LIQUID DISTRIBUTOR FOR A SEPARATION DEVICE COMPRISING A SCREEN MADE OF A CARBON COMPOSITE MATERIAL

Abstract

A liquid distributor for a separation device, such as for a mass transfer column for a packing column for absorption, stripping, scrubbing or distillation. The liquid distributor includes at least one distributor member having two or more outlet openings for an outflow of liquid in the form of jets, and the liquid distributor further includes at least one screen which is arranged in front of the outlet openings so that liquid jets outflowing through the outlet openings of the distributor member impinge onto the surface of the at least one screen and are deformed thereon to thin flowing liquid films. At least one of the at least one screen is made at least partially of a carbon composite material.

Claims

1. A liquid distributor for a separation device, the liquid distributor comprising: at least one distributor member having two or more outlet openings for an outflow of liquid in the form of jets; and at least one screen arranged in front of the outlet openings so that liquid jets outflowing through the outlet openings of the at least one distributor member impinge onto the surface of the at least one screen and are deformed thereon to thin flowing liquid films; at least one of the at least one screen made at least partially of a carbon composite material, the carbon composite material being a material made of a matrix of plastic or carbon in which at least one constituent material is dispersed.

2. The liquid distributor in accordance with claim 1, wherein the carbon composite material is a fiber reinforced carbon.

3. The liquid distributor in accordance with claim 1, wherein the carbon composite material is a carbon fiber reinforced carbon.

4. The liquid distributor in accordance with claim 1, wherein at least one of the at least one screen consists of the carbon composite material.

5. The liquid distributor in accordance with claim 1, wherein the at least one screen is at least partially a carbon composite material.

6. The liquid distributor in accordance with claim 1, wherein the carbon composite material has a porosity of 5 to 30%.

7. The liquid distributor in accordance with claim 1, which is designed for a packing column, wherein the at least one distributor member is tubular or has a trough shape, and the at least one screen is arranged so as to shield the outlet openings against a gas stream flowing upwardly.

8. The liquid distributor in accordance with claim 1, wherein the at least one screen is arranged in front of the outlet openings so that in the event of a maximum outflow of liquid, the liquid jets outflowing through the outlet openings of the at least one distributor member impinge onto the surface of the at least one screen at angles of less than 60°, and each of the angles is an angle between the direction of liquid jet outflowing through the outlet and the tangent at the point of the surface of the screen, where the liquid jets impinges.

9. The liquid distributor in accordance with claim 1, wherein at least one of the at least one screen has a shape of a sigmoidal curve in a vertical direction as well as in a jet-parallel section, and the sigmoidal curve is curved downwardly or has a largely constant curvature in the region in which the liquid jets impinge onto the surface of the at least one screen.

10. The liquid distributor in accordance with claim 1, wherein the at least one scree is arranged in front of the outlet openings so that liquid jets outflowing through the outlet openings of the at least one distributor member impinge onto the surface of the at least one screen essentially tangentially.

11. The liquid distributor in accordance with claim 1, wherein the at least one distributor member is metal or a plastic, the metal is titanium, tantalum or zirconia, or, the at least one distributor member is a carbon composite material.

12. A column for mass transfer the column comprising: at least one packing; and at least one liquid distributor in accordance with claim 1, the at least one distributor member being tubular or having a trough shape, and the at least one screen arranged so as to shield the outlet openings against a gas stream flowing upwardly through the column.

13. The column in accordance with claim 12, further comprising two or more parallel distributor members with each of the at least one screen comprising drip edges, the two or more parallel distributor members are arranged so that the two or more parallel distributor members subdivide a gas stream flowing upwardly in the column into a plurality of partial streams so that stagnation zones form beneath the distributor members, and the drip edges of the at least one screen are arranged inside the stagnation zones.

14. A screen for a liquid distributor for a separation device, the liquid distributor comprising at least one distributor member having two or more outlet openings for an outflow of liquid in the form of jets, the liquid jets outflowing through the outlet openings of the at least one distributor member, the screen comprising: a carbon composite material; and a surface, the screen configured to be arranged in front of the outlet openings such that the liquid jets are capable of impinging onto the surface of the screen and are capable of deforming into thin flowing liquid films.

15. A method comprising: operating a liquid distributor in accordance with claim 1 to perform a separation process involving corrosive components and perform a separation process with liquid irrigation densities of less than 20 m.sup.3/m.sup.2.Math.h, the separation process being an absorption process, a stripping process, a scrubbing process or a distillation process.

16. A method comprising: operating a column in accordance with claim 12 to perform a separation process involving corrosive components and perform a separation process with liquid irrigation densities of less than 20 m.sup.3/m.sup.2.Math.h, the separation process being an absorption process, a stripping process, a scrubbing process or a distillation process.

17. A method comprising: operating a liquid distributor in accordance with claim 1 to perform a separation process involving corrosive components and perform a separation process with liquid irrigation densities of less than 10 m.sup.3/m.sup.2.Math.h, the separation process being an absorption process, a stripping process, a scrubbing process or a distillation process.

18. A method comprising: operating a liquid distributor in accordance with claim 1 to perform a separation process involving corrosive components and perform a separation process with liquid irrigation densities of less than 5 m.sup.3/m.sup.2.Math.h, the separation process being an absorption process, a stripping process, a scrubbing process or a distillation process.

19. A method comprising: operating a column in accordance with claim 12 to perform a separation process involving corrosive components and perform a separation process with liquid irrigation densities of less than 10 m.sup.3/m.sup.2.Math.h, the separation process being an absorption process, a stripping process, a scrubbing process or a distillation process.

20. A method comprising: operating a column in accordance with claim 12 to perform a separation process involving corrosive components and perform a separation process with liquid irrigation densities of less than 5 m.sup.3/m.sup.2.Math.h, the separation process being an absorption process, a stripping process, a scrubbing process or a distillation process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention will be explained in more detail hereinafter with reference to the drawings.

[0034] FIG. 1 is a schematic longitudinal sectional view of a mass transfer column including a packing and a liquid distributor in accordance with one embodiment of the present disclosure.

[0035] FIG. 2 is a schematic sectional view of a liquid distributor with a screen of a mass transfer column shown in FIG. 1.

[0036] FIG. 3A and FIG. 3B are details of the liquid distributor of the mass transfer column shown in FIG. 1.

[0037] FIG. 4 is a schematic sectional view of a liquid distributor with a screen of a mass transfer column in accordance with another embodiment of the present disclosure.

[0038] FIG. 5A is a schematic view onto the surface of a screen made of a carbon fiber reinforced carbon in accordance with an embodiment of the present disclosure onto which a jet of water is impinged.

[0039] FIG. 5B is a schematic view onto the surface of a conventional screen made of metal in accordance onto which a jet of water is impinged.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The mass transfer column 10 shown in FIG. 1 comprises a packing 12 and a liquid distributor 14. The liquid distributor 14 comprises a pre-distributor 16 and several distributor members 18, each of which having a plurality of outlet openings shown in FIGS. 2, 3A and 4 for an outflow of liquid in the form of jets. During the operation of the mass transfer column 10, gas 20 ascends the mass transfer column 10, passes around the distributor members 18 and is divided by the distributor members 18 into a plurality of partial gas streams 22′, 22. Liquid 24 is fed into the liquid distributor 14 via a feed line 26 and is guided through the pre-distributor 16 into the distributor members 18.

[0041] As shown in FIG. 2, each of the distributor members 18 has the form of a trough and provides at its lower end the outlet openings 28. In front of the outlet openings 28, a screen 30 is arranged so that liquid jets outflowing through the outlet openings 28 impinge onto the surface of the screen 30 and are deformed thereon to thin flowing liquid films. In accordance with the present disclosure, each of the screens 30 is made of a carbon composite material and in particular from a carbon fiber reinforced carbon. As shown in FIG. 2, the screen has in cross-section the form of a sigmoidal curve, wherein the sigmoidal curve is curved downwardly and the sigmoidal curve has a largely constant curvature in the impinge region 32, in which the liquid jets impinge onto the surface of the screen 30. The screen 30 is affixed to the distributor member 18 at its upper end 34 with a screw 36 and is designed at its lower end as a drip edge 38. During the operation of the mass transfer column 10, liquid flows out of the outlet openings 28 in the form of liquid jets, which impinge at the impinge region 32 onto the surface of the screen 30 essentially tangentially so as to form a thin flowing liquid film, which flows down the screen down to the drip edge 38. Droplets or trickles, which form at the drip edge 38, fall down onto the surface of the packing 12, which is located closely underneath the drip edge 38 of the screen 30. On account of the curvature, the liquid film is not or at least only to a small degree disturbed by ascending gas 20, since the gas 20 is guided by the screen 30 away from the thin liquid film flowing down the surface of the screen. On account thereof, the liquid droplets formed at the drip edge 38 fall down to the underneath packing 12 without or at least essentially without any of the droplets being carried away by the ascending gas 20.

[0042] FIG. 3A shows the area around the outlet opening 28 of the distributor member 18 in more detail. More specifically, the outlet opening 28 is provided in a wall 40, which is inclined with regard to the vertical 46 with the angle α. The liquid 24 flows during the operation of the mass transfer column 10 through the outlet opening 28 and forms a liquid jet 46, which impinges onto the impinge region 32 on the surface of the screen 30 with an impingement angle β so as to form a thin flowing liquid film 48. Upon the impingement, to a minor degree fine liquid droplets 50 are formed as splashes. The smaller the impact angle, the smaller the amount of formed liquid droplets 50. As shown in FIG. 3B, the formed liquid film 48 flows down the surface of the screen 30 down to the drip edge 38, where liquid droplets 52 are formed, which fall down onto the surface of the packing 12, which is located closely underneath the drip edge 38 of the screen 30.

[0043] The liquid distributor 18 with the screen 30 shown in FIG. 4 is similar to that shown in FIG. 2 except that the liquid distributor 18 with the screen 30 of the embodiment shown in FIG. 4 further contains two skirts 54, 54′. While the first skirt 54 is affixed to the screen 30, the second skirt 54′ is affixed to the liquid distributor 18. Both skirts 54, 54′ allow to influence the stream of gas 20 advantageously, namely so that a stagnation zone 56 is formed beneath the distributor member 18, wherein the drip edge 38 of the screen 30 is arranged inside the stagnation zone.

[0044] As set out further above, the screen made of a carbon composite material as used in the liquid distributor in accordance with the present disclosure has an excellent wettability effecting that a liquid jet impinging onto the screen surface forms a broad and smooth liquid film on the screen surface. This is shown in FIG. 5A, in which a water jet 46 is impinged onto the surface of a plate made of a carbon fiber reinforced carbon imitating a screen 30 in accordance with an embodiment of the present disclosure. As shown, the water jet 46 impinging onto the screen spreads out and remains in a parabola form so that the liquid flows down the screen surface as broad water film 48.

[0045] In contrast thereto, jets of liquid impinging on conventional screens made of metal tend to spread out and then recoalesce or rejoin to give a narrow liquid stream. This is schematically shown in FIG. 5B, in which a water jet 46 is impinged onto the surface of a plate made of metal imitating a conventional screen. As shown, the water jet 46 impinging onto the screen spreads out and then recoalesces or rejoins, respectively, to give a narrow liquid stream 48.