DE2162280A1 - Liquid-gas contact device - Google Patents

Description

The invention relates to liquid-gas contactors.

I- *

The earlier GB-PS 757 1 ^ 9 and 1 O89 378 of the applicant are described a liquid-gas-KPntaktvorrichtung i-iit a housing, a .In this arranged liquid distributor and a contact plate bearing rotor in an annular contact zone radially outside of the liquid distributor, the contact plates essentially are arranged in planes that are parallel to the rotor axis stand and channels for gas and liquid flowing in countercurrent between the 'radially inner periphery and the radially outward. lying periphery of the annular contact zone. In particular, the invention relates to the arrangement and shape of the therein Device used contact plates.

_{r.-_} _ contact device of this kind can in various chemical • ^■: -J / and physical methods are used, a liquid - ■; yV ^v with a Gas'oder a gas with a liquid to be treated, for example, to elicit specific chemical reactions or the .. · '. . Elimination of certain components from gas mixtures by absorption or from liquid mixtures by dissorption, or also for the elimination of particulate oils from a gas. So far, one has without reckoning on dos Ziol dor B ^o h £ tndlung: -, fingenoimncn, last the action

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BATH ORIGINAL

The speed of the treatment depends largely on the size of the interface between dom gas and the liquid depends. For this reason it has been considered desirable to keep the liquid very thin Divide layers in order to obtain a large surface-to-volume ratio.

Investigations have now shown that in order to achieve a good effect, the thin liquid layers from the ones given below Reasons should be arranged in a very specific way.

1) Thin layers of liquid often tend to be in proportion Split fast flowing partial flows so that they represent a smaller surface compared to the gas. At the Operation of a contact device described above, in which the liquid along a surface of a plate of a radially flows inside to a radially outside edge, the flow rate of the liquid often increases slowly, which is due, among other things, to the increasing centrifugal force due to the greater distance from the rotor axis. Even if here on the inside of the surface of the contact plate an uninterrupted

forms a broken liquid layer, it often happens that this layer divides and under the effect of surface tension, The greater centrifugal force and the poor adhesion to the plate pulls together and a few, independent liquid flows forms, which have the shape of relatively thick, uneven currents. In such a case, parts of the gas over considerable distances between the contact plates flow away without getting in close with the surface of the liquid To get in touch. In addition, there is also the relationship between the surface and volume in such flows is obviously small.

2) Even if the layers of the liquid are thin, the movement of the liquid is immediately at the surface of the contact plate not so that it results in a satisfactory shuffling of the

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Liquid is coming. This can be seen from the fact that the gradient the liquid velocity of a thin layer of liquid, raked at right angles to the surface of the contact plate approaches an asymptotic curve (compared to the surface of the contact plate; this indicates relatively little movement Progressively increasing liquid movement on the surface of the contact plate with increasing distance from this surface there.

3) It is now assumed that liquid coit droplets and in particular freshly formed droplets, have a high mass transport between gas and liquid, and that repeated formation of droplets should therefore be promoted by the disruptive effect of the gas on the surface of the liquid. Indeed it will the effect of the higher surface-to-volume ratio resulting from the formation of the droplets is further reduced for other reasons. For example, if the liquid consists of a solvent for a gas to be removed from a gas mixture, the Liquid on the surface of the droplet quickly becomes saturated, while the liquid within the droplet continues to absorb gas can. Since the movement of liquid within the drop is only slight, a certain time passes before the entire volume of the drop is used for the absorption of gas. It is therefore it is desirable that the droplets converge quickly by hitting surfaces of the liquid or plate, whereupon further droplets are formed from part of the liquid layer.

k) As far as this is practically acceptable, the gas flow should be a turbulent flow in order to achieve optimal interaction or mixing of gas and liquid.

5) It is important that the counter flow contact between the

209828/095

Gas and the liquid takes place essentially along the entire length of all channels under the same favorable conditions.

6) In general, it is important that those exposed to the gas The surface of the liquid as it flows through the channels is changed often.

The invention aims to improve the effectiveness of a contact device of the type described above by increasing the contact area between liquid and gas,

7 R

by / d'xe * prevents the formation of partial flows of the liquid or is at least reduced.

It is also important to keep the fluid constant>

to move so that the surface layer of the liquid is quickly and continuously RETRY tert wherein a gleichmäs- · ■ SiGe distribution of gas and liquid in said channels is maintained.

It is also important to provide means by which the formation of droplets is promoted, which after a converge with each other and / or with the main flow of the liquid for a relatively short time. ·

Finally, it is worth noting to indicate funds through which the turbulence of the gas flow is increased by this repeatedly changes direction and / or speed.

The invention solves this problem by means of a liquid-gas contact device with a housing comprising a device distributing the liquid, a gas inlet, a gas outlet and a rotor carrying account plates, the contact plates are arranged in an annular zone that is radially outside

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BATH ORIGINAL

of the device which distributes the liquid, these contact plates being channels for gas and liquid flowing in counterflow between the radially inner and the radially outer periphery of the annular zone, the central planes adjacent panels are essentially parallel and the surface formation and arrangement of adjacent panels in this way is that the countercurrent conditions between liquid and gas are essentially the same in all channels and the pressure drop of the gas flowing through the channels is essentially the same in all channels, the plates having such a shaping and / or surface irregularities that have the interaction between liquid and gas is thereby reinforced in the channels.

In practice, the device according to the invention achieves a greater number of mass transfer units and / or a better separation of solid particles from a gas per unit length of the contact plates or, in other places, per Unit of the volume of the contact zone. This in turn means that the desired result of a gas / ash process can be achieved with a Ijasst achieve smaller heaters than before, and with a contact zone lighter construction. ;

The shaping of the plate is preferably achieved by deforming it around corrugations, corrugations or dimples or to produce any combination of these. The irregularities of the surface can be grooves, scratches or Grooves or combinations thereof in the material of the plates. In other words: the formation of the plate relates to the plate as such (ie. Deforming), while the surface irregularities for example, by removing material from the plate surface or by upsetting it from the plate.

The shaped plates and the irregularities of the surface

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fulfill three purposes, among others:

a) they increase the turbulence of the gas flowing through the channels by reducing its direction and / or speed is changed repeatedly;

b) When the rotor rotates, they serve to distribute and swirl the liquid as it flows over the plate;

c) they contribute to the formation of droplets which are torn from the main part of the liquid and enter the gas stream and then reunite with the bulk of the liquid. The formation of droplets and their reunification with the main flow of the liquid supports the interaction between liquid and gas.

In an embodiment according to the invention, the radially inside lying part of the panels transverse grooves, scratches or furrows and the remaining part of the panels grooves, scratches or furrows, which extend in the radial direction to the axis of rotation of the rotor.

For certain purposes, the contact plate can be corrugated and have grooves or scratches in their surface, which extend at right angles to the direction of flow to improve the effectiveness of the device.

As noted, dio tends to be continuous, at the inner end the liquid layer applied to the plates, in their radial outward progression to become thinner. In this case the radial grooves act to form some less thick flows opposite. The effective area of the currents in the grooves is significantly larger than that of a few currents of the same Amount of liquid.

The transverse corrugations support the formation and that rapid confluence of droplets and also contribute to

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216228Q

that the liquid is distributed sideways and thickens Liquid flows are prevented. The corrugated sheets can be arranged so that the direction of the in between flowing gas stream changes repeatedly. It can often too It may be advantageous to arrange the plates against one another in such a way that the cross-section of the channel changes along its length, see above that there are changes in the flow velocity. If the cross-section of each channel varies along its length, then it must such a change in the cross-section must be present in all channels and the number of constrictions is preferably the same, so that the flow pattern and flow resistance are essentially the same in all channels. When flowing over the tips of the cavities form droplets from the liquid, which in be thrown off the gas stream. In each individual case, the shape of the convolutions must be adapted to a large number of factors, e.g. the viscosity, or surface tension and density of the liquid, the size of the centrifugal force and the speed and pressure of the gas in order to obtain optimal results.

It has been found that the contact device according to the invention produces the best results when the mortar lines are adjacent Plates are essentially parallel. This can be achieved by arranging the plates in baskets, which each have a limited number of essentially parallel Plates included. These baskets are regularly in of said zone so that their center lines are substantially radial. Alternatively, form the center lines the baskets with the radius through the corresponding basket have the same angle. In cases where a special capacity of the contact device is required, the inner radius is very long compared to the length of the panels. In these cases, essentially parallel plates evenly arranged around the rotor since slight deviations from the exact parallelism are insignificant.

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The contact plates are preferably in baskets or the like. in accordance with of GB-PS 1 O89 378 arranged so that they are held in place will. If the side walls of the baskets are flat, the spaces between the outermost sides of the plate stack and the side walls must be sealed to prevent gas and liquid from flowing through here.

Further features and advantages of the invention emerge from the following description by way of example with reference to the accompanying drawings. Show it:
1 shows a schematic cross section through a contact device according to the invention,

FIGS. 2 to 6 show some forms of corrugated contact plates, FIG. 7 shows a contact device similar to that in FIG. 1, but with

other contact plates, une
Fig. 8 to 11 further special versions of contact plates.

In Fig. 1, 10 denotes a line indicated by dashed lines Housing with a gas inlet 12 in its peripheral wall, a gas outlet 1 * f in its upper wall and a liquid outlet 16 in its lower wall. In the practical execution form can the gas inlet must be directed tangentially.

A vertical drive shaft 18 extends through a central one Opening in the bottom of the housing upwards and is mounted on normal V / eise in transverse and drawer bearings, not shown, and is often connected to a rotary drive, e.g. an electric motor.

The upper end of the shaft 18 carries a rotor shown generally at 20 having a lower plate 22 and an annular top plate 2k. A plurality of rectangular, essentially vertical and parallel contact plates 26, which are distributed in an annular zone coaxially to the rotor, are arranged between these plates 22 and 2k. These panels can sit in removable baskets, with the panels of each basket being substantially parallel

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to stand by each other; For the sake of simplicity, however, the baskets are not shown in the figures.

In the substantially cylindrical central space 28, which by the radially inner edge of the contact plates 26 is a liquid distribution device 30 arranged. For the sake of simplicity, the device 30 is shown with a vertical, fixed central tube 32, its upper end applied to a pressure fluid source v / ground and which has a plurality of vertical rows of nozzle pipes 3 ** (of which only one row is shown), in order to inject liquid into the radial channels formed by the contact plates 26. In practice, you often become a rotating one Liquid distributor of the type described in GB-PS 858 69I use.

On top of the rotor plate 2k, a conical ring 36 is secured, v / hich a V-shaped with the surface of the plate, forming annular pocket 38th An annular flange ^ O extends downward from the top wall of the housing and has a widening edge ^ 2 which engages in the pocket 33. During operation, the pocket 38 is filled with liquid and forms a liquid seal with the flange h2 , which prevents gas from flowing directly from the inlet 12 to the outlet 1 ^ without flowing through the channels of the rotor.

During operation of the device, the liquid injected into the channels between the contact plates 26 is removed from the planar parts 26a of the plates and does not move under the influence dor centrifugal force on don plates radially still auooon. The Garj is dead Pressure is applied and flows into the channels on the periphery of the rotor between the flat plate parts 26b, and v / ird the channels are pressed radially inwards against the effect of centrifugal force, as the centrifugal force is due to the low density of the gas prevalently low i

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Figures 2 to 6 show different embodiments of corrugated Plates 26. Referring to Figure 2, the channels formed between plates 26 are generally straight, but the cross-sectional area of each Canal changes regularly over the length of the canal. The walls of the valleys between the ridges 48 of the corrugations are straight. The embodiment according to FIG. 3 differs from that according to FIG. 2 only in that the walls of the valleys are curved at 48. ■ According to Fig. 4, the plates have flat parts 50 between the inclined Sidewalls of the corrugations, the plates being arranged so that each channel is zigzag and one substantially has a constant cross-section. The plates shown in Fig. 5 are similar to those of Fig. 4, but the channels here have only a slightly zigzag design and a changing cross-section. The plates in the embodiment of FIG. 6 are similar to those of FIG. 2, the assignment of the plates being such that the channels are zigzag and have a variable cross-section to have. It can be seen that by moving the central plate to the left in Fig. 4, the crests of the corrugations are still remain horizontally aligned, but the channels have a regularly changing cross-section and a zigzag shape, so that both the direction and the flow velocity of the Gaoes

The straight walls of the valleys between the ridges 48 in the embodiments 4 to 6 can be replaced by smoothly curved walls, as is the case in FIGS. 2 and 3.

The width of the inner openings of the channels is the same for all channels, so that the liquid is evenly distributed over all channels will. As a result of the flat plate parts 26a, the angle of incidence of the liquid on the plate is also the same for all Plates. The width of the radially outer openings of the channels is also the same for all channels and all channels offer the gas flowing through the same resistance, so that to the periphery

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the compressed gas delivered by the rotor is evenly distributed. In each embodiment, only panels become one and the same Type used.

Fig.'2 to 6 are shown on an enlarged scale, with only Figure 2 illustrates both ends of the channel.

Fig. 7 shows a contact device of the same type qie Fig. 1, but with flat or planar contact plates 26. The surfaces of these plates have a plurality of parallel grooves Mf which extend in the radial direction. The effect of these grooves is explained with reference to FIGS. 8, 9 and 10, v / which Represent cross-sections along lines VIII-VIII, IX-IX and X-X in FIG.

The liquid exiting the manifold 30 forms an uninterrupted layer on the plate surfaces forming the back walls of the rotating channels. This is shown in FIG. 8. On the way radially outward, the layer becomes thinner and in a certain zone (FIG. 9) the surface of the layer and the crests of the corrugations between the grooves kk are at the same height. Finally, the layer divides into a large number of partial flows, the cross-sections of which decrease towards the outer end of the channel (FIG. 10).

It can be clearly seen that the grooves kk prevent the liquid layer from contracting into a small number of a few, thick streams. The surface area of the flow in the grooves Ml is, of course, significantly larger than that of a few flows of the same amount of liquid.

The attached to the inner end of each plate 26 in the form of rays angolieferto liquid is along dor ΙΙφηο dor plate in Intervals injected. To create a continuous layer on the

209828/0958 BATHROOM ORIGINAL

To form the surface of the panels, the rays must extend or propagate transversely across the panel. Fig. 11 shows a modification of the plates according to Fig. 7. According to Fig. 11, the radially inner ends are provided with transverse grooves k6, which can have essentially the same profile as the grooves kh. The profiles of the grooves or grooves kk and hG can according to various parameters. e.g. the viscosity of the liquid can be changed. The radially outer flanks of the transverse grooves k6 offer a certain resistance to the partial flows originally moving radially outward, so that the liquid is distributed to the side in the grooves and a continuously continuous layer is created.

According to FIGS. 8 to 10, the grooves kk are only shown on one side of the plate; however, the grooves kk and / or 46 are preferably provided on both sides of the plate 26.

If corrugated plates according to Fig. 2 to 6 with corresponding grooves or grooves are provided, this further improves the effectiveness of the device, at least in certain areas of application.

Due to the repeated changes in the direction and / or speed of the gas flow between the corrugated plates, the gas flow is turbulent in nature and repeatedly swirls the surface layer of the liquid through. When the liquid reaches a ridge k8 , at least part of the liquid kite is torn off and goes into the gas stream in the form of droplets of various sizes. Here they are carried over a short distance by the gas flow and then fall back radially inwards into the liquid. Under the effect of the swirling of the gas, these droplets strike the main stroir. of the liquid, as well as on the walls of the canal. ΛμΓ Ui a no Art and Wi; ί no been ΊΤημίΌΙιοη koiil-.i nu i nrl.ich or: * ou ;; i., M'Aioi jodool / iiu Jifilx ji. '. ii.'iuor dor oJiiunlunu'l'rü ι TcJ; n only km * : '- iüt.

■■ "» ">» "'■" ■■ * BAD

In Fig. 2 to 6 the inner cantons of the plates are shown as lying on a straight line. In practice, a solution will be preferable in which the edges lie on a cylindrical surface which is coaxial with the axis of the rotor. The same also applies to the outer edges of the panels.

From the foregoing it can be seen that the arrangement and The shape of the plates can be changed in various ways without thereby deviating from the principle of the invention. It it is also possible to use curved plates according to GB-PS 859 097.

BATH

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Claims (1)

PA ΐ E Π ΐ AHSP R Ü C II E ^: - '"K Liquid-gas contact device, comprising a housing with a liquid distributor, a gas inlet, a gas outlet and a rotor carrying contact plates, the contact plates being arranged in an annular zone outside the liquid distributor and forming channels in which gas and liquid flow in countercurrent between of the radially inner and radially outer peripheries flow, characterized in that the center planes of adjacent contact plates (26) are essentially parallel and the shape and arrangement of adjacent plates (2G) is such that the counterflow flow conditions for the liquid and the Gas are substantially the same in all channels and the pressure drop of the gas flowing through the channels is substantially the same in all channels, the plates (2b) being so shaped and / or have such surface irregularities that the 1 / the interplay between gas and liquid is strengthened as a result. 2. Device according to claim 1, characterized in that the shaping (for example h8) is generated by deforming the plate and consists of corrugations, corrugations or dimples or a combination thereof. 3. Apparatus according to claim 1 or 2, characterized in that the surface irregularities from grooves (a.B.Mf), scratches or furrows in the surface or any combination of dorcelben. BATH ORIGINAL k. Device according to one of Claims 1 to 3, characterized in that the grooves and / or grooves extend transversely to the general direction of flow of the liquid and the surface irregularities extend in the general direction of flow of the liquid. 5. Apparatus according to claim * l ·, characterized in that the Contact plates (26) or a part thereof extending transversely . Have surface irregularities. 6. Device according to one of claims 1 to 5, characterized in that that the angles of the innermost parts of the plates with tangents at the radially inner ends are substantially the same and that the circumferential distances between the innermost parts of adjacent plates are essentially the same. 7. Device according to one of claims 1 to 6, characterized in that that the V / angles between the outermost parts of the bursts and tangents at their radially outer ends essentially are equal and that the circumferential distance between the outside lying parts of adjacent plates essentially the same ict. 8. Apparatus according to claim 6 or 7, characterized in that the angles on the radially innermost and radially outermost parts of the plates are essentially the same. 9. Apparatus according to claim 6, 7 or 8, characterized in that di.ss the shapes of the contact plates (26) are such that they converge and zones of divergence between adjacent; creating n plates. ? 0 «Kwö / -0n · ■ BAD ORIGINAL 10. The device according to claim 9, characterized in that the Number of converging zones in adjacent channels is the same. 11. The device -according to claim 9 or 10, characterized in that the number of diverging zones in adjacent channels is the same. . . 12. Apparatus according to claim 10 or 11, characterized in that the flow resistance to gas in all channels essentially k is the same. 13. Device according to one of claims 1 to 12, characterized in that, that the median planes of adjacent plates (26) are substantially parallel and the plates are shaped so that the Corrugations extending transversely to the general direction of flow of the liquid, the plates being provided with grooves in the plate material are in the general direction of flow of the liquid extend. "] k. Device according to one of the preceding claims, characterized in that the liquid distributor (30) and the rotor (20) are arranged for independent rotation. 15. Device according to one of claims 1 to 1 * 1 · ,, characterized in that that the liquid discharged from the liquid distributor (30) and impinging on the plates (26) causes the rotor (20) to rotate. 16. The device according to claim 15, characterized by additional means (e.g. 18) to rotate the rotor. 209828/0958 17. Device according to one of claims 1 to 16, characterized in that ' that the contact plates (26) between.axially offset support membersrr • Are arranged, which hold the plates with essentially the same slope between adjacent contact plates. 18. The device according to claim 17, characterized in that the Rotor (20) comprises a plurality of independent epipedal baskets in which the contact plates (26) are arranged, wherein, the center planes of the contact plates in the baskets are essentially radial or essentially parallel to a radius of the rotor axis stand. 19. The device according to claim 18, characterized by at least one radially inner seal between the zones of the outer contact plates of adjacent joints or stacks first of all Rotation axis of the rotor. 20. Device according to one of the preceding claims, characterized in that that the radially outermost part of each contact plate (26) has a flat surface (26a). 21. Device according to one of the preceding claims, characterized in that that gas is delivered under pressure to the radially outer ends of the channels, the radially outer ends Portions of each plate (26) have a flat portion (26b) to ftfr all channels the same. To form gas inlet width. 209828/0958 ORIGINAL, INSPECTED 22. The device according to claim 20, characterized in that the channels formed between adjacent plates (26) are generally straight, but the cross-sectional area of each channel changes regularly over its length. 23. The device according to claim 20, characterized in that each Channel runs zigzag and is essentially constant Has cross-section. 2k. Device according to Claim 20, characterized in that each channel runs in a zigzag shape and its cross-section varies over its length. 25. Device according to one of the preceding claims, characterized in that that the walls of the valleys or depressions of the plates are curved between the crests of the corrugations. 209828/0958 originally inspected