beoperated successfully with random-filling.
It is also understandable in sprinkler columns without
-- 2
llZ()395
internal structures tha~ restrict the maintenance of the counter-
flow between the phases is impossible because of the remixing
that cannot be avoided because of turbulence. Columns with
dynamic internal structures are excluded from these considera-
tions because of economic reasons.
Finally, only in spray towers (film towers) and with
ordered packing is it possible to achieve a precise counterflow
within the column by virtue of the regular division of the
column areas. For these reasons this new type of internal
column structure is being used more and more in high-performance
columns, provided that excessive material or production costs do
not prejudice the economics use of the internal column struc-
tures. However, even with these regular internal column struc-
tures a special problem is the even distribution of liquid in
the relatively large number of vertical column spaces. The
quantity ratios of the material streams in exchange is disrupted
by a more or less unavoidable irregular supply of liquid to the
individual spaces, and this results in a reduction of the selec-
tive capacity of the overall column.
To a very great extent these difficulties and disad-
vantages have been eliminated by the configuration of the column
described in DT-PS No. 1,268,596, which has internal structures
that are arranged regularly in layers, by the fact that pris-
matic hollow bodies that are constricted at the middle and open
in the direction of flow are arranged in relation to one another
so that a number of individual streams through the hollow bGdies
can mix with one another across the whole column cross-section in
a common mantle space while forming two separate systems. In
given separation operations the liquid quantity/column area can
be increased by increasing the throughput capacity and thereby
reducing the specific column area, whereby the liquid supply to
the individual channels will be more even. In the sprinkler
112~)39~
columns and the column packings according to DT-PS No. 1,268,596
the throughput capacity is, however, limited by the fact that in
each column cross-section the liquid must run off through the
same openings through which the gases or vapours are moving
counter to the flow. Therefore, at relatively high speeds a
counterflow is no longer possible in the column since there are
liquid buildups and liquid backflow in the column packing. In
addition, the mixing of the individual streams in the mantle
area of a column cross-section is more or less restricted to the
gas or vapour streams, since the liquid films that are running
off the vertical or inclined walls of the packing remain in the
individual vertical channels and are not newly distributed. The
necessary concentration equaliziation can thus take place only by
a not completely attainable equal liquid supply only in the gas
or vapour phase.
It has now been found however that the counterflow can
also be maintained in a column at very high gas or vapour speeds
for achieving a maximum material, heat and pulse exchange, and
thereby in the individual vertical channels when liquid has
accumulated if the gas or vapour, or liquid that is passed in
counterflow flows not through the liquid layers that have accumu-
lated at the constrictions of the vertical channels but through
the side openings in the channel walls and into the adjacent
mixing chambers. This leads to an alternating flow from the
mixing chambers of one vertical channel to the mixing chambers
that surround it to the sides, and vice versa, whereby an unavoid-
ably repeated lateral mixing from mixing chamber to mixing chamber
and, thereby, a concentration equalisation of all the vertical
streams takes place across the whole column cross-section. This
facilitates the redistribution of the unequal quantities of
liquid that are supplied to the individual channels, in that the
liquid film draining off the channel walls must drop from their
~2l)395
side openings, thereby getting into the gas or vapour, or liquid,
streams that flow in alternating fashion from mixing chamber to
mixing chamber, in which connection the walls of the mixing cham-
bers serve as impact surfaces for the droplet separation and as
material exchange surfaces.
According to the present invention there is provided a
process for bringing two streams of material into contact for
direct mass or heat exchange, wherein said streams are passed in
counterflow through a column having mixing chambers defined by
prismatic hollow bodies each having a central constriction, one
of said streams entering and leaving said mixing chambers through
inlets and outlets formed by said central constrictions, and the
other of said streams entering and leaving said mixing chambers
independently of said one stream through separate openings formed
therein.
The present invention thus provides a device for effect-
ing the aforesaid process according to the present invention in
which every mixing chamber has additional openings both for the
ingress and for the egress of the gases or vapours, or liquids,
that are passed through the column, in addition to the liquid
ingress and egress openings.
The present invention will be further illustrated by
way of the accompanying drawings in which:
Figure l is a schematic representation of a device
according to one embodiment of the present invention;
Figure 2 is a detail of the device of Figure l; and
Figure 3 is a section taken along the line a-b in
Figure l.
Referring to the accompanying drawings and particularly
Figure l, the vertical stream channel ll is constricted above
and below at the locations 12 and 13, so that the liquids flow-
~ 5 -
lilZ~)395
ing from top to bottom will accumulate at the locations 12 and
13 as the result of the pressure loss of the gas or liquid
streams that are moving in counterflow. One embodiment of the
configuration of the locations 12 and 13 can be seen in Figure
2.
The gas or vapour, or liquid stream entering the verti-
cal flow channel 11 through the openings 14 that are arranged so
as to be separate from the liquid ingress and egress points 12
and 13 can leave the vertical flow channel 11 once again through
the openings 15 after it has been mixed with the liquid and
once again separated from it. The separation of the liquid and
the vapour is made possible by the impact effect on the walls
of the mixing chamber. This also makes it possible to avoid the
fact that the gas or vapour, or liquid, stream has to flow
through the liquid that has accumulated at the run-off points 12
and 13, and there~y undergo a corresponding pressure loss. The
openings 14 of a ~ertical flow channel 11, like the openings lS
of the same flow channel 11, are larger than the liquid run-off
openings 12 or 13. The pressure loss of the gas or vapour, or
liqu..d, flowing from top to bottom is thereby smaller than the
liquid head at the ingress and egress points 12 and 13 of the
liquid that is flowing through the column. By virtue of this
concept of the invention, of the vapour separated from the liquid
feed in the mixing chamber 11, the throughput capacity of the
column is not limited by the accumulation of liquid that has
flowed through, as is the case, for example, with column fillings
or duel-flow systems.
Referring to Figure 2 and Figure 3, a liquid supply
that is separate from the vapour is ensured by a liquid run-off
pipe 16 with a liquid closure 17. In addition, the quantity
of liquid that has built up as a result of the pressure loss of
the counterflow runs off through the side openings 19 onto the
llZU395
outer surfaces 20 of the triangular hollow body 18. Especially
in the case of high throughput capacities, this leads to repeated
redistribution of the liquid that runs off and is sprayed through
the counterflow in the flow channels 11 that are arranged in
parallel, whereupon the quantities of liquid that are supplied
unequally to the vertical channels 11 are equalized over the
column cross-section.
The hydrostatic liquid lock can also be achieved by a
suitable configuration of the run-off points 12, 13 in that the
free cross-section 12, 13 is smaller than the side vapour open-
ings 14, 15.
B As can be seen from Fig. 3, the openings~ and corres-
pondingly the openings 14 of Figure 1 of the channel 11 that are
below are formed by triangular hollow bodies 18 that are placed
one on top of the other, in such a manner that the faces of the
triangular hollow bodies 18 are concave or convex. When the tri-
angular hollow bodies are placed one on top of the other, this
forms the openings 14, 15 for the vertical gas or vapour, or
liquid, streams that are directed from bottom to top. Several
vertical channels 11 are formed next to each other, and connected
to each other through the openings 14 and 15 of the concave or
convex curved triangle sides, by the familiar triangular arrange-
ment of the triangular hollow bodies 18 that are curved either con-
cavely or convexly and arranged in layers next to each other and
stood Gn gaps over each other. For the sake of completeness it
is mentioned that in special cases the hollow bodies 18 may be
made of catalytic material or coated with catalytic material.
