CA1130194A - Contact plate for heat-mass exchange apparatus - Google Patents

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.

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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9.~4 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, : ::
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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Claims (3)

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.