New portable gas identification device

Abstract

The invention relates to a gas identification device (1), which comprises an analysis chamber (7) for a gaseous atmosphere, connected to the external environment by a set of inlet (51) and outlet (52) openings (5), located on the lower circumference (6) of the upper convex outer envelope (4), ensuring the penetration and circulation of the gaseous atmosphere in the chamber in which: - the chamber (7) is delimited by a concave upper wall (8) and a convex lower wall (9), - the chamber is equipped with a set of gas detection sensors (11), some at least being separated by a deflector element (12) allowing the circulation of the gaseous atmosphere to be directed according to a turbulent flow; - a series of scoops (20) for the entry of the gaseous atmosphere according to a flow crossing with the inlet flow from the series of inlet openings (51) and creating a slowdown. Figure for the summary: Fig. 2

Description

Title of the invention: New portable gas identification device technical field

[0001] The present invention relates to a gas detection and identification device. Within the scope of the invention, a device is proposed that is suitable for detecting, identifying, and even quantifying any gas of interest. In particular, with the same device according to the invention, it is possible to detect, identify, and even quantify a large list of gases, or even any type of gas.

[0002] Technological background of the invention and technical problem

[0003] Today, gas identification has a large number of applications in diverse and varied fields: - air and environmental monitoring, including the detection, identification and quantification of air pollutants, - industry, with the detection, identification and quantification of gas leaks, - Civil protection, including the detection, identification and quantification of toxic and explosive gases, illegal substances, and searches for buried persons, - agriculture and the agri-food sector, with the detection, identification and quantification of toxic gases and fermentation phenomena, - the military field, with the detection, identification and quantification of toxic gases, - transport, with the detection, identification and quantification of toxic gases and pollutants (NOx, Sulfur, etc.) - the medical field, with the detection, identification and quantification of respiratory gases, which allows for various diagnoses.

[0004] Portable gas and vapor detectors already exist in the prior art (INRS 2022, Portable Gas and Vapor Detectors, Good Practice Guide for Selection, Use and Verification, ED6088). Different technologies are available, depending on the gas to be detected. For the detection of flammable gases, catalytic sensors, catharometric sensors (which measure the variation in thermal conductivity in the presence of the gaseous atmosphere to be analyzed), and infrared (IR) sensors are mainly used. However, these different sensors have certain limitations: catalytic sensors only work in the presence of a certain minimum quantity of oxygen in the gas to be analyzed, and this type of sensor is unsuitable In the case of atmospheres containing high concentrations of substances such as organochlorines, organosulfur compounds, silicones, lead, phosphorus, mercaptans, and H2S, IR sensors can only detect gases whose molecules contain at least two different atoms.

[0005] For the detection of toxic gases, other types of sensors are generally used. These include, in particular, electrochemical sensors. With such electrochemical sensors, the main gases detected are: CO, NO, NO2, SO2, H2S, HCN, HCl, NH3, and C12. However, an electrochemical sensor designed to detect a given gas generally detects others indiscriminately. Moreover, such sensors require a minimum oxygen concentration to function, and low humidity results in the sensor drying out. It is also possible to use photoionization (PID) sensors. In this case, ionization is achieved by UV irradiation. Again, these sensors are not very selective, and the quantitative evaluation is unreliable, especially in the presence of high humidity. Semiconductor sensors are another solution proposed in the prior art for the detection of toxic gases.Detection results from a redox reaction, or simply from adsorption onto the semiconductor surface, which changes the material's resistivity by altering the number of charge carriers. Semiconductor detectors are not selective, and their sensitivity to different compounds depends on the gas used for calibration. Furthermore, they require the presence of oxygen to function. Finally, colorimetric sensors are also available, in which one or more chemical reagents are adsorbed onto an inert substrate. This type of sensor provides an indication of the presence of gas rather than identification. If several gases are present in the analyzed gaseous atmosphere, interference occurs. Finally, detection can sometimes take several minutes, the time required for the color to develop.

[0006] For oxygen detection, electrochemical sensors with liquid or solid electrolytes are used. Zirconium oxide (ZrO2) solid electrolyte behaves like a liquid electrolyte when heated, i.e., oxygen is ionized upon contact with it; it is therefore rarely used in gas detectors.

[0007] Some solutions are proposed in the prior art for combining several detection sensors within a single device. For example, EP 3114475 proposes a particle and / or gas detection device comprising a series of channels housed in a casing, each channel containing a gas / particle detection sensor. The described detector includes a suction pump used to circulate the atmosphere to be analyzed within the casing and the channels. The proposed detector also has a complex structure.

[0008] To date, existing multi-gas detectors are therefore unsatisfactory for the following reasons: the number of detectable gases is limited, to a maximum of 10; they lack selectivity, meaning they cannot differentiate between gases of the same family, nor can they differentiate the target gas from interfering gases also detected by the detector; quantification is difficult; in the case of gas mixtures, they are difficult to transport to reach areas of high contamination. Most require mechanical components (fan, pump, etc.) and concentration chambers.

[0009] In this context, there is therefore a need for new gas identification devices that offer the possibility of rapid identification of a large number of gases, while being portable and reliable. The invention proposes to provide a new gas identification device in a gaseous atmosphere, which allows the identification of a large number of gases, without any mechanical system, such as a pump or fan, for introducing and assisting the circulation of the gaseous atmosphere within the device. Summary of the invention

[0010] In this context, the present invention relates to a device for identifying a gas present in a gaseous atmosphere of interest, said device being delimited by a lower base from which rises a domed upper outer casing, preferably dome-shaped, said device comprising an analysis chamber for the gaseous atmosphere of interest, connected to the external environment comprising the gaseous atmosphere of interest by a set of openings comprising a series of inlet openings and a series of outlet openings, both located on the lower circumference of the domed upper outer casing, preferably dome-shaped, ensuring the penetration and circulation of the gaseous atmosphere of interest within the analysis chamber between the series of inlet openings and the series of outlet openings, characterized in that: - the analysis chamber is delimited by an upper wall that is at least partially concave, called the concave upper wall, and a lower wall that is at least partially convex, called the convex lower wall, the series of inlet openings and the series of outlet openings being located near a peripheral edge of the upper and lower walls and - the analysis chamber is equipped with a set of gas detection sensors, at least some of which are different, at least some of the sensors being separated by a deflector element allowing the circulation of the gaseous atmosphere of interest within the analysis chamber to be directed according to a turbulent flow, at the level of one of the sensors; - a series of scoops opening into the analysis chamber are arranged for the entry of the gaseous atmosphere of interest according to an inlet flow crossing with the inlet flow of the gaseous atmosphere of interest coming from at least part of the series of inlet openings and thus creating a slowing down of the flow of gaseous atmosphere of interest which enters the analysis chamber and which will circulate in the latter.

[0011] Due to the domed shape of the upper outer shell, the surface area of ​​the upper outer shell over which the gaseous atmosphere of interest can circulate is greater than that of the lower base. This creates a low-pressure area at the lower circumference of the upper outer shell, i.e., at the inlet openings for the gaseous atmosphere of interest, in particular. The domed upper outer shell can take various forms, especially a dome shape, which may be a faceted dome, a half-teardrop shape, or preferably a portion of a hemisphere or a hemisphere. The lower base will preferably be flat.

[0012] The upper outer shell and the lower base define an external space whose volume increases from its periphery to its center. The concave and convex nature of the upper and lower walls, respectively, is determined with respect to the analysis chamber. Advantageously, the concave portion of the upper wall and the convex portion of the lower wall are substantially parallel, that is, they are separated from each other by a substantially constant distance. By substantially constant distance, it is understood that at any point on the convex portion of the lower wall, the distance measured perpendicularly to its tangent from the concave portion of the upper wall is equal to within ±5%, preferably to within ±2%, and preferably is equal at every point.

[0013] Advantageously, the surface area of ​​the upper outer shell over which the gaseous atmosphere of interest can circulate is therefore greater than the surface areas of the upper and lower walls of the analysis chamber over which the gaseous atmosphere of interest circulates once it has entered the analysis chamber. This reinforces the low pressure created at the lower circumference of the upper outer shell, that is to say, in particular, at the inlet openings for the gaseous atmosphere of interest entering the analysis chamber.

[0014] The architecture of the device for identifying a gas present in a gaseous atmosphere of interest proposed by the invention makes it possible on the one hand to house a large number of detection sensors in a small analysis chamber, and on the other hand to increase the residence time in the analysis chamber and the contact time with the detection sensors of the gaseous atmosphere of interest which sweeps through the analysis chamber.

[0015] In particular, two deflector elements are positioned on either side of a gas detection sensor, so as to create a swirling flow at the level of a detection sensor.

[0016] According to a particular embodiment of the invention, which can be implemented regardless of the variant of the identification device according to the invention described, all the detection sensors are different from each other.

[0017] According to a particular embodiment of the invention, which can be implemented regardless of the variant of the identification device according to the invention described, the scoops extend from an opening to the external environment oriented towards the periphery of the device to an opening formed on the periphery of the lower base leading into the analysis chamber, in an angled or hemispherical profile. Preferably, the scoops have the shape of baffles which, preferably, allow the gaseous atmosphere of interest to enter perpendicularly to the lower base.

[0018] According to a particular embodiment of the invention, which can be combined with the preceding ones, a slowing groove for the circulating flow of the gaseous atmosphere of interest is provided at the periphery of the lower convex wall (9) delimiting the analysis chamber. This slowing groove can be considered to create a zone of slowing and therefore of concentration of the gases present in the gaseous atmosphere of interest. At the level of this zone, the distance separating the slowing groove from the concave part of the upper wall is greater than the distance separating the concave part of the upper wall and the convex part of the lower wall delimiting the analysis chamber.Following the path of the gaseous atmosphere of interest within the identification device according to the invention, it enters the analysis chamber through a series of inlet openings, is slowed by its collision with the other inlet flow conveyed by a scoop, is slowed by the deceleration groove when the latter is present, then travels between the concave part of the upper wall and the convex part of the lower wall delimiting the analysis chamber, to come into contact with the detection sensors, being oriented by the deflector elements so as to create a turbulent, in particular swirling, flow at least at some of the detection sensors. Then, the gaseous atmosphere of interest exits through a series of outlet openings.

[0019] According to a particular embodiment of the invention which can be combined with the preceding ones, the deflecting elements are columns which extend from the concave upper wall to the convex lower wall delimiting the analysis chamber and whose external walls have a concave profile positioned so as to direct the circulating flow of the gaseous atmosphere of interest (2) towards at least one of the detection sensors.

[0020] According to a preferred embodiment which can be combined with previous embodiments, the concave upper wall and the convex lower wall form domes whose vertices are aligned on an axis of symmetry A passing through the apex of the convex upper outer envelope, preferably dome-shaped.

[0021] According to a preferred embodiment applicable regardless of the embodiment or variant of the detection device according to the invention, the detection sensors are positioned on at least two rings whose centers are located on the axis of symmetry A. In particular on one ring, there is an alternation of detection sensors and deflector elements, which can be located at equal distances from each other.

[0022] According to a preferred embodiment applicable regardless of the embodiment or variant of the detection device according to the invention, the detection sensors are housed at the level of the concave upper wall of the analysis chamber.

[0023] According to a preferred embodiment applicable regardless of the embodiment or variant of the detection device according to the invention, the concave upper wall delimits, with the inner face of the domed upper outer envelope, in particular in the shape of a dome, a housing and the sensors, which include an active part in contact with the gaseous atmosphere of interest and an electronic part for measuring and / or processing the information obtained through the active part, are housed at the level of the concave upper wall of the analysis chamber, so that the active information part is in the analysis chamber and the electronic processing part is in the housing.

[0024] According to a preferred embodiment applicable regardless of the embodiment or variant of the detection device according to the invention, it comprises different detection sensors, preferably from 4 to 64 different sensors, belonging, preferably, to at least two, preferably to at least three and preferably to at least four of the following categories: catalytic sensors, infrared sensors, electrochemical sensors with liquid or solid electrolyte, semiconductor-based sensors, colorimetric sensors, photoionization sensors, surface acoustic wave sensors, optical fiber sensors, LED optical sensors, tunable laser diode sensors, quartz microbalance sensors and field-effect transistor sensors.

[0025] In particular, either the detection device according to the invention is intended to be fixed in operation on a support and preferably comprises a set of openings that can act as inlet or outlet openings for the gaseous atmosphere of interest, depending on the orientation of the external flow of the gaseous atmosphere of interest, or it is intended to be mobile in operation and comprises a series of inlet openings and a series of outlet openings positioned diametrically opposite each other. In both cases, the openings can be arranged around the entire circumference of the upper outer casing. Detailed description of the invention

[0026] Other features, details and advantages of the invention will become apparent from the description given with reference to the accompanying figures provided by way of example, which represent, respectively:

[0027] Fig. 1 is a schematic profile representation of a gas identification device according to the invention.

[0028] Figure 2 is a schematic top-view perspective representation of a gas identification device according to the invention shown in Figure 1, with the outer upper casing and the upper wall delimiting the analysis chamber partially missing, and highlighting the positioning of sensors and deflector elements. The location of the non-visible deflector elements is shown in dashed lines.

[0029] Figure 3 is a schematic top-view perspective representation of a gas identification device according to the invention shown in Figure 1 and Figure 2, with the outer upper casing partially shown and highlighting the positioning of sensors and deflector elements. The location of the non-visible deflector elements is shown in dashed lines.

[0030] Fig. 4 is a schematic top view representation of the lower part of the gas identification device according to the invention shown in Fig. 3.

[0031] Fig. 5 is a schematic cross-sectional representation of the gas identification device according to the invention shown in Fig. 3 in section AA, highlighting the positioning of sensors as shown in Fig. 6 at the upper wall delimiting the analysis chamber.

[0032] Fig. 6 is a schematic representation of a gas detection sensor that may be present in a device according to the invention.

[0033] The [Fig.7] is a schematic top view representation of the flow of gaseous atmosphere of interest entering the analysis chamber, in the peripheral part of the latter.

[0034] Fig. 8 is a schematic top view representation of the circulation of the gaseous atmosphere flow of interest in the analysis chamber at the level of the second series of sensors arranged in a ring, in the embodiment illustrated in the preceding figures.

[0035] Fig. 9 is a schematic profile representation of an identification device according to the invention positioned on a support, in operation.

[0036] Fig. 10 is a schematic profile representation of an identification device according to the invention carried by a drone, in operation.

[0037] As shown in [Fig. 1], an identification device 1 according to the invention is positioned in an external environment comprising a gaseous atmosphere of interest 2. The identification device 1 comprises a lower base 3, which is a plate, circular in the illustrated example, from which extends a domed upper outer envelope 4, in the shape of a dome, in particular in the shape of a hemisphere or portion of a hemisphere, particularly a portion of a hemisphere that is a hemisphere cut by a plane extending perpendicularly to its diameter, as in the example illustrated in [Fig. 1]. As in the illustrated example, the lower base 3 and the upper outer envelope 4 exhibit convolutional symmetry about an axis of symmetry A, which is vertical in [Fig. 1]. The gaseous atmosphere of interest 2 enters the identification device 1 through a series of openings 5.In the illustrated example, these openings 5 ​​take the form of parallel slits arranged along the lower circumference 6 of the upper outer shell 4, extending around its entire circumference. Advantageously, the domed upper outer shell 4 has a continuous shape, without any inflection points, except at the lower circumference 6 where the series of openings 5 ​​is located. A series 5i of these openings will serve as inlet openings and a series 52 of these openings will serve as outlet openings for the gaseous atmosphere, to and from the interior of the device, or more precisely to and from the interior of an analysis chamber 7 (not visible in [Fig. 1]) into which these openings 5 ​​open. Due to the presence of these openings 5, the incoming flow of the gaseous atmosphere of interest 2 will sweep through the analysis chamber 7 before exiting it.In the identification device 1 according to the invention, the circulation of the gaseous atmosphere 2 of interest occurs exclusively within the analysis chamber 7. In the illustrated example, the openings 5 ​​of the first series 5i of inlet openings and of the second series 5i of outlet openings are all identical and therefore indistinguishable. The domed shape of the upper outer casing 4 creates a low-pressure area in its lower part, facilitating the entry of the gaseous atmosphere of interest 2 through the series 5i of inlet openings. The shape of the openings 5 ​​is selected, at least for those that will constitute the series 5i of inlet openings, to offer the least possible resistance to the gaseous atmosphere of interest 2 that must enter the identification device 1. As in the illustrated example, they may correspond to parallel slits, which may be of different or identical widths, as in [Fig. 1].Although not visible in the figure, the walls separating the . Openings 5 ​​forming parallel slits may have an isosceles or equilateral triangular base with the apex of said triangle oriented towards the external environment.

[0038] As can be seen in [Fig. 2], which partially shows the interior of the device after removal of the upper outer casing 4, with the exception of its lower circumference 6 in which the openings 5 ​​are arranged, the analysis chamber 7 is, in particular, delimited by an upper wall 8 having a concave portion 82 (partially shown, and referred to for simplicity as the concave upper wall 8) and a lower wall 9 (referred to for simplicity as the convex lower wall 9) having a convex portion 10. The concave and convex nature of the upper wall 8 and lower wall 9 can be seen from inside the analysis chamber. The peripheral edges, 81 and 91 respectively, of the concave upper wall 8 and the lower wall 9 are located near the series of openings 5.

[0039] The analysis chamber 7 is equipped with a set of gas detection sensors 11 (not visible in [Fig. 2]), preferably different from one another, at least some of which are separated by a deflector element 12 which will disrupt the flow of the gaseous atmosphere 2 and allow its circulation to be directed within the analysis chamber 7 as will be detailed later. Figures 3 and 4 show the interior of the identification device 1 of [Fig. 2], but, in the case of [Fig. 3], with only part of the upper dome-shaped outer casing 4 present and the concave upper wall 8 delimiting the analysis chamber 7 also present, and in the case of [Fig. 4], with the upper outer casing 4 omitted except for its lower part 6 where the openings 5 ​​are provided and the concave upper wall 8 omitted.The deflector elements located in the analysis chamber 7, which are not visible in Figures 2 and 3, are represented by dashed lines. In the illustrated example, the lower wall 9 rests on the lower base 3 of the device 1, which therefore also partially delimits the analysis chamber 7. The analysis chamber 7 offers a space, notably located between the concave part 82 of the upper wall 8 and the convex part of the lower wall 9, in which a multitude of detection sensors 11 can be housed. The interlocking space between the upper concave shape and the lower convex shape creates a curved passage for the flow of the gaseous atmosphere 2 of interest and provides an optimal available surface for housing a large number of sensors 11. In the illustrated example, as can be seen in [Fig.[5] which is a cross-sectional view of the complete identification device 1, the concave part 82 of the upper wall and the convex part 10 of the lower wall 9 appear as substantially parallel domes. It can be noted that in [Fig. 5], a version of the identification device 1 in which scoops 20 are not shown. present only at the level of the 5 openings playing the role of a series of 5b openings is represented.

[0040] An example of a sensor 11 is shown in [Fig.6]: a sensor used in gas detection generally comprises an active part 13 in contact with the gaseous atmosphere 2 of interest and an electronic part 14 for measuring and / or processing the information obtained through the active part 13. The sensors 11 are housed, in the illustrated example, at the level of the concave upper wall 8 of the analysis chamber 7, so that the active part 13 is located in the analysis chamber 7 and the electronic part 14 is located in a housing 15 corresponding to the space located between the concave upper wall 8 and the upper outer casing 4.It could also be provided, according to an unshown variant, that the sensors 11 are integrated into the lower wall 9. This would, however, leave less space for the electronic components, since the electronic components 14 of the sensors 11 are also connected to each other and to a central unit 16 for storing the information generated by the sensors 11, shown schematically in [Fig. 6]. For clarity, the connections and this information storage unit 16 are not shown in the other figures. The latter could also be housed in the compartment 15, although this is not shown in the figures to avoid cluttering them. It could also be placed in a cavity 17 created between the lower base 3 and the lower wall 9, as shown in [Fig. 5].Furthermore, integrating the sensors 11 into the upper wall 8, as opposed to the lower wall 9, is preferred because it prevents dust from accumulating on them.

[0041] The gas identification device 1 according to the invention is designed to maximize the contact time between the gaseous atmosphere 2 of interest entering and flowing through the analysis chamber 7 and the multiple sensors 11 located therein. This is achieved in several ways. First, through the shape of the analysis chamber 7, which itself constitutes a curved passage for the circulation of the gaseous atmosphere 2 of interest, due to its delimitation by the concave upper wall 8 and the convex lower wall 9. This passage follows the dome shape of the walls that delimit it. Such a curved shape makes it possible to increase the mixing of the flow of gaseous atmosphere 2 of interest within the analysis chamber 7. The passage offered by the analysis chamber 7 may or may not have a constant cross-section.Next, the gas identification device 1 according to the invention comprises a series of scoops 20 opening into the analysis chamber 7, which are arranged to create a second inlet flow of the gaseous atmosphere 2 via an inlet flow intersecting with the first inlet flow of the gaseous atmosphere 2 of interest originating from at least some of the series 5i of inlet openings. These scoops 20 are visible in Figures 3 and 5, in particular. They have a shape adapted to allow the gaseous atmosphere . 2. The interest in entering it. As in the illustrated example, the scoops 20 can extend from an external opening 21 leading to the outside environment, this opening 21 being oriented towards the periphery of the identification device 1, as opposed to the center of the identification device 1. That is to say, the external opening 21 has the same type of outward orientation as the series 5i of inlet openings. From this external opening 21, the scoop 20 leads to an internal opening 22 arranged on the periphery of the lower base 3 and leading into the analysis chamber 7. In the illustrated example, the scoops 20 have a hemispherical profile of the hemispherical cap type, but an angled profile could also be provided. As can be seen from [Fig.7] (where the position of the sensors and deflector elements are shown in hatching) which schematically shows the flow of gaseous atmosphere 2 entering the analysis chamber 7 at the level of the series of inlet openings 5i and internal openings 22 of the scoops 20, the first flow of gaseous atmosphere 2 coming from certain inlet openings 5i collides with the flow of gaseous atmosphere 2 coming from internal openings 22 of the scoops 20, thus creating a disturbance and a slowing down of the flow of gaseous atmosphere 2 which enters the analysis chamber 7 and which will circulate in the latter and come into contact with the first sensors 11. A Brownian motion is thus created.Depending on whether the detection device 1 according to the invention is used in a mobile or fixed application, the scoops 20 may be located all around the perimeter of the lower base 3, as may the openings 5, which can serve as either inlet or outlet openings depending on the direction of the external flow. If the mobile application determines the position of the series 5i of inlet openings, the scoops 20 may be located only at their level, as shown in [Fig. 3]. According to an alternative (not shown), instead of being located at the lower base 3, the scoops could also be located at the peripheral part of the upper outer casing 4. Apart from the openings 5 ​​and those created at the scoops 20, there are no other openings leading into the analysis chamber 7, as this could disrupt the flow of gaseous atmosphere 2 circulating within it.In particular, the integration of the sensors 11 into either of the walls 8 or 9 of the analysis chamber 7 will provide appropriate sealing.

[0042] As can be seen in particular from [Fig. 3], the sensors 11 can be distributed over at least two rings C1 and C2, which makes it possible to maximize their number and distribute them in the space between the concave upper wall 8 and the convex lower wall 9 forming the analysis chamber 7. In particular, on one ring C1, there is an alternation of detection sensors 11 and deflector elements 12, which can to be located equidistant from each other, as in the illustrated examples. In the illustrated example, the sensors 11 are distributed across two rings C1 and C2, which are represented in [Fig. 3] by two dashed circles. In this example, 4 sensors 111 to 1114 are located on ring C1, 4 sensors 1121 to 1124 are located on ring C2, and one sensor 113 is located centrally at the top of the dome corresponding to wall 8, for a total of 9 sensors. However, many other variations are possible, including configurations with a total of 4 to 64 sensors. These sensors may all be different, or only some may differ from one another.In the illustrated example, the concave upper wall 8 and the convex lower wall 9 form domes, specifically a portion of a hemisphere or a hemisphere, whose vertices are aligned on an axis of symmetry A passing through the vertex of the dome-shaped upper outer shell 4, which also forms, in particular, a portion of a hemisphere or a hemisphere. The centers of the rings C1 and C2 lie on the axis of symmetry A. As shown in the figures, all the vertices of the domes (those of the concave upper wall 8, the convex lower wall 9, and the upper outer shell 4) are aligned on an axis extending perpendicularly to the plane of the lower base 3, and exhibit, in particular, convolutional symmetry about this plane. In the illustrated example, the domes of the concave upper wall 8 and the convex lower wall 9 are homothetic.Their curvature has the same orientation and direction as the upper outer dome 4, that is to say, their curvature deviates from the lower base 3. In order to increase the space between the upper outer envelope 4 and the concave upper wall 8 forming the housing 15, the upper outer envelope 4 may have a radius of curvature smaller than that of the upper wall 8, as exemplified in [Fig. 5].

[0043] As can be seen in [Fig. 7], for the first ring Cl encountered by the flow of gaseous atmosphere 2 entering from certain inlet openings 5i and internal openings 22 of the scoops 20, two sensors 11 of this ring Cl are separated by a deflector element 12 acting as a disruptive element for the circulating flow of gaseous atmosphere 2. On the ring Cl, there is an alternation of sensor 1 lu and deflector elements 12n, which in the illustrated example are equidistant from each other, although this may be otherwise. In [Fig. 7], only sensor 1 lu and the deflector elements 12n and 12i2 are visible. The presence of the deflector elements 12ii and 1212, on either side of the sensor lin, allows the circulation of the gaseous atmosphere of interest 2 within the analysis chamber 7 to be directed according to a turbulent flow at the level of the sensor 1 lu.A swirling flow is created between the two deflector elements 12n and 1212 which reflect the flow from the gaseous atmosphere. of interest 2 towards the sensor lin. In the devices according to the invention, the deflector elements 12 play the role of obstacles disrupting the circulating flow of the gaseous atmosphere 2 of interest in the analysis chamber 7, and allow the gas to be concentrated at the level of the detection sensors 11.

[0044] To fully fulfill their role, according to a configuration illustrated in the figures, the deflector elements 12 are columns extending from the concave upper wall 8 to the convex lower wall 9, delimiting the analysis chamber 7. The outer walls 25 of these columns have a concave profile positioned so as to direct the flow circulating from the gaseous atmosphere of interest 2 towards at least one of the sensors 11. For this purpose, the columns may have four outer walls 25 having an identical semicircular concave profile, positioned to form a four-pointed star cross-section, the points of two opposite points of the star being positioned on the ring C1, as is the center of the sensors C1, which most often have a circular cross-section. Figure 8 shows a sensor C1 positioned on the second ring C2, the one closest to the axis of symmetry A.It appears that the two deflector elements 122i and 1222, located on either side of sensor 1l2i, redirect the flow of gaseous atmosphere of interest 2 towards sensor 1l2i, creating a turbulent, particularly swirling, flow, in the same way as explained for ring C1. It also appears that the deflector element 12n located on the first ring C1 also contributes to the creation of this turbulent, particularly swirling, motion. Advantageously, when the sensors 11 are distributed over at least two successive rings, in particular C1 and C2, with alternating sensors 11 and deflector elements 12, there will be an offset between the position of the deflector elements 12 in two successive rings, in particular C1 and C2. In particular, a deflector element 12 of one of the rings may be in a radial position relative to a sensor 11 of the other ring.In the embodiment illustrated in the figures, the first ring comprises four sensors 11H and four deflector elements 12n, and the second ring comprises four sensors 112i and four deflector elements 122i, plus a central sensor 113. Many other configurations, with more or fewer rings and more or fewer sensors or deflector elements per ring, are possible.

[0045] According to a preferred embodiment illustrated in the figures, to further slow down the flow of the gaseous atmosphere of interest 2 entering the analysis chamber 7, a slowing groove 26 can be provided at the periphery of the convex lower wall 9 delimiting the analysis chamber 7. Such a slowing groove 26 is visible in Figures 2, 4, and 5. It should be noted that in [Fig. 7], the optional slowing groove is shown in dashed lines. The groove of The deceleration groove 26 creates a low-pressure area in the flow of the gaseous atmosphere of interest 2 as it flows towards the first detection sensors 11H it will encounter. The presence of the deceleration groove 26 creates a passageway for the gaseous atmosphere of interest 2, which is wider at the entrance of the analysis chamber 7 than after, and finally at its center. The internal openings 22 of the scoops 20 can open at the deceleration groove 26, as in the example illustrated in the figures, or upstream of it. At the periphery of the analysis chamber 7, the incoming volume of the gaseous atmosphere of interest 2 is greater than the volume present at the center of the device and at the top of the analysis chamber 7.This is why the scoops 20, possibly supplemented by the slowing-down groove 26, make it possible to slow down the flow of gaseous atmosphere of interest 2 circulating and thus increase the contact time with the first sensors 11 encountered by the latter.

[0046] Thus, the identification device 1 according to the invention maximizes the contact time between the active part 13 of the sensors 11 and the gaseous atmosphere 2 of interest, thereby minimizing the limitations of the sensors in terms of sensitivity and response time, in particular. Specifically, the sensors 11 are positioned at convergence centers of the gaseous atmosphere 2, these convergence centers being created by the deflector elements 12. Therefore, the contact between the sensor and the converging flow of the gaseous atmosphere 2 of interest is sufficiently long for the sensor 11 to react with the target gas. Furthermore, by increasing the number of sensors in the analysis chamber, it is possible to collect a large amount of data which, after analysis, allows differentiation between gases of the same family and distinguishes a target gas from an interfering gas for the sensors used.The identification devices 1 according to the invention are universal gas detectors, that is to say, they are capable of identifying any type of gas, in particular a gas selected from the following list: carbon monoxide (CO), alcohol selected from methanol, ethanol, n-propanol, isopropanol, butanol, dioxygen, formaldehyde, methane, propane, n-butane, isobutane, hexane, benzene, LPG, dihydrogen, nitrogen dioxide, ammonium hydroxide, carbon dioxide (CO2), sulfides, in particular H2S and SO2, dichlorine (C12), nitrogen oxide, ozone, acetaldehyde and its isomers (C2H4O), the toxic gases DMMP (dimethylphosphonate CH3PO(OCH3)), DMA (dimethyl adipate), DMG (dimethyl glutarate), DBE (a mixture of DMG, DMA and DMS: dimethyl sulfoxide).

[0047] Various types of gas detection sensors are commercially available and can be used in combination in the identification device 1 according to the invention. In particular, the sensors 11 can be of the electrochemical, thermal, mass, or optical type; they can all be of the same type or of the same type. different. In particular, a series of 11 sensors belonging to different categories listed below will be placed in the measuring chamber of the device according to the invention: - catalytic sensors, which measure the heat of combustion of flammable gases or vapors on the surface of a metallic catalyst. This type of sensor is, in particular, suitable for the detection of alkanes such as methane, in the presence of oxygen in the gas circulating in the measuring chamber; - infrared sensors for gases whose molecules comprise at least two different atoms; - electrochemical sensors, in particular, used for the detection of the following gases: CO, NO, NO2, SO2, H2S, HCN, HCl, NH3 and C12; this type of sensor can be with liquid or solid electrolyte (based on the measurement of the variation in electrical conductivity of a material, in particular an oxide such as zirconium oxide or tin oxide or even nanotubes or nanowires, especially carbon; - Semiconductor-based sensors, detecting redox or adsorption reactions on the surface of the semiconductor; - colorimetric sensors in which a chemical reagent absorbed on an inert support changes color in the presence of a gas; - photoionization sensors (also called PID); - surface acoustic wave sensors; - optical sensors using optical fibers or LEDs; - tunable laser diode sensors; - Mass sensors, which can include, in particular, quartz microbalance sensors, surface acoustic wave (SAW) sensors, or surface functionalized sensors; Microbalance and SAW sensors are based on the variation of the properties of a quartz crystal. In the case of SAW sensors, an acoustic wave source is used that passes through a substrate. The physical properties of the substrate change depending on the gas; - Field-effect transistor (FET) sensors.

[0048] Depending on the technology used, the gas detection sensors employed target specific gases and have varying detection sensitivities. In general, even if a gas is targeted by a selected gas detection sensor, the sensor also detects so-called interfering gases, with a detection sensitivity much lower than that of the target gas (i.e., to be detected, they must be present at a high concentration, whereas the target gas can be detected at a much lower concentration), which cannot be distinguished from the target gas using a single sensor. Thus, a single gas detection sensor allows, Generally, the aim is to determine if a gas belonging to a group of gases (target gas(s) and interfering gases) is present in the gaseous atmosphere of interest with which it is in contact. Specific identification of a single target gas is generally not possible. Various types of gas detection sensors are commercially available from companies such as City Technology (UK, C12 3E 50 sensor for C12 detection, C1O2 3E 1 O sensor for C1O2 detection, 4CF+ and 4CM sensors for CO detection, 4COSH sensor for COSH (CO+H2S) detection, 2CF3 sensor for COH detection, 4HS+ or 4H sensor for H2S detection, 3E 30 F sensor for HCN detection, 3E 100 SE sensor for NH3 detection, H2 3E 4% sensor for H2 detection...), DD Scientific (UK, GS+ 4DT sensor for COSH (CO+H2S) detection...), and NevadoNano (USA, MPS003 sensor...).), Ion Science (UK, which offers, among other things, PID sensors) and SparkFun Electronics (USA). These gas detection sensors, although targeting a specific gas, also detect interfering gases. These types of sensors are miniature, meaning they have dimensions on the order of a centimeter, or even less.

[0049] In general, a gas detection sensor can detect several types of gas, but with different sensitivities. The sensor's response is therefore the presence or absence of a gas corresponding to one or more target gases or to an interfering gas, often accompanied by a quantitative measurement. The internal architecture of the device according to the invention allows for the placement of a series of different gas detection sensors, which are distributed over at least one, and preferably two or three, concentric rings.

[0050] The position of a gas detection sensor on either of the rings may depend on the sensitivity of the detector and the most important gas to be detected. According to certain configurations, the most sensitive detection sensors (for example, having a sensitivity of 1 to 10 ppmv for a target gas) will be placed near the center of the analysis chamber 7 and the least sensitive ones (for example, having a sensitivity of 30 to 50 ppmv for a target gas) at the periphery.

[0051] To collect the maximum amount of relevant data for identifying the gas or gases present in the gaseous atmosphere of interest, in the identification devices 1 according to the invention, preferably, none of the gas detection sensors 11 present in the analysis chamber 7 is identical to another gas detection sensor 11; that is, they all have different detection specificities and / or selectivities. In particular, in the set of gas detection sensors 11 present in the device, preferably, at least three of them are sensors that give different results for the same gas of interest detected as the target gas or as the inferring gas.

[0052] As an example, the NH3 Gas Sensor - MQ-137 marketed by SparkFun Electronics has a minimum threshold of 5ppm for the detection of NH3 (the primary gas targeted by this detector), but it also allows the detection of other gases with higher detection thresholds: CO2 with a detection threshold of 100ppm, CO with a detection threshold of 50ppm, C12 with a detection threshold of 10ppm, H2 with a detection threshold of 100ppm, HCN with a detection threshold of 10ppm, H2S with a detection threshold of 50ppm, C3H7OH with a detection threshold of 100ppm, SO2 with a detection threshold of 50ppm, as well as other gases.The H2S Gas Sensor module - MQ-136, also marketed by SparkFun, has a minimum detection threshold of 1 ppm for H2S (the primary gas targeted by this detector), but it also allows the detection of other gases with higher detection thresholds: CO with a detection threshold of 300 ppm, H2 with a detection threshold of 1000 ppm, SO2 with a detection threshold of 5 ppm, NO2 with a detection threshold of 5 ppm, and other gases. Therefore, it is not possible to differentiate the detection of CO2 and H2S from the other detected gases with just one of these detectors, nor with these two detectors alone. This is why, to allow for the more reliable detection and identification of a greater number of gases of interest with a single device, the invention proposes a chamber with a specific architecture in which a series of different sensors can be housed and thus used simultaneously.In device 1 according to the invention, the analysis chamber 7 is unique and the gas detection sensors 11 are surrounded by the same circulating gaseous atmosphere 2, according to flows generated by the very architecture of device 1.

[0053] It will also be possible to adapt the position of the gas detection sensors 11 to make the identification of a particular gas even more reliable. Indeed, although the same device can identify a large number of gases, it will be possible to create identification devices based on one or more gases that would be of particular interest in order to further increase the sensitivity and reliability of identification. If the device according to the invention has, in particular, as its primary purpose the detection of CO, depending on the path that the gas to be analyzed will follow in the analysis chamber 7, the sensors with the highest detection thresholds for CO (the least sensitive detection sensors with respect to CO) will be placed towards the periphery and the sensors with a lower detection threshold (the most sensitive detection sensors) closer to the center of the device.

[0054] By selecting sensors providing quantitative measurements, in particular electrochemical, semiconductor and / or mass sensors, the identification device 1 according to the invention also makes it possible to determine the concentration of the identified gas in the gaseous atmosphere 2 circulating in the analysis chamber 7, and This is achieved with a sensitivity that can be on the order of ppmv. In particular, catalytic sensors should preferably be avoided.

[0055] Furthermore, the device according to the invention most often incorporates other elements necessary for its operation: a battery, with a connection for its recharging, a control unit, a storage unit for information generated by the sensors, such as a SIM card or motherboard, a Geiger counter (alpha, beta and gamma) connected to the control unit.... These elements can be integrated into the spaces of the device not used for the circulation of the gaseous atmosphere 2 of interest, in particular at the level of the housing 15 located between the upper outer casing 4 and the concave upper wall 8 or at the level of the cavity 17 present between the lower base 3 and the lower wall 9. The connection of the gas detection sensors 11, not shown in the figures, is located in the illustrated example of the housing 15 located between the upper outer casing 4.

[0056] The data obtained by the gas detection sensors 11 can be processed on-site or transferred by any wireless or wired communication means, including Bluetooth, GSM (Global System for Mobile Communications), or Wi-Fi, to a central processing unit or to another device of the same type. The devices according to the invention can be interconnected. After data processing, using any technique that can be determined by artificial intelligence through machine learning methods, a result will be provided, notably in the form of: the name of the detected gas and its concentration in ppm by volume (ppmv). The quantity of gas detected can be represented as a function of time, in particular by providing a calculated value every minute. It will also be possible to trigger an alarm in the event of detection exceeding a tolerated limit value.

[0057] The connection to the central unit can be made in real time, in particular, in the case where the identification device according to the invention is fixed. In this case, a Geiger counter (alpha, beta and gamma) connected to the control unit will preferably be integrated (for example above the sensor connectors 11 in the housing 15 or in the cavity 17), one of the main components of which is preferably an SMB20 tube or J305 or LND712 tubes.

[0058] The devices according to the invention are small and lightweight, and therefore portable. In particular, their weight is generally less than 15 kg, preferably less than 5 kg, and generally in the range of 3 to 4 kg. Their largest dimension is generally at most 60 cm, and most often at most 25 cm. Any possible weight reduction can be achieved through the choice of materials, the use of hollow columns as a deflecting element, as illustrated in [Fig. 2] in particular... The walls of the analysis chamber 7, the upper outer casing 4, and the lower base 3 of the device can be made of a lightweight material such as preferably PTFE or Fiber-reinforced plastic (FRP) or PVDF (polyvinylidene fluoride)... Housing 15 or cavity 17, in particular when electronics are housed there, can be filled with a filling gel for electronic stabilization. Specifically, an electrical insulating gel that can withstand operating temperatures from -60°C to +200°C and provides an IPx8 rating for good protection against dust and water can be used. Such a gel can be single-component or two-component, for example, silicone. Most parts of the device according to the invention can be manufactured by 3D printing.

[0059] Figure 9 shows an identification device 1 according to the invention in operation, which is mounted on a support. To maximize wind resistance, it will be positioned on a support column 30, terminating in a support platform 31, and fixed to the latter by any suitable fastening means 32, such as rivets or retaining screws. To maximize the entry of the gaseous atmosphere of interest 2 into the analysis chamber 7 through the openings 5, regardless of the wind direction or the surrounding flow of gaseous atmosphere, the openings 5 ​​are arranged around the entire lower circumference 6 of the upper outer casing 4. These openings 5 ​​can act as inlet or outlet openings for the gaseous atmosphere of interest 2, depending on the direction of the surrounding flow of the gaseous atmosphere of interest 2.

[0060] Figure 10 represents another embodiment in which the identification device 1 according to the invention is mobile during operation. In the case shown, it is transported by a drone 40 to the area where the gaseous atmosphere of interest 2 to be monitored is present. In such a mobile version, the openings 5 ​​can be arranged, as in the examples illustrated so far, along the entire lower circumference 6 of the upper outer casing 4. It is also possible to provide a series of inlet openings 51 and a series of outlet openings 52 (not visible in the figure) positioned diametrically opposite each other with respect to the axis of symmetry A of the identification device 1. In Figure 10, the identification device 1 is mobile.

[10] , the identification device 1 is placed on the drone 40 by means of a support frame 41 which will be positioned so as not to obstruct the entry and exit of the gaseous atmosphere of interest 2 through the series of inlet openings 51 and the series of outlet openings 52. The transport of the identification device 1 by the drone 40 will be in a direction which increases the entry speed of the flow of the gaseous atmosphere of interest 2 through the series of inlet openings 5b, this flow being slowed down within the device by the series of arrangements selected previously described.

[0061] Implementation examples

[0062] To understand the principle and advantage of having multiple sensors and, more generally, the identification capabilities provided by the identification devices according to the invention, the advantages of different sensors are illustrated below in the case of CO identification in a gaseous atmosphere. This involves creating an evolving matrix used to select the sensors and define their relative positions in the analysis chamber (peripheral ring C1, ring closer to the center C2, and central position C3). A problem frequently encountered with electrochemical or semiconductor sensors for CO is that they are all sensitive to H2S and H2. These two gases are interfering gases that, in many cases, lead to false identification.

[0063] In this example, the Winsensor MQ136, MQ137, and MQ9 sensors, which are semiconductor-based detection sensors, are initially considered: in the first ring C1, various MQ136 sensors can be positioned, and in the ring C2, various MQ137 sensors and the MQ9 sensor, also a semiconductor-based detection sensor, in the central position due to their sensitivity to CO. The cross-sensitivities of these sensors with respect to different gases are given in Table 1 below: [Table 1] MQ137 MQ136 MQ9 NH3 x (5ppm) CO2 î (lOGOppm) CO 1 (50ppm) i (300ppm) (2Cppm) C3H7GH § (WOQppm) 302 § (50ppm) § (5ppm) NQ2 (5ppm) NO î (50ppm) C2H4 1 (lOOppm) QH4 J (lœppm) X: target gas i: interference

[0064] The sensitivities given in Table 1 (and Table 2 which follows) are those provided by the sensor suppliers, bearing in mind that, due to the concentration of the gases to be identified obtained at the sensors in the analysis chamber of an identification device according to the invention, the detection thresholds obtained are lowered according to the implementation of the invention. However, the MQ137 will have a reaction, as will the MQ9, leading to detection.

[0065] It is therefore possible at this stage to establish that there is potentially CO in the air. However, by observing Table 1, it appears that there is another gas that can also trigger the MQ137 and MQ9 sensors: H2. If the CO concentration is below the threshold of the MQ136 sensor, it is not detected by the latter, just like CO. Similarly, if there is H2S in the atmosphere, it can be detected by all three sensors. Therefore, the addition of the MQ8 sensor, whose sensitivity to different gases has been added in Table 2 below, allows for the differentiation and thus the identification of CO: [Tables 2] MQ137 MQ136 MQ9 MQ8 W3 (lOppm) H2 § (lOOppm) ? (lOOOppm)? (ZOOppm) X (IQGppm) H2S (50ppm) (SOppm) C2rU 1 (lŒppm) (ICOpprn) CH4 ï (lOOppm) C3H8O 1 (læppm) X: target gas; l: interference

[0066] With the addition of the MQ8 sensor in the second ring C2, if the sensor sends no signal, it means there is no H2 or H2S present, and it can be concluded that the detected gas is indeed CO. Such a device leads to its identification.

[0067] This very simple example illustrates the methodology for selecting sensors to cover all the target gases and choosing an optimal position within the analysis chamber. By increasing the number of sensors and using different sensors with varying sensitivities, the possible distinctions between gases are increased, making it possible to identify the other gases shown in Tables 1 and 2.

[0068] For quantification, a person in the field can determine it using the formula: Rs\RL = (Vc-VRL) / VRL Rs: surface resistance of the sensor RL: load resistance Vc: supply voltage VRL: output voltage which varies according to the concentration of the gas (typically from 0 to 5 Volts).

Claims

Demands

1. A device for identifying (1) a gas present in a gaseous atmosphere of interest (2), said device being delimited by a lower base (3) from which rises a domed upper outer casing (4), preferably dome-shaped, said device comprising an analysis chamber (7) for the gaseous atmosphere of interest (2), connected to the external environment comprising the gaseous atmosphere of interest (2) by a set of openings (5) comprising a series of inlet openings (5i) and a series of outlet openings (52), both located on the lower circumference (6) of the domed upper outer casing (4), ensuring the penetration and circulation of the gaseous atmosphere of interest (2) within the analysis chamber (7) between the series of inlet openings (5i) and the series of outlet openings (52), characterized in that: - the analysis chamber (7) is delimited by a upper wall (8) at least partly concave,said upper wall (8) concave and a lower wall (9) at least partly convex, said lower wall (9) convex, the series of inlet openings (5i) and the series of outlet openings (52) being located near a peripheral edge (8i and 9i) of the upper (8) and lower (9) walls and - the analysis chamber (7) is equipped with a set of gas detection sensors (11), at least some of which are different, at least some of the sensors (11) being separated by a deflector element (12) allowing the circulation of the gaseous atmosphere of interest (2) within the analysis chamber (7) to be directed according to a turbulent flow,at the level of one of the sensors (11); - a series of scoops (20) opening into the analysis chamber (7) are arranged for the entry of the gaseous atmosphere of interest (2) according to an inlet flow crossing with the inlet flow of the gaseous atmosphere of interest (2) coming from at least part of the series of inlet openings (5i) and thus creating a slowing of the flow of gaseous atmosphere of interest (2) which enters the analysis chamber (7) and which will circulate in the latter.

2. A gas identification device (1) according to claim 1, characterized in that the scoops (20) extend from an opening to the external environment oriented towards the periphery of the device towards an opening made on the periphery of the lower base (3) leading into the analysis chamber (7), according to an angled or hemispherical profile.

3. Device for identifying (1) a gas according to claim 1 or 2, characterized in that a slowing groove (26) for the circulating flow of the gaseous atmosphere of interest (2) is provided at the periphery of the lower convex wall (9) delimiting the analysis chamber (7).

4. A gas identification device (1) according to any one of claims 1 to 3, characterized in that the deflecting elements (12) are columns extending from the concave upper wall (8) to the convex lower wall (9) delimiting the analysis chamber (7) and whose external walls (25) have a concave profile positioned so as to direct the circulating flow of the gaseous atmosphere of interest (2) towards at least one of the sensors (11).

5. A gas identification device (1) according to any one of claims 1 to 4, characterized in that the concave upper wall (8) and the convex lower wall (9) form domes whose apexes are aligned on an axis of symmetry A passing through the apex of the convex upper outer envelope (4).

6. Gas identification device (1) according to claim 5, characterized in that the sensors (11) are positioned on at least two rings whose centers are located on the axis of symmetry A.

7. Gas identification device (1) according to any one of claims 1 to 6, characterized in that the sensors (11) are housed at the level of the concave upper wall (8) of the analysis chamber (7).

8. A gas identification device (1) according to any one of claims 1 to 7, characterized in that the concave upper wall (8) delimits, with the internal face of the domed upper outer casing (4), a housing (15) and the sensors (11), which comprise an active part (13) in contact with the gaseous atmosphere of interest (2) and an electronic part (14) for measuring and / or processing the information obtained through the active part (13), are housed at the level of the concave upper wall (8) of the analysis chamber (7), so that the information active part (13) is located in the analysis chamber (7) and the processing electronic part (14) is located in the housing (15).

9. A gas identification device (1) according to any one of claims 1 to 8, characterized in that either it is intended to be immobilized in operation on a support and preferably comprises a set of openings (5) which can act as inlet openings or outlet openings for the gaseous atmosphere of interest (2), depending on the orientation of the external flow of the gaseous atmosphere of interest (2), or it is intended to be mobile in operation and comprises a series of inlet openings (5i) and a series of outlet openings (52) positioned diametrically opposite.

10. A gas identification device (1) according to any one of claims 1 to 9, characterized in that it comprises different sensors (11), preferably from 4 to 64 different sensors (11), in particular belonging to at least two, preferably to at least three and preferably to at least four of the following categories: catalytic sensors, infrared sensors; electrochemical sensors with liquid or solid electrolyte, semiconductor-based sensors, colorimetric sensors, photoionization sensors, surface acoustic wave sensors, optical fiber sensors, LED optical sensors, tunable laser diode sensors, quartz microbalance sensors and field-effect transistor sensors.

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