阅读说明：本技术 保护烟雾至洗涤器中的吸入的装置和包括该装置的清洁设施 (Device for protecting the inhalation of fumes into a scrubber and cleaning installation comprising such a device ) 是由 B·锡雷特 A·吉戈尔 F·古尔默隆 于 2019-09-25 设计创作，主要内容包括：保护装置(10),适于布置在洗涤器内部并且包含顶端主体(11),当保护装置安装于洗涤器中时,顶端主体放置在用于允许烟雾进入洗涤器中的竖向管道的下游口的上方,以便保护所述管道免于引入水,同时容许离开所述管道的烟雾通过。为了使该保护装置特别好地工作,顶端主体的上表面(12)设置有水收集通道(14),所述通道各自从顶端主体的中心区域(11A)纵向地延伸至顶端主体的周边(11B),所述通道围绕所述中心区域分布,周边完全地被通道占据。每个通道在其整个长度上具有大致三角形的横截面,并且横截面的下顶点沿着所述通道限定底部边缘(15)。通道的相应的底部边缘搁置于圆锥形表面上,圆锥形表面向上汇聚并且圆锥形表面的顶角在90°与170°之间。(A protection device (10) adapted to be arranged inside the scrubber and comprising a tip body (11) placed above the downstream mouth of the vertical duct for allowing the fumes to enter the scrubber when the protection device is installed in the scrubber, so as to protect said duct from the introduction of water, while allowing the fumes exiting said duct to pass. In order for the protection device to work particularly well, the upper surface (12) of the tip body is provided with water collecting channels (14) which each extend longitudinally from a central region (11A) of the tip body, around which they are distributed, to a periphery (11B) of the tip body, which periphery is completely occupied by the channels. Each channel has a substantially triangular cross-section throughout its length, and the lower apex of the cross-section defines a bottom edge (15) along the channel. The respective bottom edges of the channels rest on a conical surface which converges upwards and the apex angle of which is between 90 ° and 170 °.)

1. A protection device (10) for protecting the inhalation of fumes into a scrubber,

said protection device being adapted to be arranged inside a scrubber (1) and comprising a top body (11) which, when it is installed in the scrubber, is placed above the downstream mouth of a vertical duct (2) for allowing the fumes (F) to enter the scrubber, so as to protect the duct from the introduction of water, while allowing the fumes exiting the duct to pass,

characterized in that an upper surface (12) of the top end body (11), which faces upwards when the protection device (10) is mounted in the scrubber, is provided with channels (14) for collecting water, which channels each extend longitudinally from a central area (11A) of the top end body to a periphery (11B) of the top end body, which channels are distributed around the central area (11A), which periphery (11B) is completely occupied by the channels,

characterized in that each channel (14) has a substantially triangular cross-section over its entire length, and that one of the vertices of the cross-section, which faces downwards when the protection device is installed in the washer, defines a bottom edge (15) along the channel,

and in that the respective bottom edge (15) of the channel (14) rests on a conical surface having an apex angle between 90 ° and 170 ° and converging upwards when the protection device is installed in the washer.

2. The protective device according to claim 1, characterized in that the apex angle of the conical surface is between 100 ° and 140 °.

3. The protection device according to claim 1 or 2, wherein six to eighteen channels (14), preferably six to twelve channels (14), are provided.

4. The protection device according to any one of the preceding claims, wherein the substantially triangular cross-section of each channel (14) has an angle (a) of between 30 ° and 120 °, preferably between 60 ° and 90 °, at its vertex located on the bottom edge (15) of the channel.

5. The protection device according to any one of the preceding claims, wherein the depth and the substantially triangular cross-section of each channel (14) increase when proceeding along the channel from the central region (11A) to the periphery (11B) of the tip body (11).

6. The protection device according to any one of the preceding claims, wherein the bottom edge (15) of the channel (14) has, at the periphery (11B) of the tip body (11), a respective end (16) lying on a circle (C16) substantially concentric with the duct (2) and having a diameter of 1.1 to 2 times the inner diameter of the duct, preferably 1.25 to 1.65 times the inner diameter of the duct.

7. The protection device according to any one of the preceding claims, characterized in that the protection device (10) further comprises a collar (18) fastened to the tip body (11) so as to be arranged below the tip body (11) when the protection device is mounted in the scrubber, while extending substantially vertically from the tip body with a height (h) between 15mm and 75mm and while being located completely within the vertical projection of the tip body.

8. The protection device according to claims 6 and 7 considered together, characterized in that the outer diameter of said collar (18) is between 0.86 and 0.985 times the diameter of said circle (C16).

9. Protection device according to any one of the preceding claims, characterized in that the protection device (10) further comprises a flow deflector (19), the flow director (19) has a conical shape or a pyramidal shape with four, six or eight sides, the conical shape or the pyramidal shape is truncated at its apex and has a through hole, the diameter of said through hole is at least equal to 100mm and, when said protection device is installed in said washer, arranged below said tip body (11) and vertically at a distance from said tip body (11), such that the truncated apex of the conical or pyramidal shape of the deflector faces downwards and the respective end (16) of the bottom edge (15) at the periphery (11B) of the tip body is at least 85mm vertically from the deflector.

10. A facility for wet cleaning of exhaust fumes from an engine of a marine vessel, the facility comprising:

-a scrubber (1) in the bottom of which a vertical duct (2) is formed for sucking fumes (F) into the scrubber,

-a protection device (10) according to any one of the previous claims, arranged inside the scrubber (1), the top body (11) of which is placed above the downstream mouth of the duct (2) in order to protect it from the introduction of water while allowing the passage of the fumes (F) leaving it, and

-a distribution device (3) arranged inside the washer (1) above the protection device (10) and adapted to distribute water in the washer (1) in the form of falling rain water (P).

Technical Field

The present invention relates to a device for protecting the inhalation of fumes into a scrubber. The invention also relates to a plant for wet cleaning of exhaust fumes from an engine of a marine vessel, comprising such a protection device.

Background

Marine vessels (whether passenger or other) use fuel oil as a fuel for diesel engines that propel them. The fuel contains up to 5 wt%, most commonly between 0.5 and 3.5 wt% sulphur. During the combustion process in an engine, this sulfur is converted to sulfur dioxide (SO)₂). As a result, the exhaust fumes from these engines are acidic. Maritime regulations tend to limit the amount of sulfur dioxide emissions from the fumes emitted by ships into the atmosphere. Therefore, ships must contain equipment for reducing these sulfur dioxide emissions. Several solutions can be considered.

Firstly, the sulfur content of the fuel used can be reduced, or even liquefied gases can be used, which directly reduce the sulfur dioxide emissions. However, fuel oil or liquefied gas fuel with very low sulfur content is expensive, so this method is not very economical.

Another method involves the use of a wet scrubber, where a special scrubbing liquid is used, usually with the alkali of seawater, whose natural alkalinity is used to neutralize the sulphur dioxide. Subsequently, in the remainder of this document, this washing liquid is called "water", wherein it is understood that this term "water" corresponds to an aqueous liquid in the liquid state, used to purify fumes in a scrubber, this water being generally sea water to which a neutralizing agent, such as sodium hydroxide (NaOH), magnesium oxide (MgO, mg (oh))₂) Or lime (Ca (OH)₂) And the seawater may also contain salts and other solids resulting from the purification of the fumes.

In practice, the use of scrubbers on ships faces certain limitations. Space on the vessel is limited, which requires a high compactness of the washing installation. Furthermore, several operating modes of the washer must be provided, in particular: an open-loop mode in which a large amount of seawater is admitted into a scrubber from which it is discharged without recirculation, the seawater being discharged after any post-treatment; and a closed loop mode in which most of the water leaving the scrubber is recycled and typically spiked with an alkaline agent supplement, with only minimal wash being discharged. Furthermore, the pressure drop across the scrubber must be very low, since in addition to a possible stalling of the engine, the energy efficiency, for example in kilowatts per kilogram of fuel, decreases considerably when the head loss increases, which is economically undesirable. Finally, maintenance and upkeep operations are more difficult to perform on an offshore vessel than on a land-based unit.

Furthermore, in the specific limits of marine scrubbers, whatever the operating conditions of the marine scrubber (whether operating, shut-down or during transitional periods), the so-called "water ingress" problem is encountered, i.e. it is related to the passage or flow of water from the scrubber towards the equipment located upstream of the scrubber, and in particular towards the pipes that allow the fumes to be cleaned to enter the scrubber. Indeed, water ingress must be avoided, since the intrusion of water into the duct so that fumes enter the scrubber will increase the problems of corrosion of the boiler and of the heat recovery unit located upstream of the scrubber, or even the safety problems related to the engine itself, in particular for the so-called "in-line" scrubbers, in which the suction for the fumes to be cleaned is located below the scrubber. In practice, the scrubber operates with 500 to 4000 cubic meters per hour of water, depending on the design of the engine, the required performance and the power; at the same time, it is intolerable to introduce a small portion of water and several liters of water per hour into the pipes for fumes. One therefore uses protection means, which usually take the form of a cone or a double cone, in particular in the form of a bamboo hat, that is to say in the form of such a cone: the tip of the cone points upward. However, the existing protection devices are insufficient in view of the very low admission of water allowed (in particular during the transient operating periods of the scrubber).

For a clear understanding of this water ingress problem, reference may be made to fig. 1. Fig. 1 shows a very simplified view of a marine scrubber 1, in which exhaust fumes F from one or more diesel engines of a vessel are introduced into the bottom of the scrubber 1 while being admitted therein through a vertical duct 2, said vertical duct 2 passing through the bottom of the scrubber while being generally centered on the bottom of the scrubber. At the top of the interior of the washer, the dispensing device 3 dispenses water, for example by spraying, which is shown in fig. 1 in the form of rain water P, the description being merely symbolic, since the water first falls in the form of droplets and not necessarily vertically. The fumes F circulating inside the scrubber 1 from the bottom to the top, in contact with water, are purified by transferring the sulphur dioxide they contain into the water coming from the distribution device 3, and circulate inside the scrubber 1 from the top to the bottom by gravity, this water being then discharged from the bottom of the scrubber via the outlet 4, said water being at the same time partly recirculated to the distribution device 3, in a manner not shown in fig. 1, if applicable. In order to prevent a portion of the water dispensed by the dispensing device 3 from entering the duct 2, a protection device 5 is arranged inside the washer 1 between the downstream mouth of the duct 2 and the dispensing device 3, while being placed vertically above the downstream mouth of the duct 2: the protection means 5 allow the passage of the fumes F leaving the duct 2, while protecting the duct from the introduction of water. In fig. 1, the protection 5 is shown in the form of a bamboo hat, but other arrangements are possible. Various examples are proposed in WO 2014/128261, WO 2017/198653 and EP 3,260,187.

With the known embodiment of the protection device 5, the effectiveness of said protection device can be significantly impaired, in particular during transient operating periods of the washer 1, due to two troublesome phenomena.

These phenomena are related to the liquid film E1 formed on the upper surface of the protection device 5 by the rainwater P reaching the protection device 5. This film E1 is relatively thin, while the thickness of said film is generally between 1mm and 5mm and depends on the specific geometry and slope of the upper surface of the protection device 5, and on the flow of water introduced by the dispensing device 3. In all cases, this film E1 is distributed over the entire upper surface of the protection device 5 and reaches by flow the entire periphery of this surface. A first phenomenon that may occur is that a small part of the liquid film E1 remains attached to the lower edge of the protection 5 due to capillary action and moves along the lower surface of the protection towards the central axis of the washer 1 until it is detached from this lower surface vertically above the pipe 2 in the form of a drop E2, said drop E2 then being able to enter the inside of the pipe 2 by gravity. A second phenomenon that may occur is that, due to the small momentum, the film of liquid E1 leaves the protection means 5 at the periphery of the upper surface of the protection means 5, forming at the same time one or several thin curtains of water E3, for which it is easy to extract a portion due to the movement of the fumes represented by the arrow T, said portion being carried to the inside of the duct 2. The above-mentioned movement T of the fumes may correspond to a recirculating movement of the fumes F inside the washer 1, or to a convective movement of the fumes that occurs during the transit operating period of the washer.

It will therefore be understood that the current embodiment of the protection device 5 is not sufficient to completely prevent the water from entering the pipe 2, once it has entered more than a few litres per hour, or an infinitesimal portion of water brought about by the dispensing device 3 (generally less than 1/50000 of the quantity of water dispensed by the device 3), which is intolerable.

Disclosure of Invention

The invention aims to provide a protective device with higher performance.

To this end, the invention relates to a device for protecting the inhalation of fumes into a scrubber as defined in claim 1.

The invention also relates to a plant for wet cleaning of exhaust fumes from an engine of a marine vessel as defined in claim 10.

Thanks to the invention, water coming from the distribution device, reaching the upper surface of the top body of the protection device according to the invention (such as rain water P of fig. 1), is concentrated in the bottom of each channel of the protection device, flowing on the lateral slopes of each channel up to the bottom edge of the channel. Thus, water is collected in the bottom of each channel and forms a flow in which it flows in a dense flow (as at the bottom of a turbulent river bed) from the central region of the tip body to the periphery of the tip body where it leaves the upper surface of the tip body at the respective ends of these channels with greater momentum. Of course, the geometrical properties of the channels, in particular the depth of the channels and the opening angle of the channels, are set accordingly by the person skilled in the art, so that water falling on the upper surface of the top body and possibly having a flow rate of several hundred cubic meters per hour in a marine scrubber is concentrated by the channels in the form of the above-mentioned dense flow. Thus, although the rain water P reaches the tip body over the entire upper surface of the tip body, the water is completely concentrated in the bottom of the channel and leaves the tip body only at the ends of the bottom edge of the channel in the form of the above-mentioned dense flows, the accumulation of these ends representing only a small part of the periphery of the tip body. Due to their thickness and their momentum, these streams leave the tip body of the protection device according to the invention as liquid jets having a high velocity and traveling far away, while maintaining a dense flow overall, somewhat like water from garden watering hoses. Then, since these streams of water immediately escape from the tip body of the protector while leaving the protector, any capillary phenomena that would lead to the formation of droplets (such as droplet E2 of fig. 1) are greatly limited. Furthermore, these dense streams of water, which detach from the protection device with greater momentum, adhere less to the movement of the smoke (such as movement T of fig. 1) than the thin curtain of water E3 of fig. 1. The invention thus prevents the two phenomena described above which are detrimental to the effectiveness of the known embodiment of the protection device 5 of fig. 1. Thus, the performance of the protection device according to the invention is unusual, as observed by the inventors in laboratories and large facilities.

Optional advantageous features of the protective device and the cleaning installation according to the invention are specified in the further claims.

Drawings

The invention will be better understood from reading the following description, provided purely by way of example and made with reference to the accompanying drawings, in which:

figure 1 is a schematic view of a plant for treating fumes, belonging to the prior art and already described above;

figure 2 is a perspective view of a protection device according to the invention;

figures 3 and 4 are front views along the arrow III of figure 2 and the arrow VI of figure 3, respectively; and

fig. 5 and 6 are views similar to fig. 3, in which two embodiment options of the protection device according to the invention are shown, respectively.

Detailed Description

Fig. 2 to 4 show a protection device 10 which makes it possible to protect the inhalation of fumes into the scrubber. The protective device 10 is arranged to be used in the cleaning installation shown in fig. 1 instead of the protective device 5. Thus, in a facility for wet cleaning of exhaust fumes from the engine of a marine vessel, a protection device 10 is associated with the scrubber 1 and the distribution device 3 described in detail above, so that when the cleaning facility is operational, the protection device 10 and the distribution device 3 are mounted inside the scrubber, with the distribution device 3 being located above the protection device 10.

Given the environment in which the scrubber 1 is used, i.e. on a marine vessel, the internal diameter of the scrubber is typically at least two meters.

As clearly shown in fig. 2 to 4, the protection device 10 comprises a top end body 11, which constitutes the uppermost part of the protection device 10 when it is mounted in the washer 1. Within the purification installation, the top body 11 is placed vertically above the downstream mouth of the vertical duct 2 for drawing the fumes F into the washer 1, so as to protect the duct from the introduction of water, while allowing the passage of the fumes leaving the duct 2: to this end, the rainwater P from the distribution device 3 falls under the effect of gravity onto the upper surface 12 of the tip body 11, while the lower surface of the tip body 11 is vertically distanced from the downstream mouth of the duct 2, so that the fumes F leaving the duct can pass between this downstream mouth and the lower surface of the tip body 11 in order to rejoin the rest of the interior of the washer 1.

Indeed, still according to the environment of implementation of the invention, the vertical projection of the upper surface 12 of the tip body 11 represents a considerable fraction (fraction), about 40% or more, of the internal cross section of the washer 1.

In the exemplary embodiment considered in the figures, the tip body 11 defines a central axis Z-Z that passes through the upper surface 12 of the tip body 11 in the central region 11A of the tip body 11. When the protection device 10 is installed in the washer 1, the axis Z-Z extends vertically and is advantageously concentric with the duct 2.

In fact, the protection device 10 comprises fastening means 13 which make it possible to fixedly secure the protection device 10 to the inside of the washer 1. In the exemplary embodiment considered in the figures, these fastening means 13 comprise a flange adapted to be fixedly attached around the apex of the pipe 2 and a foot connecting the flange to the head body 11. Of course, other embodiments are conceivable for the fastening means 13, which do not limit the invention.

As clearly shown in fig. 2 to 4, the upper surface 12 of the tip body 11 is provided with a channel 14 delimited by the tip body 11. Each channel 14 extends longitudinally substantially linearly from a central region 11A of the tip body 11 to a periphery 11B of the tip body, the channels 14 being distributed around the central region 11A. In the exemplary embodiment considered in the figures, each channel 14 extends longitudinally and radially to the axis Z-Z, from an end close to the axis Z-Z to an opposite end located on the periphery 11B of the tip body 11. The shape and extent of the central region 11A of the tip body 11 from which the channel 14 extends is not limited to the example considered in the figures. In contrast, in all cases, the perimeter 11B of the tip body 11 is completely occupied by the channels 14, so that this perimeter 11B is divided into portions that are successive to one another around the tip body 11, each of these portions being occupied by one of the channels 14, as clearly shown in fig. 4.

In the exemplary embodiment considered in the figures, the channels 14 are identical to one another and are arranged in eight replicas, as is clearly shown in fig. 4. In this case, in a variant not shown, a greater or lesser number of channels 14 can be considered, advantageously sized to provide six to eighteen channels 14, preferably six to twelve channels 14.

As clearly shown in fig. 2 and 3, each channel 14 has, in cross section, a triangular section, the first of the three vertices of which is lower in the vertical direction than the other two vertices when the protection device 10 is installed in the washer 1. In other words, each channel 14 has a triangular vertical cross-section with the tip oriented downward. There is a triangular shaped cross section of each channel 14 over the entire length of the channel, it being noted that in the exemplary embodiment considered here it is advantageously provided that, for each of the channels 14, the triangular cross section increases as one travels over the channel from the central region 11A to the periphery 11B of the tip body 11.

In each case, the first vertex of the triangular-shaped cross-section of each channel 14 defines a bottom edge 15 along the channel. Likewise, the other two vertices of the triangular shaped cross-section of each channel 14 each define a top edge 17 along the channel. For each channel 14, each of the top edges 17 is connected to the bottom edge 15 by a lateral slope of the channel.

Along each channel 14, the bottom edge 15 is vertically lower than each of the top edges 17. The corresponding difference in vertical spacing characterizes the depth of the channel 14, which channel 14 depth can be measured vertically at any point along the length of the channel between the bottom edge 15 and the top edge 17. In the exemplary embodiment considered here, it is advantageously provided that the depth of each channel 14 increases as one flows through it from the central region 11A to the periphery 11B of the tip body 11. In fig. 3, this depth at the periphery 11B of the tip body 11 has a value marked Δ: according to an advantageous dimensioning, this value Δ is at least 70 mm. In practice, particularly with regard to the specificity of the embodiment of the channels 14, it will be understood that the value of the depth along the channels may be related to the number of channels 14.

The triangular cross-section of each channel 14 has an angle at its apex on the bottom edge 15 of the channel, which angle is denoted as a in fig. 3 and which angle characterizes the opening of the channel. According to an advantageous dimensioning, the angle α is between 30 ° and 120 °, preferably between 60 ° and 90 °. In practice, particularly with regard to the particularity of the embodiment of the channels 14, it will be understood that the value of the angle α may be related to the number of channels 14.

Furthermore, the respective bottom edge 15 of the channel 14 rests on a conical surface which converges upwards and the vertex angle of which is between 90 ° and 170 °, preferably between 100 ° and 140 °, when the protection device 10 is installed in the washer 1. In fact, the aforementioned conical surface on which the bottom edge 15 rests may be imaginary, since it does not constitute a material or physical continuity, but merely represents a geometric surface. In the exemplary embodiment considered in the figures, the above-mentioned conical surface is substantially centered on the axis Z-Z. Thus, in all cases, each of the bottom edges 15 extends linearly and obliquely with respect to the horizontal from the central region 11A to the periphery 11B of the tip body 11, it being noted that these bottom edges 15 come together at the central region 11A (but not necessarily co-dotted), while they intersect the periphery 11B of the tip body 11 at their respective ends 16 opposite the central region 11A.

According to a preferred embodiment implemented in the example considered in the figures, the respective end 16 of the bottom edge 15 lies on a circle C16, as can be clearly seen in fig. 4. In practice, and still in accordance with the environment of practice of the invention, the circle C16 will typically be greater than one meter in diameter.

This circle C16 is arranged substantially concentric with the duct 2 and has a diameter strictly greater than the internal diameter of the duct 2, so that the tip body 11 projects vertically, sufficiently covering the downstream mouth of the duct 2, without causing excessive head loss to the fumes F leaving the duct, within the cleaning installation. More specifically, the diameter of the circle C16 is advantageously between 1.1 and 2 times the inner diameter of the pipe 2, preferably between 1.25 and 1.65 times the inner diameter of the pipe 2. In this case, and as clearly shown in fig. 4, the vertical projection of the periphery 11B of the tip body 11 is not necessarily circular due to the particularity of the embodiment of the channel 14.

When the protection device 10 is installed in the washer 1 and inside the washer the rain water P coming from the distribution device 3 reaches the upper surface 12 of its top end body 11, the water flows from the top edge 17 on the lateral slope of each channel 14 to concentrate in the bottom of each channel along its bottom edge 15. The channel 14 thus collects all the water on the upper surface 12 of the top body 11 of the protection device 10. The inclination of the bottom edge 15 causes the collected water to flow in the bottom of each channel 14 from the central region 11A to the periphery 11B of the tip body 11. As the water is concentrated in the bottom of the channel 14, it flows along each bottom edge 15 in a dense flow which reaches the end 16 of the bottom edge 15 at a higher speed and therefore with a greater momentum. Each of the dense flows of water reaching the end 16 of the corresponding bottom edge 15 leaves the tip body 11 while maintaining a dense flow pattern, leaving immediately and cleanly the tip body 11 and distancing with respect thereto. Beyond the respective ends 16 of the bottom edge 15 of the channel 14, the periphery 11B of the tip body 11 is not wetted, since the water reaching the upper surface 12 does not leave the tip body 11, since it has collected in the bottom of the channel 14. In other words, water that reaches the upper surface 12 of the tip body 11 leaves the tip body 11 with a greater momentum only through the end 16 of the bottom edge 15 of the channel 14.

In practice, since in the cross section of the scrubber 1 the protection device 10 occupies a significant fraction of the interior of the scrubber, a similar fraction of the rain water P reaches the upper surface 12 of the tip body 11, as described immediately above. Still according to the environment of implementation of the invention, this means that the upper surface 12 of the tip body 11 therefore receives typically hundreds of cubic meters of water per hour.

Fig. 5 shows an alternative embodiment of the protective device 10 from fig. 2 to 4. According to this alternative development, the protection 10 comprises at the bottom of its top end body 11a collar 18 fastened to the top end body 11 so as to be arranged below the top end body when the protection 10 is mounted in the washer 1, while extending substantially vertically from the lower surface of the top end body 11 with a height h of between 15mm and 75mm and while being located completely within the vertical projection of the top end body 11. Thus, the collar 18 makes it possible to interfere with any water flow from the tip body 11, so as to disengage said tip body and prevent any potential migration of water on the lower surface of the tip body 11. In the exemplary embodiment considered in fig. 5, the collar 18 is cylindrical while having a diameter advantageously between 0.86 and 0.985 times the diameter of the circle C16.

Fig. 6 shows a further alternative embodiment of the protective device 10 from fig. 2 to 4, which can be combined with the collar 18 from fig. 5. The protection device 10 of fig. 6 therefore comprises a flow director 19, said flow director 19 having a conical shape or a pyramidal shape with four, six or eight sides, said conical shape or said pyramidal shape being truncated at its apex and having a through hole with a diameter at least equal to 100 mm. The aforementioned equivalent diameter is generally defined as the ratio between four times the surface of the through-hole and the perimeter of the through-hole. In the exemplary embodiment considered here, the conical or pyramidal shape of the deflector 19 is substantially centred on the axis Z-Z. When the protection device 10 is installed in the washer 1, the deflector 19 is arranged below the tip body 11 and vertically at a distance from the tip body 11 such that the truncated tip of the conical or pyramidal shape of the deflector 19 faces downwards and each end 16 of the bottom edge 15 of the channel 14 is vertically spaced from the deflector 19 by a distance d at least equal to 85 mm. The deflector 19 makes it possible to reduce the head loss caused by the protection device 10 on the fumes F leaving the duct 2.

Finally, various embodiments and further variants of the protection device 10 considered up to now are conceivable. As an example, the cross section of the channel 14 may be only substantially triangular, rather than strictly triangular, as long as it defines for each channel a lower bottom edge on which the lateral slope of the channel concentrates the water collected by the channel and along which it flows until reaching the perimeter 11B of the top body 11 of the protector 10, after which it leaves the protector 10. The bottom edge and the top edge may thus be more or less blunt.