CONTACT PLATE FOR HEAT-MASS EXCHANGE APPARATUS

PLAQUE DE CONTACT POUR ECHANGEUR THERMIQUE

English Abstract

CONTACT PLATE FOR HEAT-MASS EXCHANGE
APPARATUS
ABSTRACT OF THE DISCLOSURE
The present invention relates to contact plates for heat-
-mass exchange apparatus and may be used in various branches
of industry and in production of polymeric materials. The
plate has a base provided with at least one perforation widen-
ing in one direction, its edge with its widening end contact-
ing the apparatus walls. With a plate having a plurality of
perforations the edges of the perforations disposed along the
periphery of the base contact the apparatus walls and the
edges of adjacent perforations contact each other, thus reduc-
ing the development of stagnant zones on the plate, decreasing
its hydraulic resistance and improving the efficiency of heat-
-mass exchange.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A contact plate for heat-mass exchange apparatus, com-
prising: a base fixed to the apparatus walls; at least one per-
foration provided in said base and widening at least in one di-
rection; the edge of said perforation contacting with its wid-
ening end the apparatus walls.
2. A contact plate for heat-mass exchange apparatus, com-
prising a base fixed to the apparatus walls; a plurality of
perforations provided in said plate and widening at least in
one direction; the edges of said perforations disposed along
the periphery of said base with their widening ends contacting
the apparatus walls; the edges of said perforations disposed
in said base and being adjacent relative to each other and to
the perforations disposed along the periphery contacting each
other.
3. A contact plate as claimed in claim 2, wherein said
edges of said perforations contact each other so that the zo-
nes of said base between adjacent perforations form ribs.

Description

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CONTACT PLATE FOR HEAT-M~SS EXCllANG~
APPARATUS
The present invention relates to heat mass exchange
apparatus and more particularly to contact plates of such appar-
atus and may be used in chemical, food, microbiological, phar-
moceutical and other industries. A contact plate may be most
successfully used in the production of polymeric materials.
Description of the Prior Art
At present solid contact plates having overflow pipes
are employed in the production of polymeric materials. In
carrying out the process of degassing aqueous polymer solutions
with the use of such plates it is necessary to provide continu-
ous mixing of the interacting phases of polymeric material and
live steam. For this purpose mechanical mixers are used. How-
ever, in service the apparatus equipped with mechanical mixers
for mixing polymeric material are extremely complicated, because
the polymeric material sticks gradually to the mixer blades and
to the apparatus walls, the latter has to be stopped periodi-
cally for cleaning.
It is also well known to provide a great number of
contact plates employed in various branches of industry (see,
for example British Patent No. 1,296,455, 1972, BOld 3/22), the
base of which is provided with one or a plurality of frusto-
;~ conical perforations, widening at least in one direction for
the passage of phases. Such plates are usually employed in
vertical columns, wherein technological process takes place in
a counter-current flow of the interacting phases. However, it
` is not practical to use such plates in the production of poly-
meric materials, because with the process taking place in a
3C counter-current flow of the lnteracting phases stagnant zones
are developed on the plate base between the perforations, where-
on polymer particles set~tle and, as a result, the perforations
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are clogged and the process is interrupted~
Summary of the Invention
The primary object oE the invention is to provide a
contact plate for a heat-mass exchange apparatus, on which the
possibility of development of stagnant zones will be precluded.
Another object of the invention is to improve the
efficiency of the contact plate by lowering the hydraulic resis-
tance of the plate and thereby reducing longitudinal mixing of
the c~ntacting phases.
Brief Description of the Drawings
The invention will now be described in greater detail
with reference to a preferred embodiment thereof, taken in con-
junction with the accompanying drawings, wherein:- ~
Fig. 1 is a diagrammatic view of a contact plate having ,
one perforation;
Fig. 2 is a diagrammatic view of a contact plate having
a plurality of perforations;
Fig. 3 is an enlarged partial top view of the contact ~-
plate as shown in Fig. 2;
Fig. 4 is a diagrammatic view of a contact plate
having a plurality of perforations widening at both ends;
Fig. 5 is a top view of the plate as shown in Flg. 4.
Detailed Description of the Invention ~-
The herein-proposed contact plate is mounted in a
column-type heat-mass exchange apparatus along its vertical
extent thereacross and separates its volume into sections.
;~ A contact plate comprises a base 1 (Fig. 1, 2 and 4)
which is provided with one perforation 2, as is shown in Fig. l,
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or with a plurality of perforations 3, as is shown in Fig.~2-4.
Due to their frusto-conical shape the perforations 2
(Fig. 1) or 3 (Fig. 2) are widened in one direction, or, as lS
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~ shown ~n Fig. 4 are widened in both dlrections, which is attained
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by making them in the shape of two frusto-cones connected at
constrictions 4~
In a preferred embodiment of a contact plate having
one perforation 2 (Fig. 1) its edge 5 with its upwardly widen-
ing end, that is, from the upper surface of the base, contacts
the apparatus walls 6; at the lower surface of the base edge 7
of the perforation 2 may be disposed as shown in Fig. 1 or may
contact the apparatus walls (not shown in the Figure).
In a preferred embodiment of a contact plate having
a plurality of perforations 3 (Fig. 2), upwardly widening, as
shown in Fig. 2, or upwardly and downwardly widening, as shown
in Fig. 4, edges 8 of the perforations 3 disposed along the
periphery contact with their widening ends the apparatus walls
6 and edges 9 of the adjacent perforations 3 (Fig. 3), the edges
8 of the perforations 3 contacting the apparatus walls only
with one of its widening ends. In this case the edges 9 of the
adjacent perforations 3 disposed in the base itself contact
each other, as sho~m in Fig. 3. As a result, zones 10 between
the perforations 3 have a small area on which polymeric material
practically does not settle, because in the counter-current
flow of the interacting phases settling particles are caught
by them, and do not upset the technological process taking
place in the apparatus.
The edges 9 (Fig. 4) of the adjacent perforations 3
may contact each other with their widening ends so that the
zones between these perforations form ribs 11 (Fig. 5). For
this purpose the larger base of the frusto-conical portion of
the perforation 3, instead of being round, is made in the form
of a square or of a rectangle, as shown in Fig. 5. In this
case the like sides of the square or of rectangle coincide and
as a result of this the zones of the base betweell the perfora-
tions 3 are presented by the ribs 11. The square or rectangular ~ ~
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snape of the perforations 3 disposed along the base periphery
and contacting -the apparatus walls take the shape of these walls,
as shown in Fig. 5, and the edges of the perforations contact
adjacent perforations along straight lines - the ribs 11.
In the process of operation of a column heat-mass
exchange apparatus provided with such contact plates in-teract-
ing phases pass through the perforations 2 (Fig. 1) or 3 (Figs.
2-5) in a counter-current flow. Thus, an intensive interaction
of the phases is accomplished not only over the contact plates
in the sections, but also in the perforations 2 and 3. During
this interaction process the settling of polymeric material on
the base zones 10 (Fig. 3) or on the ribs 11 (Fig. 5) does not
take place, because their area is small in comparison with the
diameters of these perforations even in their narrow portions,
' and all -the settling particles are carried away by the inter-
acting phases.
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