US2310829A - Process of and apparatus for degasifying liquids and washing gases - Google Patents

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R. BECKER 2,310,829 PROCESS OF AND APPARATUS FOR DEGASIFYING LIQUIDS AND WASHING GASES;

Filed Aug. 6. 1940 INVENTOR RUDOLF BECKER RNEY rectification. degasification of liquids by counter-currentlying to the invention thereto,

atented Feb. 9, 1943 H Eff A maze PROCESS OF AND A a LlQS AND TUS FOR DEGAS- WASHING GASES lltudoli Becker, Munich-Solln, Germany: vested in perty Custodian In Germany August 17, 1939 5 Claims. (01. 261-413) to a process of and apfor washing This invention relates paratus for degasifying liquids and gases.

Gas washing as well as the degasification of liquids is generally carried out by permitting the liquid to flow over individual trays in a wash column against the flow of the'gas, whereby gas and liquid are brought into intimate contact and attain a state of substantial equilibrium with one another. When iacedby this problem, which is very similar to rectification, it appears obviously advisable to utilize those apparatus arrangements which have been proven successful in the field of rectification.

In so far as this relates to columns with simple insets or filler bodies, it is possible to utilize such apparatus as washers or degasification towers without major construction alterations.

However, in attempting to utilize particularly eficient rectification trays, such as circular or annulartrays, for washing gases with liquids, for example, dimculties have been encountered. chiefly due to the fact that in gas washing appreciably more liquid is employed compared to the gas volume throughput than is employed in The same conditions exist in the conducted gas.

If, however, a circular tray column of the known type is operated with a large volume of liquid, the pressure drop especially through the individualtrays rises very appreciably because the high liquid throughput results in very large liquid cross-sections and correspondingly high liquid levels. Such high liquid levels however cannot be reduced by increasing the velocity of flow because, due to the continuous changes in direction undergone by the liquid, the centrifugal force an unequal distribution of the liquid over the Due to the large pressure dr "through the individual trays, it is naturally impossible to construct wash-columns of this type with a greater number of trays. However, according to the invention, it is still possible to apply to gas washing the circular tray principle used with great success in rectification, namely. the maintenance of a concentration-gradient within each individual tray. It. has been found that the abovementioned difliculties can be eliminated by interchanging the paths followed by the liquid or gas in the known circular tray. Accordthe preferably finely divided liquid flows vertically downwards through perforations of the trays while the gas is conducted in cross-current thereto in a circular path over the individual'trays.

The formation of a concentration-gradient within each tray, which improves the efficiency of the column in the'known manner, is favored by the fact that the flow of the gas over the individual trays is effected always in the same way for example, always clockwise or always counter-clockwise in a substantially helical path.

Thus a principle object of the invention is to provide a method ficient gas and liquid contact providing the advantages of annular rectifying trays for gas washing and for degasification of liquids. The above. and other objects of. the invention will become evident fromthe following description in connection with the accompanying drawing which is a perspective view of a portion of an at too high a velocity would cause exemplary washing tower with a part broken away to illustrate the internal arrangement.

An operating example of the process accord- 7 ing to the invention will be described with the aid of the illustration. The drawing shows a section including -four trays of the newly developed wash column with a portion of the shell 8 broken away. IIhe trays consist of perforated plates it provided with narrow holes or slits Ii, said plates being inserted between the outer cylindrical casing 8 and aninner axially disposed displacement or filler body 9 and supporting a radial separating wall or partition M which entirely closes off each circular chamber at a point adjacent a tray to the next higher tray. Each wall it ex: tends through and above the next higher tray sufficiently to'form a barrieror dami2 so that the liquid is dammed up on the tray and forced to flow down through the holes or slits H in *the tray. The separating walls M are so staggered on consecutive trays it that gas can flow through the remaining sector or opening 15 in the tray between walls M and barriers i2. The

- dammed up height of liquid on each periorated plate is thereby dependent upon the volume of liquid throughput. Nevertheless, it is possible for the liquid throughput to fluctuate extensively without disturbing the functioning of the column due to the fact that the volume flowing downward through the holes H of each per forated plate increases with the growing hydrostatic pressure of the liquid volume on the tray. The liquid trickles through II in the perforated I plate in, a finely sdivided state to the next tray,

whereby it passes through and apparatus for effecting efgas passage i5 through the the holes or slits Y gas is limited by the partition id in such a way that the gas is guided in a circle and in a clockwise direction over each perforated tray and after flowing around the chamber above one tray, it enters into the next higher chamber through the opening l5 cut in the next higher perforated plate and flows through said higher chamber in the same circular direction. By conducting the gas and liquid in cross-section fashion, and

causing the liquid to pass through successive revolutions of the gas, an intimate contact between liquid and vapor is attained.

According to a further thought of the invention, a number of radial partitions may be provided on the perforatedplates, the height of such partitions being so measured that they prevent an intermixing of the liquid on the perforated plate in a peripheral direction, but do not limit the flow of the gas. Such partitions confine the -ing out gas washing under pressure, whereby appreciable savings in material are possible due dimensions of the column because of the much greater liquid and gas contact emciency. A further advantage of the new process consists therein that the number of wash trays required is very low; furthermore, the pressure drop between the ends of the column is incomparably smaller than with the heretofore known forms of constructio What is claimed is:v

1. A process for degasifying a liquid or for washing gas with a liquid which comprises feed; ing the liquid into the upper portion of a washing column conducting the gas upwardly through said column in a succession of substantially annular paths and always in the same direction of revolution: causing all the liquid fed to the column to flow vertically downward through the column across said succession o1 paths and in substantially parallel finely divided streams whereby the movement of all liquid in the column is transversely across the paths'of gas flow; and'eflecting substantially uniform distribution of said liquid streams throughout each of said substantially annular paths.

liquid and a ing; an inner axial member; a series of annular perforated trays forming annular chambers with said outer casing andvsaid member; apartition extending across each annular chamber and Joining consecutive trays: said partitions being disposed in staggered relation to each other; each tray being provided with a gas passage opening therethrough, each such gas passage opening being adjacent to and on the same corresponding side of the respective partition across the chamber above the tray having such opening; and at least one darn extending across each annular tray for maintaining a desired maximum depth of liquid on each tray; 7 q

3. Apparatus as claimed in claim 2 in which each of said perforated annular trays is provided with a series of peripherally spaced radial barrier walls of a height sunicient to prevent substantial intermixing of the liquid on the tray but of insumcient height to substantially interfere with the flow of the gas.

4. Apparatus for effecting contact between a gas which comprises an outer casing; an inner axial'member; a series of annular perforated trays forming annular chambers with said outer casing and said inner member; a partition extending across each and joining consecutive trays; each of said partitions being offset with respect to each next lower partition by approximately the same discolumn, each of said partitions extending above the tray next above it for a distance suflicient to form a dam, each of said trays having a gas passagetherethrough located between the dam formed by the next lower partition and the partition next above said tray, and the height of each dam being sufiicient to retain liquid on the corresponding tray to a desired maximum height and cause such liquid to flow downwardly through the perforations in such tray.

5. Apparatus for effecting contact between a liquid and a gas which comprises a washing col- 2. Apparatus for effecting contact between a umn having therein contact means including a series 01' annular perforated trays, constructed and arranged for conducting a gas upwardly through said column in a toconfine the flow of all

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