TRAY FOR EXCHANGE COLUMN COMPRISING GAS CHIMNEYS SURMOUNTED BY HATS WITH A STREAMLINED PROFILE

Abstract

A tray (100) for a gas/liquid contact column, comprising a plurality of chimneys (108) jutting over a portion (101) of the upper face of the tray for the exclusive passage of gas through the tray; they are substantially parallelepipedal and mutually parallel. At least one of the chimneys (108) is surmounted by an elevated hat (108) with a streamlined profile which prevents the passage of liquid through the chimney. The hat comprises a lower body (180) which is substantially semi-cylindrical, elongated along the longitudinal axis Y and open towards the top, extended laterally by two planar fins (181, 182) inclined towards the axis of revolution (R) of the lower body at an angle in the range 0 to 30 with respect to the axis Z passing through the chimneys, aligned with their height.

Claims

1. A tray (100) for a column for the exchange of heat and/or matter between a gas and a liquid, comprising: an upper face and a lower face, a plurality of chimneys (108) jutting over a portion (101) of the upper face of said tray (100) for the exclusive passage of said gas through said tray (100), said chimneys comprising an opening for the escape of gas at their top, an axis Z passing through them in the direction of their height and being elongated along a longitudinal axis Y orthogonal to the axis Z, and being substantially parallelepipedal and mutually parallel, and in which at least one of said chimneys (108) is surmounted by a hat (108) with a streamlined profile in order to prevent the passage of liquid through said chimney (108), said hat (108) being elevated with respect to the gas escape opening of the chimney (108), said hat (108) comprising a lower, substantially semi-cylindrical body (180) which is elongated along the longitudinal axis Y and open on the side opposite to the escape opening of the chimney (108), extended laterally by two planar fins (181, 182) inclined towards the axis of revolution (R) of the lower body at an angle in the range 0 to 30with respect to the axis Z, the diameter (D) of the lower body (180) being at least equal to the width (L) of the chimney (108), and the length (1) of the lower body (108) being at least equal to the length (1) of the chimney (108).

2. The tray as claimed in claim 1, in which each chimney (108) is surmounted by a hat (180) with a streamlined profile.

3. The tray as claimed in claim 1, in which the lower body (180) comprises a section in the form of an arc of a circle with a length that is less than or equal to that of a semi-circle and which has an axis of symmetry that coincides with the axis Z, and defines an angle formed between the centre O of the circle, the axis X and the junction J between a fin and the lower body which is in the range 0 to 30.

4. The tray as claimed in claim 1, in which the lower body (180) is a half-cylinder.

5. The tray as claimed in claim 1, in which the lower body (180) comprises a section in the form of an arc of a circle with a length that is less than or equal to that of a semi-circle and has an axis of symmetry which coincides with the axis Z, and the length (a) of the fin (181, 182) is in the range 10 mm to a maximum value a.sub.max which is equal to a.sub.max=(D*cos())/(2*sin()), in which is the angle formed between the centre O of the circle, the axis X and the junction J between the fin (181, 182) and the lower body, is the inclination of the fins (181, 182) with respect to the axis Z, and D is the diameter of the lower body (180).

6. The tray as claimed in claim 1, in which said fins (181, 182) are substantially in the shape of a rectangle.

7. The tray as claimed in claim 1, in which said chimneys (108) are substantially in the shape of a parallelepipedal rectangle.

8. The tray as claimed in claim 1, in which at least one of said chimneys (108), and preferably all of said chimneys (108), comprises a dispersive element for gas disposed inside said chimney (108), the dispersive element preferably comprising a perforated plate (103) comprising circular orifices (104) or slots for the passage of gas.

9. The tray as claimed in claim 1, further comprising means for the passage of liquid through the tray and/or a liquid collection zone (109).

10. The tray as claimed in claim 9, for the distribution of gas at the bottom of a column for the exchange of heat and/or matter between a gas and a liquid, in which the collection zone (109) comprises two weirs (109) which are diametrically opposed and orthogonal to said portion (101) of the upper face of the tray (100) supporting the chimneys (108), said chimneys (108) extending parallel to the weirs (109).

11. The tray as claimed in claim 9, for the distribution of gas and liquid in a column for the exchange of heat and/or matter between a gas and a liquid, in which the means for the passage of liquid through the tray (100) comprise a plurality of orifices and/or chimneys for the passage of liquid.

12. A column for the exchange of heat and/or matter between a gas and a liquid, comprising at least one gas/liquid contactor (7) bringing the gas (g) and the liquid (1) into contact, and at least one tray (100) as claimed in claim 1 to distribute the gas, and optionally the liquid, over said gas/liquid contactor (7).

13. The column as claimed in claim 12, in which said tray is disposed at the bottom of the column upstream of any gas/liquid contactor (7) in order to distribute the gas at the base of said gas/liquid contactor (7).

14. The column as claimed in claim 12, comprising a plurality of sections, each of said sections comprising a gas/liquid contactor (7), and in which a tray is disposed between an upper section and a lower section, said upper and lower sections being successive in the column, in order to distribute the gas at the base of said gas/liquid contactor (7) of the upper section and to distribute the liquid at the top of the gas/liquid contactor (7) of the lower section.

15. A method which comprises using a column as claimed in claim 12 in a process selected from the group consisting of the treatment of gas, the capture of CO.sub.2, the dehydration of a gas, or distillation.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0046] FIG. 1, as already described, is a diagram illustrating a particular case of a gas/liquid contact column for the absorption of acidic compounds contained in a gas using an aqueous amine solution, in the context of treatment of a gas or capture of CO.sub.2, equipped with a distributor tray in accordance with the prior art or in accordance with the invention.

[0047] FIG. 2, as already described, illustrates a chimney tray in accordance with the prior art for the collection of liquid and the distribution of liquid and gas.

[0048] FIG. 3, as already described, illustrates a gas distributor chimney tray in accordance with the prior art which can be placed at the bottom of a gas/liquid contact column.

[0049] FIG. 4, as already described, illustrates another example of a prior art chimney tray.

[0050] FIG. 5 is a perspective view illustrating a gas distributor tray in accordance with one embodiment of the invention.

[0051] FIG. 6 is a sectional diagram of a hat of a chimney of a distributor tray in accordance with the invention.

[0052] FIG. 7 illustrates the interior of a chimney of a tray in accordance with one embodiment of the invention.

[0053] FIGS. 8 and 9 are images of the velocity fields for a gas, obtained by modelling the function of a chimney tray distributor in accordance with the prior art and in accordance with one embodiment of the invention.

[0054] In the figures, identical reference numerals designate identical or analogous elements.

DESCRIPTION OF THE INVENTION

[0055] The detailed description of the tray in accordance with the invention below refers to FIGS. 5 and 6, illustrating a non-limiting embodiment of the tray.

[0056] The tray 100 is shown in a perspective view in FIG. 5, in its position of use in a gas/liquid contact column. As is conventional, the tray 100 is inscribed in a cylinder with a diameter 100 , which is substantially equal to that of the gas/liquid contact column. The tray in accordance with the invention is well suited for use in large diameter columns, typically 1 metre or more, and preferably 3 in or more; they may reach 7 to 8 m, for example.

[0057] The tray 100 for the column for the exchange of heat and/or matter between a gas and a liquid comprises a plurality of chimneys 108 jutting over a portion 101 of the upper face of the tray for the exclusive passage of gas through the tray 101.

[0058] The term upper face of the tray 100 is used for the face of the tray which is orientated towards the top of the exchange column. In contrast, the lower face of the tray is that which is orientated towards the bottom of the column via which the gas arrives.

[0059] The tray 100 may comprise means for the passage of liquid through the tray (not shown) and/or a liquid collection zone 109.

[0060] The term plurality of chimneys means at least two chimneys. The number of chimneys may vary and depends on the design of the tray, in particular on parameters such as the size of the tray, the desired number of openings for gas, the volume of the collection zone, etc. By way of solely non-limiting indication, the tray may comprise in the range 2 to 100 chimneys 108, for example in the range 3 to 32 chimneys.

[0061] An axis Z passes through the chimneys 108 in the direction from their height and is coincident with the vertical when the tray is in the position of use in the column. The chimneys 108 are substantially parallelepipedal in shape, preferably rectangular, and are elongated along a longitudinal axis Y orthogonal to the axis Z, and are mutually parallel in disposition. Each chimney 108 is formed by a plurality of walls which delimit an internal volume that is open to either side of the tray 100. They thus comprise a gas escape opening 105 at the top. At their base, they comprise an inlet opening for gas coming from the lower portion of the distributor tray 100.

[0062] Preferably, a regular gap separates the chimneys 108. The shape of the parallelepiped, preferably rectangular, produces a wide opening for the passage of gas, in particular in comparison with known cylindrical chimneys such as those used in FIG. 2; this means that pressure drops can be limited.

[0063] The length 1 and width L of the chimney 108 are defined in the plane (XY) formed by the portion 101 of the tray supporting the chimneys 108, which is the horizontal plane when the tray is in the position of use in a column. For the purposes of simplification, reference will be made in the remainder of the description to a horizontal plane/axis, or in fact to the horizontal, to designate any plane/axis contained in the plane formed by the portion of the chimney tray support. The height h of the chimney is defined in a plane orthogonal to that formed by the portion of the tray supporting the chimneys, i.e. in a vertical plane when the tray is in the position of use in a column. The axis Z passes through the chimney, as described above, and is therefore an axis which is orthogonal to the plane XY formed by the portion 101 supporting the chimneys 108. The gas passes through the chimney 108 in the direction of its height, along this axis Z. For the purposes of simplification, reference will be made in the remainder of the description to a vertical plane/axis, or in fact to the vertical, to designate any plane/axis contained in a plane orthogonal to the plane formed by the portion of the chimney support tray.

[0064] By way of non-limiting example, the height of the chimneys may be in the range 0.15 m to 1.00 m, and preferably in the range 0.2 m to 0.6 m.

[0065] At least one chimney 108 is surmounted by a hat 108 in order to prevent the passage of liquid through the chimney, the hat 108 being elevated with respect to the escape opening for gas so as to leave a gap e for the passage of gas and the hat 108 comprising a streamlined profile. The hat thus comprises a lower body 180 which is substantially semi-cylindrical, elongated along the axis Y and open on the side opposite to the escape opening 105 of the chimney, extended laterally by two planar fins 181, 182 which are inclined towards the axis of revolution R of the lower body 180 by an angle in the range 0 to 30 with respect to the axis Z. Preferably, the angle of inclination of the fins is in the range 5 to 20, and is, for example, equal to 15. It should be understood that because the lower body 180 is open on the side opposite to the escape opening 105 of the chimney 108, i.e. towards the top of the column when the tray is in the position of use, it is a portion of a hollow cylinder; there is no material in this lower substantially semi-cylindrical portion of the hat.

[0066] The diameter D of the lower body 180 of the hat 108 is preferably at least equal to the width L of the chimney 108.

[0067] The length l.sub.c of the lower body 180 of the hat 108 is preferably at least equal to the length 1 of the chimney 108.

[0068] The term substantially semi-cylindrical means that the lower body 180 forms a half-cylinder or almost half a cylinder, i.e. it comprises a section in the form of a circular arc with a length which is less than or equal to that of a semi-circle, having an axis of symmetry which is coincident with the axis Z, and defining an angle formed between the centre O of the circle, the axis X and the junction J between a fin and the lower body which is in the range 0 to 30. This angle is equal to 0, for example. The streamlining of the hat profile increases with the value of the angle . FIG. 6 illustrates in detail the profile of the hat 108 of a tray in accordance with the invention, which shows the angles and , and the characteristic dimensions of the two portions 180 and 181/182 of the hat.

[0069] Put another way, the section in the form of an arc of a circle has an axis of symmetry which coincides with the axis Z, and the angle of the angular sector defining the arc of a circle formed by the section of the lower body is in the range (1802) to 180, i.e. in the range 120 to 180.

[0070] The term elevated element means that the base of said element is at a level (elevation) which is more elevated with respect to a reference surface. Thus, a hat 108 which is elevated with respect to the gas escape opening 105 of the chimney means that the base of the hat is at a higher elevation than the gas escape opening of the chimney, in this case at a height e from the opening 105.

[0071] By way of non-limiting example, the gap between the hat and the gas escape opening of the chimney may be in the range 0.005 m to 0.20 m, and preferably in the range 0.03 m to 0.10 m. By way of non-limiting example, the ratio e/L, i.e. the ratio between the gap e left between the hat and the gas escape opening of the chimney and the width L of the chimney, is preferably in the range 1/16 to 8/5, and preferably in the range 1/4 to 1.25, in order to comply with a given kinetic energy factor (.Math.v.sup.2, in which is the density and v is the velocity), with a view to preventing any flooding of the packing located above the tray.

[0072] The two fins 181, 182 are elongated along the longitudinal axis Y of the chimney 108, which is parallel to the axis of revolution R of the lower body 180. The length of the fin (reference not shown) is defined as the largest dimension in the plane formed by the fin. The width a of the fin is the smallest dimension defined in the plane formed by the fin. The width a of the fin is preferably in the range 10 mm to a maximum value a.sub.max equal to a=(D*cos())/(2*sin()). Preferably, the maximum value a.sub.max corresponds to a configuration in which the two fins join up on the axis Z.

[0073] Preferably, the fins 181, 182 are in the form of a rectangle.

[0074] Advantageously, the length l.sub.a of the fins 181, 182 is equal to the length l.sub.c of the lower body 180 of the hat 108.

[0075] In accordance with one embodiment as shown in FIG. 5, all of the chimneys 108 are provided with a hat with a streamlined profile as described. This configuration means that the distribution of the gas is homogenized better.

[0076] In accordance with another embodiment, the tray comprises chimneys provided with a hat with a streamlined profile as described above, as well as chimneys provided with conventional hats, for example flat hats, or in the form of Chinese hats, or semi-cylindrical hats. Preferably, in accordance with this embodiment, the chimneys provided with conventional hats are positioned at the periphery of the tray.

[0077] Particularly because of the streamlined profile of the chimney hats as described, the tray in accordance with the invention has good gas distribution quality, which is better, for example, than in the case of a tray with gas chimneys with flat hats or with semi-cylindrical hats, while allowing the pressure drop linked to the use of trays in the column to be limited.

[0078] The quality of the gas distribution may be quantified by various means, for example by determining a specific index IQ, defined as follows:

[00001]$\begin{array}{cc}\mathrm{IQ}=1-\frac{\underset{i=1}{\overset{n}{.Math.}}.Math.\left(.Math.u_i-\stackrel{\_}{U}.Math.\right).Math.A_i}{2.Math..Math.\stackrel{\_}{U}.Math..Math.\underset{i=1}{\overset{n}{.Math.}}.Math.A_i}& \left(1\right)\\ \stackrel{\_}{U}=\frac{\underset{i=1}{\overset{n}{.Math.}}.Math.u_i.Math.A_i}{\underset{i=1}{\overset{n}{.Math.}}.Math.A_i}& \left(\mathrm{II}\right)\end{array}$

[0079] u.sub.i: local velocity over facet i

[0080] A.sub.i: surface area of facet of computational mesh

[0081] The pressure drop, which is a drop in pressure between two levels of the column, may, for example, be measured using manometers, or estimated using CFD (Computational Fluid Dynamics) during simulations.

[0082] The hats 108 may be fixed above the chimneys using any means known to the person skilled in the art, for example by means of fixing tabs attached to the chimney and the hat.

[0083] The tray illustrated in FIG. 5 is a gas distributor tray 100 adapted for use in the bottom of a column for the exchange of heat and/or matter between a gas and a liquid functioning using a counter-current flow, with the gas rising from the bottom of the column through the chimneys 108 of the gas distributor tray for the exclusive passage of gas, and the descending liquid being collected in a liquid collection zone 109, which can then be evacuated from said column. A tray of this type does not include liquid distribution means, allowing liquid to be distributed towards a gas/liquid contactor which would be placed upstream (below the tray).

[0084] The gas distributor tray 100 thus comprises a liquid collection zone 109 comprising two diametrically opposed weirs 109 to collect liquid on the tray 100.

[0085] The term weir means a portion of the tray which is inclined, typically substantially orthogonally, with respect to the portion 101 of the upper face of the tray 100 supporting the chimneys 108, which is positioned at the periphery of the tray and which allows a liquid to overflow towards the base 109 of the tray 100 located at a lower elevation than that of the portion 101 of the upper face of the tray 100. The elevations are evaluated when the tray 100 is in the non-inclined position (i.e. portion 101 of the tray supporting the chimneys in a substantially horizontal plane XY) and disposed in a manner such that the axis Z passing through the chimneys 108 is vertical, corresponding to the position of use of the tray in the gas/liquid exchange column. This can be transposed to all of the elevations mentioned in the present description.

[0086] The weirs 109 are preferably located at the periphery of the gas distributor tray in two diametrically opposed zones and are orthogonal to the portion 101 supporting the chimneys 108. They are, for example, flat plates connecting the portion 101 supporting the chimneys 108 and the base 109 of the distributor tray 100 orthogonal to the planes formed by the portion 101 and the base 109 of the tray 100.

[0087] The collection zone 109 is equivalent to a volume which can be calculated from the diameter of the cylinder in which the tray 100 is inscribed, the height h.sub.1 of the collection zone defined between the base 109 of the tray and the portion 101 supporting the chimneys, and the width L.sub.p of the portion 101 of the tray.

[0088] The collection zone 109 preferably comprises two distinct volumes, each volume being partially delimited by one of the two weirs and a base portion 109 of the tray. The limits of such a volume for the collection zone 109 are represented in dashed lines in FIG. 5. When the tray is positioned in the gas/liquid contact column, each of the two volumes is then also delimited by the internal wall of the column to which the tray is fixed. The two volumes are open towards the top of the tray, i.e. on the side of the chimneys 108, in a manner such as to collect the liquid, and are closed towards the base of the tray, i.e. at the level of the base 109 of the tray. Means for evacuating the collected liquid, such as openings in the tray and conduits, not shown, may be provided in the collection zone 109, in particular in the two volumes of the collection zone. Thus, the liquid can be evacuated from the collection zone towards the bottom of the column in a zone of the column where a liquid trap is formed and from which it can then be withdrawn from the column.

[0089] In accordance with the embodiment illustrated in FIG. 5, the weirs 109 are located at the periphery of the tray 100, for example at two opposed ends of the tray. However, in a tray in accordance with the invention which is adapted for placement at the bottom of the column for the distribution of gas, without a liquid redistribution function, the weirs may be located on central sections for the multi-pass trays, depending on the diameter of the column.

[0090] The present invention is not limited to a gas distributor tray of this type, which can be disposed in the bottom of a column, without a liquid distribution function. In fact, the tray in accordance with the invention may include both a gas distribution function and a liquid distribution function. It always has a liquid collection function.

[0091] In this case, the tray in accordance with the invention may be placed in a column comprising a plurality of sections, each of the sections comprising a gas/liquid contactor, typically a bed of packing, for example a structured bed of packing, and disposed between an upper section and a lower section, the upper and lower sections being in succession in the column, in a manner such as to distribute the gas at the base of the gas/liquid contactor of the upper section and to distribute the liquid at the top of the gas/liquid contactor of the lower section.

[0092] The means for the passage of liquid through the tray carrying out the liquid distribution function may comprise, and preferably be, an assembly of chimneys for the passage of liquid jutting over the upper face of the tray and/or over the lower face of the tray. So that the liquid can pass via the chimneys for the passage of liquid and not via the chimneys for the exclusive passage of gas, the chimneys for the passage of liquid are advantageously lower compared with the chimneys for the passage of gas. The chimneys for the passage of liquid may have different shapes, and be substantially cylindrical, or substantially parallelepipedal, and preferably substantially cylindrical.

[0093] Alternatively, the means for the passage of liquid through the tray may comprise, and preferably be, an assembly of orifices disposed on the tray, in similar manner to the orifices of the plate in accordance with the prior art illustrated in FIG. 2.

[0094] In accordance with another exemplary embodiment of the invention, the means for the passage of liquid through the tray comprise both chimneys and orifices.

[0095] These means for the passage of liquid are preferably disposed between the chimneys for the exclusive passage of gas. The number of means for the passage of liquid is advantageously greater than the number of chimneys for the exclusive passage of gas. The pitch of the means for the passage of liquid may be triangular or square. In order to produce a good distribution of liquid and a good apportionment of liquid over the gas/liquid contactor, the means for the passage of liquid are uniformly distributed over the tray, i.e. located over the whole of the surface of the tray, between the chimneys for the passage of gas.

[0096] Advantageously, a dispersive element for gas is provided inside at least one of the chimneys 108, i.e. an element which ensures the dispersion of gas as it passes through the chimney, thereby generating better distribution (in the sense of homogenization) of gas in the chimney, and thus at the outlet from the chimney.

[0097] Preferably, all of the chimneys of the distributor tray are provided with a dispersive element of this type, in a manner such as to promote homogenization of the stream of gas downstream of the distributor tray.

[0098] This dispersive element is preferably positioned at the base of the chimney, for example in the first third of the chimney. By thus being closer to the base of the chimney than its top, the dispersive element can redistribute the gas over the whole of the surface of the chimney while leaving a sufficient height for stabilization of gas which has passed through the chimney.

[0099] An example of such an embodiment is illustrated in FIG. 7. The dispersive element advantageously comprises a perforated plate 103 comprising circular orifices 104. The plate may alternatively comprise orifices or slots for the passage of gas. The plate 103 is preferably positioned closer to the inlet opening 106 for gas than the gas escape opening 105 of the chimney 108.

[0100] The dispersive element may also be a bulk or structured type packing, preferably of the structured type, in particular because a structured packing can be used to provide the dispersive medium with a uniform density. It may also be a combination of one or more of these elements.

[0101] The term bulk packing is used for disordered, random piles of unitary elements with specific shapes, for example rings, coils, etc. They are generally used to carry out exchanges of heat and/or matter, which occur within these unitary elements. These unitary elements may be formed from metal, ceramic, plastic or analogous materials. The patent applications EP 1 478 457 and WO 2008/067031 describe two examples of a unitary bulk packing element. The bulk packing offers interesting qualities in terms of transfer efficiency, low pressure drop and ease of installation. The geometric area of bulk packing may be in the range 70 to 250 m.sup.2/m.sup.3. The term structured packing is applied to a pile of plates or sheets which are bent and corrugated (i.e. rippled substantially at right angles) and arranged in an organized manner in the form of large blocks as described, in particular, in patent applications FR 2 913 353 (US 2010/0213625), U.S. Pat. No. 3,679,537 and U.S. Pat. No. 4,296,050. They are generally used to carry out exchanges of heat and/or matter which occur on these plates. The structured packings have the advantage of offering a large geometric area for a given representative diameter. The geometric area of structured packing may be in the range 100 to 500 m.sup.2/m.sup.3.

[0102] When the packing is bulk or structured in type, the dispersive element may be distributed inside the chimney or chimneys for the exclusive passage of gas in a uniform manner in the direction of the height of the chimney (along the axis Z) and in a uniform manner along a plane orthogonal to the height of the chimney (in a plane XY). In this manner, the dispersion of the gas passing through the chimney or chimneys is as homogeneous as possible, which means that a constant stream of gas leaves the outlet from the chimney or chimneys over a section corresponding to the section of the chimney or chimneys.

[0103] Again, when a bulk or structured type packing is used, the dispersive element may be uniformly distributed in the chimney over a thickness at least equal to 5 cm in the direction of the height of the chimney. In this manner, the particles of gas passing through such thicknesses of dispersion material are sufficiently dispersed to ensure that the stream of gas leaving the chimneys is homogeneous. It may also be distributed uniformly over the entire height of the chimney or chimneys for the exclusive passage of gas.

[0104] Again, when a bulk or structured type packing is used, the dispersive element is preferably more capacitive than the packing used as a gas/liquid contactor in the column for the exchange of matter and/or heat between a gas and a liquid, and positioned in the form of a bed occupying the whole diameter of the column.

[0105] The invention also concerns a column for the exchange of matter and/or heat between a gas and a liquid, in which the two fluids are brought into contact by means of at least one gas/liquid contactor. A gas/liquid contactor of this type is preferably a bed of structured or bulk packing, as defined above. It may also be any means for gas/liquid contact which can be used to exchange matter and/or heat, such as trays.

[0106] The column in accordance with the invention may be a column as described with reference to FIG. 1, for example adapted to a process for the absorption of acidic compounds such as CO.sub.2, H.sub.2S, COS, carbon disulphide (CS.sub.2), sulphur dioxide (SO.sub.2) and mercaptans (RSH) such as methyl mercaptan (CH.sub.3SH), ethyl mercaptan (CH.sub.3CH.sub.2SH) and propyl mercaptan (CH.sub.3CH.sub.2CH.sub.2SH), contained in a gas to be treated, by the liquid which is an aqueous solution of amine(s). Without an exhaustive repetition of the description already made above of such a column, the column may thus comprise at least one inlet for a liquid (termed the depleted solvent) disposed at the top of the column, at least one inlet for a gas to be treated at the bottom of the column, at least one outlet for the treated gas at the top of the column, and at least one outlet for liquid enriched in contaminants initially contained in the gas to be treated at the bottom of the column (termed the rich solvent). The column advantageously comprises at least one gas/liquid contactor 7, preferably a bed of structured packing, in order to bring the gas to be treated into contact with the depleted solvent.

[0107] The column in accordance with the invention also comprises at least one distributor tray as described above, in order to distribute the gas in a homogeneous manner over the gas/liquid contactor 7, and optionally the liquid, while limiting the pressure drop.

[0108] In accordance with one embodiment, the column comprises a distributor tray as described above, and in particular a tray for the distribution of gas and the collection of liquid comprising a liquid collection zone 109 with diametrically opposed weirs 109, without a liquid redistribution function as illustrated in FIG. 5, disposed at the bottom of the column upstream of any gas/liquid contactor, in order to distribute the gas at the base of said gas/liquid contactor in a homogeneous manner. The distributor tray at the bottom of the column may be preceded by a pre-distribution device for the gas phase (placed upstream of the tray in accordance with the invention).

[0109] The column may comprise a plurality of sections, each section comprising a gas/liquid contactor, preferably a bed of structured or bulk packing, and more preferably a bed of structured packing.

[0110] In accordance with one embodiment, the column is configured in this manner, and a tray in accordance with the invention is disposed between two successive sections in the column, an upper section and a lower section, in order to distribute the gas at the base of said gas/liquid contactor 7 of the upper section and to distribute the liquid at the top of the gas/liquid contactor of the lower section. Such a tray in accordance with the invention advantageously comprises liquid distribution means, or alternatively is associated with a separate liquid distribution device positioned upstream (in the direction of the flow of gas) which can be used to distribute the liquid collected by the tray in accordance with the invention.

[0111] The column in accordance with the invention may be used in a process for the treatment of gas, in particular in a process for the elimination of acidic compounds contained in a gas, by means of a liquid solution based on amine(s), for example in order to treat natural gas, or in a process for the capture of CO.sub.2 which is typically a process for the treatment of gas by means of a liquid solution based on amine(s), for example in order to treat combustion fumes. The column in accordance with the invention may also advantageously be used in a process for the dehydration of gas with the aim of eliminating water (drying) contained in a gaseous effluent, such as natural gas, by bringing the gas into contact with a liquid solvent such as glycol, or in fact it may be used in a process for the distillation of liquid. Other types of solvents may be used in these processes where a column in accordance with the invention may be used.

EXAMPLE

[0112] The example below illustrates certain advantages of the present invention, by comparing the results obtained by using a tray equipped with gas passage chimneys in accordance with the invention, and a tray comprising gas passage chimneys in accordance with the prior art, during a three-dimensional digital simulation based on the fluid mechanics of gas alone.

[0113] In this simulation, only a section of the distributor tray, composed of three chimneys, was simulated. The distribution quality was measured 45 cm above the distributor tray.

[0114] The two tray examples (tray portions) were tested with a surface velocity of gas of 4.3 m/s. The surface velocity of gas in the column is the surface velocity of gas in an empty vessel, which is taken to be the ratio between the volume flow rate of gas under the conditions prevailing in the section (m.sup.3/s) of the column and the section of the column (m.sup.2).

[0115] The example with the tray portion in accordance with the invention had the following features: [0116] diameter of lower body of hat: 0.072 m [0117] angle of hat: 15. [0118] angle of hat: 0. [0119] pitch of dispersive element in the chimneys: [0120] fin length a: 93 mm [0121] gap e: 6.4 cm [0122] chimney height: 55 cm [0123] number of chimneys: 3

[0124] The example with the tray portion in accordance with the prior art had the following features: [0125] type of hat: flat, rectangular in shape [0126] pitch of dispersive element in the chimneys: [0127] gap e: 10 cm [0128] chimney height: 55 cm [0129] number of chimneys: 3

[0130] The results of the simulation are presented in Table 1 below, and also in FIGS. 8 and 9.

TABLE-US-00001 TABLE 1 Pressure drop Index IQ (mbar) (%) Tray in accordance with prior art 1.688 mbar 0.51 (see FIG. 8) Tray in accordance with the invention 0.0654 mbar 0.72 (see FIG. 9)

[0131] The performances of the two trays were evaluated in terms of pressure drop and quality of distribution.

[0132] The quality of the gas distribution could be evaluated by calculating an index IQ. This index may take a value in the range 0 to 1, with the limiting values included. A value close to 1 indicates a good distribution quality, and in contrast, a value close to 0 indicates a poor quality of distribution.

[0133] This index was calculated as follows:

[00002]$\begin{array}{c}\mathrm{IQ}=\mathrm{IQ}=1-\frac{\underset{i=1}{\overset{n}{.Math.}}.Math.\left(.Math.u_i-\stackrel{\_}{U}.Math.\right).Math.A_i}{2.Math..Math.\stackrel{\_}{U}.Math..Math.\underset{i=1}{\overset{n}{.Math.}}.Math.A_i}\\ \stackrel{\_}{U}=\frac{\underset{i=1}{\overset{n}{.Math.}}.Math.u_i.Math.A_i}{\underset{i=1}{\overset{n}{.Math.}}.Math.A_i}\end{array}$

[0134] u.sub.i: local velocity on facet i

[0135] A.sub.i: surface area of facet of computational mesh

[0136] Referring to Table 1 and FIGS. 8 and 9, it will be observed that the use of the tray in accordance with the invention as exemplified means that the gas distribution quality can be significantly improved, compared with the exemplified prior art tray.

[0137] The distribution quality index for the tray in accordance with the invention is in fact 0.72, instead of 0.51 with the distribution elements in accordance with the prior art.

[0138] An image of the velocity of the gas is shown in FIG. 8 in the case of a tray in accordance with the prior art, and in FIG. 9 in the case of the tray in accordance with the invention. More precisely, the contours of the gas velocity fields are given in shades of grey, the scale being shown on the right hand side of each figure, giving the gas velocities in (m/s). The zones Z1 and Z2 have been drawn so that the shades of grey associated with the various velocities are easier to read. Thus, in zone Z1 of the image, reference should be made to the shades of grey for the zone Z1 on the corresponding scale. This is the same for the zone Z2.

[0139] It will be observed in these FIGS. 8 and 9 that the gas velocities are more homogeneous in the case of the tray in accordance with invention (FIG. 9) than in the case of the tray in accordance with the prior art (FIG. 8).

[0140] The proposed invention can also be used to reduce the pressure losses (pressure drops) by 61%.

[0141] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.

[0142] In the foregoing and in the examples, all temperatures are set forth uncorrected in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.

[0143] The entire disclosures of all applications, patents and publications, cited herein and of corresponding French application No. 17/62.231, filed Dec. 15, 2017, are incorporated by reference herein.

[0144] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.

[0145] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.