WIRE FILLING FOR A GAS-LIQUID EXCHANGE DEVICE WITH RADIAL HEAT TRANSFER CAPACITY

Abstract

The invention relates to a basic wire packing unit made of a thermally conductive material, for a gas-liquid exchange apparatus, consisting of three first wires (51, 52, 53) comprising a common upper end (54) located at the apex of an irregular tetrahedron, and each extending vertically to a lower end (57, 55, 56). One of these lower ends (55) is connected to a common upper end (58) of three second vertical wires (59, 510, 511) located at the apex of a regular tetrahedron. A lower portion (515) of the first wire (52) connected to the common upper end (58) of the three second wires has a first curvature, and an upper portion (516) of one of the three second wires (59) connected to the common upper end (58) of the three second wires has a second curvature, the inverse of the first curvature.The unit cell further comprises at least one element of a thermally conductive material oriented horizontally (517). Figure for the abbreviation: Figure 5.

Description

Title of the invention: WIRE PACKING FOR A GAS-LIQUID EXCHANGE APPARATUS WITH RADIAL HEAT TRANSFER CAPACITY Technical field

[0001] The invention relates to a wire packing, that is to say comprising wires, or even consisting of wires, for a gas-liquid exchange apparatus such as a distillation column.

[0002] More specifically, the invention relates first of all to an elementary mesh, or elementary pattern, of wired packing.

[0003] The invention then relates to a filling element comprising these elementary meshes or patterns.

[0004] The invention also relates to a packing comprising these packing elements.

[0005] The invention also relates to a method for preparing a filling according to the invention.

[0006] Other objects of the invention are a packing block formed on the basis of a packing according to the invention, an internal for a “HIDiC” column consisting of several such packing blocks and a column with an internal thermal coupling comprising such an internal.

[0007] The invention also relates to a gas-liquid exchange apparatus comprising a packing according to the invention.

[0008] The technical field of the invention can, in general, be defined as that of packings for gas / liquid exchange devices such as distillation columns, absorption columns (with or without chemical reaction) and gas washing columns.

[0009] The invention finds its application in particular in columns with internal thermal coupling, or energy integrated distillation columns, called “Heat Integrated Distillation Column” (“HIDiC”) in English. STATE OF THE PRIOR ART

[0010] A packed column, whether a distillation column or otherwise, is a column which is filled with elements making it possible to increase the contact surface between a gas phase and a liquid phase.

[0011] The packing creates a series of obstacles on the path of the liquid and gas within the column and allows: - to increase the contact surface between the two phases; - to increase the residence time of the two phases in the column and therefore their contact time; - to create a turbulent regime in the gas phase, and recirculation in the liquid phase.

[0012] The efficiency of a packed column depends on the surface area of ​​the packing, the contact time between the two phases, gas and liquid, and the hydrodynamics within each phase. These phases must be brought into contact homogeneously over the entire length of the column and over the entire section.

[0013] The distillation columns may be tray columns or packing columns as defined above.

[0014] The packings currently marketed are of two types, namely structured packings and loose packings or more simply packings. These two types of packing are however based on the same principle, namely a flow of a liquid film on a flat surface.

[0015] One of the first structured fillings was made of sheets, corrugated iron.

[0016] The improvements made to these fillings, which make it possible to increase their performance, are: - modification of the surface condition of corrugated sheets, most of the time by adding roughness or perforations which will create turbulence and improve wettability; - machining of slats made up of twisted elements equipped with notches; - the addition of flat walls between the corrugated sheets.

[0017] The sheets can also be replaced by woven metal cloths. These woven cloths develop large contact surfaces and thus significantly increase the transfer efficiency. However, it seems that these packings require low-fouling fluids and a very homogeneous liquid distribution. In addition, these packings are limited to beds of small thickness because they are unable to maintain a good liquid distribution over a great height. Finally, due to their very tight mesh, these packings made of woven metal cloths have a low hydrodynamic capacity. For these reasons, these packings are not or are rarely used on an industrial scale, but rather only on a laboratory pilot scale.

[0018] Recently, packings made of wires, and generally having a lattice structure, have been proposed.

[0019] Indeed, the flow of liquid, in the form of a film, on a wire forming part of a packing, has an interfacial surface greater than the geometric surface of the wire.

[0020] On the other hand, in the case of packings made up of plates, the interfacial surface of the liquid flow on a plate is more or less equal to the geometric surface (neglecting the waves at the interface and the problems of wettability).

[0021] Thus, for the same geometric surface, the interfacial surface is higher for a packing made up of wires, than for a packing made up of plates, in the case where the entire surface of the wire is wetted by the liquid.

[0022] These packings made up of wires, and generally having a grid structure, also called wire “lattice” packings, can have different geometries, in particular a geometry with a fractal structure created by the assembly of regular tetrahedra or a geometry created by the assembly of structures analogous to DNA (deoxyribonucleic acid).

[0023] These wire packings are more efficient in terms of material transfer and pressure loss than known structured packings.

[0024] Thus, document FR-A1-3 113 610 describes a wire packing for a material exchange apparatus, in particular a gas-liquid exchange apparatus, such as a distillation column. The wires of this packing have a cross-section whose general shape is a polygon, at least one of the sides of said polygon being concave and / or convex. These wires form elementary structures also called basic structures which are repeated, assembled in space to form the packing.

[0025] The elementary structures can be regular or irregular polyhedra.

[0026] In particular, the packing may be constituted by packing patterns formed by the vertical assembly of a lower regular tetrahedron 11 and an upper irregular tetrahedron 12. Figure 5B of document FR-A1-3 113 610, as well as the present [Fig.l], [Fig.2] and [Fig.3] show such an assembly, in which the upper tetrahedron 12 is an irregular tetrahedron and the two tetrahedra 11, 12 are connected by two curved, rounded wire portions 13, 14. In other words, the packing pattern comprises two curvatures (“splines”) 13, 14 and the tetrahedra are then called “tetraspline” (TS).

[0027] The packing pattern may be referred to as a TS packing pattern, and the overall packing may be referred to as a TS packing, which may be described as a porous periodic network structure composed of the previously described packing patterns.

[0028] The TS structure is characterized by the geometric parameters listed below and shown herein [Fig.l], [Fig.2] and [Fig.3]: - dw: wire diameter (mm), generally the same for all wires, -11: length of the edge in the lower regular tetrahedron (mm), -12: length of the edge in the upper irregular tetrahedron (mm), generally equal to 11, - al: angle of the tangent of the curvature (“spline”') with the vertical in the regular tetrahedron (°), fixed for example at 30°, - a2: angle of the tangent of the curvature (''spline'') with the vertical in the irregular tetrahedron (°), fixed for example at 40°.

[0029] The repetition of the elementary patterns along the axes e1, e2, and e3 shown in [Fig.l] gives a parallelepiped. A cylindrical block of TS filling, as shown in [Fig.4], can then be extruded.

[0030] The nomenclature used for TS structures is as follows: TS-X-dw-11, where X is the material constituting the wires (for example PA for polyamide, AI for 316L stainless steel) and where dw and 11 have already been defined above.

[0031] The material transfer and hydrodynamic capacity of the wire packing described in document FR-A1-3 113 610 are good.

[0032] However, the performance in terms of heat transfer, heat transfer of distillation columns comprising wire packing, for example wire packing made up of “tetrasplines” such as that described in document FR-A1-3 113 610, is very insufficient.

[0033] Furthermore, if the wire packings made up of "tetrasplines" prevent preferential vertical flows of gas in the distillation columns, in particular in the "HIDiC" columns, it has been found that the wire packings made up of "tetrasplines" nevertheless cause a preferential flow, but this time lateral, of the gas.

[0034] Furthermore, in the material and energy processing industries, and in particular in the chemical industry, energy costs are mainly due to separation processes which are generally thermal separation processes, and distillation remains one of the most important thermal separation processes in the chemical process industry.

[0035] However, despite its many advantages and widespread use, the major drawback of distillation lies in its significant energy requirements. Indeed, distillation can generate more than 50% of the operating costs of a facility. It alone represents 40% of the total energy consumed by the chemical industry, and approximately 3% of global energy demand.

[0036] Reducing the energy consumption of distillation columns is therefore a major issue in the current energy context.

[0037] The current high energy consumption of distillation columns is coupled with a very low thermodynamic efficiency, between 5 and 15%. Indeed, in a conventional distillation, the energy is supplied to the boiler at a high temperature level and removed from the condenser at a low temperature level, which constitutes a high exergy degradation.

[0038] In order to increase the energy and / or exergy efficiency of these columns, several solutions have been proposed, namely: - a column with vapor recompression (VRC), - an adiabatic column, - two columns with external thermal coupling, - a column with internal thermal coupling, or energy-integrated distillation column, called an energy-integrated distillation column (“Heat In-tegrated Distillation Column” in English) (“HIDiC”).

[0039] The "HIDiC" column combines the advantages of the CRV column and the adiabatic column. In a "HIDiC" column, heat is transferred from the hot enrichment zone to a cooler depletion zone, leading to gradual evaporation throughout the depletion zone, while managing condensation throughout the enrichment zone. In order to make this heat exchange feasible, the enrichment zone operates at a higher pressure than the depletion zone. The advantage of a "HIDiC" column compared to a CRV column lies in the pressure jump to be achieved which is much lower in a "HIDiC" column than in a CRV which minimizes re-compression costs. The principle of "HIDiC" columns is widely documented and examples are published in the literature which show the expected gain on test mixtures.

[0040] “HIDiC” columns, due to the type of packing they use, can achieve highly efficient heat transfer. On the other hand, “HIDiC” columns, also due to the type of packing they use, can have a very low separation capacity.

[0041] A column of the “HIDiC” type is described in document WO-A1-2020 / 169934, which relates to a device capable of carrying out a heat transfer between a first and a second fluid circulating respectively on either side of a thermally conductive wall. This device comprises a first thermally conductive three-dimensional alveolar structure capable of being crossed by the first fluid and a second thermally conductive three-dimensional alveolar structure capable of being crossed by the second fluid. The first three-dimensional alveolar structure and the second three-dimensional alveolar structure are located on either side of said wall and secured to said wall, so that the heat transfer is carried out from the first fluid to the second fluid through said wall. Said device may be a distillation column, in particular an “HIDiC” column.In the device of this document, the packing which is in the form of a foam allows to obtain an excellent efficiency of the thermal transfer, but the hydrodynamic capacity of the column is very insufficient.

[0042] There therefore exists, in view of the above, a need for a packing for a gas-liquid exchange apparatus, such as a distillation column, which has, like the packing described in document FR-A1-3 113 610, excellent properties of material transfer and high separation capacity, but which also has, unlike this packing, improved performance in terms of thermal transfer, heat transfer, and which furthermore does not have preferential flow paths, in particular preferential gas flow paths.

[0043] There also exists, in view of the above, a need for a packing for a gas-liquid exchange apparatus, such as a distillation column, in particular a “HIDiC” column, which has, like the packing described in document WO-A1-2020 / 169934, excellent heat transfer and mass transfer properties but which also has, unlike this packing, a high hydrodynamic capacity.

[0044] There is still a need for a packing which does not have the drawbacks, defects and disadvantages of the packings of the prior art, such as those described above, and which solves the problems posed by the packings of the prior art.

[0045] Finally, there is a need for such a filling which can be manufactured simply, easily, and at low cost, even if it has a complex shape.

[0046] The aim of the present invention is to meet, among other things, these needs. Statement of the invention

[0047] This aim, and others still, are achieved, in accordance with the invention, by an elementary mesh (or pattern) of wire packing made of a thermally conductive material, for a gas-liquid exchange and / or heat transfer apparatus for example. This elementary mesh comprises, preferably is constituted by, three first wires comprising a common upper end located at the upper vertex of a first irregular tetrahedron, said three first wires each extending vertically from said first upper end, along three edges of the first tetrahedron, to three lower ends located at the three lower vertices of a base triangle of the first tetrahedron.A lower end of one of said three first wires is connected to a common upper end of three second wires, located at the upper vertex of a second regular tetrahedron, said three second wires each extending vertically from said upper end, along three edges of the second tetrahedron, to three lower ends located at the three lower vertices of a base triangle of the second tetrahedron. A lower part of said first wire connected to the common upper end of the three second wires has a first curvature, and an upper part of one of the three second wires connected to the common upper end of the three second wires has a second curvature, inverse to the first curvature. The elementary mesh further comprises at least one element made of a thermally conductive material oriented horizontally.

[0048] The threads can also be called strands or rods.

[0049] The first curvature and the second curvature can be called "splines".

[0050] Materials defined as thermally conductive materials, also called heat-conducting materials, are known to those skilled in the art.

[0051] By thermally conductive material or heat-conducting material, we generally mean a material whose thermal conductivity X is from 20 to 400 W / mK, preferably from 160 to 400 W / mK.

[0052] The elementary packing mesh according to the invention differs from the elementary mesh described in document FR-A1-3 113 610 by the characteristic according to which it further comprises at least one element made of a thermally conductive material oriented horizontally.

[0053] It has been found that the presence, in the elementary packing mesh according to the invention, of at least one element made of a thermally conductive material oriented horizontally greatly improves the heat transfer of a wire packing in which it is integrated, compared to the packing of document FR-A1-3 113 610, and this, without degrading the transfer of material and the hydrodynamic capacity of the packing.

[0054] In other words, in a wire packing comprising the elementary packing mesh according to the invention, preferably entirely formed of such elementary meshes, and thanks to said at least one element made of a horizontally oriented thermally conductive material, the transfer of material is maintained, the capacity is maintained, or even considerably increased compared to the foam packing of document WO-A1-2020 / 169934, and the heat transfer is improved compared to the packing of document FR-A1-3 113 610, but also, surprisingly, compared to the packing of document WO-A 1-2020 / 169934, even though the foam packings of this document already have excellent heat transfer properties.

[0055] The elementary packing mesh according to the invention may comprise any number of elements made of a thermally conductive material oriented horizontally. It may, for example, comprise two, three, four or even five.

[0056] There is no limitation on the shape that said elements made of a thermally conductive material oriented horizontally can take.

[0057] In the elementary mesh according to the invention, such an element made of a horizontally oriented thermally conductive material can connect together two of said first wires, and / or two of said second wires. At least one such element preferably connects together two lower ends of said first wires, and / or two lower ends of said second wires. Said element made of a horizontally oriented thermally conductive material can also, or otherwise, be arranged in such a way that it is capable of connecting one of said tetrahedron vertices of the elementary mesh elementary, with a tetrahedron vertex of another elementary mesh, located at the same height in a wire packing in the constitution of which these elementary meshes enter.

[0058] Each of the elements made of a thermally conductive material oriented horizontally can be chosen from straight, rectilinear horizontal wires, curved or rounded horizontal wires, also called arcs, vertical plates, straight, rectilinear horizontal wires, each supported by vertical half-plates, and straight, rectilinear horizontal wires extending on either side of the vertices of the tetrahedra and supported symmetrically on either side of these vertices by vertical quarter-plates.

[0059] The arcs can be convex or concave in the vertical direction.

[0060] Here too, the threads can also be called strands or rods.

[0061] The invention further relates to a wired packing element comprising, preferably consisting of, the assembly of two elementary meshes as described above, superimposed vertically, one of said meshes having undergone a rotation of 180° relative to a vertical axis, relative to the other of said meshes.

[0062] The packing element according to the invention has all the advantageous properties of the elementary meshes which constitute it and which have already been described above.

[0063] Furthermore, the rotation of one of the meshes relative to the other by 180° makes it possible to control the flow, in particular the flow of gas, in the wire packing in which this packing element is integrated, and to avoid all preferential flows, in particular lateral gas flows such as those which occur in the packing which is the subject of document FR-A1-3 113 610.

[0064] Thus, the packing element according to the invention comprises, preferably consists of, two elementary meshes each comprising two “Tetraspline” type patterns, i.e. a total of four “Tetraspline” type patterns.

[0065] A first characteristic of the wire packing element according to the invention, namely the presence of elementary meshes with at least one element made of a thermally conductive material oriented horizontally, makes it possible to greatly improve the heat transfer of the wire packing in which it is integrated, while retaining, or even improving, the transfer of material and the hydrodynamic capacity of the packing. A second characteristic, namely the 180° rotation of the two elementary meshes relative to each other, provides a solution to the problem of preferential flows, in particular preferential gas flows.

[0066] The combination of these two characteristics further improves the transfer of material.

[0067] The assembly of the two elementary meshes can be carried out at the level of any zone of the upper elementary cell and of any zone of the lower elementary cell, the upper elementary cell being defined as the elementary cell located above above the other unit cell along the vertical axis, and the lower unit cell being defined as the unit cell located below the other unit cell along the vertical axis. For example, the lower unit cell may be joined to the upper unit cell by connecting a lower end of a second vertical wire of the second tetrahedron (lower tetrahedron) of the upper unit cell to the upper vertex of the first tetrahedron (upper tetrahedron) of the lower unit cell. Elements made of a thermally conductive material oriented horizontally may also, or otherwise, be connected with those of another unit cell.

[0068] The invention also relates to a wire packing comprising, preferably consisting of, the assembly of several packing elements as described above.

[0069] The wire packing (global, complete) according to the invention, comprising the assembly of several packing elements, may in particular have a cylindrical shape, which is the most common shape of the devices in which the wire packing according to the invention can be used.

[0070] This packing has a radial heat transfer capacity. It is particularly optimal for energy integration / heat transfer.

[0071] The invention also relates to a method for preparing a wire lining according to the invention as described above, according to which the wire lining is manufactured by an additive manufacturing technique, preferably by a laser melting technique.

[0072] The laser melting technique is the preferred manufacturing technique because it allows obtaining the finesse required for the desired applications.

[0073] The invention also relates to a packing block comprising a body formed from wire packing according to the invention, said packing block preferably being a circular cylindrical packing block for a circular cylindrical concentric “HIDiC” column, typically formed by the vertical assembly of several circular cylindrical packing blocks. The body of said packing block is of circular cylindrical shape and is defined respectively by an upper cross section and a lower cross section. It is crossed by a circular cylindrical internal vertical wall extending between this upper cross section and this lower cross section and comprising an upper edge at the level of said upper cross section.Circular cylindrical vertical orifices pass through said body between said upper cross section and said lower cross section, preferably at the level of the circular cylindrical internal vertical wall. The upper edge of the circular cylindrical internal vertical wall is further provided with a groove intended to receive a sealing gasket.

[0074] This packing block can be manufactured by an additive manufacturing technique, for example by a laser melting technique, the packing and the circular cylindrical internal vertical wall preferably being formed simultaneously. In particularly preferred embodiments of the invention, the packing and the circular cylindrical internal vertical wall are further formed in one piece. Such a characteristic advantageously makes it possible to obtain particularly good thermal performance, in particular because the packing block obtained is then free of thermal bridges, unlike the packing blocks of the prior art in which the packing and the circular cylindrical internal vertical wall are made up of two separate pieces assembled to each other.

[0075] Advantageously, a resin may further be placed in the groove of the upper edge of the circular cylindrical internal vertical wall, preferably under the seal, to compensate for roughness, due for example to additive manufacturing and to avoid a complicated machining operation.

[0076] Advantageously, indexes or markers may be provided at the level of the upper cylindrical cross-section of the body formed from wire lining, in particular at the level of the upper edge of the cylindrical internal vertical wall, in order to control the rotation of one block relative to another block, and ensure geometric continuity, when assembling the lining blocks to each other to form the column.

[0077] The invention further relates to an internal for a concentric circular cylindrical “HIDiC” column, constituted by the vertical assembly of several packing blocks according to the invention, as defined above, of circular cylindrical shape, a sealing joint being placed in the groove of at least one of said packing blocks, preferably of each of said blocks, and the assembly being ensured by: - ​​threaded rods, at least at one of their ends, preferably at least at their two opposite ends, passing through all of said packing blocks and placed in the circular cylindrical vertical orifices of each of said packing blocks, so as to assemble them to each other along the axis of the rods; - and clamping bolts mounted on these threaded rods, engaging with the thread(s) of the latter, so as to lock the assembly of said packing blocks.

[0078] The groove combined with the seal of a given packing block ensures the sealing of the assembly to the packing block arranged immediately above, while the threaded rods and the associated clamping bolts ensure the pressure resistance of this assembly.

[0079] The invention also relates to a gas-liquid exchange apparatus comprising a wire packing according to the invention, in particular an assembly, in particular vertical, of packing blocks according to the invention, and more particularly an internal according to the invention.

[0080] This gas-liquid exchange apparatus can be chosen from distillation columns, absorption columns, stripping columns and heat exchangers.

[0081] In particular, this gas-liquid exchange apparatus may be a column with internal thermal coupling, also called an energy integrated distillation column, called a “Heat Integrated Distillation Column” (“HIDiC”) in English, preferably a concentric “HIDiC” column.

[0082] These gas-liquid exchange devices can be already existing devices in which the wire packing according to the invention can replace an old packing with lower performance, or new devices.

[0083] The gas-liquid exchange devices using wire packing according to the invention can also be called, for simplification, “packed columns”.

[0084] An object of the invention is in particular a column with an internal thermal coupling, also called an energy integrated distillation column, called a “Heat Integrated Distillation Column” in English (“HIDiC”\ preferably a concentric “HIDiC” column, comprising an internal according to the invention, as defined above, and a cylindrical external vertical wall inside which this internal is arranged.

[0085] The invention will be better understood upon reading the following detailed description of particular embodiments. This description is given for illustrative and non-limiting purposes and is made in relation to the attached drawings. Brief description of the drawings

[0086] [Fig.l] [Fig.l] is a 3-dimensional (3D) perspective view of a “Tetraspline” packing mesh, showing the repeat axes e1, e2, and e3.

[0087] [Fig.2] [Fig.2] is a side sectional view in the XZ plane of a mesh of “Tetraspline” packing, showing the diameter dw and the axis e3.

[0088] [Fig.3] [Fig.3] is a side section sketch in the XZ plane of a mesh of “Tetraspline” packing, showing the curvature angles (“spline”) and the lengths 11 and 12 of the wires, strands of the tetrahedra.

[0089] [Fig.4] [Fig.4] shows a cylindrical block formed from a TS packing.

[0090] [Fig.5] [Fig.5] is a 3D perspective view showing an example of a first embodiment of an elementary wire packing mesh according to the invention, in which the horizontally oriented elements are curved horizontal wires or strands.

[0091] [Fig.6] [Fig.6] is a 3D perspective view showing an example of a second embodiment of an elementary wire packing mesh according to the invention, in which the horizontally oriented elements are plates vertical.

[0092] [Fig.7] [Fig.7] is a 3D perspective view showing another example of the second embodiment of an elementary wire packing mesh according to the invention.

[0093] [Fig.8] [Fig.8] is a 3D perspective view which shows a still different example of the second embodiment of an elementary wire packing mesh according to the invention.

[0094] [Fig.9] [Fig.9] is a 3D perspective view showing an example of a third embodiment of a wire packing unit mesh according to the invention, in which the unit mesh comprises an additional wire (it is then a “Pentaspline” (PS) unit mesh) and this unit mesh comprises additional horizontal elements.

[0095] [Fig. 10] [Fig. 10] is a 3D perspective view showing an example of a fourth embodiment of an elementary wire packing mesh according to the invention, in which the horizontally oriented elements are straight, rectilinear horizontal rods or strands, each supported by vertical half-plates.

[0096] [Fig. 11] [Fig. 11] is a 3D perspective view showing an example of a fifth embodiment of an elementary wire packing mesh according to the invention, in which the horizontally oriented elements are constituted by straight horizontal rods extending on either side of the vertices of the tetrahedra and supported symmetrically on either side of these vertices by vertical quarter plates.

[0097] [Fig. 12] [Fig. 12] is a view in the XZ plane of the elementary packing cell of [Fig. 11].

[0098] [Fig. 13] [Fig. 13] is a partial sectional view of a still different example of the fifth embodiment of an elementary wire packing mesh according to the invention, without a net.

[0099] [Fig. 14] [Fig. 14] shows, in the XZ plane, a geometry of a classic TS packing with a vertical repetition of the elementary TS patterns along an inclined axis e3 and a horizontal repetition along the X axis.

[0100] [Fig. 15] [Fig. 15] shows, in the XZ plane, a geometry of a wire packing according to the invention comprising the assembly of elementary meshes TS, formed by the periodic repetition, along the X and Z axes, of the assembly of two elementary meshes, one of which has undergone a rotation of 180 degrees relative to the other along the Z axis.

[0101] [Fig. 16] [Fig. 16] is a 3D perspective view showing a wire packing element according to the invention, comprising two elementary meshes according to the fifth embodiment of the invention described below, the lower mesh having rotated 180° about the vertical Z axis.

[0102] [Fig. 17] [Fig. 17] shows a packing block according to the invention for a circular cylindrical concentric “HIDiC” column.

[0103] [Fig. 18] [Fig. 18] shows components of a packing block according to the invention, for a concentric circular cylindrical “HIDiC” column, more particularly, in a / a perspective view of the circular cylindrical internal vertical wall of this packing block, and in b / a perspective view cut at 1 / 4 of this packing block.

[0104] [Fig. 19] [Fig. 19] illustrates the assembly, to constitute an internal according to the invention, of the circular cylindrical internal vertical walls of two packing blocks according to the invention, in perspective cut at 1 / 4.

[0105] DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0106] With reference to [Fig. 5], the elementary mesh of wire packing according to the invention, made of a thermally conductive material, for a gas-liquid exchange device, comprises three first wires 51, 52, 53 comprising a common upper end 54 located at the upper vertex of a first irregular tetrahedron, said three first wires 51, 52, 53 each extending vertically from said first common upper end 54, along three edges of the first tetrahedron, to three lower ends respectively 57, 55, 56 located at the three lower vertices of a base triangle of the first tetrahedron, a lower end 55 of one of said three first wires (referenced 52 in [Fig.5]) being connected to a common upper end 58 of three second wires 59, 510, 511 located at the upper vertex of a second regular tetrahedron, said three second wires 59, 510, 511 each extending vertically from said common upper end 58, along three edges of the second tetrahedron, to three lower ends respectively 514, 512, 513 located at the three lower vertices of a base triangle of the second tetrahedron. A lower portion 515 of the first wire 52, connected to the common upper end 58 of the three second wires 59, 510, 511, has a first curvature, and an upper portion 516 of one of the three second wires (referenced 59 in [Fig. 5]), connected to the common upper end 58 of the three second wires, has a second curvature, this second curvature being the opposite of the first curvature. The elementary mesh further comprises at least one element made of a thermally conductive material 517, oriented horizontally.

[0107] The elementary wire packing mesh, also called elementary wire packing pattern, according to the invention can be defined as an elementary TS packing pattern, as described above and in Figures 1, 2, and 3, the structure of which has been modified by adding one or more horizontally oriented elements which improve the radial heat flow, such as horizontal strands, wires or vertical plates.

[0108] The addition of horizontally oriented elements does not degrade the hydrodynamic properties of the wire packing.

[0109] The description given above of the elementary TS filling patterns also applies to the elementary patterns according to the invention. However, unlike the patterns described in document FR-A1-3 113 610, the shape of the section of the wires of the elementary patterns according to the invention can be any, and is not limited to a polygon shape, at least one of the sides of the polygon being concave and / or convex. The shape of the section of the wires of the elementary patterns according to the invention can in particular be a circle, ellipse, or polygon shape. Furthermore, the elementary patterns according to the invention comprise one or more horizontally oriented elements 517 that the elementary TS patterns do not comprise.

[0110] The parameters defining the elementary meshes according to the invention are therefore the following, as shown in [Fig.l], [Fig.2] and [Fig.3]: - dw: largest dimension of the section of the wires arranged along the edges of the tetrahedra, for example diameter of the wires (mm), generally the same for all the wires, generally from 0.5 to 3.0 mm, preferably from 1.5 to 3.0 mm; -11: length of the edge in the lower regular tetrahedron (mm), generally 7 to 20 mm, preferably 12 to 16 mm; -12: length of the edge in the upper irregular tetrahedron (mm), generally equal to 11, generally 7 to 20 mm, preferably 12 to 16 mm; - al: angle of the tangent of the “spline” (curvature) with the vertical in the regular tetrahedron (°), generally from 30 to 40°, for example 30°; - a2: angle of the tangent of the “spline” (curvature) of a single strand with the vertical in the irregular tetrahedron (°), generally from 30 to 50°, for example for example 40°.

[0111] Preferably, the angles al and a2 are different, for example a2 = al + 10°.

[0112] The horizontally oriented elements can take various forms.

[0113] According to a first embodiment of the elementary wire packing mesh according to the invention, an example of which is shown in [Fig.5], the horizontally oriented elements may be curved horizontal wires, rods or strands 517, in other words arcs, preferably concave arcs oriented upwards.

[0114] In [Fig.5], the tangent of the arc forms an angle of 45° with the horizontal. The diameter of the wires of the horizontal strands is the same as that of the wires of the elementary pattern TS arranged along three tetrahedron edges.

[0115] In [Fig. 5], three horizontal strands 517 have been added per elementary mesh. Two horizontal strands are placed in the upper tetrahedron and each connect two lower vertices, respectively at the lower ends 55, 56, and 55, 57, of the wires of the upper tetrahedron, and the third is placed in the lower tetrahedron and connects two lower vertices at the lower ends 512, 513 of the wires of the bottom tetrahedron. The horizontal strands 517 are placed so as to repeat the symmetry of the elementary cell.

[0116] Any other number of horizontal strands may be provided according to the invention, in particular a number of 4 or more.

[0117] Said horizontal wires, rods or strands 517 are preferably curved. They may have a larger cross-sectional dimension, for example a diameter, of between 1.5 and 3 mm.

[0118] According to a second embodiment of the elementary wire packing mesh according to the invention, examples of which are shown in [Fig.6], [Fig.7] and [Fig.8], the horizontally oriented elements may be vertical plates 61, 71, 72, 81, 82.

[0119] The vertical plates improve radial heat transfer without significantly affecting the hydrodynamic performance (capacity) of the TS geometry. Heat flow is better due to the orientation of the vertical plates and the additional surface area. In addition, the steam flow is not significantly disturbed.

[0120] The thickness, number, and positioning of the vertical plates may vary.

[0121] Generally, the thickness of the plates can range from 0.3 mm to 2 mm, in particular being approximately 0.5 mm.

[0122] The number of vertical plates is generally 1 to 3, especially 2. It is not advantageous to add more than three plates because this would clutter the geometry, create a significant pressure drop and increase the probability of premature flooding of the column packed with such elementary meshes.

[0123] In all cases, the plates are designed to follow the same curvature (“spline”) as the wires of the elementary TS pattern.

[0124] Two types of positioning of the vertical plates can be distinguished.

[0125] A first type of positioning, examples of which are shown in [Fig.6] and [Fig.7], is a positioning between two adjacent elementary meshes. In other words, each plate 61, 71, 72 fills the space between two wires belonging to different elementary meshes.

[0126] This first positioning is better from a hydrodynamic point of view because the plates do not add additional obstacles to the gas flow. The gas flow is oriented laterally, but the pressure drop is not affected.

[0127] [Fig.6] and [Fig.7] show only one of the two elementary meshes.

[0128] The elementary mesh shown in [Fig.6] comprises only one plate vertical 61 fixed to one of the wires 513 of the bottom tetrahedron of the elementary mesh TS, with a thickness for example of 0.5 mm, 1 mm, or 2 mm.

[0129] In the elementary mesh shown in [Fig.7], in addition to a first plate 71 in the lower tetrahedron, a second plate 72, with a thickness of e.g. 0.5 mm, is added in the upper tetrahedron.

[0130] A second type of positioning, shown in [Fig.8], is a positioning of the plates 81, 82 between two wires of the same elementary mesh TS.

[0131] According to a third embodiment of the elementary mesh of wire packing according to the invention, an example of which is shown in [Fig. 9], the elementary mesh may comprise a first additional vertical wire and / or a second additional vertical wire (it is then a “Pentaspline” (PS) elementary mesh, i.e. a 3-dimensional mesh with 5 faces, and no longer a “Tetraspline” TS)). This elementary mesh may further comprise one or more additional horizontal elements, for example in the form of arcs, as already described above with reference to [Fig. 5].

[0132] Thus, the elementary mesh shown in [Fig.9] comprises two regular pentahedra 91, 92 with edges formed from wires of the same length, for example 15.35 mm, and of the same diameter, for example 2.25 mm. This elementary mesh further comprises two horizontal elements 93, 94 respectively connecting two vertices of the top pentahedron and two vertices of the bottom pentahedron.

[0133] The angle of the curves ("spline") with the vertical axis Z is 35° for all the wires of the elementary mesh TS. This angle is chosen so that the porosity is 90%.

[0134] According to a fourth embodiment of the elementary wire packing mesh according to the invention, an example of which is shown in [Fig. 10], the horizontally oriented elements are straight, rectilinear horizontal wires, rods or strands, each supported by vertical half-plates.

[0135] This fourth embodiment is a combination of the first and second embodiments described above.

[0136] The reason for using a half-plate is that the structure is thus less cluttered and the heat flux is less dispersed. In addition, the change caused on the fluid flow is small because the horizontal strands are added between the wires of two adjacent TS elementary meshes.

[0137] In the embodiment shown in [Fig.10], three straight horizontal rods 101, 102, 103, supported by vertical half-plates 104, 105, 106, are added to the elementary mesh TS.

[0138] The diameter of the vertical wires of the elementary mesh TS is for example chosen at 2.25 mm, giving the elementary mesh good hydrodynamic and separation performance, as well as better wetting.

[0139] Generally, said straight horizontal wires, rods or strands may have a larger dimension of the cross-section of the wires, for example a diameter, of 1.0 to 3.0 mm, this larger dimension being able to be constant or variable according to the axis of the strands.

[0140] The diameter of the straight horizontal rods 101, 102, 103 is preferably equal to or less than that of the vertical wires, so as to limit the solid density of the structure and to maximize its porosity rate. This diameter is for example 2 mm, which is slightly less than the diameter of the wires, strands of the elementary mesh TS which is for example 2.25 mm. Such a diameter of 2 mm also makes it possible to avoid superfluous details and annoying points of intersection between the rods and the wires, strands.

[0141] As shown in [Fig.10], the shape of the upper half-plate 104 makes the structure slightly asymmetrical.

[0142] The thickness of the half-plates can range from 0.3 mm to 2 mm, preferably being approximately 0.5 mm.

[0143] Generally, for each of the embodiments described here, the number, positioning and / or diameter / thickness of the horizontal strands / vertical plates or half-plates may vary.

[0144] According to a fifth embodiment of the elementary wire packing mesh according to the invention, examples of which are shown in [Fig. 11], [Fig. 12] and [Fig. 13], the horizontally oriented elements are constituted by straight, rectilinear horizontal rods 111, 112, 113 extending on either side of the vertices of the tetrahedra and supported symmetrically on either side of these vertices by vertical quarter plates respectively 114 and 115, 118 and 119, 116 and 117.

[0145] In [Fig.11], [Fig.12] and [Fig.13], the elementary mesh comprises three straight horizontal rods 111, 112, 113, namely two straight horizontal rods 112, 113 at the top of the bottom tetrahedron and one straight horizontal rod 111 at the top of the top tetrahedron.

[0146] The main difference compared to the fourth embodiment is that this geometry is symmetrical with respect to the vertical plane (XZ), as can be seen in particular in [Fig. 11].

[0147] The use of quarter plates makes the geometry less cluttered. In addition, the preferential passages for the gas are limited due to the symmetry. The quarter plates, as shown in the figures, are preferably triangular in shape. Alternatively, they may have an arc of a circle shape.

[0148] In this configuration, generally, said straight horizontal wires, rods or strands may have a larger cross-sectional dimension, for example a diameter, of 1.5 to 3.0 mm.

[0149] For example, the rods, horizontal strands 111, 112, 113 may have a diameter of 1.5 mm.

[0150] Generally, the thickness of the quarter plates can range from 0.3 mm to 2 mm, preferably from 0.5 mm to 2 mm. The thickness of the quarter plates can for example be 0.5 mm. The main role of quarter plates is to support the rods, horizontal strands, which is why their volume is advantageously limited, since they are quarter plates. Another advantage of quarter plates is the increase in surface area.

[0151] A net 121, for example 1.5 mm in diameter, may be added between the quarter plates and the rods, horizontal strands, as shown in [Fig. 12], for example, between the rod 113 and the quarter plates 116, 117. This net 121 is a rounding of the edges between the rods, horizontal strands and the vertical quarter plates which support them. Such nets make the structure more aerodynamic compared to the same structure but without a net, shown in [Fig. 13].

[0152] As mentioned above, when describing the geometry of a conventional TS packing, this geometry does not include a vertical repetition of the elementary patterns along the Z axis, but along an inclined axis e3, as shown in [Fig. 14]. Each rectangle drawn in [Fig. 14] represents a conventional TS elementary pattern which is periodic along X, Y and e3.

[0153] When an elementary mesh is repeated twice vertically, along the inclined axis e3, and one of these meshes is rotated 180° relative to the other mesh along the Z axis, a wire packing element is then created comprising the assembly of two elementary meshes arranged vertically relative to each other, one of said elementary meshes having undergone a rotation of 180° relative to a vertical axis, as illustrated in [Fig. 15]. Each rectangle drawn in [Fig. 15] represents a wire packing element according to the invention, which is periodic along X, Y, and Z. It is a rotation of this type which is carried out in the wire packing elements according to the invention, which however comprise, not TS elementary meshes, but elementary meshes according to the invention, comprising horizontally oriented elements.

[0154] A wire packing element according to the invention, comprising two elementary meshes according to the fifth embodiment described above, the lower mesh having undergone a rotation of 180° relative to the Z axis, is shown in [Fig. 16]. The constituents of a first elementary mesh according to the invention (upper mesh) are observed there, in particular the horizontal strands 111, 112, 113 and the vertical quarter plates respectively 114 and 115, 118 and 119, 116 and 117, which support them; as well as the constituents of a second elementary mesh according to the invention (lower mesh), in particular the horizontal strands 111', 112', 113' and the vertical quarter plates respectively 114' and 115', 118' (the quarter plate 119' not being visible in the figure), 116' and 117', which support them.

[0155] In the embodiment shown in [Fig.16], the lower link is assembled to the upper link by connecting a lower end 514 of a second vertical wire 52 of the second tetrahedron (lower tetrahedron) of the upper elementary mesh, to the upper vertex 54' of the first tetrahedron (upper tetrahedron) of the lower elementary mesh. Such an embodiment is however in no way limiting of the invention.

[0156] To prepare the final complete wire packing according to the invention, the wire packing elements described above are repeated until a piece of rectangular section is obtained which can then be subjected to cutting to obtain the final complete wire packing corresponding to the geometry of the exchange apparatus, for example corresponding to the geometry of the section of the column in which the wire packing is to be integrated.

[0157] The wire lining can be produced by 3D printing.

[0158] The wire packing according to the invention may be a wire packing for a concentric circular cylindrical “HIDiC” column constituted by the vertical assembly of several circular cylindrical wire packing blocks.

[0159] [Fig. 17] shows one of these wire packing blocks before assembly.

[0160] The packing block 170 comprises a body 176 formed from a wire packing according to the invention as described above. This body 176 is of circular cylindrical shape and is defined, delimited, by an upper cross section 171 and a lower cross section 177 (bottom face in the representation of [Fig. 17]). The body 176 is crossed by a circular cylindrical internal vertical wall 172 extending between its upper cross section 171 and its lower cross section 177.

[0161] This circular cylindrical internal vertical wall, hereinafter called internal wall, 172 is shown alone at a / in [Fig. 18]. It has an upper edge 178, located at the level of the upper straight section 171 of the body 176, and an opposite lower edge 179, located at the level of the lower straight section 177 of the body 176. The upper edge 178 is provided with a groove 173 intended to receive a sealing gasket.

[0162] The internal wall 172 has an internal face 1721 and an external face 1722.

[0163] Circular cylindrical vertical orifices 174 pass through the body 176 between the upper straight section 171 and the lower straight section 177. These orifices are preferably arranged at the level of the internal wall 172. In the embodiment shown in the figures, they constitute the central orifice of longitudinal cylinders 180 secured to the internal wall 172, preferably at the level of the external face 1722 of this wall. In the particular embodiment shown in the figures, these circular cylindrical vertical orifices 174 are 3 in number, uniformly distributed around the internal wall 172, such a number and such an arrangement being in no way limiting of the invention.

[0164] [Fig. 18] shows, in b / , the packing block 170 comprising the body 176 formed from the wire packing and the internal wall 172. The latter defines a so-called internal zone 181 of the body 176, arranged inside the internal wall 172, and a so-called external zone 182 of the body 176, arranged outside the internal wall 172.

[0165] In [Fig. 17], indexes or markers 175 are shown, provided at the level of the upper edge 178 of the internal wall 172, so that, during the assembly carried out by a rotation of one block relative to another block, the geometric continuity of the assembly is ensured.

[0166] The packing block according to the invention is preferably formed in a single block, preferably by an additive manufacturing technique.

[0167] At the end of the manufacturing steps, a resin can be applied in the groove 173 to compensate for the roughness due to the technique used for manufacturing the packing block, for example the additive manufacturing technique, and to avoid a complicated machining operation. This resin is ultimately located under the seal.

[0168] The wire packing block according to the invention can be used for the manufacture of an internal part of a circular cylindrical concentric “HIDiC” column. The height constraint of such columns requires that they be made up of several packing blocks which must be assembled to form the internal part of the column. The assembly system must be leaktight and must not impair the separation performance or take up too much volume. The packing block 170 according to the invention advantageously meets these constraints.

[0169] The assembly of several circular cylindrical wire packing blocks 170 as described above, to form an internal according to the invention, is carried out by the vertical stacking of the different packing blocks one above the other, the upper straight section 171 of one being deposited on the lower straight section 177 of another.

[0170] Such an assembly of two packing blocks is illustrated in [Fig. 19], the packing blocks being represented there by their internal walls only, respectively 172, 172'.

[0171] The assembly can be ensured by threaded rods 183 received successively in the vertical orifices 174, 174' of the different blocks, and clamping bolts 184 mounted on these rods 183, preferably at each of their opposite ends projecting respectively outside the vertical orifices 174, 174'. These threaded rods 183 and the associated clamping bolts 184 ensure the assembly is held under pressure.

[0172] An annular seal 185, placed in the groove 173 of the internal wall 174 of the lower block, is interposed between the latter and the internal wall 174' of the upper block. This seal ensures the sealing of the assembly. It also ensures insulation between the internal zone 181 and the external zone 182 of the packing body 176.

[0173] Small O-ring seals 186 are further preferably interposed between the longitudinal cylinders 180, 180' of the superimposed blocks, for insulation between the circular cylindrical vertical orifices 174, 174' and the external zone 182 of the packing body 176.

[0174] The clamping bolts 184 are preferably screwed onto the threaded rods 185 until the various sealing gaskets 185 and 186 are tightened and compressed.

[0175] The invention will now be described with reference to the following examples, given for illustrative and non-limiting purposes. EXAMPLES

[0176] These examples implement packing blocks formed from: - comparative elementary wire packing meshes, not in accordance with the invention, named TS-2.25-15.35-30, of tetraspline structure (TS) for which dw = 2.25mm, 11 = 15.35mm, al = 30° and a2 = 40° (packing block named TS-2.25); - or elementary meshes of wire packing according to the invention, named TS-3HSP-SA-1.5F, as illustrated in [Fig.5], corresponding to the tetraspline geometry (TS) for which dw = 2.25mm, 11 = 15.35mm, al = 30° and a2 = 40° and comprising the following modifications compared to TS-2.25: 3 horizontal strands (diameter 1.5 mm) are each supported by a quarter plate, with a fillet between the strand and the quarter plate (3HSP), modification of the symmetry of the tetraspline with an alternation of rotation of 180° of the strands in the z axis every 2 layers and with fillet between the plates and the horizontal strands (1.5F). This packing block is named TS-HSPi.

[0177] A / Design and production of a HIDiC column based on TS-HSPi packing blocks according to the invention

[0178] Al / Design of packing blocks

[0179] To make the packing block, the desired mesh structure is designed in computer-aided construction (CAD) software, then an "STL" file is generated. The latter is a triangular mesh describing the surface of the structure. The higher the number of triangles, the higher the resolution.

[0180] A.2 / Production of polymer packing blocks

[0181] For the production of polymer packing blocks, the "STL" structure file is opened using the NAUTA printer preprocessing software and the document with the "fictor" extension is generated. The prepared file is loaded into an XFAB 3500PD printer. The printer is loaded with the material (e.g., Therma DM500 resin), and then the printing process is started. After printing is complete, the produced packing block is cleaned and postprocessed before proceeding with experimental tests. The cleaning is carried out either with 95% ethanol or isopropanol, and then the packing block is dried. The alcohol cleaning is repeated if any residue remains. The packing block is then rinsed thoroughly under water. running for a few seconds then dried with an air blower and placed in a UV curing unit (DWS brand). The post-curing time is 30 min.

[0182] A.3 / Production of metal packing blocks

[0183] For the production of metal packing blocks, the cutting in the CAD software of the complex structure in cylindrical shape generates the formation of incomplete strands / plates and / or suspended at the edges of the packing. The structure is carefully cleaned of all peripheral elements that could disturb the production of packing: element (strand, plate) in the void / without support, very thin elements (thickness < 0.5mm). Then the file in "STL" format is generated and is loaded into a printer (such as the GE printer, Concept laser M2 Cusing). The printer is loaded with the material (for example an AlSi7Mgo,6 powder) and then the printing process is launched. Then, the metal structure is depowdered and separated from the printing platform using electroerosion. Finally, it is cleaned in an ultrasonic bath including a degreasing product.

[0184] A.4 / Assembly of the packing blocks

[0185] The TS-HSPi packing blocks according to the invention obtained are as shown in [Fig. 18]. For this example, their height is 218.7 mm (one of the blocks however having a height of 109.4 mm) and their diameter is 145 mm.

[0186] For the assembly of the various packing blocks, as illustrated in [Fig. 19], the annular seals 185 used are of dimensions 3 mm x 81 mm, and the O-ring seals 186 are of dimensions 1.5 mm x 9.5 mm. The number and diameter of the threaded rods 183 are set at 3 and 6 mm, respectively, depending on the mechanical force required to sufficiently compress the seals. The material of the seals is fluorocarbon rubber (FKM), known as Viton®, chosen for its chemical compatibility with organic mixtures (cyclohexane / n-Heptane) and its resistance to high temperatures. The material of the threaded rods 183 and the clamping bolts 184 is stainless steel, chosen for its chemical and mechanical resistance. The dimensional characteristics of the produced TS-HSPi packing blocks, as illustrated in [Fig. 17] and [Fig. 18], are summarized in Table 1.

[0187] [Tables 1] Dimensions Value Periodic packing element height 54.68 mm Maximum packing block height 218.7 mm Diameter of the inner area 181 of the packing block 87 mm Diameter of the outer area 182 of the packing block 145 mm Thickness of the inner wall 172 1.5 mm Variation range of the diameter of the inner area 181 of the packing block (varied to accommodate the groove 173) 87-74.8 mm for a height of 29.7 mm Number and diameter of threaded rods 183 3x6 mm Inner and outer diameter of the cylinders 180 for receiving the threaded rods 183 7.5 mm / 10.5 mm Thickness and diameter of the annular seals 185 3 mmx81 mm

[0188] Table 1 - Dimensions of a TS-HSPi packing block according to the invention

[0189] 9 such packing blocks are assembled to form the column. The mesh ele Since the TS-HSPi structure is symmetrical and vertically periodic, the strands of the 9 packing blocks match well and form a perfectly continuous packed column about two meters high (1.9683 m). By visual observation, it is confirmed that the liquid flow is well distributed within the packing. The rotation integrated into this structure ensures adequate mixing of the fluids.

[0190] Three groups of experiments were implemented to compare different prior art technologies with the technology according to the invention: numerical study to evaluate the pressure drop and the thermal efficiency with a gas flow (single-phase model), experimental study of the hydrodynamic performances and the capacity and the separation efficiency of the packings without an internal wall (Experimental Study 1), and finally experimental study to evaluate the heat transfer performance and all the performances combined in the HIDiC column with metal packing blocks equipped with an internal wall (Experimental Study 2).

[0191] B / Numerical studies and experimental study 1

[0192] B. 1 / Digital study protocols

[0193] B. 1.1 / Convection model

[0194] For the numerical study, a domain of a half-cylinder with an external diameter of 90 mm and a height between 200 and 230 mm, which contains the solid part and the fluid part (gas), was used. The solid part was composed of the internal part studied and a peripheral external wall, which is integral with it, with a thickness of 2 mm. The model The turbulence model chosen for this study was the kw-SST of the Ansys Fluent 2020 Al software with the associated wall laws. The liquid inlet was carried out at the bottom of the domain and the outlet at the top of the domain. At the inlet, the fluid temperature was set at 70 °C and the gas velocity was set between 0.8 and 2.8 m / s, which corresponds to a turbulent regime, with a Reynolds number Re between 7000 and 28000. A flow establishment zone with a height of 100 mm was adopted upstream of the packing and a void zone of 20 mm was adopted downstream of the packing. A symmetry condition was applied to the XZ plane, and a heat flux fixed at 5 kW / m2 was applied to the external surface of the wall.

[0195] With this model, the pressure drop dP / dzsec generated by the dry packing (gas flow only) was evaluated, and the average packing thermal conductance, hA, due to convection in the fluid and in the solid and to conduction in the solid (wall and packing) was estimated (conjugate heat transfer). The convergence of the variables, the mesh independence, and the domain size independence (packing height) were checked and confirmed before the estimation of each quantity.

[0196] B. 1.2 / Conduction model

[0197] Another simpler model to study the conduction, effective thermal conductivity ETC, through the packing, was used. In this model, a parallelepiped domain which contains the packing structure studied was designed. The division of this domain was done in such a way as to have an integer number (2, 3 or 4) of elementary meshes in each direction (X, Y, Z). The conduction was studied in the three directions X, Y, Z. For each direction, the effective thermal conductivity ETC was evaluated, by imposing a temperature difference of 2°C between two planes of the packing opposite and perpendicular to the direction studied (planes called respectively hot and cold). In this model, there is no flow; the fluid is stagnant.

[0198] B.2 / Experimental Study Protocol 1

[0199] For the experimental tests below, two packing columns were printed in polymer and experimentally tested for their separation capacity and their hydrodynamic performances. These are the TS-HSPi packing according to the invention in polymer without the internal wall, and the TS-2.25 packing not in accordance with the invention, of the same dimensions. Comparative tests were also carried out with a metal foam produced by molding, without an internal wall. This foam contains Kelvin cells (85% theoretical porosity) and will be abbreviated as KC-P85.

[0200] Two experimental pilots were used to evaluate the hydrodynamic performances (pressure drop, wetting, liquid distribution, flow, capacity) and the separation performances (equivalent height of a theoretical HEPT plate, capacity - gas factor at bottleneck Fengorgement).

[0201] B.2.1 / Hydrodynamic pilot

[0202] The hydrodynamic pilot consists of a 150 mm diameter, 2 m high column, 1 m of which is filled with the investigated packing and 1 m of which is empty to allow flow establishment. The loaded packing is 145 mm in diameter and consists of several blocks stacked vertically to form 1 m of packing. A Keller Series 30 differential pressure transmitter with a digital pressure indicator (EV-120) measures the pressure difference, providing a high accuracy measurement of ±0.01%. The pressure drop is recorded using the ControlCenterSeries30 (CCS30) acquisition software. The pressure sensors are positioned at the inlet and outlet of the packing. Two experiments were conducted using this pilot.

[0203] The first experiment is carried out with a gas flow alone, air at room temperature and atmospheric pressure. This involves measuring the dry pressure drop profile for the loaded packing. The dry pressure drop profile is recorded for about twenty air flow values, between the 100 and 300 m3 / h graduations of the flow meter, which correspond to different gas speeds between 0.5 and 3 ms *.

[0204] The second experiment analyzes the pressure drop with countercurrent flow of gas and liquid. The pressure drop profiles are measured for three different liquid flow rates (water at room temperature): 162, 270 and 378 L / h (9.2, 15.3 and 21.4 m3 / m2 / h). For each liquid flow rate, the air flow rate is increased from 100 Nm3 / h (flow meter graduation) in increments of 10 m3 / h up to the clogging points, corresponding to Fengorgement, or to the maximum value of the flow meter air flow rate, 300 Nm3 / h. The visual signs, bubbling and liquid entrainment, as well as the exponential increase in pressure drop, define the clogging point of the packing, which indicates its separation capacity at a specific liquid flow rate.

[0205] For each air flow rate value, the pressure drop dP / dz is recorded every second for 6 min, because the countercurrent flow needs more time to stabilize. Before starting the gas / liquid countercurrent experiments, the column is irrigated with the maximum liquid flow rate and a high air flow rate close to flooding, allowing adequate wetting of the packing.

[0206] B.2.2 / Material transfer pilot

[0207] The experimental mass transfer device consists of a glass distillation column with a diameter of 150 mm and a packing height of 1 m, a reboiler integrated into a flask at the bottom of the column, and a vertical total condenser at the top of the column. The reboiler heats and vaporizes the binary mixture using a steam-fed coil. It is filled with the binary mixture of cyclohexane / n-heptane (standard binary mixture), with approximately 20% by mass of cyclohexane. The pressure drop is measured between the top and the bottom of the packing section. By fixing the heating power at the reboiler level, a pressure difference dP is fixed and a gas loading factor F is calculated. This separation is carried out in a distillation column operating at total reflux, i.e. without discharge / outlet of the upper (distillate) and lower products.

[0208] Four to six other measurements with F between 0.8 Pa05 and 0.8xFengorgement are carried out after reaching steady state ensured by the temperature measurement at the top and bottom of the column, the condensate flow rate, indicating the heating power. For each value of F, several samples of the products at the top and bottom of the column are collected to determine the mixture density which is correlated to the mixture composition. For each experiment (value of F), the HEPT (equivalent height of a theoretical plate) is determined by examining the binary liquid-vapor diagram of the cyclohexane / n-heptane mixture under atmospheric pressure. The Wilson model is the thermodynamic model chosen to calculate the V / L equilibrium curve.

[0209] B.3 / Results

[0210] The experimental and numerical performances of the three packings studied are summarized in Table 2.

[0211] [T ableaux2] Packing Performance KC-P85 TS-2.25 TS-HSPi Geometric Exp. Porosity e (%) 82.9% 89.6% 86.4% As (m 9 291 176 245 Hydrodynamic Exp. dP / dzsec (mbar / m) @ F=2 Pa0 5 8.49 0.82 1.19 Separation Exp. F fPa0'5) 1.1 2.5 2.6 HEPT(m) 0.27 0.37 0.38 Thermal Num. ETChor (W / m / K) 11.9 3.0 6.0 hA (W / K) @ F=1.6 Pa05 348 111 194

[0212] Table 2 - Performance of the different packings - where As = specific geometric surface area; dP / dzsec (mbar / m) = dry packing pressure drop; Fengorgement = gas factor F at the point of congestion (F = gas velocity multiplied by the square root of the gas density); HEPT = equivalent height of a theoretical plate; ETC hor = effective thermal conductivity in the horizontal direction; hA = thermal conductance; Exp. = experimentally measured values; Num. = numerically calculated values merically according to digital study protocols

[0213] It is observed that the packing block according to the invention TS-HSPi has the same separation efficiency and capacity as the packing block TS-2.25 (Fengorgement and HEPT), and increases the heat transfer efficiency (hA) by 75% compared to the TS-2.25 according to the simulation. Its specific geometric surface area is 38% higher than that of the packing block TS-2.25. In addition, thanks to its vertical periodicity, its separation efficiency is stable over the entire range of gas loading factor F, which proves a good distribution of liquid and gas over the entire section and the entire height of the packing column according to the invention, unlike other structured packings available on the market or studied here. The packing according to the invention TS-HSPi also generates dry pressure drops comparable to those of the comparative packing TS-2.25.The KC-P85 packing is very efficient in heat transfer, according to the numerical study, but very limited in separation capacity. It also generates enormous pressure losses, according to Experimental Study 1.

[0214] C / Experimental study 2

[0215] This experimental study is carried out with the lining according to the invention in metal, with internal wall, in order to evaluate and compare on the one hand its performances in heat transfer, and on the other hand all its performances combined in the HIDiC pilot. The comparison is made mainly with the KC-P85 lining in metal (aluminum) produced for molding with an internal wall.

[0216] The separation and energy gain performances were evaluated for concentric HIDiC columns of 150 mm diameter and 1 m height for the heat transfer performance experiment or 2 m height for the experiment covering all performances combined, and whose internals are formed, as described above, by assembling packing blocks respectively: - TS-HSPi, in accordance with the invention, as described in the previous example, but comprising an internal wall 172 with an average thickness of 1.9 mm (1.5 mm outside the assembly zone), - KC-P85, not in accordance with the invention, in which the filling is a complex structure of metal foams based on the Kelvin cell, with an internal wall 172 of 5 mm thickness, - SSR, not in accordance with the invention, in which the packing is formed from loose super Raschig rings, with a free internal wall (not integral with the packing) 5 mm thick.

[0217] Each column comprises two zones separated by a central wall formed by the internal walls 172 of the stacked packing blocks, namely an internal zone, formed by the packing located inside the central wall, and an external zone, formed by the packing located outside the central wall.

[0218] C. 1 / Heat transfer performance

[0219] For each column, in the external zone, water vapor circulates at a specific pressure (boiling temperature) and condenses on the packing and the central wall. In the internal zone, a pure chemical product enters the liquid state with a temperature close to its boiling point and is partially vaporized thanks to the heat coming from the external zone (water vapor) and exchanged via the assembly (central wall and packing). The vapors in the internal zone are condensed at the top of the column and measured to calculate the heat exchanged. The measurements made make it possible to determine the normalized overall thermal conductance (UAexpnormen W / K) as a function of the vapor fraction in the internal zone.

[0220] Two organic products were tested for SRR (n-Butanol and n-Heptane) and one for each complex structure: n-Butanol for KC-P85 and n-Heptane for TS-HSPi.

[0221] The measurements carried out allow us to conclude that the heat exchange for the KC-P85 and TS-HSPi monoblocks is significantly more efficient than for the SRR which has a free wall which creates thermal bridges with the bulk packing. Under the same operating conditions, the TS-HSPi structure according to the invention achieves the same level of thermal performance as the KC-P85.

[0222] Such good thermal performance of the TS-HSPi column according to the invention is achieved thanks to: - a low thickness of the central wall (around 1.9 mm), possible thanks to additive manufacturing; - the presence of horizontal strands promoting thermal conduction from the internal zone to the external zone; - a profiled shape of TS-HSPi which promotes good contact with fluids (wetting rate), generating good heat transfer by conduction and convection.

[0223] C.2 / Overall performance

[0224] Hereinafter, for the HIDiC columns implemented (column with internal formed from TS-HSPi packing blocks in accordance with the invention and column with internal formed from KC-P85 packing blocks not in accordance with the invention), the internal zone, playing the role of rectification zone, is hereinafter called InCo and the external zone, playing the role of annular exhaustion zone, is hereinafter called ExCo.

[0225] The operation applied for the columns is as follows.

[0226] The fluid, formed from a mixture of cyclohexane and n-heptane at 50% by mass of cyclohexane, stored in a 100 liter feed tank, is pumped, heated and admitted to the top of the ExCo. It is distributed over the packing in the ExCo using a ring distributor. At the bottom of the ExCo, a reboiler generates vapor from the fluid which rises to the top of the ExCo. Then, the vapor is sent by a compressor to the bottom of the InCo.

[0227] The pressure difference between the two zones, generated by the compressor, results in a temperature difference. A check valve ensures that the vapor flow in the compressor and its recycle line is in one direction only. The InCo is subjected to a higher pressure / temperature; therefore, heat transfer occurs from the InCo to the ExCo via the column center wall and the packing. This results in condensation in the InCo and vaporization in the ExCo. The liquid falling from the condenser passes through a reflux system that sends the liquid either to the distillate tanks or to the InCo (reflux). The reflux liquid is returned through a distributor and joins the condensate that forms on the InCo packing (due to the heat exchange). Both liquids are collected at the bottom of the InCo and conveyed to the top of the ExCo, thanks to the pressure difference between the two zones.Excess fluid at the reboiler flows by gravity to the lower product tank (called residue).

[0228] The pressure in the InCo is kept stable by the admission or discharge of nitrogen via two valves that can be controlled by a regulator. The pressure in the ExCo is controlled by the compressor frequency. The heat exchanged between the two zones reduces the need to supply a lot of heat to the reboiler. Therefore, this column configuration is considered less energy-intensive than a conventional distillation column and more interesting from an ecological and economic point of view. A nitrogen flow admitted into the ExCo ensures an inert atmosphere inside the pilot, thus reducing the risk of fire or explosion. The pilot is equipped with six control loops that allow the steady state to be maintained. These control loops concern: the feed temperature, the ExCo pressure, the InCo pressure, the pressure drop in the ExCo, the reflux ratio, the liquid level at the bottom of the InCo.

[0229] Tables 3 to 7 present the operating conditions and test results for the column based on KC-P85 not in accordance with the invention (2 tests, named 1k and 2k) and for the column based on TS-HSPi in accordance with the invention (5 tests, named 1, 2, 4, 5 and 7), more precisely: - Table 3: tests under variable operating conditions (feed flow rate F, cyclohexane (C6) composition wEjC6, internal zone pressure Pin, external zone pressure drop dPEx, flow distribution between distillate and bottom products D / F:W / F. The other operating conditions are unique for all tests, no reflux, pressure in the external zone PEx=1.01 bar, and temperature at the inlet of the external column TF=85°C); - Table 4: Separation efficiency (mass flow rates of distillate D and residue W, purities (mass fraction of C6) wC6,d and wC6,w, recovery rate of C6 in the distillate Tc6,d, recovery rate of n-heptane (C7) in the residue rC7,w, and recovery factor SPF separation performance. SPF is a mathematical indicator and calculated as the geometric mean of wC6,f, wC6,d, wC7.w- ^c6,d and rC7,w- H allows to compare the separation performances of different experiments); - Table 5: Performance indicators of heat transfer capacity and efficiency (mass flow rate at the top of the external zone F' (F+Ll), mass flow rate VI', and mass fraction wC6,vi' of vapor at the bottom of the internal zone (also at the top of the external column), flow rate Ll, and mass fraction wC6,li of liquid at the bottom of the internal zone, gas load factor FlnCOjbOt calculated at the bottom of the internal zone, according to equation 1:

[0230] [Math.l] VT SlnCo P g (Equation 1)

[0231] where VI' is the mass flow rate of vapor at the bottom of the internal zone (also at the top of the external column), pg is the density (volume) of vapor at the bottom of the internal zone and SlnCo is the minimum cross-section of the internal zone (equal to jr(Dmin>lnCo / 2)2). The minimum diameters of the internal zone Dmin>lnCo are 80 mm and 74.8 mm for KC-P85 and TS-HSPi, respectively); - Table 6: Energy consumption (reboiler energy Qb, pilot heat losses Qioss, heat exchange between internal and external zones QEx, and calculated compressor power requirement with 25% isentropic efficiency, W COmp,25%, the latter is estimated using the steam flow rate and pressures upstream and downstream of the compressor); - Table 7: Energy gain (HIDiC energy consumption at reboiler QbjHiDic (Qb-Qioss), reflux ratio RDC and minimum energy consumption QbjDc of the typical distillation column with the same separation specifications, and percentage energy saving. QbjDc is calculated using the commercial simulation software ProSim, and the percentage energy saving is calculated according to equation 2:

[0232] [Math.2] r- . Economy deneoe = 1 - -—!—--------- (Equation 2).

[0233] [Tables3] Column TS-HSPI KC-P85 Test No. 1 2 4 5 7 1k 2k F (kg / h) 11.8 18.5 12.0 20.5 17.4 11.0 10.5 Wc6,F 0.48 0.46 0.47 0.49 0.50 0.49 0.42 Pin (mbar) 1.25 1.25 1.30 1.31 1.35 1.50 1.50 dPEx (mbar) 0.569 0.581 0.553 0.612 0.640 1.241 1.239 D / F:W / F (%) 50:50 41:59 41:59 46:54 50:50 49:51 35:65

[0234] Table 3 - Variable operating conditions of the tests

[0235] [Tables4] TS-HSPI KC-P85 Column Test No. 1 2 4 5 7 1k 2k D (kg / h) 6.0 7.5 5.0 9.4 8.7 5.4 3.7 Wc6,D 0.75 0.79 0.82 0.78 0.78 0.79 0.87 ^06.0 (%) 79 70 72 73 78 78 72 W (kg / h) 5.9 11.0 7.0 11.1 8.7 5.6 6.9 Wc6,W 0.20 0.23 0.22 0.24 0.22 0.22 0.18 ^C7,W (%) 76 84 86 80 78 79 92 SPF (%) 71 70 71 70 72 72 72

[0236] Table 4 - Separation efficiency

[0237] [Tables5] TS-HSPI KC-P85 column Test No. 1 2 4 5 7 1k 2k F' (kg / h) 16.9 26.0 18.4 28.6 27.1 19.7 18.4 VI' (kg / h) 11.1 15.0 11.4 17.4 18.4 14.0 11.6 Wc6,Vl 0.64 0.67 0.66 0.66 0.65 0.65 0.65 FInCo,bot (Pa0'5) 0.40 0.55 0.42 0.64 0.67 0.45 0.37 L1 (kg / h) 5.1 7.5 6.4 8.0 9.7 8.66 7.90 Wc6,Ll 0.50 0.54 0.54 0.53 0.53 0.56 0.55

[0238] Table 5 - Heat transfer capacity and efficiency

[0239] [Tableauxô] TS-HSPI KC-P85 Column Test No. 1 2 4 5 7 1k 2k Qb (kW) 2.07 2.25 1.75 2.22 2.37 1.27 1.45 Qioss (kW) 1.41 1.41 1.21 1.21 1.41 0.72 1.00 Qex (kW) 0.48 0.71 0.62 0.76 0.93 0.83 0.76 Wcomp.25% (kW) 0.087 0.118 0.107 0.169 0.199 0.208 0.171

[0240] Table 6 - Energy consumption

[0241] [Tables?] Column TS-HSPI KC-P85 Test No. 1 2 4 5 7 1k 2k Qb.HIDiC (kW) 0.66 0.84 0.54 1.01 0.96 0.55 0.45 Rdc 1.03 1.45 1.61 1.19 1.13 1.27 2.29 Qb,Dc(kW) 1.20 1.83 1.29 2.06 1.84 1.21 1.21 Energy saving (%) 38 48 50 43 37 37 49

[0242] Table 7 - Energy gain

[0243] No experiments were performed at the same pressure difference for the TS-HSPi column and the KC-P85 column. However, it is possible to compare the two technologies using tests No. 5 and No. 7 for the TS-HSPi technology and No. 1k for the KC-P85 technology. These tests give similar SPF values, comparable recovery rates and purity, which indicates comparable separation efficiency. Furthermore, these columns have a similar flow distribution between distillate and bottoms, approximately 50:50. TS-HSPi achieves a similar separation efficiency with a feed flow rate twice as high as KC-P85. Both technologies achieve similar energy savings, in the order of 40%. However, by increasing the pressure / temperature difference to 0.5 bar, the packing according to the invention TS-HSPi could achieve better separation efficiency and higher energy savings.This can be justified by the high condensate flow rate (Ll) observed during the transition state, which indicates a higher exchange rate.

[0244] The high capacity of the TS-HSPi column was demonstrated in the hydrodynamic and HETP results, F=2.6 Pa°\ In the HIDiC experiments, the highest value of the gas load factor F is 0.67 Pa05 in experiment No. 7 for the TS-HSPi column, compared to 0.45 Pa0 5 for the KC-P85 column. It is 74% away from the flooding of the TS-HSPi column. The experimental setup did not allow the separation of a higher feed flow. Operation under optimal packing conditions, at 60% of the flooding point, is expected to maintain or slightly increase the energy saving rate. Indeed, increasing the vapor and liquid flow rate would improve heat exchange.

[0245] In conclusion, several experiments using HIDiC columns have demonstrated that the separation efficiency of TS-HSPi is at least as high as that of KC-P85. In addition, the separation capacity is at least doubled for the TS-HSPi packing according to the invention. TS-HSPi allows an equivalent energy saving of 40% despite the application of a lower pressure difference than KC-P85 (a difference of 0.35 bar compared to 0.50 bar for KC-P85).

Claims

Claims

1. Elementary mesh of wire packing made of a thermally conductive material, for a gas-liquid exchange device, comprising three first wires (51, 52, 53) comprising a common upper end (54) located at the upper vertex of a first irregular tetrahedron, said three first wires (51, 52, 53) each extending vertically from said first upper end (54), along three edges of the first tetrahedron, to three lower ends (57, 55, 56) located at the three lower vertices of a base triangle of the first tetrahedron, a lower end (55) of one of said three first wires (52) being connected to a common upper end (58) of three second wires (59, 510, 511) located at the upper vertex of a second regular tetrahedron, said three second wires (59, 510, 511) each extending vertically from said upper end (58), along three edges of the second tetrahedron,up to three lower ends (514, 512, 513) located at the three lower vertices of a base triangle of the second tetrahedron; a lower part (515) of said first wire (52) connected to the common upper end (58) of the three second wires (59, 510, 511) having a first curvature, and an upper part (516) of one of the three second wires (59) connected to the common upper end (58) of the three second wires (59, 510, 511) having a second curvature, inverse to the first curvature; and the elementary mesh further comprising at least one element made of a thermally conductive material oriented horizontally.,

2. Elementary mesh according to claim 1, wherein said horizontally oriented element connects two of said first threads (51, 52, 53) and / or two of said second threads (59, 510, 511), preferably two lower ends (55, 56, 57) of said first threads and / or two lower ends (512, 513, 514) of said second threads, and / or said horizontally oriented element (517; 111, 112, 113) may be capable of connecting one of said vertices with a vertex, located at the same height, of another elementary mesh.

3. Elementary mesh according to claim 1 or 2, wherein said horizontally oriented element is chosen from straight, rectilinear horizontal wires, curved or rounded horizontal wires also called arcs (517), vertical plates (61, 71, 72, 81, 82), straight, rectilinear horizontal wires (101, 102, 103) each supported by half- vertical plates (104, 105, 106), and the straight, rectilinear horizontal wires extending on either side of the vertices of the tetrahedra (111, 112, 113) and supported symmetrically on either side of these vertices by vertical quarter plates (114, 115, 118, 119, 116, 117).

4. Wire packing element comprising the assembly of two elementary meshes according to any one of claims 1 to 3 superimposed vertically, one of said elementary meshes having undergone a rotation of 180° relative to a vertical axis.

5. Wire packing comprising the assembly of several wire packing elements according to claim 4.

6. A method of preparing a wire lining according to claim 5, characterized in that the wire lining is manufactured by an additive manufacturing technique, preferably by a laser melting technique.

7. A packing block (170) comprising a body (176) formed of a wire packing according to claim 5, said body (176) being of circular cylindrical shape and being defined by an upper cross section (171) and a lower cross section (177), and being crossed by a circular cylindrical internal vertical wall (172) extending between said upper cross section (171) and said lower cross section (177) and having an upper edge (178) at said upper cross section (171), circular cylindrical vertical orifices (174) passing through said body (176) between said upper cross section (171) and said lower cross section (177), and said upper edge (178) of said circular cylindrical internal vertical wall (172) being provided with a groove (173) intended to receive a seal (185).

8. A packing block (170) according to claim 7, wherein a resin is further placed in the groove (173) to compensate for roughness, for example due to additive manufacturing and to avoid a complicated machining operation.

9. Internal for a concentric circular cylindrical “HIDiC” column, consisting of the vertical assembly of several packing blocks (170) of circular cylindrical shape according to any one of claims 7 or 8, a sealing gasket (185) being placed in the groove (173) of at least one of said packing blocks (170), and the assembly being ensured by threaded rods (183) passing through said packing blocks (170) and placed in the vertical cylindrical orifices cir- culars (174) of each of said packing blocks (170), and clamping bolts (184) mounted on said threaded rods (183).

10. A gas-liquid exchange apparatus comprising a wire packing according to claim 5.

11. A gas-liquid exchange apparatus according to claim 10, which is selected from distillation columns, absorption columns, stripping columns and heat exchangers.

12. Column with an internal thermal coupling comprising an internal according to claim 9, and a cylindrical external vertical wall inside which said internal is arranged.

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