WO2015052394A1

WO2015052394A1 - Air-separation device and corresponding inerting device and aircraft

Info

Publication number: WO2015052394A1
Application number: PCT/FR2014/052304
Authority: WO
Inventors: Xavier Roussin-Bouchard; Aurélie CAILLAUD; Pierre GIANESE; Elodie DUMONT; Jean-Marc DEJONGHE
Original assignee: L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude
Priority date: 2013-10-09
Filing date: 2014-09-16
Publication date: 2015-04-16
Also published as: FR3011483B1; FR3011483A1

Abstract

The invention relates to an air-separation device comprising a casing (1, 2) housing a fibre bundle (3) forming a membrane, the longitudinal axis of the fibres being parallel to the longitudinal axis (A) of the casing (1, 2) and each of the two longitudinal ends of the fibre bundle (3) comprising a layer (8) of rigid material. The device also comprises a cylindrical jacket (7) disposed longitudinally around the fibre bundle (3) and a system for maintaining the fibre bundle (3) in the casing (1, 2), said system comprising a longitudinal end-stop mechanism (6) formed between an element of the casing (1, 2) and an element of a first longitudinal end of the fibre bundle (3) in order to block the movement of the fibre bundle (3) in relation to the casing (1, 2) in a direction parallel to the longitudinal axis (A) of the casing (1, 2). The aforementioned maintenance system also comprises a mechanical supporting member (9) between the casing (1, 2) and the jacket (7), and the second longitudinal end of the fibre bundle (3) is mounted in the casing (1, 2) such that it can move freely in translation in a direction parallel to the longitudinal axis (A) of the casing (1, 2).

Description

Air separation device, inerting device and

corresponding aircraft

The present invention relates to an air separation device and an inerting device and an aircraft comprising such a device.

The invention more particularly relates to an air separation device comprising a generally cylindrical housing housing a filter element comprising a hollow oblong fiber bundle forming a membrane, the longitudinal axis of the fibers being parallel to the longitudinal axis of the housing, the housing comprising, at a first end, an air inlet opening and, at a second end, a purified gas outlet port, the two longitudinal ends of the fiber bundle each comprising a layer of rigid material, the device further comprising a cylindrical liner disposed longitudinally around the bundle of fibers between the two longitudinal ends of the bundle of fibers, the device comprising a fiber bundle holding system in the housing.

Filtration of air gases by hollow fiber membrane is a method widely used in industry and in particular in the aeronautical field. This technology consists in taking air from compressors or motor (s) and circulating it in a separation system containing a selective porous membrane allowing only "molecules" of a chemical species (oxygen or nitrogen for example). By compartmentalizing this system in a sealed manner it is possible to recover on the one hand air depleted of oxygen and therefore very rich in nitrogen, and on the other hand, air enriched with oxygen. The nitrogen enriched air can be used to inert fuel tanks for example while the oxygen can be simply released to the atmosphere.

The air separation systems generally comprise a housing comprising a metal cylinder, closed at one end by a bottom (welded, glued or screwed) and closed at the other end by a cover (generally screwed or assembled by a flange) . The lid is pierced with an inlet port for admission of air while the bottom is pierced with an outlet for collecting the nitrogen-enriched gas at the output of the system. Another port is provided for the separated gas (oxygen). The cylindrical portion (sometimes called envelope) may for example be provided with an orifice perpendicular to the axis of the cylinder for the evacuation of oxygen filtered by the system.

The geometry of the inlet and outlet ports may be of different types and geometries. The filtration element disposed inside the casing generally consists of a bundle of hollow polymeric fibers present in very large numbers. The longitudinal axis of the fibers is aligned with the longitudinal axis of the housing cylinder.

At the ends of these fibers can be provided a rigid cohesion material such as a thermosetting material, ideally epoxy, cast and re-machined. These ends of rigid material allow mechanical retention of the fibers and cooperation with a system of O-ring (s) to maintain the seal between the various chambers of the system.

US7717983B2 discloses an axial holding member of the beam consisting of cones centered on each side in hollow cylinders present on each side of the outer faces of the membranes.

However, this assembly generates a rigidity of the entire device and causes harmful stresses in the membranes during certain operating phases of the system.

An object of the present invention is to overcome all or part of the disadvantages of the prior art noted above.

To this end, the device according to the invention, furthermore in accordance with the generic definition given in the preamble above, is essentially characterized in that the holding system comprises a longitudinal stop mechanism formed between a housing element. and an element of a first longitudinal end of the bundle of fibers to ensure a blocking of the bundle of fibers relative to the housing in a direction parallel to the longitudinal axis of the housing, the holding system further comprising a mechanical support member between on the one hand the housing and, on the other hand, the liner and in that the second longitudinal end of the fiber bundle is mounted free in translation in the housing in a direction parallel to the longitudinal axis of the housing.

Such a device allows assembly and effective maintenance of the fiber bundle.

Such a structure makes it possible to assemble and effectively maintain a bundle of fibers while limiting the shear forces experienced by the ends of the bundle of fibers. The arrangement according to the invention makes it possible to reduce, with respect to the prior art, the shear stresses at the level of the composite part of the fiber bundle (composite part comprising one end of the fibers embedded in the rigid material) and at the level of the material rigid protruding beyond the fibers (rigid material only).

According to other possible features: - The holding system consists solely of said longitudinal stop mechanism and the mechanical support member between the housing and the liner, the second longitudinal end of the fiber bundle being guided in translation in a sealed manner in the housing in a direction. parallel to the longitudinal axis of the housing,

the longitudinal stop mechanism formed between the housing and a first longitudinal end of the fiber bundle is located at the periphery of the bundle of fibers,

the longitudinal stop mechanism is formed between the layer of rigid material and a wall of the housing,

the longitudinal stop mechanism comprises an insert secured to the periphery of a first longitudinal end of the bundle of fibers and at least one shoulder formed by the housing or an element structurally connected to the housing, the insert being locked longitudinally by the less a shoulder, - the mechanical support member between the housing and the liner comprises a first end rigidly fixed to the housing, or respectively fixed rigidly to the liner, and a second end supported or fixed against the liner, respectively against the case,

the mechanical support member between the housing and the liner comprises at least one profile comprising a first part which extends against at least a part of the circumference of the liner and a part in contact with the housing,

the support member is fixed to the housing, respectively to the jacket, by at least one of: screwing, gluing, welding, riveting, snapping,

the support member comprises a folded portion of the liner, that is to say that a portion of the liner is mechanically connected directly to the housing,

the longitudinal stop mechanism is formed between on the one hand a part of the layer of rigid material projecting beyond the fibers of the membrane and, on the other hand, a wall of the housing or a fixed element relative to the housing ,

the mechanical support member between the casing and the casing transmits forces between the casing and the casing in a direction perpendicular to the longitudinal axis of the casing,

the insert has the shape of a ring integral with one end of the liner, the longitudinal abutment mechanism comprises a projection formed on the case or, respectively, on the layer of rigid material of the bundle of fibers, and a housing receiving the flute, said housing being formed in the layer of rigid material, respectively in the housing, - The longitudinal stop mechanism comprises a fitting or clamping of the first longitudinal end of the beam in the housing.

The invention also relates to an aircraft tank inerting device comprising a separation device according to any one of the above characteristics or below, wherein the fiber bundle is of the type with selective adsorption of oxygen. .

The invention also relates to an aircraft comprising such an inerting device.

Other particularities and advantages will appear on reading the following description, made with reference to the figures in which:

FIG. 1 represents a schematic and partial longitudinal sectional view illustrating a possible embodiment of the invention,

FIG. 2 illustrates an enlarged view of a detail of FIG. 1,

FIG. 3 illustrates a view similar to that of FIG. 2 according to another possible embodiment,

FIG. 4 represents a view in longitudinal section of a detail of a separation device according to another possible embodiment of the invention,

- Figure 5 schematically and partially illustrates the possible use of such a device for inerter an aircraft tank.

The air separation device shown in Figure 1 comprises a housing

1, 2 of cylindrical general shape housing a filter element comprising a bundle 3 of oblong hollow fibers. For example, these membranes are those marketed by the company "MEDAL".

The two longitudinal ends of the bundle 3 of fibers each comprise a layer 8 of rigid material, for example a thermosetting resin, in particular an epoxy resin. That is to say that the two longitudinal ends of the fibrous membranes are embedded in a rigid material 8. In addition, this rigid material can extend on the periphery of the bundle 3 beyond the fibers, to form a layer 88 of "pure" rigid material intended to mechanically cooperate and seal with the housing 1, 2 via appropriate seals 12, 13. As illustrated in FIGS. 2 and 4 in particular, ring seals 12, 13 may be arranged in machined grooves in the periphery of the layer 88 of rigid material.

The device further comprises in the casing 1, 2 a cylindrical sleeve 7 (for example metallic) disposed around the bundle 3 of fibers. The liner 7 can be held by clamping between the layers 88 of rigid material of the two longitudinal ends of the bundle 3 of fibers. The liner has an orifice 13 which coincides with a lateral orifice of the casing 1, 2 to form an outlet 14 (see FIG. 4) of filtered gas (the oxygen of the air having migrated radially through the hollow fibers).

As illustrated in Figure 1, the housing 1, 2 may be formed by two ends 1, 2 assembled to one another and forming respectively a bottom and a cover of the cylindrical housing. One or both ends 1, 2 may also delimit the cylindrical central portion of the housing.

The device comprises a system for holding the fiber bundle 3 in the housing 1, 2.

The maintenance system is composed of:

- A longitudinal mechanical stop mechanism 9 formed between the housing 1, 2 and a first longitudinal end of the fiber bundle 3 to ensure a blocking of the bundle 3 of fibers relative to the housing 1, 2 in a direction parallel to the longitudinal axis A of the housing 1, 2, and

a mechanical support member 9 between the housing 1, 2 and, on the other hand, the jacket 7.

The stop mechanism 9 is schematized by a dotted pin in FIGS. 1 and 2. This longitudinal stop mechanism 6 is preferably formed between the layer 8, 88 of rigid material and a wall of the casing 1, 2. Preferably the mechanism longitudinal stop 6 is formed between on the one hand a portion of the layer 88 of pure rigid material protruding beyond the bundle 3 of fibers and, on the other hand, a wall of the housing.

In addition, the second longitudinal end of the bundle 3 of fibers is mounted free in translation in the housing 1, 2 in a direction parallel to the longitudinal axis A of the housing 1, 2. Just like the first longitudinal end, the second longitudinal end the bundle 3 of fibers (peripherally) is in sealing contact with the interior of the housing 1, 2, for example via at least one O-ring 12. This second end is not impeded or in contact with a holding element, even mobile. That is to say that in a plane perpendicular to the longitudinal direction, this second end end of the fiber bundle is free and without contact with a holding member.

This architecture has many advantages over known systems. Indeed, according to this configuration, in the configuration of use of the device, the cylindrical bundle 3 of fibers is perfectly maintained and immobilized in the casing 1, 2 while allowing this bundle 3 of fibers to expand or retract according to the temperatures and accelerations within the device (in the longitudinal direction A). According to this configuration, none or only one of the two faces of the longitudinal ends of the fiber bundle 3 can be brought into contact with one end of the housing 1, 2 (bottom or cover).

The pressure forces are therefore completely and directly taken up by the liner 7, the support member 9 and the housing 1, 2.

Unlike some solutions of the prior art, this solution also makes it possible not to affect the gas exchange surface (circular surface of the bundle 3 of fibers perpendicular to the longitudinal axis).

The longitudinal stop mechanism 9 may comprise a projection formed on the housing or respectively on the layer 8, 88 of rigid material of the fiber bundle, and a housing receiving the mesh, said housing being formed in the layer 8, 88 of rigid material , respectively in the housing 1, 2. Of course, this embodiment is not limiting. Thus, the longitudinal stop mechanism 6 may comprise a fitting or tightening of the first longitudinal end of the beam 3 in the casing 1, 2. This can be obtained by a suitable choice of the relative dimensions of the end of the fiber bundle relative to to the dimensions of the housing that receives this end.

In addition, in the example illustrated in the figures the longitudinal stop mechanism 6 is located at the end of the fiber bundle 3 located on the side of the air inlet port 4 and the end of the bundle 3 Free to slide longitudinally is located on the side of the enriched gas outlet 5. Of course, the opposite can be expected.

As can be seen in FIGS. 1 and 2, the mechanical support member 9 between the casing 1, 2 and the casing 7 comprises a first end rigidly fixed to the casing 1, 2, and a second bearing against the circumference of the casing 7 For example, the support member 9 comprises a section having a section of generally bent shape, a portion of which may be pressed against the housing 1, 2 via a screwed clamping piece 29 on the housing 1, 2. portion of the support member extends against at least a portion of the circumference of the sleeve 7.

Preferably, the support member 9 is located closest to the application of the pressure.

Of course, this embodiment is not limiting. Thus, the support member 9 can be fixed on the housing 1, 2 and / or on the sleeve 7 by welding and / or riveting and / or bonding or any other appropriate means.

Similarly, and as illustrated by way of example in Figure 3, the support member 9 may consist of a folded portion 17 of the sleeve 7 itself.

Finally, the holding member 9 shown in Figures 1 to 3 is located near the air inlet 4 (and connected to the portion 2 of the cover housing). Of course, alternatively it could be arranged on the other side (for example connected to the part 1 of the housing forming the bottom).

Figure 4 illustrates yet another alternative embodiment. As illustrated, the longitudinal stop mechanism 6 may comprise an insert 16 secured to the periphery of a first longitudinal end of the bundle 3 of fibers and one or more shoulders 26, 36 formed by the housing 2 or an element 19 structurally connected to the housing . The insert 16 is locked longitudinally by the shoulder (s) 26, 36.

The insert 16 has for example the shape of a ring integral with a circular end of the cylindrical sleeve 7. The longitudinal locking of the insert 16 towards the second end (towards the outlet orifice 5) is for example made by the clamping piece 19.

The longitudinal blocking of the first end of the fiber bundle 3 to the adjacent end of the housing (to the left in FIG. 4) can be achieved by the shape of the housing itself (cover 2). That is to say that the end end of the layer 8, 88 of rigid material is blocked by the housing 2. Alternatively or cumulatively, the insert 16 is blocked against a stop formed by the housing 2.

The architecture requires only a small number of component parts. As illustrated in FIG. 5, the air separation device 1 1 may advantageously be used to produce a nitrogen-enriched gas for inerting a fuel tank 10 of an aircraft.

The use of such a system makes it possible to have no decrease or increase in volume of the various gas compartments of the device during acceleration or deceleration of the aircraft.

It is therefore easy to conceive that, while being of simple and inexpensive structure, the invention offers numerous advantages, in particular:

ease of assembly,

no significant harmful effort is exerted on the end faces of the bundle 3 of fibers,

a structure of high reliability and durability, the bundle 3 of fibers can expand or contract freely while being perfectly maintained in the housing.

Such a device allows in particular a symmetrical machining of the constituent rigid parts and thus an undifferentiated assembly in one direction or in the other along the longitudinal axis.

Claims

1. Air separation device comprising a housing (1, 2) of generally cylindrical shape housing a filter element comprising a bundle (3) of oblong hollow fiber forming a membrane, the longitudinal axis of the fibers being parallel to the longitudinal axis (A) of the housing (1, 2), the housing (1, 2) comprising, at a first end, an air inlet (4) and, at a second end, an outlet (5) of purified gas, the two longitudinal ends of the bundle (3) of fibers each comprising a layer (8) of rigid material, the device further comprising a cylindrical jacket (7) arranged longitudinally around the bundle (3) of fibers between the two longitudinal ends of the bundle (3) of fibers, the device comprising a system for holding the bundle (3) of fibers in the housing (1, 2), characterized in that the holding system comprises a longitudinal stop mechanism (6) formed between an el housing (1, 2) and an element of a first longitudinal end of the bundle (3) of fibers to ensure a blocking of the bundle (3) of fibers relative to the housing (1, 2) in a direction parallel to the longitudinal axis (A) of the housing (1, 2), the holding system further comprising a mechanical support member (9) between on the one hand the housing (1, 2) and, on the other hand, the sleeve (7) and in that the second longitudinal end of the bundle (3) of fibers is mounted free in translation in the housing (1, 2) in a direction parallel to the longitudinal axis (A) of the housing (1, 2 ).

2. Device according to claim 1, characterized in that the holding system consists solely of said longitudinal stop mechanism (6) and the mechanical support member (9) (9) between the housing (1, 2). and the liner (7), the second longitudinal end of the fiber bundle (3) being translationally guided in leaktight manner in the housing (1, 2) in a direction parallel to the longitudinal axis (A) of the housing (1, 2).

3. Device according to claim 1 or 2, characterized in that the longitudinal stop mechanism (6) formed between the housing (1, 2) and a first longitudinal end of the bundle (3) of fibers is located at the periphery. beam (3) of fibers.

4. Device according to any one of claims 1 to 3, characterized in that the longitudinal stop mechanism (6) is formed between the layer (8, 88) of rigid material and a wall of the housing (1, 2).

5. Device according to any one of claims 1 to 4, characterized in that the longitudinal stop mechanism (6) comprises a insert (16) integral with the periphery of a first longitudinal end of the bundle (3) of fibers and at least one shoulder (26, 36) formed by the housing (2) or a member (19) structurally connected to the housing, insert (16) being longitudinally locked by the at least one shoulder (26, 36).

6. Device according to any one of claims 1 to 5, characterized in that the mechanical support member (9) between the housing (1, 2) and the liner (7) comprises a first end rigidly fixed to the housing (1, 2), or respectively fixed rigidly to the liner (7), and a second end supported or fixed against the liner (7) respectively against the housing (1, 2).

7. Device according to claim 6, characterized in that the mechanical support member (9) between the housing (1, 2) and the jacket (7) comprises at least one profile comprising a first portion which extends against at least a portion of the circumference of the liner (7) and a portion in contact with the housing (1, 2).

8. Device according to claim 6 or 7, characterized in that the support member (9) is fixed to the housing (1, 2), respectively to the jacket (7), by at least one of: a screwing, gluing, welding, riveting, snapping.

9. Device according to any one of claims 6 to 8, characterized in that the support member (9) comprises a folded portion of the sleeve (7), that is to say that a portion of the jacket (7) is mechanically connected directly to the housing (1, 2).

10. Device according to any one of claims 1 to 9 characterized in that the longitudinal stop mechanism (6) provides longitudinal locking of the beam (3) relative to the housing (1, 2) in both directions in one direction parallel to the longitudinal axis (A) of the housing.

1 1 .Dispositif according to any one of claims 1 to 10 characterized in that the stop mechanism (6) longitudinal is formed between the layer (8, 88) of rigid material and a wall of the housing (1, 2).

12. Device according to any one of claims 1 to 1 1 characterized in that the mechanism (9) of longitudinal abutment comprises at least one of: a projection formed on the housing or respectively on the layer (8, 88) of rigid material of the fiber bundle, and a housing receiving the mesh, said housing being formed in the layer (8, 88) of rigid material, respectively in the housing (1, 2); a fitting or tightening of the first longitudinal end of the beam (3) in the housing (1, 2).

13. Device according to any one of claims 1 to 12 characterized in that the second end of the beam that is to say its end face is not in contact with a holding member, and in particular not in contact with a movable holding member.

14. An inerting device for an aircraft tank (10) comprising a separation device (1 1) according to any one of claims 1 to 13 wherein the bundle (3) of fibers is of the type with selective adsorption of oxygen.

Aircraft comprising an inerting device according to claim 14.