FR3096664A1 - FUEL TANK AND AIRCRAFT, RELATED TREATMENT PROCESS AND ASSEMBLY METHOD - Google Patents

Abstract

Fuel tank and aircraft, associated treatment method and method of mounting The invention relates to an aircraft fuel tank comprising a bottom wall (12), a side wall and a top wall, the bottom walls (12), side and upper delimiting an internal volume for receiving fuel. The reservoir comprises a settling basin (16), the settling basin (16) being integral with the lower wall (12). Figure for abstract: 2

Description

Fuel tank and related aircraft, processing method and mounting method

The present invention relates to an aircraft fuel tank comprising a bottom wall, a side wall and a top wall, the bottom, side and top walls delimiting an interior volume for receiving fuel.

A fuel tank presents an environment conducive to the development of microbial pollution. Over time, water condenses in the fuel and collects at the bottom of the tank. At the interface between water and fuel, micro-organisms such as bacteria are likely to develop.

This development is favored in the stagnant zones of the tank, and during long immobilizations of the aircraft on the ground. In addition, this development is also favored by the environment outside the fuel tank and in particular the humidity level of this outside environment.

Micro-organisms, when they proliferate, pollute the tank which is the cause of its corrosion.

To avoid such an inconvenience, it is necessary to prevent microbial proliferation by regularly carrying out a manual purge of the tanks.

However, these purges are binding. Known manual purge systems indeed lack compactness, and are complex to implement.

For these reasons, operators are reluctant to carry out the necessary fuel tank draining operations.

Another known method to prevent microbial proliferation is to inject the water accumulated in the tank, during the aircraft's climb phase, into the fuel pumped to the aircraft's propulsion engines to eliminate it through of these engines.

However, this method is not sufficient because the pumping of water is only done in flight while microbial pollution appears and develops when the aircraft is immobilized on the ground during potentially long stops.

The aim of the invention is to improve the treatment of microbial pollution of an aircraft fuel tank, in particular when the aircraft is immobilized on the ground.

To this end, the subject of the invention is an aircraft fuel tank of the aforementioned type, characterized in that the tank comprises a settling basin, the settling basin being integral with the lower wall.

The fuel tank may also include one or more of the features below, taken alone or in any technically possible combination:

- the bottom wall has a low point, and the settling basin being arranged to be able to collect water flowing by gravity on the bottom wall towards said low point, the settling basin being preferably arranged at the level said low point;

- the lower wall has an inner surface, the settling basin extending back from the inner surface;

- the settling basin comprises a bottom and a basin wall extending from the bottom, the basin wall being fixed to the lower wall of the tank;

- The bottom wall has an outer surface and the wall of the basin is attached against the outer surface;

- the settling basin comprises at least one porthole arranged in the basin wall, the porthole being transparent to biocidal rays, the porthole advantageously having a height greater than 25% of the height of the basin;

- the bottom or part of the bottom is removable with respect to the basin wall;

- an active water displacement device is configured to displace water accumulating on an interior surface of the lower wall towards said basin;

- the tank comprises at least one partition extending into the interior volume at least from the bottom wall; at least the bottom wall and the partition delimiting a plurality of compartments, the tank comprising a settling tank for each compartment, each settling tank being respectively integral with the bottom wall;

- the tank comprises an evacuation system for the water contained in the settling tank, the evacuation system comprising a water recovery pipe and a fuel supply system for an engine system of the aircraft , the recovery pipe opening into the basin and being connected to the fuel supply system; And

- the basin wall has a collar at a free end opposite the bottom of the basin, the basin being fixed to the lower wall of the tank by means of the collar.

In addition, the subject of the invention is an aircraft comprising a fuel tank as described above.

The aircraft may also include one or more of the features below, taken alone or in any technically possible combination:

- the settling basin comprises a bottom and a basin wall extending from the bottom, the basin wall being fixed to the lower wall of the tank, the settling basin comprising at least one porthole arranged in the basin wall, the aircraft further comprising a device for emitting biocidal rays comprising at least one light source of biocidal rays, the light source being fixed relative to the fuel tank and being arranged to irradiate the inside of the basin with biocidal rays through the porthole, the porthole being transparent to said biocidal rays;

- the device for emitting biocidal rays also comprises a system for guiding the light of the biocidal rays emitted by the light source towards the porthole, the guidance system comprising for example optical fibers configured to guide the biocidal rays from the said light source towards the porthole ; And

- the basin is configured to contain a predetermined quantity of water corresponding to an accumulation of water during an average stoppage period of the aircraft, the basin having predetermined dimensions to contain said predetermined quantity of water when the basin is inclined at an angle greater than 15°, preferably greater than 20°.

The invention also relates to a method for treating the contamination of an aircraft fuel tank as described above, comprising the following steps:

- accumulation of water in the settling tank; And

- treatment of water contamination accumulated in the basin.

The treatment method may further comprise the following optional feature: the treatment step comprises discharging the accumulated water to a fuel supply system of an engine system of the aircraft; and/or the irradiation of the inside of the basin with a light source of biocidal rays and through a window, the window being transparent to said biocidal rays and being arranged in the wall of the basin, the irradiation being implemented during a predetermined duration.

In addition, the subject of the invention is a method for mounting an aircraft fuel tank comprising the following steps:

- supply of a settling tank;

- supply of an aircraft fuel tank, the tank comprising a lower wall, a side wall and an upper wall, the lower, side and upper walls delimiting an interior volume for receiving fuel; And

- assembly of the settling basin to the lower wall so that the settling basin is integral with the lower wall.

The invention will be better understood on reading the following description, given solely by way of example, and made with reference to the appended drawings, in which:

FIG. 1 is a schematic view of a detail of an aircraft fuel tank according to a first embodiment of the invention;

Figure 2 is a schematic sectional view of a settling basin of the fuel tank of Figure 1; And

FIG. 3 is a schematic view of a detail of an aircraft fuel tank according to a second embodiment of the invention.

The invention relates to an aircraft comprising a fuel tank 10 illustrated in FIG. 1 in a first embodiment.

The aircraft more advantageously comprises a device 11 for emitting biocidal rays (FIG. 2).

As detailed below, the tank 10 and the emission device 11 form a system for treating the contamination of the fuel tank 10.

The aircraft also typically comprises an engine system, not shown, intended for the propulsion of the aircraft and/or its electrical power supply.

The fuel tank 10 comprises a lower wall 12, a side wall and an upper wall, the lower 12, side and upper walls delimiting an interior volume for receiving fuel 14.

For reasons of clarity, the side and top walls have not been shown in Figure 1.

The interior volume 14 is for example filled with fuel, the fuel being for example kerosene.

Reservoir 10 also includes at least one settling basin 16 secured to bottom wall 12, as described in more detail below.

The reservoir 10 also advantageously comprises an active device 18 for moving water towards the basin 16.

In addition, the reservoir 10 preferably comprises a system 20 for discharging the water contained in the basin 16.

The bottom wall 12 of the tank 10 has an interior surface 22 delimiting the interior volume 14. In particular, the interior surface 22 of the bottom wall 12 is in contact with the fuel when the tank 10 is filled.

The bottom wall 12 also has an exterior surface 24 extending outside the interior volume 14.

The lower wall 12 is advantageously bi-curved over its entire length.

Thus, the inner surface 22 of the lower wall 12 has two curvatures in the same direction along two intersecting axes. It forms for example a bi-domed surface.

Interior surface 22 of bottom wall 12 preferably has no flat area.

The inner surface 22 of the lower wall 12 is, in the example of Figure 1, devoid of internal stiffener structure projecting from the surface 22 into the inner volume 14.

The bottom wall 12 has a low point 28 in the interior volume 14.

Low point 28 is defined as an area of bottom wall 12 and not a single point.

The interior surface 22 of the bottom wall 12 of the tank 10 is inclined towards the low point 28 all around the low point 28.

In other words, the low point 28 is an area having an outline such that the interior surface 22 of the bottom wall 12 has a positive slope from any point of this outline in any direction outward from the area.

Advantageously, when the aircraft is on the ground, the interior volume 14 of the tank 10 is entirely arranged vertically above the low point 28.

Thus, the inner surface 22 of the lower wall 12 is shaped so that, when water 27 (see FIG. 2) condenses in the reservoir 10, the water 27 flows by gravity over the inner surface 22 of the lower wall 12 towards the low point 28.

In the example of Figure 1, the bottom wall 12 of the tank 10 has a single low point 28. In particular, the inner surface 22 of the bottom wall 12 is here preferably devoid of bumps and hollows.

The lower wall 12 delimits a space 30 for receiving the settling tank 16, as detailed below.

According to the invention, the reception space 30 is arranged so that the basin 16 is suitable for collecting water flowing by gravity on the lower wall 12 towards said low point 28, as described below.

In the preferred example of Figure 1, the reception space 30 is arranged at said low point 28.

The reception space 30 defines for example a through opening 32 in the lower wall 12.

Thus, the inner surface 22 of the lower wall 12 of the tank 10 is inclined towards the through opening 32.

In the example of Figure 1, the interior surface 22 of the bottom wall 12 of the tank 10 is inclined towards the through opening 32 in any direction around an outline of the through opening 32.

The through opening 32 leads to the outer surface 24 of the lower wall 12.

The settling basin 16 is arranged to be able to collect water flowing by gravity on the lower wall 12 towards said low point 28.

In the example illustrated in Figure 1, the settling basin 16 is arranged at the level of the low point 28, and in particular at the level of the through opening 32 of the reception space 30.

The settling basin 16 is in this example a separate element from the lower wall 12. In particular, it is not one piece with this wall 12.

The settling tank 16 is fixed to the lower wall 12, for example by means of fixing systems 34 (see FIG. 2), such as screws or rivets.

The basin 16 protrudes outside the fuel tank 10, relative to the outer surface 24 of the lower wall 12.

The basin 16 is recessed relative to the inner surface 22 of the lower wall 12.

It therefore does not protrude into the interior volume 14 relative to the interior surface 22 of the bottom wall 12.

There is therefore no obstacle to the flow of water 27 towards the basin 16.

The settling basin 16 is illustrated more precisely with reference to Figure 2.

In this example, the settling basin 16 is attached against the outer surface 24 of the lower wall 12.

It is attached in particular around the through opening 32 of the reception space 30.

The settling basin 16 is suitable for collecting the water 27 condensing in the tank 10 and flowing by gravity on the inner surface 22 of the lower wall 12.

The basin 16 thus has an inner surface 36 delimiting a water collection zone 38, in which the water 27 accumulates. This collection zone 38 is described in more detail below.

The basin 16 is thus configured to contain a predetermined quantity of water corresponding to an accumulation of water during an average period of stoppage of the aircraft.

This average aircraft shutdown period is the estimated average time during which the aircraft is stationary between two flight missions. During an aircraft stop, the aircraft is on the ground and not moving.

The basin 16 has predetermined dimensions to contain said predetermined quantity of water.

In addition, the basin 16 also preferably has predetermined dimensions to contain said predetermined quantity of water when the basin 16 is inclined at an angle greater than 15°, preferably greater than 20°.

Thus, when the aircraft is in a take-off phase after having been stopped during said average stoppage period, the water 27 contained in the basin 16 does not come out outside the water collection zone 38.

The basin 16 has for example a height greater than 50 mm.

The settling basin 16 includes a bottom 40 and a peripheral basin wall 42 extending from the bottom 40.

Settling basin 16 also advantageously comprises at least one porthole 44 arranged in basin wall 42, as described below.

The bottom 40 is for example here a flat plate on which the basin wall 42 is fixed.

The bottom 40 is for example made of aluminum, titanium or stainless steel.

The bottom 40 is preferably completely removable and dismountable with respect to the basin wall 42.

The bottom 40 is then fixed to the basin wall 42 by means of detachable fixing systems 46, such as screws.

The bottom 40 thus allows a manual purge of the water 27 contained in the collection zone 38.

In a variant not shown, only part of the bottom 40 is removable with respect to the basin wall 42.

The basin wall 42 is for example made of aluminum, titanium or stainless steel.

The basin wall 42 comprises for example a lower flange 48 attached against the bottom 40 of the basin 16.

The basin wall 42 is fixed to the bottom 40 via its lower collar 48.

The basin wall 42 advantageously comprises an upper flange 50 at a free end opposite the bottom 40 of the basin 16.

The basin wall 42 is fixed to the lower wall 12 of the tank 10, in the example of Figure 2, via the upper flange 50.

The upper collar 50 is thus in this example attached against the outer surface 24 of the lower wall 12.

In addition, the basin wall 42 comprises side faces 52 joining the lower flange 48 to the upper flange 50. In section in a median vertical plane, the side faces 52 and the bottom 40 here define a trapezium.

The side faces 52 flare out from the lower flange 48 towards the upper flange 50.

The water collection zone 38 is thus more precisely delimited by the bottom 40 and the side faces 52 of the basin wall 42.

In the example of Figure 2, in a plane perpendicular to at least one side face 52 and to the bottom 40, the inner surface 36 of the basin 16 delimiting the water collection zone 38 has a substantially trapezoidal section.

In the example of Figure 2, in a plane parallel to the bottom 40, the inner surface 36 of the basin 16 delimiting the water collection zone 38 has a substantially rectangular section.

Each of the lower and upper flanges 48, 50 extend outside of the water collection area 38.

The side faces 52 and the upper collar 50 form an elbow 54.

The elbow 54 has a ridge 56, which is preferably flush with the through opening 32 of the bottom wall 12.

The ridge 56 runs along the edge of the through opening 32.

In the preferred example of Figure 2, the basin 16 includes at least two portholes 44.

The two portholes 44 of the basin 16 are here arranged facing each other. In particular, they face each other.

Each porthole 44 is configured to be transparent to biocidal rays, in particular to those of the emission device 11 described below.

Each porthole 44 is for example made of quartz.

Each porthole 44 has a face in contact with an air mass outside the tank 10.

Each porthole 44 has for example a height greater than 25% of the height of the basin 16. This height of the basin 16 is taken in particular along an axis perpendicular to the bottom 40.

Each porthole 44 is integral with the basin wall 42, in a sealed manner.

The resulting assembly, between each porthole 44 and the basin wall 42, is in particular capable of holding the tank pressure.

In particular, each porthole 44 is arranged in a through hole 58 of the basin wall 42.

Each through hole 58 is defined in one of the side faces 52 of the basin wall 42.

In addition, each porthole 44 is held together with the basin wall 42 by two frames 60 attached against the basin wall 42, on either side of the basin wall 42 and of the porthole 44.

Each frame 60 is a plate fixed to the basin wall 42.

Each frame 60 delimits a window 62.

The windows 62 of the two frames 60 which hold the same porthole 44 face each other.

Thus, through the windows 62 and the porthole 44, it is possible to irradiate the water collection zone 38 of the basin 16 with biocidal rays.

The active water displacement device 18, shown only in Figure 1, is configured to displace water 27 accumulating on the interior surface 22 of the bottom wall 12 towards the basin 16.

In an exemplary embodiment, the active device 18 for moving water is configured to circulate fuel contained in the interior volume 14.

For this, the active device 18 comprises for example a tube 64 and a pump 66, and is capable of projecting fuel contained in the interior volume 14 towards the interior surface 22 of the lower wall 12.

The active device 18 is configured to circulate fuel during a predetermined time interval, and advantageously periodically by regular time interval.

The movement of the fuel, imposed by the active device 18, forces the water 27 condensing on the walls of the tank 10 to flow towards the low point 28.

The evacuation system 20 of the water 27 contained in the basin 16, only illustrated in FIG. 2, comprises a water recovery pipe 68 and a fuel supply system 70 for the engine system of the aircraft.

The recovery pipe 68 opens into the basin 16.

The recovery pipe 68 thus has a free end placed in the collection zone 38. This free end is in particular placed between the side faces 52.

In addition, the recovery pipe 68 is connected to the fuel supply system 70.

The recovery pipe 68 is connected to a fuel transport line to the engine system, not shown.

Thus, the evacuation system 20 is configured to suck the water 27 contained in the basin 16 through the pipe 68, and to mix the sucked water with fuel intended to supply the engine system.

The device 11 for emitting biocidal rays is represented schematically in FIG. 2.

The emission device 11 comprises at least one light source 78 of the biocidal rays and advantageously a control unit 80 of the or each light source 78.

For example, the emission device 11 comprises a light source 78 per porthole 44 of the basin 16.

Each light source 78 comprises for example a neon or a plurality of neons.

Each light source 78 is arranged to be able to irradiate the interior of the basin 16 with biocidal rays through one of the portholes 44.

In the embodiment illustrated in Figure 2, each light source 78 is arranged facing one of the portholes 44 of the basin 16.

In particular, a biocidal ray emitted by each source 78 is able to pass through one of the windows 44.

Each light source 78 is advantageously fixed relative to the fuel tank 10, and is for example removable.

The control unit 80 is connected to each light source 78.

The control unit 80 comprises a processor 82 and a memory 84, the memory 84 comprising a control module 86 capable of being executed by the processor 82.

The control module 86 is configured to control a triggering of the emission of biocidal rays by each light source 78 and a predetermined duration of irradiation by the biocidal rays.

The control module 86 is also configured to control the triggering at predetermined instants, preferably periodically at regular time intervals.

The control module 86 is further configured to control the triggering, when the aircraft is on the ground, preferably when the aircraft is stationary, for example when it is parked.

Biocidal rays are defined as rays capable of destroying, repelling or rendering harmless the micro-organisms liable to develop at the interface between the water 27 and the fuel in the tank 10.

The biocidal rays are for example ultraviolet rays, in particular UV-C ultraviolet rays.

These UV-C rays have, for example, a wavelength between 200 nm and 280 nm.

The microbial pollution likely to develop at the interface between the water 27 and the fuel in the tank 10 includes several different bio-contaminants, such as for example bacteria, yeasts, fungi, molds, and algae.

Each bio-contaminant has a different resistance to ultraviolet rays.

Each source controls 86 ultraviolet rays and the predetermined duration of irradiation is chosen so that the irradiation destroys the bio-contaminant with the highest resistance to ultraviolet rays.

Thus, a treatment of the contamination can be implemented automatically, independently of the situation of the aircraft.

A method for treating contamination of the aircraft fuel tank 10 described above will now be described.

The process initially comprises the condensation of water in the tank 10 and the gravity flow of the water 27 on the interior surface 22 of the lower wall 12 towards the low point 28.

The water 27 then accumulates in the settling tank 16.

This accumulation is advantageously favored by the active water displacement device 18.

The method also includes the treatment of contamination of the water accumulated in the basin 16.

The treatment step preferably comprises the irradiation of the interior of the basin 16 with a light source of biocidal rays, in particular ultraviolet rays, through at least one of the windows 44, the irradiation being implemented for a predetermined duration. of irradiation.

As indicated above, the UV light source and the predetermined irradiation time are chosen so that the irradiation step destroys the bio-contaminant with the highest UV resistance.

The light source 78 is for example that(s) of the emission device 11 described above. In this case, the processing step is for example implemented by the control module 86.

The biocidal rays thus destroy the microbial pollution likely to have developed in the water 27 contained by the basin 16.

During the same period of shutdown of the aircraft, the irradiation step is preferably implemented several times. It is for example implemented periodically, at regular time intervals.

As a variant or in addition, the treatment step comprises the evacuation of the accumulated water 27 towards the fuel supply system of the engine system of the aircraft.

This evacuation step is implemented by means of the evacuation system 20 described above.

In a variant not shown, the emission device 11 comprises a light guidance system for the biocidal rays emitted by at least one light source 78 towards one of the windows 44.

The light source 78 is then for example arranged away from the tank and is not in particular arranged facing any of the portholes 44.

The light source 78 is thus able to irradiate the interior of the basin 16 via the light guidance system.

The guidance system comprises, for example, optical fibers configured to guide the biocidal rays from said light source 78 towards the porthole 44.

For this purpose, the optical fibers form, for example, an optical fiber mesh.

In a variant embodiment not shown, the lower wall 12 comprises internal stiffeners extending from the inner surface 22 and projecting into the interior volume 14. The internal stiffeners then each have at least one through-hole for drainage specific to allow the gravity flow of water on the inner surface 22 towards the basin 16. The locations of the through holes are advantageously chosen so that the internal stiffeners do not retain water flowing by gravity on the inner surface 22.

In another variant, the aircraft does not have the device for emitting biocidal rays described above. The treatment step of the method then comprises the evacuation of the accumulated water towards the fuel supply system 70, and/or the irradiation of the interior of the basin 16 with another light source of biocidal rays at through window 44. The other light source of biocidal rays is then, for example, mobile and manipulable by an operator during the irradiation step.

As a variant, the basin 16 comprises only a single porthole 44. In another variant, the basin 16 comprises more than two portholes 44.

In addition, the tank 10 comprises at least one other settling basin arranged at another location on the bottom wall 12.

A method of mounting the aircraft fuel tank 10 described above will now be described.

The assembly method includes supplying the tank 10 above, without basin.

In particular, no basin is arranged at the level of the through opening 32 of the tank 10 provided.

The assembly method includes the provision of the settling tank 16.

Basin 16 is initially provided away from tank 10.

The mounting method then includes assembling the settling basin 16 to the lower wall 12 so that the settling basin 16 is integral with the lower wall 12.

The assembly is in particular such that the settling basin 16 is arranged to be able to collect water flowing by gravity on the lower wall 12 towards said low point 28, advantageously arranged at the level of said low point 28.

The tank 10 as described above is then obtained.

In addition, the mounting method preferably comprises the fixing, relative to the reservoir 10, of each light source 78 so that each source 78 is arranged facing one of the portholes 44 of the basin 16.

A second embodiment of the fuel tank 10 is illustrated in Figure 3.

For reasons of clarity, the light sources have not been represented in FIG. 3. Only the differences with the first embodiment will be mentioned below.

This second embodiment thus differs from the first in that the tank 10 comprises at least one partition 72.

The partition 72 extends into the interior volume 14 at least from the bottom wall 12.

At least the bottom wall 12 and the partition 72 delimit a plurality of compartments 74.

The bottom wall 12 has a low point 76 in each compartment 74.

The second embodiment illustrated in Figure 3 comprises only one partition 72 delimiting two compartments 74.

Advantageously, when the aircraft is on the ground, each compartment 74 has a respective interior volume which is entirely disposed vertically above the low point 76 of the compartment 74.

The respective interior volumes of the compartments 74 are for example different from each other.

In the example illustrated in Figure 3, the tank 10 includes a settling tank 16 for each compartment 74.

Each settling basin 16 is here respectively arranged in a reception space 30 delimited by the lower wall 12 and arranged to be suitable for collecting water flowing by gravity, in the respective compartment 74, on the lower wall 12 towards said low point 76.

In the example of Figure 3, each settling tank 16 is here respectively arranged at said low point 76 of the respective compartment 74.

The dimensions of each settling basin 16, in particular of each collection zone, are chosen according to the respective interior volume of the compartment 74 in which the basin is arranged.

Advantageously, if a first compartment 74 has a respective interior volume greater than the respective interior volume of a second compartment 74, then the collection zone of the bedpan 16 associated with the first compartment 74 has a larger volume than the collection zone of the basin 16 associated with the second compartment.

In addition, not shown, the same compartment 74 has at least two settling basins 16.

In a variant not shown, the reservoir 10 comprises at least one other partition and delimits more than two compartments.

In another variant, the same partition 72 alone delimits more than two compartments 74.

Thanks to the characteristics previously described, the water 27 which condenses only accumulates in one place, namely the collection zone 38 of the basin 16. This therefore facilitates and improves the treatment of microbial pollution.

In addition, thanks to the basin 16, the surface at the interface between the condensed water 27 and the fuel is also reduced and controlled. Insofar as the development of microbial pollution depends on the extent of this surface at the interface, the tank 16 according to the invention reduces the microbial pollution likely to develop in the tank 10.

In addition, the part of tank 10 likely to be affected by corrosion, due to the development of microbial pollution, is limited to basin 16, which can subsequently be easily opened, cleaned and/or possibly changed.

In addition, the fact that the bottom 40 or part of the bottom 40 is removable facilitates the cleaning of the basin 16, which is the zone of the tank 10 most at risk for microbial contamination. In addition, if the tank 10 is cleaned with pressurized water, for example with a high-pressure cleaner, this allows rapid evacuation of the cleaning water.

Claims (17)

Aircraft fuel tank (10) comprising a bottom wall (12), a side wall and an upper wall, the lower, side and upper walls delimiting an interior volume (14) for receiving fuel,
characterized in that the reservoir (10) comprises a settling basin (16), the settling basin (16) being integral with the bottom wall (12). Reservoir (10) according to Claim 1, in which the lower wall (12) has a low point (28), and the settling tank (16) being arranged to be able to collect water flowing by gravity on the lower wall (12) towards said low point (28), the settling basin being preferably arranged at the level of said low point (28). Reservoir (10) according to any one of Claims 1 or 2, in which the lower wall (12) has an interior surface (22), the settling basin (16) extending set back with respect to the interior surface ( 22). A tank (10) according to any of claims 1 to 3, wherein the settling basin (16) includes a bottom (40) and a basin wall (42) extending from the bottom (40), the basin wall (42) being attached to the bottom wall (12) of the tank (10). Reservoir (10) according to Claim 4, in which the lower wall (12) has an outer surface (24) and the wall of the basin is placed against the outer surface (24). Tank (10) according to any one of claims 4 or 5, in which the settling tank (16) comprises at least one porthole (44) arranged in the basin wall (42), the porthole (44) being transparent to biocidal rays, the window (44) advantageously having a height greater than 25% of the height of the basin. Tank (10) according to any one of claims 4 to 6, in which the bottom (40) or part of the bottom (40) is removable with respect to the basin wall (42). A reservoir (10) as claimed in any one of claims 1 to 7 including an active water displacement device (18) configured to displace water accumulating on an interior surface (22) of the bottom wall (12 ) to said basin (16). Tank (10) according to any one of claims 1 to 8, comprising at least one partition (72) extending into the interior volume (14) at least from the bottom wall (12); at least the bottom wall (12) and the partition (72) delimiting a plurality of compartments (74), the tank (10) comprising a settling basin (16) for each compartment (74), each settling basin (16) being respectively secured to the bottom wall (12). Reservoir (10) according to any one of Claims 1 to 9, comprising an evacuation system (20) for the water contained in the settling basin (16), the evacuation system (20) comprising a water recovery (68) and a fuel supply system (70) of an engine system of the aircraft, the recovery pipe (68) opening into the basin (16) and being connected to the supply system in fuel (70). Aircraft comprising a fuel tank (10) according to any one of claims 1 to 10. The aircraft of claim 11, wherein the settling tank (16) includes a bottom (40) and a tank wall (42) extending from the bottom (40), the tank wall (42) being attached to the bottom wall (12) of the tank (10), the settling basin (16) comprising at least one porthole (44) arranged in the basin wall (42),
the aircraft further comprising a device (11) for emitting biocidal rays comprising at least one light source (78) of biocidal rays, the light source (78) being fixed relative to the fuel tank and being arranged to irradiate the inside the basin (16) with biocidal rays through the porthole (44), the porthole (44) being transparent to said biocidal rays. Aircraft according to Claim 12, in which the device (11) for emitting biocidal rays also comprises a system for guiding the biocidal rays emitted by the light source (78) towards the window (44), the guidance system comprising by example of the optical fibers configured to guide the biocidal rays from said light source (78) towards the porthole (44). Aircraft according to any one of Claims 11 to 13, in which the basin (16) is configured to contain a predetermined quantity of water corresponding to an accumulation of water during an average period of stoppage of the aircraft, the basin (16) having predetermined dimensions to contain said predetermined quantity of water when the basin is inclined at an angle greater than 15°, preferably greater than 20°. A method of treating contamination of an aircraft fuel tank (10) according to any one of claims 1 to 10, comprising the following steps:
- accumulation of water in the settling tank (16); And
- treatment of water contamination accumulated in the basin. A method according to claim 15, wherein the step of treating includes draining accumulated water to a fuel supply system (70) of an engine system of the aircraft; and/or irradiating the inside of the tank (16) with a light source (78) of biocidal rays and through a window (44), the window (44) being transparent to said biocidal rays and being arranged in the basin wall (42), the irradiation being implemented for a predetermined duration. Method of mounting an aircraft fuel tank (10) comprising the following steps:
- provision of a settling basin (16);
- provision of an aircraft fuel tank (10), the tank (10) comprising a bottom wall (12), a side wall and a top wall, the bottom, side and top walls delimiting an interior volume (14) fuel reception; And
- Assembly of the settling basin (16) to the bottom wall (12) so that the settling basin (16) is integral with the bottom wall (12).