Tangential flow water-gas separator, method of assembling the separator and use of a cover with an outlet duct carrying a gutter in such a separator

Abstract

The water-gas separator for a fuel cell includes a housing with a lid equipped with an outlet conduit (4) that has an external, annular rim. The outlet (S) communicates with a separation chamber where the gas stream to be purified (F1) undergoes tangential circulation around the conduit, with the separated water falling to the bottom (2a). The external rim, forming a gutter (6), is arranged around a lower end (4b) of the conduit (4). Thus, from a lateral inlet, tangential circulation is carried out around the central conduit (4), defining a longitudinal axis (X), partly within an axially delimited zone between the gutter and a radial sealing portion of the lid (3), from which the conduit (4) projects downwards into the chamber. The external rim helps accelerate the rotation of the flow and prevents water flowing along the conduit from rejoining the purified stream. (See abstract figure: Figure 3A)

Description

Title of the invention: Tangential flow water-gas separator, method for assembling the separator and use of a cover with an outlet duct carrying a gutter in such a separator. Technical field

[0001] The present disclosure relates to the field of circuits used in fuel cell equipment, particularly liquid impurity separators for purifying a gas stream discharged from a fuel cell. More specifically, the invention relates to a device for separating liquid water from a tangentially flowing stream of hydrogen (H2) or air, as well as a method for assembling a water separator with a tangential flow inlet for a fuel cell circuit. The use of a cover incorporating an annular external rim on the outlet duct of a separator to prevent / limit water re-entrainment is also proposed. Technological background

[0002] During the operation of a fuel cell, byproducts such as water and nitrogen, as well as unconsumed hydrogen, can form on the anode side of the cell. In some known systems, water accumulation is controlled to prevent a reduction in fuel cell performance and / or system shutdown. One known approach is to release the water through a passage downstream of the fuel cell. The byproducts can be recirculated so that the unconsumed hydrogen is returned to the anode side of the fuel cell stack. Recirculation can also be used to humidify the anode side to promote efficient chemical conversion and extend the life of the cell membrane.However, it may be necessary to remove liquid water contained in the recirculation stream, such as droplets, to prevent water from becoming blocked in the flow field channels of the fuel cell stack or in an ejector, and also to protect the compressor blades.

[0003] Traditional water separators are equipped with flow paths, screens, and / or meshes that carry the separated water droplets through an impaction surface in order to efficiently remove this water. However, the design of these conventional devices results in a relatively large pressure drop in the system for a given volume of the separation device. We know, from the US document 20140377675 Al, of a tangential circulation mode which can limit the effects of pressure drop, while still allowing the largest droplets to be eliminated.

[0004] There is room for improvement in limiting the pressure drop on the one hand, and the amount of water discharged from the outlet on the other, in water-gas separation devices for discharging a gas stream from a fuel cell, without excessive complexity. In the following, the term "hydrogen" should be understood as the gaseous molecule with the formula H2. Summary

[0005] This disclosure improves the situation.

[0006] To this end, a liquid separation device, in particular for water, is proposed for the gaseous flow of a fuel cell circuit, the device comprising a housing delimiting an internal volume which includes or corresponds to a separation chamber, the device comprising: - a housing component, provided with a side wall (which extends for example from a bottom of the housing or from a base) formed around a central axis; - a lateral impaction surface, delimiting the separation chamber; - a shuttering part, preferably made in the form of a cover, and allowing to cover a top of the side wall, the housing component and the shuttering part belonging to the housing; - a partitioning device which includes a plate with several openings to delimit the separation chamber from below, so that the separation chamber forms an upper compartment in the internal volume; - a lower compartment provided between the bottom and the partitioning device (typically to allow for water accumulation), below the upper compartment; - an inlet, to bring a raw gas flow tangentially into the separation chamber, preferably perpendicular to the longitudinal axis, and an outlet, the inlet and outlet being provided in the casing; in which the sealing part carries or includes a conduit defining the outlet, the conduit communicating with the upper compartment by an axial outlet being oriented towards the bottom, projecting internally from the sealing part, the conduit including / carrying a collar or gutter, which defines a rim projecting radially outwards from the conduit by being arranged around a lower end of the conduit or formed on an outer circumference of the conduit in a position adjacent to the lower end of the conduit.

[0007] With these arrangements, it is possible to combine the advantages of a separation that effectively removes water with the advantages of a tangential circulation method, limiting pressure loss, given that the inlet of the casing (with a lateral internal outlet into the chamber) communicates laterally with the upper compartment by a section of the inlet located higher than the axial outlet of the conduit and higher than the collar or gutter. The device promotes outward circulation via tangential flow, without hindering the fall of droplets to the outside, but by creating a gutter / barrier effect at the bottom of the duct, typically around its circumference. This is compatible with operation without excessive pressure loss. The impaction surface can be formed, in whole or in part, by the side wall. The impaction surface can be formed by the side wall and / or an element (lining component or component inserted within the interior volume) covering the side wall internally.

[0008] The conduit may project axially (downward from a connection point with the obturation portion) toward a central region of the base, typically remaining axially separated from a central, preferably non-perforated, portion of the plate. The radial extension of the flange or gutter may be greater than 5 or 6 mm, for example, at least 7 mm, and less than 10 or 12 mm. The flange or gutter must be radially separated from the impaction surface, for example, by a radial distance at least twice or three times the radial extension of the flange / gutter. The minimum spacing from the impaction surface, forming an outer periphery / circumference of the separation chamber, may thus exceed 15 or 25 mm, for example.

[0009] The collar creates a deflection and separation effect between the axial outlet and a liquid droplet flow zone, while also retaining droplets that may form along the conduit. This allows the liquid droplets to fall further out into the separation chamber. This can effectively contribute to: - prevent or limit the re-entrainment of water droplets towards the outlet, which have not followed a rotational / tangential trajectory around the conduit (but on the contrary have struck this conduit); - to obtain an acceleration effect of the vortex(s) around the conduit, with optimization of the separation by impact of the droplets on the impaction surface formed by the side wall (which may belong to the housing) which delimits the separation chamber from the outside.

[0010] In certain embodiments, the collar or gutter, preferably connected around the entire circumference of the duct, is solid and / or watertight. In some designs, the collar or gutter includes one or both of the following features: - it is made of plastic material, for example resulting from a one-piece molding. - it is arranged to extend the conduit, with an axial connection or contact against an axial edge of the conduit provided at the lower end of the conduit. - a shoulder of the collar or gutter is formed to allow a connection and / or axial contact against the conduit, from below. - it is flat in shape, optionally being provided with one or more means of clipping on an inner circumference of the collar or gutter. - it has a central hollow whose internal diameter is approximately equal (typically equal) to an internal diameter of the conduit.

[0011] According to one particular feature, the collar or gutter is provided with an annular surface, opposite the plate, which extends radially to an outer edge, curving upwards towards said outer edge, preferably with said annular surface gradually curving upwards as one approaches said outer edge. Independently or in addition, on the collar or gutter, a top or annular surface oriented opposite to the bottom (and typically to the plate) may be provided with an annular groove or recesses / concavities. In some options, the top of the collar or gutter can form a downward slope towards the outer edge, for example by providing a truncated cone shape in the collar or gutter.

[0012] The housing may have a lid forming an upper component that is shorter than the first housing component. More generally, the housing may be made according to different designs that allow for the sealing of an internal volume. In embodiments of the housing of the separation device, at least one of the following features may be provided: - the inlet opens into the internal volume through a radial outlet allowing tangential circulation of the gas flow in an upper zone of the internal volume; - the inlet is delimited by a bent conduit. - the conduit, preferably bent, allows the gas flow to be admitted from the bottom, in contrast to the orientation of the outlet which makes the purified flow exit from the top. - the side wall extends from a bottom to an annular end with an opening (opening wider than the passage section of the conduit). - the sealing part allows the annular end to be covered to close the opening formed at the annular end (upper end axially opposite to the bottom). - the radial outlet is at least partly formed in / delimited by the obturation part or formed adjacent to the obturation part. - the sealing part may have a recess, adjacent to the conduit, allowing to delimit all or part of the passage section of the radial outlet of the entrance into the interior volume (upper compartment). - the radial outlet is at least partly formed in a projection or outgrowth of the obturator part or adjacent to the obturator part, the obturator part being designed and arranged to allow, at least over an angular sector of 180° around an internal portion of the conduit, a progressive increase in the height or axial distance between the collar or gutter and the obturator part as one approaches the radial outlet / approaches an angular sector including the radial outlet of the inlet.

[0013] The device allows water to be collected in the lower compartment provided under the partitioning element, with, for example, a plate which extends perpendicularly to the central / vertical axis of the device to avoid or limit the risk that a jolt (in the mounted position of the device in a vehicle, for example a moving vehicle) will cause too much water to rise into the upper compartment. The plate may have openings with a passage cross-section with a diameter of between 3 and 6 mm, preferably between 3.4 and 5.5 mm. This size, well under 1 cm, promotes a backflow prevention effect.

[0014] In embodiments of the device, the plate may be wider than the duct, preferably covering the entire bottom, and / or one or more of the following provisions are provided: - the axial outlet has a diameter D4 which can optionally correspond to a diameter of the conduit, the latter being typically straight. - the central part of the plate, which is a non-perforated part, is crossed by the central axis and has a diameter d5. - the following relationship is satisfied: 1 / 2 < d5 / D4 < 1. - the plate has a substantially convex upper surface or is bulging upwards, so that the central part (which is not perforated) is higher than a portion of the annular margin of the plate.

[0015] In various designs of the outlet, carried by the sealing part, one or more of the following provisions apply: - relative to an external (lateral) cylindrical surface of the duct, the collar or gutter has a radial extension, measured perpendicular to the central axis, which may be greater than a thickness of the duct and / or greater than or equal to 6 mm. - the cross-section of the conduit is approximately constant. - the collar or gutter forms an end of the conduit, covering a lower axial edge of the conduit. - the conduit defining the outlet is a rigid, cylindrical conduit, allowing upward fluid circulation.

[0016] According to one particular feature, the device housing carries or includes an external rigid conduit for an initial upward circulation of the gas flow upstream of the separation chamber. This external rigid conduit forms part of the inlet and may extend lower than the plate or lower than the bottom of the first housing component. The rigid inlet duct and the duct defining the outlet can be straight ducts, with the inlet duct offset laterally from the central axis. Optionally, one or more of the following features are provided: - the duct for the first upward circulation forms a first section of the inlet, parallel to the central axis, while the section of the inlet communicating laterally with the upper compartment forms / is a second section of the inlet that complements the said first section. - the second section is arranged transversely with respect to the central axis (A). - the conduit defining the outlet is a rigid cylindrical conduit, for a second upward circulation of the gas flow downstream of the separation chamber, extending around a longitudinal axis parallel to or coinciding with the central axis, thanks to which the second upward circulation is parallel to the first upward circulation starting from the axial outlet which is entirely lower than the second section.

[0017] The separation device may have an in-line filter structure with the inlet and outlet which allow connections at two opposite axial ends of the device.

[0018] One of the following, a metallic filter medium, a coalescer, or a fabric-like medium (e.g., hydrophobic), may be provided in the separation chamber, surrounding the duct and joining axially or adjacent to the partitioning element. This element may cover an inner face of the first component, forming the impaction surface. In some options, the impaction surface may be heterogeneous, for example, with at least one rigid annular section formed by the inner face of the housing (typically by the first component) and an annular section formed by a coating or covering element of a complementary annular section. When such a covering element is provided, it can be placed entirely above the partitioning element.

[0019] According to another aspect, a method is proposed for assembling a liquid separation device, in particular for water, which makes it possible to purify a gaseous stream from a fuel cell circuit by circulating this stream in an upper compartment. of a box having an input and an output, the process comprising the steps essentially consisting of: - provide a first housing component, preferably in the form of a bowl, having a base and an annular upper end delimiting an opening (O); - to mount internally, in the first housing component and preferably by insertion through the opening, a partitioning element which may include a plate (in the form of one piece or several plate components) to allow separation of the upper compartment from a lower compartment, the lower compartment intended for the collection of the liquid being able for example to be delimited by the bottom after assembly, several orifices in the plate allowing to pass (under the effect of gravity) droplets of liquid from the upper compartment to the lower compartment; - install the outlet in the housing, in the form of a conduit with an internal portion of the conduit that protrudes internally into the housing, towards the bottom; - arrange the inlet in the housing to allow a raw flow of hydrogen to be brought into the upper compartment tangentially, around the inner portion of the conduit and opposite an impaction surface arranged around the conduit with a spacing, preferably by covering or being formed by a side wall of the first housing component; This process involves attaching a collar or gutter to a second casing component: - by forming or connecting the collar or gutter on the bottom of the inner portion of the duct, to form an external protruding rim and by making the duct integral with the second housing component which is specially adapted to constitute a sealing part or cover covering the annular end to close the opening.

[0020] Typically in this method, a gas-tight connection is made between the second housing component and the first housing component, to constitute said housing of the device, such that: - the duct communicates with the upper compartment via an axial opening in the inner portion, which extends along a longitudinal axis; and - the collar or gutter defines a rim projecting radially outwards from the duct, presenting an annular surface, opposite the plate, which extends radially to an external edge, preferably going up towards said external edge.

[0021] The assembly limits the number of components, without the need for moving parts or complex mechanisms in the separation device. The conduit can be arranged compactly and the height footprint can be optimized while having completely equivalent or identical passage sections for the radial outlet of the inlet and the axial outlet allowing evacuation. The inner portion of the duct may be the only part projecting downwards from the sealing portion and / or the only axial flow path opening into the upper compartment. The periphery of this inner portion may be accessible / uncovered (at least in the upper region of the upper compartment, adjacent to the sealing portion), so that the raw gas flow brought tangentially by the radial inner outlet of the inlet can go around and directly along this inner portion, circulating in the annular peripheral space delimited, on the inside, only by the surface of the inner portion of the duct (preferably a cylindrical surface).

[0022] The collar (forming a gutter or annular retainer) can, during the joining step, be positioned around one end of the conduit or formed on an outer circumference of the conduit adjacent to that end. Clipping or welding, for example, allows the formation of an annular (circumferential) contact that is preferably continuous and watertight. It is also possible to mold the collar directly.

[0023] In the process, the leak-tight connection step may include a leak-tight fixing of a part forming the conduit (for the evacuation of the purified gas stream), before securing the flange or gutter to the conduit in the second housing component by inserting the conduit through a mounting hole provided in the second housing component. For example, the mounting hole has an inside diameter that is larger than the diameter of the axial outlet of the conduit. The collar may have an inner circumference which has an internal diameter equal to the (internal) diameter of the duct at the lower end, so that the collar / gutter does not reduce the cross-section of passage provided at the axial outlet through which the purified gas is discharged, out of the separation chamber.

[0024] According to another aspect, it is proposed to use, for water-gas separation (separation of water in a gas stream, in particular in a gas stream discharged from a fuel cell, the gas being air or hydrogen), a lid with a conduit having an external, annular rim, the lid constituting a casing component of a water separator for a fuel cell, the external rim being formed on a gas stream outlet carried by the lid, the outlet being in communication with a separation chamber of the water separator where a tangential circulation of a gas stream to be purified is carried out from an inlet opening laterally into said chamber through an internal inlet outlet, such that this stream rotates around the conduit constituting the outlet, the separated water that can be collected on a base formed as a lower end of the separator opposite the lid, use in which the outer rim is: - in the form of a collar or gutter, such that the outer rim projects radially outwards from the duct, the collar or gutter being arranged around a lower end of the duct or formed on an outer circumference of the duct in a position adjacent to the lower end of the duct; and - supported by the cover of the water separator, lower than the internal inlet outlet, so that tangential circulation is achieved, around the conduit defining a longitudinal axis, partly in an axially delimited area between the collar or gutter on one side and a radial sealing part, belonging to the cover, from which the conduit protrudes downwards into the separation chamber.

[0025] The arrangement of the lid with the flanged / guttered duct allows for simple assembly, on the one hand, and optimizes separation, on the other, by enabling a tangential separation mode due to the extension of the protruding duct under the sealing portion. The gas flow can therefore be rotated around the duct, and the undesirable effect of water being drawn into the duct by droplets or quantities of water that may have accumulated while flowing along it is limited, by promoting the entrainment of this water in the vortices that rotate around the longitudinal axis of the duct. Brief description of the drawings

[0026] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0027] [Fig.1] illustrates a liquid water separation unit allowing tangential circulation of the gas flow, typically air or hydrogen (H2), around the outlet conduit which protrudes inside the housing which also delimits a lower compartment for collecting the liquid water, formed under a partitioning element. [Fig.2] illustrates, by a longitudinal cross-sectional view, an example of a conduit constituting the outlet, equipped with a gutter-effect collar to make water droplets trickle away from the internal axial outlet of the conduit. [Fig.3A] is a view quite similar to that of [Fig.1], showing the gas inlet offset to one side relative to a central axis of the housing which can be confused with the longitudinal axis of the outlet duct. Figure [Fig. 3B] shows, by a cross-sectional view passing through the longitudinal axis of the conduit, the bottom of the separation chamber and the lower compartment containing the separated liquid, with a liquid purging system from the bottom. [Fig.4] is a cross-sectional modeling view, illustrating the flow lines in the water separation chamber, with indications of gas velocity according to the circulation zones around the inner portion of the outlet duct. [Fig.5] shows the separation device with a view of the interior to illustrate gas trajectories in the upper compartment that can form the separation chamber, here with a schematically illustrated water drain line. Description of the implementation methods

[0028] Several non-limiting examples of embodiments are set out in detail below. In the various figures, identical reference numerals indicate identical or similar elements.

[0029] With reference to Figures 1, 3A-3B and 5, a liquid separation unit or device 1 (in particular liquid water) is shown, which can be delivered as a pre-assembled unit, ready to connect two pipes (flexible or not): - one for the supply of a gaseous flow, which includes for example air or hydrogen (H2), - the other for the evacuation of the purified gas. In addition, a liquid water circulation line (visible in [Fig.5]) can be provided to allow drainage from the side of a bottom 2a of device 1.

[0030] The housing of the device 1 includes a first component 2, such as a bowl or the like, and a lid 3, forming a functional part called a sealing part. A conduit 4, extending from an upper end 4a to a lower end 4b, can be carried by the sealing part, for example, by projecting outwards to allow connection to the upper end 4a. This conduit 4 projects internally into the housing, so that the lower end is located on an internal portion 4i of the conduit 4. Figure 1 shows the non-limiting case where the base 2a and the side wall 20 are part of the same piece or component (first component 2). Of course, the first component 2 can also be designed differently, not necessarily as a single piece: for example, by having a tubular structure to which a separately designed base is attached, or by integrating the sealing portion and the side wall 20, possibly resulting from an assembly of parts. In all cases, the side wall 20 can be designed to extend around the inner portion 4i with a spacing, for example, a spacing that is equal to or greater than the diameter of a radial opening of the inlet E of the housing, where the inlet opens into the inside of the housing.

[0031] The separation device 1 is a tangential flow device, with a suitable arrangement of the internal radial outlet of the inlet E relative to the internal portion 4i of the conduit 4. With reference to Figures 1, 3A-3B and 5, it can be seen that the inlet E allows admission opposite the sealing portion, while opening internally (into an internal volume V) by a radial outlet allowing tangential flow of the gas stream into an upper area of ​​the internal volume V. The inlet E can be delimited / formed by a bent conduit, with a bent area EC, allowing admission of the gas stream from below, opposite to the orientation of an outlet S which exits the purified stream from above, typically beyond the sealing portion of the cover 3. Compartmentalization of the interior volume

[0032] The sealing portion, when formed as a second component or cover 3, allows for the upper delimitation of a separation chamber of the device 1. The housing delimits an internal volume V and may have a side wall 20 extending around a central axis A (typically forming the central axis of the housing). A partitioning element 5 may be provided within the internal volume, while the internal portion 4i of a conduit 4 also extends into this internal volume V, facing the partitioning element 5 with its lower end 4b. The internal volume V may be divided into several sub-volumes or compartments, for example, an upper compartment C1 where vortices form around the internal portion 4i of the conduit 4 and a lower compartment C2 allowing water to accumulate on the bottom 2a.

[0033] A plate 25 or similar perforated part of the partitioning member 5 can be fixedly arranged to cover the bottom 2, so that the lower compartment C2 is delimited between the bottom 2a and the plate 25, below the upper compartment CL. The separation chamber thus extends above the plate 25 and several orifices 05 of this plate allow the droplets G to reach the collection area in the lower compartment C2. The orifices 05 are distributed substantially over the entire plate except for a central area 5c, visible in particular in figures 3A and 5, possibly with progressive spacings relative to the central axis A. A distribution of the orifices 05 can be helical, with rows of orifices 05 not straight (but which follow a curve, as in the case of [Fig.3A]).

[0034] In embodiments, each of the orifices 05 may have a calibrated passage cross-section, for example with a diameter between 3 and 6 mm, preferably between 3.4 and 5.5 mm. At least four arrangements are provided for these orifices 05, with the first orifices, corresponding to a first arrangement, being closer to the central zone 5c with the same radial spacing with respect to the axis A, then several other successive arrangements in each of which the orifices 05 have the same radial spacing. Thus, we find orifices close to the lateral wall 20 and other orifices far from the lateral wall 20. In a configuration with a bulge in the plate 25, at least the orifices distributed in an annular manner near the central zone 5c, with the first arrangement, are raised due to the bulge compared to other orifices. Integration of a glued gutter / reel on the inner portion of the outlet

[0035] Regardless of how the internal volume V is delimited, the conduit 4 can be substantially vertical towards the bottom 2a, with a lateral face of the internal portion 4i at the same height as the internal outlet of the inlet, through which a raw gas flow Fl arrives substantially horizontally or at least tangentially. The conduit 4 opens axially from below into the separation chamber to allow the purified gas arriving in a low and central area of ​​the upper compartment Cl to be evacuated. This conduit 4 can be coaxial with respect to an external lateral delimitation (tubular wall) delimiting the upper compartment Cl, for example, by having the internal portion 4i of the conduit extending around a longitudinal axis X, remaining axially spaced from the central part 5c of the plate 25 on the one hand, and maintaining a regular or constant space with respect to the lateral wall 20.The central part 5c is preferably not perforated, to avoid undesirable effects of vertical suction of water collected in the lower compartment C2. The longitudinal axis X of the inner portion 4i can be confused with the central axis A.

[0036] On or near its lower end 4b, the conduit 4 includes or carries a collar or gutter 6 formed over all or part of the circumference of the inner portion 4i, typically without reducing the axial passage cross-section around the longitudinal axis X, which is formed at the bottom of the conduit 4. An external rim is then formed, spaced from the impaction surface S20 that delimits the upper compartment Cl, thus forming the outer circumference of the separation chamber. With such circumferential spacing, the collar or gutter 6 does not prevent vortices formed far from the inner portion 4i, along the impaction surface S20, from following a downward trajectory. Conversely, along / very near the inner portion 4i of the conduit 4, a guiding effect of the gutter allows: - limit the downward component of gas flow trajectories, which makes it possible to obtain vortices and tangential circulation trajectories with an acceleration effect (see arrow Fr, [Fig.5]), on the one hand; - and to push radially outwards any water droplets that may have fallen onto gutter 6, on the other hand.

[0037] With reference to [Fig.2], 3A and 3B, the collar or gutter 6 defines a rim projecting radially outwards from the conduit 4. It may have a continuous circular outer edge, for example with a diameter at least 6 or 7 mm greater than the outer diameter of the inner portion 4i. More generally, with respect to a cylindrical outer surface of the conduit 4, the collar or gutter 6 has a radial extension e6. This radial extension e6, measured perpendicular to the central axis A, can be greater than a thickness of the conduit 4 and / or greater than or equal to 6 or 7 mm.

[0038] In some options, the gutter 6 can be arranged around a lower end 4b of the conduit 4, in simple embodiments of the conduit 4, which is devoid of external ribs or reliefs. In certain designs, with or without a simple structure of the conduit 4 (for example, including ribs), reliefs or ribs, possibly helical, can form a transition between an outer surface of the conduit 4 and the gutter 6. It is understood that the gutter 6 can be a piece or added part formed on an outer circumference of the conduit in a position adjacent to the lower end 4b of the conduit 4. This gutter 6 can constitute an end piece without an insertion part coming into the hollow of the conduit 4.

[0039] Knowing that the conduit 4 makes it possible to obtain a diameter D4 for the area of ​​the axial outlet of the conduit 4 fitted with the collar or gutter 6, it can be provided to prevent any straight upward flow of water droplets G located directly above the / sub-conduit 4. For this purpose, the central part 5c of the plate 25, which is not perforated, can have a diameter d5 less than the diameter D4 while exceeding half of this diameter D4.

[0040] In the non-limiting example of [Fig. 4], the conduit has a cylindrical internal surface and an annular end piece forms the gutter 6. An internal face F5 of the gutter 6, for example, has a diameter equal to the internal diameter D4 of the internal portion 4i, which constitutes the projecting portion of the conduit 4 in the upper compartment Cl. An end with a relief, ridge, or barbed region may be provided at the end 4a, opposite the axial internal opening formed on the lower end 4b, oriented towards the bottom 2a. The axial internal opening O may be in the form of an opening in a plane P4 (an opening plane that may be horizontal or parallel to the plate 25). The plane P4 can be a plane tangent to the gutter 6, as in the case of figures 1 and 3A-3B in particular when the gutter 6 is formed of a single piece which extends in an annular manner around a central hollow allowing the passage of the purified flow F2 joining the conduit 4.

[0041] The inner portion 4i may be the sole axial flow path formed as a downward projection / protrusion from the obturation portion. The conduit 4 may also define the single portion projecting axially outwards to allow end 4a to connect a complementary / compatible conduit. The conduit 4 can communicate directly with the upper compartment Cl, using the entirety of its passage section which is not obstructed by the collar or gutter 6. The central region of the bottom 2a is located directly above the internal axial opening O allowing this communication.

[0042] To avoid creating turbulence near the outer edge 6c of the gutter 6, this outer edge 6c can be thinned or formed into a lip 6b which joins a section of the nozzle, aligned with the thicker inner portion 4i of the conduit 4. The thickness of the lip 6b (annular in the case of Figures 2 and 3A-3B) can be equal to or of the same order of magnitude as the thickness of the conduit 4. The collar or gutter 6 may include a tubular body 6a, here cylindrical, for a watertight radial connection around the circumference of the inner portion 4L. The top of the body 6a may form a first annular shoulder adjacent to the conduit 4, while the lip 6b may connect to the body by forming a groove open from above. The body 6a and the lip 6b have a bottomless, cap-like shape, with the lip 6b forming the edge transversely to the direction of the body 6a.

[0043] With reference to [Fig. 2], the collar or gutter 6 is provided with a lower annular surface, opposite the plate 25, which extends radially to the outer edge 6c, curving upwards in the direction of said outer edge 6c. The annular surface may gradually rise as it approaches the outer edge 6c. If necessary, the collar or gutter 6 may be designed with a slope angle α for the lip. This angle, which is measured here from the outside and with respect to the plane P4 of the lower opening / access of the central hollow, may be between 10° and 55°, preferably between 15° and 45°. With this angle α, the lip can define a flow groove in a circumferential direction, where water droplets can be received without continuing their descent. On the contrary, an upward movement is required, following the slope of angle α. Deflection functions and acceleration effects

[0044] With reference to Figures 1, 3A-3B and 5, the raw gas flow Fl, entering the upper compartment Cl, can be directed for circulation between the inner portion 4i and the wall 20, using an inlet recess or cavity delimited by / under the cover 3, typically under a hollow axial projection or hollow bump b3, which makes it possible to form a bent zone EC (visible in Figures 1 and 5) when the inlet E extends from a lower end 7 of an external conduit 14 which can be formed parallel to the side wall 20, possibly with a gap when joining the cover 3. More broadly, an EC elbow zone can be provided for: - to correctly direct the flow Fl into the internal compartment, - and allow easy connection of a pipe to the inlet E, which is typically an axial / parallel extension to the pipe 4.

[0045] In the non-limiting example of [Fig. 5], a rotating section of conduit is provided, delimited on top by the hollow axial projection or hollow bump b3, which forms part of the sealing portion (in the cover 3). Thus, this flow Fl is not oriented centripetally towards the inner portion 4i, but tangentially with a rotating trajectory, substantially circular, for example, around the inner portion 4L To gradually guide the descent of the gas flow, the sealing portion of the lid 3 may have a downward profile, starting from the angled area EC or similar area forming the internal radial outlet of the inlet E. As clearly visible in [Fig. 1], the hollow axial projection b3 can define a maximum distance or height H1 between a section of the outer edge 6c and the sealing portion, which is greater than the distance or height H2 obtained in a diametrically opposite area. Typically, the lid 3 is less convex or no longer has a projection in this area diametrically opposite the internal radial outlet of the inlet E.

[0046] From a top view, the gas flow can be counterclockwise. With reference to [Fig. 4], the flow lines can be seen in the upper compartment Cl, with indications of gas velocity according to the flow zones around the inner portion 4i of the duct 4. At least over a significant angular sector b, which typically exceeds 90°, a significant acceleration effect is observed for the linear velocity measured along / as close as possible to the inner portion 4L. In the acceleration zone ZA, the velocities rise to more than 55 or 60 m / s. In the same angular sector, in areas closer to the impaction surface S20, the velocities are on average slightly greater than or equal to 50 m / s, while the inlet velocities through the angled zone EC are less than 35 m / s.

[0047] The collar or gutter 6 has a beneficial effect on acceleration and minimizes the re-entrainment of water droplets. The reduction in height (H1>H2) also appears to limit pressure losses: the progressive decrease in height, from the greatest height H1, appears to have a beneficial effect in facilitating the transfer of droplets from the gutter 6 to the outer periphery of the upper compartment Cl, by taking advantage of vortices that spread these droplets radially outwards without the undesirable effect of rapid entrainment towards the underside of the duct 4.

[0048] Although the drawings show the case of an external rigid conduit 14, supported by the cover 3 of the housing, for a first upward circulation of the gas flow upstream of the separation chamber, other designs may allow the supply of the raw gas flow Fl. In variants, the inlet E can allow downward circulation. In these cases, with an inlet arranged axially for its first section, it can be provided that the first section of the inlet E is parallel to the central axis A, while the section of the inlet communicating laterally with the upper compartment Cl forms a second section of the inlet which complements the first section by being arranged transversely with respect to the central axis A.

[0049] The conduit 4, defining the outlet S, allows a second upward circulation of the gas flow downstream of the separation chamber, extending around a longitudinal axis X (parallel or coincident with the central axis A), so that the second upward circulation is parallel to the first circulation (whether upward or downward, in the first section), starting from the axial outlet O which can be located entirely lower than the second section of the inlet E. This axial offset makes it possible to obtain rotating vortices between the second section of the inlet E and the level of the gutter 6. Assembly examples

[0050] The inlet E can be divided into two sections, one of which is included in component 2 when an annular flange C permanently connects the external rigid conduit 14 and the tank or bowl. To complete the external rigid conduit 14 formed as the first section, a second section is provided in the cover 3, which also has a flange 32. The second section defines the angled area EC in the case illustrated in Figures 1 and 5. A junction plane can be obtained by attaching the cover 3, via the underside of the flange 32, to the top of the flange C. A gasket J3, for example, ensures the sealing of the connection, under the flange C of the cover 3.

[0051] More broadly, the fixing of the cover 3 on the body or housing component 2 is carried out in a gas-tight manner (in particular, gas-tight against oxygen and hydrogen), by including one or more sealing elements J3 and with tightening permitted by suitable fixing means FM. In the illustrated embodiments, it can be seen that anchoring the component or cover 3 by the screws or MF fasteners, for example metallic ones, ensures a flat arrangement of a flange C of the cover 3 where sealing can be achieved by the gasket J3, in an area offset internally relative to the margin / external area traversed by the screws or MF fasteners. The height of the bowl forming the boundary of the separation chamber (bowl constituted by the first component 2) can be reduced by adapting the length of the conduit 4 and / or by providing an axial bulge / projection b3 to raise the area of ​​the watertight seal with the gasket J, which rests against the conduit 4 from its outside. Alternatively, the conduit 4 can be welded to be fixed to the sealing part (therefore to the cover 3), or the conduit 4 can be included in a molded part forming all or part of the cover 3 (conduit integrated into the sealing part in this case).

[0052] In embodiments, the attachment of the cover 3 can be permanent and / or achieved by welding, typically by eliminating the seal J3 in the case where an (annular) weld is made. Optionally, a single seal is sufficient, or even the (complete) housing that delimits the internal volume V is obtained without a seal.

[0053] Before assembling the cover 3 as the second component onto the first component 2 to obtain the annular watertight joint line LJ, the conduit 4 with the collar or gutter 6 can be arranged in a predetermined configuration to adjust the height Hl. Referring to Figures 1 and 2, a watertight fixing of a part forming the conduit 4 can be achieved on the sealing portion (belonging to the cover 3) before attaching the collar or gutter 6 to the conduit 4, thus also making it fixed to this second component. The outer diameter of the inner portion 4i allows the conduit 4 to be inserted through a mounting hole 03 provided in the second housing component, here centrally located in the cover 3 in the illustrated, non-limiting case. Naturally, the mounting hole 03 has an inner diameter that is larger than the diameter D4.Here, this mounting hole 03 receives only a single-tube structure constituting the conduit 4. No inner skirt of the cover 3 acts as a barrier between the inner radial outlet of the inlet 4 and the inner portion 4i, once the cover 3 is installed on the housing component 2.

[0054] In certain options, an annular insert is deposited in the internal volume Vn to form the lateral impaction surface S20, which internally covers the lateral wall 20.

[0055] The separation device 1 can form a compact arrangement in height, limiting the pressure loss and efficient for the recovery of liquid droplets, which can advantageously avoid water entrainments, avoid turbulence near the axial outlet of the outlet.

[0056] The assembly allows for some versatility in the choice of the component(s) 2 that are assembled with the cover 3. The collar or gutter 6 can be obtained and arranged during a design phase of the cover 3, with the outer rim already in place, forming an annular relief up to the outer edge 6c. The outer rim of the collar or gutter 6 is thus pre-formed on the lower end 4b of the conduit 4 or on an outer circumference of the conduit in a position adjacent to the end 4b), by placing / mounting a component of this outer rim / gutter on the cover 3 of the water separator device 1, lower than the angled area EC or internal inlet outlet, so that tangential circulation can be achieved around the conduit 4. The arrangement of the cover with the conduit and the gutter 6 can therefore be advantageously used in a Water separation device 1, without increasing the number of parts to be assembled. Furthermore, the planned parts can have a simple structure, so the manufacture of device 1 does not require a very complex mold. Drainage

[0057] In some embodiments, a drain orifice or conduit 15 is provided, and a valve V2 (for example, a butterfly valve) associated with this liquid water drain conduit LW can open when the quantity of water is too high. If so, the liquid water outlet can follow a mechanical (passive) process. An Archimedes' thrust effect (force FA on the [Fig. 3B]) can allow the lifting of a downward-projecting rod or rod 30, attached to the plate 5. A cavity, for the axial (typically vertical) displacement of such a rod 30 or similar guiding element, can be formed by a support or hollow pillar 8 provided in the base 2a of the component 2. This hollow pillar 8 can be directly part of the base 2a, being formed as a single piece with the component 2. Alternatively, the support function of the plate 25 or the partitioning element 5 can result from internal reliefs or shoulders.

[0058] In options using a solenoid valve, the opening threshold can be chosen so that the collected water does not rise back up to the plate 25. Regardless of the control method (passive or active) to release one or more drainage ports 15 to drain water out of the lower compartment C2, the collected water W, accumulated in the lower compartment C2, can thus be drained.

[0059] To delimit the lower compartment Cl, the plate 25 can be of a given thickness and have a convex upper surface. The plate 25 is optionally curved upwards, so that the unperforated central portion 5c is higher than a portion of the annular margin of the plate 25.

[0060] This disclosure is not limited to the embodiments described above, only by way of example, but encompasses all the variants that a person skilled in the art may consider within the framework of the protection sought.

[0061] The separation unit or device 1 may include a covering or insert element 9, such as a fabric or rigid support with fabric, this element 9 being formed separately from the body / component 2. This design can simplify the production of the device 1, since the element 9 is not welded or attached directly to the component 2, but to another part of the support (designed separately). A welding process on the conduit 4 of the collar or gutter 6 may also be provided, which can be a less expensive and faster solution, without the complexity of the welding tool, for example. This may also make the device more robust.

[0062] Furthermore, although the conduit 4 has been presented as forming a single channel, without partitions or diverter elements, it may alternatively have raised features, guides, or diverter elements, or possibly at least part of a longitudinal partition. It may also have a crenellated or corrugated end, possibly fitting into the collar or gutter 6. The projecting part of the latter may optionally form one or more undulations, for example with radial ribs separated from each other by grooved areas.

[0063] The connection of the sealing portion or second component has been illustrated as being made directly on the first component 2, using at least one seal. In alternative versions, the watertight connection can be achieved by placing a connecting interface, for example by using an interposed (e.g., annular) piece between these two components.

Claims

1. Demands Liquid separation device (1), in particular for water, for gaseous flow from a fuel cell circuit, the device comprising a housing delimiting an internal volume (V) which includes a separation chamber, the device (1) comprising: - a housing component (2), provided with a side wall (20) which extends around a central axis (A); - a lateral impaction surface (S20), delimiting the separation chamber; - a shuttering part, preferably made in the form of a cover (3), and allowing to cover a top of the side wall, said housing component (2) and the shuttering part belonging to the housing; - a partitioning element (5) which includes a plate (25) with several orifices (05) to delimit the separation chamber from below, so that the separation chamber forms an upper compartment (Cl) in the internal volume (V); - a lower compartment (C2) provided between a bottom (2a) of the case and the partitioning element (5), under the upper compartment (Cl); - an inlet (E), to bring in a raw gas flow (Fl) of tangentially in the separation chamber, preferably perpendicular to the central axis, and an outlet (S), the inlet and outlet being provided in the housing; in which the sealing part carries or includes a conduit (4) defining the outlet (S), the conduit (4) communicating with the upper compartment (Cl) by an axial opening (O) being oriented towards the bottom (2a), projecting internally relative to the obturating part: - axially towards a central region of the bottom (2a), - while remaining axially spaced from a central part (5c), preferably not perforated, of the plate (25), characterized in that the conduit (4) includes or carries a collar or gutter (6), which defines a rim projecting radially outwards from the conduit (4) by being arranged around a lower end (4b) of the conduit (4) or formed on an outer circumference of the conduit in a position adjacent to the lower end (4b) of the conduit, and in that the inlet (E) of the housing communicates laterally with the upper compartment (Cl), by a section of the inlet located higher than the axial outlet (0) and higher than the collar or gutter (6).

2. Device according to claim 1, wherein the collar or gutter (6) is provided with an annular surface, opposite the plate (25), which extends radially to an outer edge (6c) by moving upwards towards said outer edge, preferably having said annular surface which rises progressively as one approaches said outer edge (6c).

3. Device according to claim 1 or 2, wherein the inlet (E) opens into the internal volume (V) through a radial outlet allowing tangential circulation of the gas flow in an upper zone of the internal volume (V), the inlet (E) being delimited by an angled conduit allowing admission of the gas flow from below, opposite to the orientation of the outlet (S) which brings out the purified flow from above.

4. Device according to claim 1, 2 or 3, wherein the side wall (20) extends from a bottom (2a) to an annular end (2c) having an opening (0), while the sealing part covers the annular end (2c) to close the opening (0), and wherein the radial outlet is at least partly formed in a projection or protrusion of the sealing part or adjacent to the sealing part, the sealing part being designed and arranged to allow, at least over an angular sector of 180° around an internal portion (4i) of the conduit (4), the height or axial distance between the collar or gutter (6) and the sealing part to be progressively increased as one approaches an angular sector including the radial outlet of the inlet.

5. Device according to any one of the preceding claims, wherein the orifices (05) have a passage section with a diameter which is between 3 and 6 mm, preferably between 3.4 and 5.5 mm.

6. Device according to any one of the preceding claims, wherein the axial outlet (0) has a diameter D4 corresponding to an internal diameter of the conduit (4), wherein the central part (5c) of the plate (25), which is a non-perforated part, is traversed by the central axis (A) and has a diameter d5, and wherein the following relationship is satisfied: < d5 / D4 < 1.

7. Device according to any one of the preceding claims, wherein the plate (25) has a convex upper surface or is curved upwards, so that the central part (5c), which is not perforated, is higher than a portion of the annular margin of the plate (25).

8. Device according to any one of the preceding claims, wherein, with respect to a cylindrical outer surface of the conduit, the collar or gutter (6) has a radial extension (e6), measured perpendicular to the central axis (A), which is: - greater than a thickness of the conduit (4), the passage section of which is substantially constant; - and / or greater than or equal to 6 mm.

9. A device according to any one of the preceding claims, comprising an external rigid conduit (14), supported by the housing, for a first upward circulation of the gas flow upstream of the separation chamber, the external rigid conduit (14) forming a first section of the inlet (E), parallel to the central axis (A), while the section of the inlet communicating laterally with the upper compartment (Cl) forms a second section of the inlet which completes said first section by being arranged transversely with respect to the central axis (A), in which the conduit (4) defining the outlet (S) is a rigid cylindrical conduit, for a second upward circulation of the gas flow downstream of the separation chamber, extending around a longitudinal axis (X) parallel to or coinciding with the central axis (A),This is why the second ascending circulation is parallel to the first ascending circulation, starting from the axial outlet (0), which is located entirely lower than the second section.

10. Method of assembling a liquid separation device (1), in particular for water, which purifies a gaseous stream discharged from a fuel cell circuit by circulating this stream in an upper compartment (Cl) of a housing having an inlet (E) and an outlet (S), the process comprising the steps essentially consisting of: - provide a first housing component (2), preferably in the form of a bowl, having a base (2a) and an annular upper end (2c) delimiting an opening (O); - to mount internally, in the first housing component (2) and preferably by insertion through the opening (O), a partitioning element (5) which includes a plate (25) to allow separation of the upper compartment (Cl) from a lower compartment (C2), the lower compartment (C2) intended for the collection of the liquid being delimited by said bottom (2a) after assembly, several orifices (05) of the plate (25) allowing droplets of liquid to pass under the effect of gravity from the upper compartment (Cl) to the lower compartment (C2); - to set up the outlet (S) in the housing, in the form of a conduit (4) with an inner portion (4i) of the conduit which protrudes internally into the housing, towards the bottom (2a); - to arrange the inlet (E) in the housing to allow a raw gas flow (Fl) to be brought into the upper compartment (Cl) tangentially, around the inner portion (4i) of the conduit (4) and opposite an impaction surface (S20) arranged around the conduit (4) with a spacing relative to this impaction surface; characterized in that a collar or gutter (6) is attached to a second housing component: - by forming or connecting the collar or gutter (6) on the bottom of the inner portion (4i) of the conduit (4) and by making the conduit (4) integral with the second housing component, which is specially adapted to constitute a sealing part or cover (3) covering the annular end (2c) to close the opening (O); and in that a gas-tight connection is made between the second housing component and the first housing component (2), to constitute said housing of the device (1), so that: - the conduit (4) communicates with the upper compartment (Cl), through an axial opening (O) of the inner portion (4i), which extends along a longitudinal axis (X); and - the collar or gutter (6) defines a rim projecting radially outwards from the conduit (4), presenting a surface annular, opposite the plate (25), which extends radially to an external edge (6c), preferably going upwards towards said external edge (6c).

11. Assembly method according to claim 10, wherein the sealing connection step includes a sealing fixing of a part forming the conduit (4), before securing the collar or gutter (6) to the conduit (4), in the second housing component by inserting the conduit (4) through a mounting hole provided in the second housing component, the mounting hole (03) having an internal diameter which is greater than a diameter (D4) of the axial outlet (0) of the conduit (4).

12. Use, for separating water from a gas stream, in particular from a gas stream discharged from a fuel cell, of a lid (3) with a conduit (4) having an external, annular rim, the lid constituting a housing component of a water separator (1) for a fuel cell, the external rim being formed on a gas stream outlet (S) carried by the lid (3), the outlet (S) being in communication with a separation chamber of the water separator where a tangential flow of a gas stream to be purified (Fl) is carried out from an inlet opening laterally into said chamber through an internal inlet outlet, such that this stream (Fl) rotates around the conduit (4) constituting the outlet (S), the separated water being able to be collected on a base (2a) formed as a lower end of the separator (1) opposite the lid (3), in which the external rim is: - in the form of a collar or gutter (6),so that the outer rim projects radially outwards from the conduit (4), the collar or gutter (6) being arranged around a lower end (4b) of the conduit (4) or formed on an outer circumference of the conduit in a position adjacent to the lower end (4b) of the conduit; and - supported by the cover (3) of the water separator (1), lower than the inner inlet outlet, so that tangential circulation is achieved, around the conduit (4) defining a longitudinal axis (X), partly in an axially delimited zone between the collar or gutter (6) on the one hand and a radial sealing portion, belonging, to the cover (3), from which the conduit (4) protrudes downwards into the separation chamber.

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