CN108700331B

CN108700331B - Weather-proof ventilation grille

Info

Publication number: CN108700331B
Application number: CN201680081772.XA
Authority: CN
Inventors: 菲利普·查宾; 纪尧姆·德·拉·维尔·蒙巴宗
Original assignee: Electricite de France SA
Current assignee: Electricite de France SA
Priority date: 2015-12-15
Filing date: 2016-12-07
Publication date: 2021-02-02
Anticipated expiration: 2036-12-07
Also published as: JP2018537648A; GB2561776B; FR3045138B1; JP6936227B2; WO2017102480A1; GB2561776A; FR3045138A1; GB201811622D0; CN108700331A

Abstract

The present invention relates to a weather-resistant ventilation grille, comprising: a series of rigid bars (100) substantially parallel and non-vertical to each other, having a first substantially vertical front edge (110) intended to be directed outwards, and two auxiliary faces converging at a distance from the main face (110), defining between two adjacent bars (100) a channel diverging from the outside towards the inside; and a series of deflecting fins (200) respectively connected to the base of the main face (110) of each bar (100), the fins (200) being inclined towards the outside with a certain inclination and height with respect to the main face (110) so that the free edge (210) of one fin (200) is at least on the same horizontal line as the upper edge (112) of the main face (110) from the bar (100) below, or even overlaps said main face (110), so that the fins (200) form a deflector and have a certain height greater than a distance separating the lower edge of the main face (110) from one bar (100) from the upper edge of the main face (110) from the bar (100) below.

Description

Weather-proof ventilation grille

Technical Field

The present invention relates to the field of ventilation grills.

The ventilation grille is designed to allow the ventilation of the equipment by sucking or blowing air and to protect the equipment from the elements of bad weather, the risk of entry of animals and/or projectiles and from the effects of overpressure or depression waves.

Background

In particular, but not exclusively, buildings subject to high safety requirements, such as for example production sites in the chemical or petrochemical industry, or nuclear production sites, must be protected from a variety of potential external attacks, and in particular the following risks:

weather (rain, ice, frost, wind, hail, strong wind … …),

projectiles or animals (in particular birds) into the ventilation duct,

pressure waves, such as sudden overpressure due to a blast of air from an external explosion, or even underpressure due to tornadoes/hurricanes or similar phenomena.

If the outer walls of a building constitute an effective defense against the current attacks that are affected by sufficient dimensions, the openings made in these walls, such as windows but more particularly the openings that receive the ends of the ventilation ducts, are directly exposed to said attacks and require a specific dimensioning.

In practice and not by way of limitation:

the intrusion of fluids, typically rain in liquid state or hail in solid state, can cause a series of damages, such as for example circuit corrosion,

by partially or completely blocking the opening, ice may significantly reduce the efficiency of the ventilation system, particularly due to load losses,

the overvoltage waves may cause damage to the internal circuits and to the ventilation unit, as well as to all the equipment housed in the building,

the low pressure waves of a tornado may cause effects similar to those of an overpressure wave.

In the latter two cases, the movement of the fluid of interest, i.e., air or other gas, may transport projectiles that may cause serious damage.

The first function of the ventilation system is to ensure thermal regulation of the house as a normally operating one. Second, these systems must perform air renewal in the house by circulating the air in a set of distribution circuits. These two functions are in particular the guarantee of the proper operation of the plant and accordingly contribute to the safety, in particular for the nuclear production site, and then to a lesser extent to the comfort of the personnel, or even their integrity.

Devices designed to help block the external attacks described above must not degrade the main functionality of the system.

Many types of ventilation grills have been proposed, but none are entirely satisfactory.

To address the issues of rain, animal ingress, and ice, the ventilation system may be placed in a suitable location, uniformly arranged and sized and oriented so that rain does not penetrate into the interior space of the building to be protected. Moving the vent away from the interior space is configured so that birds do not enter the interior space, if possible. The outer dimensions of the device are generally defined so as to ensure the required air flow even in the event of partial blockage of the device by ice.

However, ventilation systems do not provide effective protection against high velocity projectiles and thus against substantial kinetic energy.

It has therefore been proposed to sometimes replace the vent by a more rigid rod.

This solution gives an effective protection against projectiles with strong kinetic energy. With a suitable arrangement of the rod it is even possible to prevent the intrusion of animals and the risk of ice condensation.

It is also possible to orient the profile of the rod so as to limit the intrusion of rain.

However, due to their shape, the rods proposed so far disrupt the flow and produce considerable load losses, thereby reducing the air flow during normal operation.

The following attempts made for the solution may also be cited:

adding a buffer defense before the air input grille of the ventilation system to prevent tornadoes in this respect, however this solution is costly and does not solve the problem of external explosions.

An electric damper is implanted to rapidly block the ventilation network, controlled by the differential pressure transmitter. This solution is very expensive and based on active devices. Furthermore, resistance of the device to PGEW (projections generated by extreme winds) projectiles and tornadoes is not possible.

In summary, to date, no solution has effectively solved all the problems posed and, in particular, provided a mechanically effective protection against all projectiles and ensured a reliable protection against rapid variations in external pressure.

In fact, the devices proposed so far only slightly mitigate the fluctuations of pressure that may result from, for example, explosions or hurricanes.

To date, designers of ventilation systems have had no other choice than to multiply the number of equipment and facility configurations in the area of the interface to be protected.

As a result, in practice, protection devices of the type shown in fig. 1 are often used today, comprising a pile of complex levels for circumventing all external attacks: an outer level formed by a rain-and bird-protection grille 10, a level formed by reinforcing bars 12 intended to prevent the intrusion of projectiles, a frost-protection level 14, a level 16 formed by an anti-explosion flap constituted by a quick-closing flap, and then a level of an anti-tornado isolation damper 18 connected to a ventilation duct.

However, such devices are complex to manufacture and have a number of disadvantages:

they are expensive and, therefore,

they produce considerable load losses, usually requiring an oversizing of some of the elements of the ventilation circuit, and

their efficacy is not always manifested, particularly for explosion-proof flaps.

Document DE7534836 describes an example of a weather-resistant ventilation grille comprising rigid rods and deflecting fins.

In short, there is currently no simple means to effectively defend against all possible attacks.

Disclosure of Invention

In this connection, the object of the invention is in particular to propose a novel ventilation grille which:

facilitating the air flow under normal operating conditions,

-dispersing the incident pressure front,

-limiting the rise of pressure in the inner space.

The above object is achieved according to the present invention by a weather-resistant ventilation grille comprising:

-a series of rigid bars, globally parallel and non-vertical to each other, having: a first forward edge directed towards a first side of the grid intended to be directed to the outside, globally parallel to a mean plane of the grid, and intended to be globally vertical for use; and two auxiliary faces converging when moving away from the main face, defining between two adjacent stems a channel which diverges from said first side, intended to be directed to the outside, in the direction of a second side of said grid, intended to be directed to the inside, and

a series of deflecting fins, attached respectively to the base of the main face of each rod, said fins being inclined with respect to said main face towards a first side intended to be directed to the outside according to a certain inclination and height, so that the free edges of said fins are at least collinear with, or even span, the projection of the mean plane orthogonal to the grid on the upper edge of the main face of the underlying rod, so that said fins form deflectors and have a specific height greater than a distance separating the lower edge of the main face from one rod from the upper edge of the main face from the underlying rod.

The operation and advantages of the present invention will appear from the following detailed description.

The invention provides in particular a synergistic effect of the following technical effects:

on the one hand, the section of the bars defining the divergent passage from the outside inwards, and therefore the edges provided by the bars towards the inside, limit the load losses for the air extraction from the inside outwards, while the divergence factor provided with respect to the component of the incident pressure wave from the outside inwards, is adapted to attenuate the effect of this wave,

on the other hand, the overall vertical main face of the rod forms a deflector/reflector for the incident wave or another component of the object,

and in addition, the inclined fins not only form rain barriers, but also act as potential deflectors for some waves and incident objects, and in addition cooperate with the main face to send back in different directions suitable for breaking the incident wave front (the horizontal wave component striking the main face is sent back horizontally, while the horizontal wave component striking the fins is sent back perpendicular to the fins, partly to the outside and upwards overall, and before being sent back by the main face, partly towards the main face if the angle of inclination between the fins and the horizontal is adjusted to be typically less than 45 °, while potentially in the event of excessive pressure (the lower edge of the fin in this case can rest on the lower bar), forming by deformation a "gate" suitable for closing the passage between the bars, the height of the fins being greater than the spacing between two adjacent bars.

The invention also relates to a building comprising at least one grid such as previously defined according to the invention.

Drawings

Other characteristics, objects and advantages of the invention will emerge from the following detailed description and with respect to the accompanying drawings, given by way of non-limiting example, and in which:

the aforementioned figure 1 shows a schematic view of a system according to the prior art,

figure 2 shows a partial view corresponding to the view in vertical section of the weathering grid according to the invention,

figures 3, 4, 5, 6, 7 and 8 show views in vertical section of a rod according to a variant of the invention,

figure 9 shows the load loss caused by the grille according to the invention as a function of the air speed,

figure 10 shows the residual pressure after the grating according to the invention as a function of the angle of the auxiliary surface of the bars with respect to the horizontal plane,

figure 11 shows the load loss caused by the grid according to the invention as a function of the angle of the auxiliary surface of the bars with respect to the horizontal plane,

figure 12 shows the residual pressure after the grid according to the invention as a function of the spacing between the bars,

figure 13 shows the load loss caused by the grid according to the invention as a function of the spacing between the bars,

figures 14, 15 and 16 show two opposite perspective views and a partial section respectively of a grid according to the invention, and

figures 17 and 18 show two implantation variants of the grid in a not strictly vertical arrangement.

Detailed Description

The weather resistant ventilation grille according to the present invention is formed by a combination of a series of rods 100 and deflecting fins 200.

Fins 200 are fixed to the base of each rod 200.

The bar 100 is preferably fixed to a post 310 of the frame 300. As a variant, however, the bar 100 can be feasibly fixed directly to the structural product of the building at the level of the frame of the ventilation opening to be protected.

The same applies to fin 200, which may be secured to a strut 310 of frame 300. As a variant, however, provision may be made to fix the fins 200 directly to the structural product of the building at the level of the frame of the ventilation opening to be protected.

Preferably, the ventilation grille according to the invention is mounted in a vertical position. However, the grid according to the invention may also be mounted at an inclination with respect to the vertical (mean plane M defined by the frame which is not vertical), for example in the range of +/-20 ° with respect to the vertical.

The weathering grid according to the invention will be described below with reference to the vertical or semi-vertical position that the weathering grid occupies in the position of use and with reference to the horizontal plane H and the vertical plane V shown in fig. 2.

The bar 100 is rigid and is preferably formed of metal and highly preferably made of steel.

The bars 100 are parallel to each other and are non-vertical. More specifically, the bar 100 is preferably horizontal to about +/-10. In other words, each rod 100 is centered on a longitudinal axis that is used approximately plus or minus 10 ° horizontally.

The linear section of the rod 100 is constant over its entire length. All of the rods 100 preferably have the same linear section.

As is apparent in fig. 2, the bar 100 preferably has rectilinear sections that are triangular in shape as a whole.

The bar 100 may be formed from a solid body or may be formed by assembling three pieces or strips of steel (welded in pairs in the region of their adjacent edges).

The bar 100 has a first forward edge 110 and two

auxiliary surfaces

120, 130.

The first forward edge 110 is attached to the upper auxiliary surface 120 in the region of the horizontal edge 112 and also to the lower auxiliary surface 130 in the region of the horizontal edge 114.

The two

auxiliary surfaces

120 and 130 are joined together in the region of a common inner and also horizontal edge 116.

The distance separating the edges 116 of two adjacent bars 100 is marked d in fig. 2.

The distance separating the upper edge 112 from one bar 100 from the lower edge 114 of an adjacent bar 100 is labeled h1 in FIG. 2.

In order to limit the load losses with respect to the directed suction flow from the inside to the outside, the junction between the two

auxiliary faces

120, 130 opposite the main face 110 defines an inner edge 116 of the bar, which is sharp or rounded and provides a maximum radius of curvature of 5mm, advantageously less than 3 mm.

The first forward edge 110 is intended to point to the outside. It is generally vertical and its vertical height (or width) is labelled h2 in figure 2.

Those incident pressure waves it receives are reflected to the outside at the leading edge 110.

Preferably, all the first front faces 110 of the bars 100 of the same grid are coplanar and vertical.

The two

auxiliary surfaces

120 and 130 converge as they move away from the main surface 110. Thus, the straight section of the rod 100 becomes smaller from the outside to the inside. Between each pair of two adjacent bars 100, the two

auxiliary surfaces

120 and 130 define a channel 140 that diverges from the outside to the inside and therefore converges in comparison to the air flow moving from the inside to the outside. The evolution of the section of the channel 140 is gradual, that is to say without abrupt changes, so as not to disturb the flow and to optimise the load losses.

The first forward edge 110 is preferably flat as shown in fig. 2, 3 and 6-8.

It may be convexly curved as shown in fig. 4 or concavely curved as shown in fig. 5.

Preferably, the rectilinear section of the bar 100 is isosceles, with the two

auxiliary faces

120 and 130 having the same width, as is apparent in fig. 3. Even more precisely, the rectilinear section of the bar 100 is preferably equilateral, the two

auxiliary faces

120 and 130 and the first forward edge 110 of which have the same width, as is apparent in fig. 2.

However, by way of a variant, the two

auxiliary surfaces

120 and 130 can have different widths, as is evident in fig. 6 (the rectilinear section of each bar remains constant over its entire length and all bars have the same section).

The two

auxiliary surfaces

120 and 130 are preferably flat, as shown in fig. 2 to 6.

They may be concavely curved as shown in fig. 7 or convexly curved as shown in fig. 8.

The deflection fins 200 are attached to the base 114 of the major face 110 of each rod 100, respectively, such as by welding.

The fin 200 is relatively rigid and is preferably formed of metal and highly preferably made of steel.

The fins 200 are parallel to each other. The straight section of the fin 200 is constant over its entire length. All fins 200 preferably have the same straight sections.

As is apparent from fig. 2, the fins 200 are preferably formed by flat metal blades of constant width L and therefore have straight rectilinear sections at rest.

The fins 200 are inclined outwardly relative to the major face 110. In other words, each fin 200 moves away from the vertical plane of the leading edge 110 to which it is attached, either by moving away from its joined edge 114 on the aforementioned associated leading edge 110, or by moving towards its free edge 210. The inclination and height of the fins 200 are such that the free edges 210 of the fins 200 are at least on the same horizontal line as the upper edges 112 of the main faces 110 of the underlying bars 100. If desired, each fin 200 may span the major face 110 of the underlying bar 100, according to a horizontal projection.

Thus, the fins 200 form deflectors and have an intrinsic height (or width) L greater than the distance h1 (d-h2) separating the lower edge 114 of the major face 110 from a bar 100 from the upper edge 112 of the major face 110 from the bar 200 below.

The ratio between the vertical height h2 of each main face 110 and the vertical height h1 ═ of the spacing defined between two adjacent bars 100 (d-h2) is preferably between 0.5 and 2, preferably of the order of about 1 to ± 10%. With this arrangement, the cross-section of the rod 100 provides the most reflective surface for the overpressure wave without thereby generating critical load losses.

As previously indicated and as is apparent in fig. 14 to 16, the bar 100 can be fixed to the uprights 310 of the frame 300, the dimensions of which are adapted to those of the ventilation system. In fig. 14-16, the upper cross-beam of the frame 300 is labeled 320 and the lower cross-beam is labeled 330.

The inclination α of the

auxiliary surfaces

120 and 130 with respect to the horizontal plane is preferably less than 40 °, preferably less than 30 °, and the height is advantageously less than 25 °.

This inclination has been calculated to promote the flow of fluid during normal operation during the air extraction from the inside outwards to obtain a flow rate of conventional magnitude of 2.5m/s in order to limit the load losses.

The distance h1 between the rods 100 is also calculated so that it prevents the intrusion of projectiles and limits the risk of jamming due to frost.

The distance h1 separating two adjacent rods 100 is preferably less than or equal to 90 mm.

Highly advantageously, the distance h1 separating two adjacent bars 100 is between 50 and 85mm, highly advantageously between 60 and 80 mm.

Furthermore, the height h2 of the main face 110 of each bar 100 is preferably greater than or equal to 70 mm.

Highly advantageously, the height h2 of the main face 110 of each bar 100 is between 70 and 85mm, highly advantageously between 60 and 80 mm.

Due to their orientation (angle β) and their width (L), the fins or vents 200 fixed to the base of each bar 100 and preferably to the frame support 300 by their ends are resistant to the intrusion of rain and limit the additional load losses incurred during normal operation.

The inclination β between each fin 200 and the horizontal plane H is less than 50 °, preferably less than 45 °, and the height is advantageously less than 30 °.

According to the invention, the width L of each fin 200, shown between its joining edge on a bar 100 and its free edge 210, the inclination β between each fin 200 and the horizontal plane, the distance d separating the inner convergence point 116 between the two

auxiliary faces

120, 130 of two adjacent bars 100 and the vertical height h2 of each main face 110 of a bar 100 follow the following relationship: (L × sin β) > (d-h 2).

The thickness of the fins 200 made of steel is dimensioned so as to be resistant to explosions and variations in tornado waves, and is generally at least equal to 0.8 mm.

According to a first embodiment of the invention, at least some of the fins 200, and preferably all of the fins 200, are connected by a joint fixed to the base 114 of the relative rod 100.

However, according to a second embodiment of the invention, at least some, preferably all, of the fins 200 may be connected to the base 114 of the associated bar 100 by hinged joints.

In this latter case, in the region where they join the base 114 of the bars 100, the vents or fins 200 can be fitted with restoring means forming springs adapted to allow, in the event of significant overpressure, a permissible degree of freedom of rotation between the fins 200 and the relative bars 100, respectively, while allowing the vents or fins 200 to fold over the openings of the channels 140 and block them, further enhancing the protection against said overpressure. Once the overpressure is over, the springs ensure that the vent or fin 200 returns to the original position.

When the free edge 210 of the fin 200 is positioned at the same level as the free edge 112 of the underlying bar 100 or beyond the free edge 112, the height L of the fin 200 is greater than the spacing h1 between two adjacent bars 100. Thus, in the event of excessive pressure, the fins 200 may close the channels 140 between the bars 100 by deforming or hinging, the lower edges 210 of the fins 200 resting on the lower bars 200.

Due to the combination of the above features, the weathering grid according to the invention is suitable for covering and optimizing the blocking of many things (PGEW or "missile caused by extreme wind" attack, tornados, external explosions, icing). It also protects the ventilation systems and equipment in the room.

In particular, the weathering grid according to the invention:

-effectively stopping both the projectiles projected in tornado conditions and the projectiles caused by extreme winds (PGEW).

The sudden changes in pressure caused by tornadoes and external explosions are effectively absorbed, so as not to damage the ventilation network (pipes, ventilators, flaps) inside the building.

Without causing significant load losses on the ventilation network on which they are installed (in order to avoid having to install load recovery fans or modify the characteristics of installed fans).

The function of conventional ventilation grills (rain and bird protection) is fulfilled, so that the installation of the grille according to the invention can be carried out in place of the previous grille.

-to take into account the problem of icing.

In order to optimize the weatherable grating according to the present invention, the inventors have conducted a series of parameter studies on each of the main characteristics of the grating based on the following reference parameters:

air speed at normal operation: 2.5m/s, in a volume of the solution,

inclination α of the

auxiliary surfaces

120 and 130 with respect to the horizontal plane: at an angle of 25 DEG,

the geometry at the front edge 110 of the triangular section of the bar: the straight-line shape is formed by the straight-line shape,

the spacing h1 between two adjacent bars 100: 80 mm.

The parameter "air speed" in normal operation was studied on the basis of the above-mentioned reference grid.

The results obtained for the load loss (Pa) as a function of the air speed (m/s) are shown in fig. 9.

Examination of this fig. 9 shows that the load loss rises sharply as the air speed increases. However, the load loss of the grid according to the invention (about 50Pa vs. 2.5m/s for a grid of dimensions 1000X 1000 mm) is relatively low. By contrast, a classical rain protection grid shows a load loss of the order of 30Pa to 2.5m/s and an explosion-proof flap shows a load loss of the order of 200Pa and up to 350Pa, so that the classical combination shows a load loss at least four times higher than the grid according to the invention.

The results obtained for the residual pressure, measured after the grid, i.e. on its inner side, during the simulation of the external explosion according to the angle of incidence α, to optimize the angle of incidence of the triangular section are shown in fig. 10.

These results show that a reference grid responsive to predefined parameters is effective for explosions and thus tornadoes, as it divides the blast wave by 10.

Even with the addition of the pressure generated by the fans of the HVAC network (typically 500Pa), the residual pressure value of 1000Pa downstream of the grille is much lower than the conventional value for HVAC equipment performance (2000 Pa).

The effect of the value of angle a is negligible (less than 1%) in terms of its ability to "break" the blast wave.

In contrast, as shown in fig. 11, the value of the angle α plays an important role in load loss to the grid from 25 ° under normal conditions. The smaller the angle, the less the streamline is disturbed.

The spacing h1 between the bars 100 of the grid has been studied on the basis of fig. 12, which shows the residual pressure downstream of the grid as a function of the spacing during the simulated application of the explosion.

Figure 12 shows that the aerodynamic performance of the grid in the face of an explosion is the same starting from a spacing h1 of 60mm under the chosen simulation conditions.

Fig. 13 shows the load loss of the grid according to the reference as a function of the spacing h1 between the bars 100 in normal operation.

Figure 13 shows that the more the rods 100 are tightened, the more effective the grid is against explosions (and thus against tornadoes), but the greater the specific load loss of the grid. In addition, the rods 100 must be spaced less than 80mm apart to hold the PGEW projectiles and the projectile "Steel pipe type Tornado 170mm in diameter".

However, the distance h1 between the bars must be as large as possible in order to improve the protection of the grille with respect to icing blockage.

Fig. 9 to 13 show, for each graph, a curve corresponding to the average value of the obtained simulated values in a solid line, and show, in a broken line, the upper and lower ends of the values corresponding to the range of possible values.

In view of the above, the inventors consider that a spacing h1 of about 80mm between the bars of the grid:

ensuring a considerable efficiency of the grid in the face of the explosion,

projectiles obstructing tornadoes and PGVEs

Limiting the exposure of the grid to frost phenomena.

The efficacy of the geometry of the triangular cross-section at the leading edge 110 of the bar has been studied with respect to the profiles shown in fig. 3, 4 and 5.

The correlation simulations performed showed that:

for a flat leading edge 110 as shown in fig. 3: for a load loss at normal operation of 49Pa, the residual pressure downstream of the grate under the influence of the explosion is 990Pa,

for a convex leading edge 110 with a radius of curvature of 44mm as shown in fig. 4: for a load loss at normal operation of 88Pa, the residual pressure downstream of the grate under the influence of the explosion was 984Pa, an

Concave front edge 110 for a radius of curvature of 44mm as shown in fig. 5: for a load loss at normal operation of 42Pa, the residual pressure downstream of the grid under the influence of the explosion was 998 Pa.

The above results show that the effect of the attack profile 110 of the rod 100, i.e. the profile is flat, convex or concave, is negligible (effect less than 1%) with respect to the explosion (and therefore with respect to the tornado).

Thus, a grid according to the invention may comprise bars 100 which correspond to any of these geometries, flat, convex or concave at the front edge 110.

The flat geometry at the leading edge 110, which gives highly satisfactory results in terms of interception and reflection against explosions and waves generated by the tornados, may be considered to be preferable for the triangular profile cross-section of the pole, to the extent that such a flat leading edge 110 has the advantage of being simple to manufacture. Furthermore, implantation of the fins or vents 200 is facilitated by such a rod profile.

The geometry of the fins 200 was also investigated.

The rain-proof function is one of the basic functions of the ventilation grille. The optimized design of the rain fins 200 prevents rain from entering the building interior (even horizontal rain) and also has sufficient horizontal spacing between the two rods to avoid significant load loss, typically on the order of 80 mm.

The proposed structure benefits from the vertical face 110 of the bar 100, which is used to fight explosions and tornados to redirect the rain downwards, and reduces the number of rain fins by two to gain in terms of load loss when operating normally.

The simulations also give the following results.

Of course, the present invention is not limited to the foregoing embodiments, but relates to any modifications in terms of meaning.

The weather resistant grille according to the present invention can be installed on a new facility, but it can also be installed at the location of an existing ventilation grille to replace the existing ventilation grille.

The weathering grid according to the present invention may be installed on many facilities, such as, but not limited to, electrical energy production facilities from nuclear energy sources.

The weathering grid according to the invention has been described above with reference to the vertical or semi-vertical position which the weathering grid occupies in the position of use and with reference to the horizontal plane H and the vertical plane V shown in fig. 2.

One side called the "outside" of the grid (the outside being the outside of the building with reference to the use position) corresponds to the "first side". One side called the "inside" of the grid (the inside being the inside of the building with reference to the position of use) corresponds to the "second side".

And as indicated earlier, in some implantation conditions, depending on the structure of the building, the mean plane M of the grid cannot be strictly vertical during implantation.

In this case, it may be provided that the main faces 110 of the bars 100 remain coplanar with each other and parallel to the mean plane M of the frame 300 of the grid, as shown in fig. 17, or that the main faces 110 of the bars 110 are inclined with respect to the mean plane of the frame 300, remain parallel to each other but offset so that these faces 110 remain vertical for use, as shown in fig. 18. In all cases, the width of the fins 200 is preferably adapted so that the free edges 210 of the fins are positioned at least on the same horizontal line as the upper edge 114 of the main face 110 of the underlying bar 100, or even below this line.

Claims

1. A weather resistant ventilated grille, comprising:

-a series of bars (100) that are rigid and globally parallel to each other and non-vertical, each bar (100) having: a main face (110) directed towards a first side of the grid, intended to be directed to the outside, globally parallel to a mean face of the grid, and intended to be globally vertical for use; and two auxiliary faces (120, 130) converging when moving away from the main face (110), defining between two adjacent bars (100) a channel (140) diverging from said first side, intended to be directed to the outside, in the direction of a second side of the grid, intended to be directed to the inside, and

-a series of deflecting fins (200), each fin (200) being attached to a lower edge (114) of a main face (110) of a respective bar (100), and inclined according to a certain inclination and height with respect to the main face (110) of the respective bar (100) towards a first side intended to be directed towards the outside, such that the free edges (210) of the fins (200) are at least collinear with a projection orthogonal to the mean plane of the grid on the upper edge (112) of the main face (110) of an adjacent rod (100) of the series of rods, or even across the main face (110), such that the fins (200) form deflectors and have a specific height greater than a distance (h1), the distance (h1) separates a lower edge (114) from the major face (110) of the one adjacent bar (100) from an upper edge (112) from the major face (110) of another adjacent bar (100) in the series of bars.

2. Grid according to claim 1, characterized in that the bars (100) extend according to a longitudinal central axis at plus or minus 10 ° with respect to the horizontal direction.

3. Grid according to any one of claims 1 or 2, characterized in that the bars (100) have a triangular cross section.

4. Grid according to any one of claims 1 or 2, characterized in that the main face (110) of each bar (100) is flat.

5. Grid according to any one of claims 1 or 2, characterized in that the auxiliary faces (120, 130) of the bars (100) are flat.

6. Grid according to any one of claims 1 or 2, characterized in that the bars (100) have the form of isosceles triangles.

7. Grid according to any one of claims 1 or 2, characterized in that the ratio between the vertical height (h2) of each main face (110) and the vertical height (h1) of the spacing defined between two adjacent bars (100) is between 0.5 and 2.

8. Grid according to any one of claims 1 or 2, characterized in that the height (h2) of the main face (110) of each bar (100) is greater than or equal to 70 mm.

9. Grid according to any one of claims 1 or 2, characterized in that the height (h2) of the main face (110) of each bar (100) is between 70 and 85 mm.

10. Grid according to any one of claims 1 or 2, characterized in that the inclination (α) between the auxiliary surfaces (120, 130) of the bars (100) and the horizontal plane is less than 40 °.

11. Grid according to any one of claims 1 or 2, characterized in that the distance (h1) separating two adjacent bars (100) is less than or equal to 90 mm.

12. Grid according to any one of claims 1 or 2, characterized in that the distance (h1) separating two adjacent bars (100) is between 50 and 85 mm.

13. Grid according to any one of claims 1 or 2, characterized in that the width L of each fin (200) considered between the lower edge (114) of the respective bar (100) and its free edge (210), the inclination β between each fin (200) and the horizontal plane, the distance d separating the inner convergence points of the two auxiliary faces (120, 130) of two adjacent bars (100), and the vertical height h2 of each main face (110) of the bars (100) follow the following relationship: (L × sin β) > (d-h 2).

14. Grid according to any one of claims 1 or 2, characterized in that at least one of said fins (200) is connected to the relative bar (100) by a fixed joint.

15. Grid according to any one of claims 1 or 2, characterized in that at least one of said fins (200) is connected to the relative bar (100) by means of an articulated joint.

16. Grid according to any one of claims 1 or 2, characterized in that the junction between two auxiliary faces (120, 130) opposite the main face (110) defines a sharp or rounded inner edge providing a maximum radius of curvature of 5 mm.

17. Grid according to any one of claims 1 or 2, characterized in that the inclination β between each fin (200) and the horizontal plane is less than 50 °.

18. Grid according to any of claims 1 or 2, characterized in that the bars (100) and the fins (200) are formed of metal.

19. Grid according to any one of claims 1 or 2, characterized in that the thickness (e) of the fins (200) made of steel is at least equal to 0.8 mm.

20. A grid according to any one of claims 1 or 2, characterized in that the bars (100) are carried by frame supports (300).

21. Grid according to any of claims 1 or 2, characterized in that it comprises at least one hinge joint connecting at least one fin (200) and the lower edge (114) of the bar (100) to which said fin is attached, and a spring positioned in the vicinity of said hinge joint.

22. A building comprising at least one grid according to any one of claims 1 or 2, comprising:

-a series of bars (100) that are rigid and generally parallel and non-vertical to each other, each bar (100) having a main face (110) pointing to the outside, and two auxiliary faces (120, 130) that converge when moving away from the main face (110), defining between two adjacent bars (100) a channel (140) that diverges from the outside towards the inside, and

-a series of deflecting fins (200), each fin (200) being attached to the lower edge (114) of the main face (110) of a respective bar (100) and being inclined towards the outside with respect to the main face (110) of the respective bar (100) according to a slope and a height such that the free edge (210) of the fin (200) is at least on the same horizontal line as the upper edge (112) of the main face (110) of an adjacent bar (100) of the series of bars, or even crosses this main face (110), such that the fin (200) forms a deflector and has a specific height greater than a distance (h1) that separates the lower edge (114) of the main face (110) from the adjacent bar (100) from the upper edge (112) of the main face (110) of another adjacent bar (100) from the series of bars.