WO2005025711A2

WO2005025711A2 - Method and device for airborne ventilation and decontamination by mixing an air delivery and suction flux bound by coanda effect

Info

Publication number: WO2005025711A2
Application number: PCT/FR2004/002309
Authority: WO
Inventors: Jean-Marie Billiotte; Frédéric Basset; Elena Vladimirovna Volodina; Alexandre Vladimirovich Nagolkin
Original assignee: Airinspace Limited
Priority date: 2003-09-10
Filing date: 2004-09-10
Publication date: 2005-03-24
Also published as: EP1670565A2; CA2538227A1; CN1863584A; US20070202798A1; FR2859522A1; RU2347149C2; JP2007505283A; WO2005025711A3; FR2859522B1; RU2006111437A

Abstract

The invention concerns a device (101) for airborne decontamination of a room (3) by mixing, an air delivery (19) and suction (21) flux bound by Coanda effect (C). A vertical piping (103) comprises a suction port lower end (104) and an air delivery upper end (105). An actuating means (106) circulates air (A) inside and outside. A suction nozzle (118) provides a vertical suction surface (Sa), for sucking air (A) along a suction duct (55) parallel and bonded to the floor (6) by Coanda effect (C). A blow nozzle (129) with ceiling surface effect (20) provides a front porous blowing surface (Ss). Said nozzle produces a primary air jet (19) bound to the ceiling (20) by Coanda effect (C). A decontaminating means (127) decontaminates the air (A). The active section (Sae) of the suction surface (Sa) is lower than the active surface (Sse) of the blowing surface (Ss). Thus the unwanted shunt air stream commonly associated with bound air flow ventilation systems is eliminated.

Description

Method and device for airborne ventilation and decontamination by mixing with blowing and suction flows attached by Coanda effect.

Technical field of the invention

The present invention relates to airborne ventilation and decontamination methods and devices for reducing the proportion of contaminating particles suspended in the air of a room, of the operating type: by mixing, with double Coanda effect, with primary blowing jet. attached to the ceiling, and suction flow attached to the floor.

State of the prior art

Traditionally, air conditioning processes are classified technically according to the way in which the air is distributed in the treated room. We can thus classify the air conditioning methods of a room in: ventilation by displacement of piston air by unidirectional flow, ventilation by displacement of air by stratification with thermal effect, ventilation by zone, ventilation by mixture, ventilation by localized jet. In the vocabulary of ventilation, the term “primary air jet” means air that has been conditioned beforehand (cooled, warmed, decontaminated, humidified, dehumidified, etc.) introduced into a room by a blowing mouth, such as a grate, a perforated panel, a diffusing ceiling ... Total air is called the mixture between the primary air introduced into the room and the air in the room gradually entrained by the primary air and mixed with it. In the piston air displacement strategy, also called unidirectional flow, or "laminar flow rooms", the air movement is provided by a primary unidirectional air jet occupying a whole section of the room. The entire surface of a wall of the room, such as generally the ceiling or sometimes a side wall, is used as the surface for blowing the primary air flow into the room. The air is blown in at a sufficient speed to pass through the room in parallel veins in the direction of the opposite wall (generally the ground) which is porous to serve as a suction surface. It is also common to carry out the air intake by suction wall grilles located near the floor, in the lower part of the walls. Laminar flows operate on the "piston" principle. The primary air flow pushes, like a syringe, the contaminated air which is extracted from the room. "Laminar flow rooms" are used to achieve very low concentrations of contaminants. The exhaust air is taken up in an air handling unit, linked to the building, decontaminated by filtration, mixed with fresh air. Then it is re-injected into the room by the blowing surface (usually the ceiling), equipped with high efficiency HEPA filters. The speed of the flow is substantially uniform over a whole section of the part, and reaches between 0.3 m / s and 0.5 m / s over the whole of the part to be protected. The blowing and suction surfaces are located:

- either on opposite walls (perforated ceiling and floor),

- either on perpendicular walls (ceiling and lower side return grilles),

- but never on the same wall. The air flow rate blown by a laminar flow represents 10 to 100 times that of a ventilation device by turbulent flow mixing or of a device by air displacement by thermal effect stratification. In addition, the entire ceiling must be fitted with a HEPA filter wall. Piston air displacement ventilation systems (laminar flow) have: an investment cost of an order of magnitude higher, and an energy cost about ten times greater than that of mixing ventilation devices (rooms turbulent flow) or air displacement devices by thermal effect stratification. In addition, their blown integral wall structure (ceiling or wall) makes it impossible to produce them in the form of a mobile system. Piston air displacement ventilation devices are used exclusively in decontamination and "ultra-cleanliness" applications and not for air conditioning purposes for which their cost is too high. In the strategy of ventilation by displacement of air by stratification with thermal effect, there is one or more air diffusers at low temperature (fresh air) on the ground or near the ground. This method works by difference in air density inside the room. The level of “new” fresh primary air introduced from below, but denser than the ambient air, gradually pushes the ambient air (warmer which floats on the fresh air) upwards. The stratification strategy is less expensive than the piston strategy. Its purpose is mainly to ensure thermal comfort for the occupants of the room. But she is very sensitive to disturbances thermal, and it is not very effective in ensuring aerological decontamination (in particular bacterial or fungal). In addition, the diffusers it uses are bulky and require significant infrastructure work at ground level. Their realization is impossible in the form of a mobile system. Ventilation devices by air displacement by thermal effect stratification are mainly used in air conditioning applications. In the zone ventilation strategy, the principle consists in treating certain zones or volumes of the room, while the rest of the room is left without particular attention. It is generally accepted that the efficiency of ventilation by zone is better than that by mixing in ventilated zones. On the other hand, the low overall dilution of the contaminants generally leads to an ineffective overall decontamination of the part.

In the mixing ventilation strategy, the movement of air is mainly ensured by the energy supplied by one (or more) jet (s) of primary air (s) introduced (s) into the room. The theoretical aim of the mixing strategy is to establish uniform conditions for the air inside the room. To do this, the primary air jet (s) which is (are) injected into the room mixes (s) with a large volume of ambient air. This phenomenon is called induction. Mixed ventilation is generally preferable to ensure the best thermal comfort for the occupants. The part of the room where the occupants are usually located is called occupancy area. It is normally defined as the space delimited by a surface 50 cm from the walls including windows, 20 cm from the other walls, and rising up to 180 cm from the ground. The mixing ventilation strategy aims to mix (as completely and as homogeneously as possible) the primary air with the air in the room, so that the impurities and contaminants in the room are not only attenuated by dilution but also , traditionally, evenly distributed. In the same way, we want the room temperature to be as homogeneous as possible to avoid the occupants' dis-comfort. However, the dimensions of the room, the reasonable size and the number of diffusers, generally require that the injection speed of the primary air jet (s) (fresh air) is generally greater than that acceptable for the comfort of the occupants when the jet reaches them. One can technically divide the methods of ventilation by mixture into two subtypes: ventilation by mixture with free primary jet, ventilation by mixture with primary jet attached by Coanda effect. According to free primary jet mixing ventilation methods, the primary air jet is injected into the room (usually vertically) through a diffuser usually located in the central part of a wall of the room (usually the ceiling). The primary air jet passes substantially perpendicularly through the envelope of the occupancy area. The air movements in the room are almost disordered. The air jet reaches the occupants almost directly before being significantly mixed with the air in the room. This often results in thermal dis-comfort for the occupants. According to the methods of ventilation by mixture with primary jet attached by Coanda effect, the primary air is injected into the room through a diffuser located in a lateral region of a wall of the room (generally in the vicinity of the ceiling ), and in a direction substantially parallel and tangent to this wall of the room (generally the ceiling). So that the primary jet is deployed outside the occupation zone, between the envelope of the occupation zone and the attachment wall of the jet. The primary air jet therefore travels a long way and is mixed with a large amount of ambient air before reaching the occupied zone. This arrangement is deemed to be more comfortable thermally for the occupants. It has been known since 1910, following experiments in aeronautics by the Romanian engineer Coanda, that when an air jet is placed close enough to a surface, such as a ceiling, the air jet tends to stick to the surface and continue its movement in contact with it. We call this phenomenon: Coanda effect or surface effect. This is due to the fact that an air jet tends to suck the ambient air in contact with it to mix it with it (diffusion). But in the vicinity of a surface, no ambient air can be sucked in. This results in a vacuum between the air flow and the surface, which tends to stick the air jet against the surface.

The invention relates to a method of ventilation of the mixture type, with a primary jet attached to the ceiling by the Coanda effect and with air intake by a suction mouth in the form of a suction flow attached to the floor, also by Coanda effect.

In this type of ventilation, when the dimensions of the room allow it, the air jet keeps its efficiency and reaches the wall opposite the blowing wall, before "diluting". The total air flow continues its downward movement, along the opposite wall, then returns in the direction of the suction mouth near the ground. This gives a kind of "envelopment" of the area of occupation by the air flow flowing between the blowing surface and the suction surface. The first experimental data on ventilation methods using a Coanda effect attached primary jet ventilation date back to 1939 when Baturin and Hanzhonkov demonstrated the phenomenon of “reverse flow” deflected by the ceiling and the opposite wall towards the area of occupation. . Baturin and Hanzhonkov concluded from their analyzes of the shapes of the air configurations obtained, that the shape of the air movements depended on the location of the supply air grille and was only slightly influenced by the configuration of the air grille ) of suction and the conditions of aspiration. Subsequent theoretical studies published by Nelson, Stewart, Bromleys and Gunes provide information on the distribution of temperatures and velocities in the case of attached primary jet mixing ventilation. Other theoretical studies conducted by Linke show that there is a maximum length of room that can be properly ventilated according to this principle. He shows in particular that for linear primary jets "attached" to the ceiling, having a Reynolds number between 1825 and 12000, the length of the part must not exceed 3 times its width, to allow an establishment of the "enveloping" flow.

When the length of the part is less than this limit (<about 3 times its width), we end up with an enveloping flow in "one zone". We can see the description of this phenomenon with regard to Figure 2 described below. The play is said to be "short".

Beyond this limit, the part is said to be "long". There is an aeraulic "partitioning" of the room. A first air movement in a loop, similar to that obtained in “short” rooms, consists of a total air jet which follows the ceiling, and descends vertically through the occupancy zone in the central part, before joining the suction surface horizontally near the ground. Other “closed” loops of vortex air develop between the first loop and the other end of the room and penetrate inside the zone of occupation. We can see the description of this phenomenon with reference to Figure 3 described below. These published scientific, theoretical and experimental studies show that: if no particular condition is imposed (see below the conditions recommended by the invention concerning the mean blowing speeds and mean suction speed), then, from a certain horizontal distance from the lateral action wall (including the blowing and suction surfaces) situated at about one height of the room, there appears a “parasitic inclined air flow of shunt”. This “parasitic inclined shunt air flow” tends to rise from the ground and cross the occupancy area in an inclined manner and upwards towards the blowing mouth. We can see the description of this phenomenon with reference to Figures 2 and 3 described below. The theoretical studies published on the air flow diagrams and the air speeds in a room implementing a ventilation method by mixing with attached primary jet, are only interested in the thermal applications of ventilation. They aim to ensure that the speeds and temperatures in the occupancy area are as pleasant as possible for the occupants. The effect generally sought by the prior art, in the implementation of the ventilation method by mixing with attached primary jet, is to lengthen the distance that the primary jet travels in the room before entering the occupancy area . Those skilled in the art [represented by the community of scientists who published the scientific publications mentioned above] have not so far been interested in the means to be implemented in order to optimally implement the methods of ventilation by mixing attached primary jet for airborne decontamination, and to reduce the proportion of contaminating particles suspended in a room ventilated in this manner. For those skilled in the art, who are interested, as we have seen above, essentially in the thermal effects of ventilation and in the thermal comfort of the occupants, the “parasitic inclined shunt air flow”, which tends to rise from the floor of a room ventilated by primary jet attached to the ceiling by Coanda effect, rather has “favorable” effects within the framework of its logic. In the logic of a person skilled in the art, this “inclined shunt air flow inclined” promotes mixing and therefore the efficiency of thermal ventilation. It will therefore be understood that those skilled in the art have not sought to reduce or eliminate this “parasitic shunt inclined air flow”, the effects of which are however essentially harmful in terms of airborne decontamination. In the usual mind of a person skilled in the art, the problems of airborne contamination are: either acute and resolved by the ventilation strategy by displacement of piston air by unidirectional flow, the main defect of which is cost, or unimportant and resolved by conventional ventilation by mixing with a free primary jet, or by ventilation by mixing with an attached primary jet, ignoring the “parasitic inclined shunt air flow” (the negative consequences of which are then neglected) , or very weak and, in this case, conventional air purifiers by recycling are implemented, leading to ineffective decontamination, so that the flows parasitic air charged with contaminating particles from the ground and amplified by the presence of the “parasitic shunt inclined air flow” are negligible.

The main aim sought by the invention is to allow: to benefit from the recognized intrinsic advantages of the ventilation method by attached primary jet and in particular - its cost of production and implementation lower than that of ventilation by air displacement with piston by unidirectional flow, - and its comfort for the occupants, while allowing to implement it for applications of advanced decontamination and "ultra-cleanliness". To do this, the invention aims to reduce (or eliminate) the effects of re-ascending movement of contaminated particles sedimented to the ground that are usually encountered in rooms ventilated by attached jet mixing.

The main objective of the invention is therefore to propose means of improvement to the ventilation process by primary jet attached to the ceiling by Coanda effect, aiming to reduce or eliminate the presence of the “parasitic inclined shunt air flow” which tends to rise from the ground. A secondary objective of the invention is to propose a new architecture of a mobile air decontamination device independent of the structure of the building, implementing this ventilation process by attached primary jet, without “parasitic inclined air flow of shunt ”. Mobile air decontamination devices independent of the building structure: either operate according to an air dilution principle similar to that of rooms with turbulent flow, or use, such as purifiers, ventilation of the jet type located. The distant technological background of the invention includes mobile devices for decontaminating air sucking in and discharging air horizontally at almost the same height. Among this class of devices, mention may be made of that described in US patent 6,425,932 Huehn, Deros and Bourque. It is clear that this type of device cannot use a primary jet attached to the ceiling and a suction air flow attached to the floor.

Among the distant technological background, there are also mobile air decontamination devices sucking the air in the upper part and blowing the air in the lower part.

US patent 5,240,478 Messina describes a purifier by HEPA filter with upper suction and lower blowing. US Patent 5,612,001 Matschke describes a purifier by UN lamps with upper suction and lower blowing.

US patent 5,656,242 Morrow and Me Lean describes a purifier by UN lamps and electrostatic filter with upper suction and lower blowing. It is easy to understand that these purifiers aspirating the air in the upper part and blowing the air in the lower part do not establish a primary air jet attached to the ceiling and that their blowing from the bottom only increases the establishment of contaminated parasitic air flow from the ground.

Among the distant prior art, there are also mobile air decontamination devices which draw air in the lower part and reject it in the upper part but at too great a distance from the ceiling to attach the primary air jet to the ceiling. by Coanda effect.

US Patent 4,900,344 Lansing describes a filter purifier equipped with a sucking nozzle of the suction type lower to the ground and upper blowing at low height, without attachment to the ceiling.

US Patent 5,997,619 Knuth and Carey describes a purifier by filter and UN lamps with lower side suction and upper blowing at low height, without attachment to the ceiling.

US Pat. No. 6,001,145 Harnmes describes a purifier by filters provided with a sucking nozzle of the type with suction lower to the ground and upper blowing at low height, without attachment of the primary flow to the ceiling.

US patent 5,453,049 Till an and Smith describes a triangular section purifier provided with a large lower suction through a HEPA filter and with vertical upper blowing through a small opening at low height without attachment of the primary flow to the ceiling .

US patent 4,210,429 Golstein describes a purifier by filter and UN lamps with lower lateral suction and upper lateral blowing at low height, without attachment of the primary flow to the ceiling.

These purifiers are of the localized jet type. None of these documents relates to a device using a primary air jet attached to the ceiling by effect

Coanda or not describe a means to reduce or eliminate "parasitic inclined shunt air flow" between the floor and the ceiling.

Finally, there are mobile air decontamination devices sucking the air in the lower part and rejecting it in the upper part near the ceiling, which could theoretically allow the j and of primary air to be attached to the ceiling by the Coanda effect. US Patent 5,290,330 Tepper, Suchomski and Mex, describes an independent air decontamination device of vertical parallelepiped shape with lower suction and upper blowing, both horizontal. The air decontamination is carried out by cylindrical filter cartridges arranged vertically inside the device. It is specified in this document that the suction and the blowing are separated vertically to ensure a movement of air from the ceiling to the floor. The document in no way describes the installation of an air jet attached to the ceiling by the Coanda effect or a suction stream attached to the floor by the Coanda effect. This document in no way describes the existence of an “inclined shunt parasitic air flow” which tends to rise inclined from the floor to the ceiling. This document does not describe any way to avoid this phenomenon. Finally, it will be noted that, on seeing the drawings, the suction and blowing grids are similar and of the same dimensions. So that the blowing speed and the suction speed are substantially equal. US Patent 5,225,167 Wetzel describes an independent air decontamination device of substantially parallelepiped shape, to be mounted on the wall of a room and decontaminating the air using HEPA filters and UN lamps. The air intake takes place in the vicinity but at a distance from the ground through a grid. The air is blown near the ceiling through a quarter cylinder HEPA filter. The document in no way describes the installation of an air jet attached to the ceiling by the Coanda effect or suction flow attached to the floor by the Coanda effect. The quarter-cylinder shape of the HEPA filter air outlet tends to tilt the primary air jet towards the ground and is unfavorable for its attachment to the ceiling by the Coanda effect. The suction mouth placed voluntarily away from the ground does not aim either to facilitate the establishment of a suction flow attached to the ground by Coanda effect. This document in no way describes the existence of an “inclined air flow parasitic of shunt” which tends to rise from the floor to the ceiling. This document does not describe any way to avoid this phenomenon. Finally, it will be seen that, on seeing the drawings, the suction and blowing grids are substantially of the same dimensions. So that the blowing and suction speeds are substantially equal.

US Patent 5,616,172 Tuckerman, Russel, Knuth and Carey constitutes the closest prior art to the invention. It describes an independent mobile air decontamination device of substantially elongated parallelepiped shape, arranged vertically along a wall of the room to be treated. Air decontamination is carried out by UN lamps and HEPA filters. The air intake is carried out by the floor by means of a suction nozzle of the suction type on the ground, formed between the base of the device and the ground. The blowing mouth is placed in the upper part of the device and blows vertically in front of the ceiling. The shape of the device is described as voluntarily elongated, in order to increase the distance between the suction grille and the blowing grille in order to avoid “short circuits” between the two. It is also described the installation of fins on the blowing grid to tilt the primary jet blown in the upper part towards the ceiling so that the primary air jet is deployed along the ceiling. We can therefore consider, although it is not clearly expressed, that the primary air jet is glued to the ceiling by Coanda effect. On the other hand, this document considers that the only way to avoid the “shunt effect” between the suction and blowing grilles is to separate them as much as possible from each other. This provision is certainly necessary. But as the scientific documents mentioned above show and as the demonstrations made later show, this is not enough. First of all, this document does not take into account the existence of an "inclined air flow parasitic of shunt" which tends to rise from the ground (in the middle of the room), and cross the occupied zone inclined and upwards towards the blowing mouth. It is only concerned with the direct "shunt" between suction and blowing, which is another problem. This document therefore does not recommend any means relating to: the ratio between suction speed and blowing speed, or the ratio between effective suction surface and effective blowing surface, in order to reduce and / or eliminate the "air flow inclined shunt parasite which tends to rise from the middle of the ground towards the ceiling, despite the spacing of the grids. The relative dimensions of the effective suction and blowing surfaces are not specified. However, without these geometrical precautions and particular flow velocities, the scientific studies mentioned above and the demonstrations made below, show that the spacing of the blowing and suction grids is not enough to eliminate this phenomenon of “flow of 'inclined shunt stray air'. Those skilled in the art consider, as we saw above, that the suction outlets are of little importance in the movement of air and that they only influence their close neighborhoods. No, we will show further on that the man of the art is wrong. The prior art is therefore interested very little in the influence of the shape and location of the suction outlets. It seems that no scientific study has been conducted to date on the subject. It therefore appears that, although the method of ventilation by mixture of primary blowing jet attached to the ceiling and suction flow attached to the floor by Coanda double effect is known and widely used for its thermal qualities in the field of air conditioning, its use is almost nonexistent in the field of airborne decontamination because the effect of "inclined shunt air flow parasitic" which it generates has not been resolved by the prior art and this degrades its performance. decontamination.

Summary of the Invention The invention firstly relates to a method of ventilating a room by mixing a primary blowing jet attached to the ceiling and a suction flow attached to the floor, by Coanda double effect. The invention relates specifically to ventilation methods of the type according to which a primary jet of pre-treated air is blown into the room (heated, cooled, decontaminated, humidified, dehumidified, etc.), through a blowing surface , located opposite a so-called treatment side wall, in the vicinity of the ceiling, and in a direction of blowing incidence [average over the blowing surface of the mean directions of the portions of the primary jet] oriented towards the ceiling (or parallel to this), so as to attach by Coanda effect said primary blowing jet on the surface of the ceiling. Concomitantly, a suction of polluted air is sucked in, with a flow equivalent to the primary jet, through a substantially vertical suction surface, located opposite the same lateral treatment wall, in the vicinity of the floor of the room. In this way, air is sucked at ground level according to a substantially horizontal suction stream, parallel and attached to the ground surface by the Coanda effect. The empirical experiments carried out to date on ventilation systems by mixing with a primary blowing jet attached to the ceiling and suction flow attached to the floor and the computer simulations which have been carried out by the inventors show that in a closed room, this type ventilation causes the appearance of an "inclined air flow parasitic shunt" which tends to rise from the ground and cross the occupied area in an inclined manner and upwards towards the blowing mouth. This phenomenon is widely described by the prior art and the scientific publications described above, without any solution having been found to eliminate it. In its simplest form, the ventilation method according to the invention consists in that, in addition, the average blowing speed (Vs) is imposed [average of the speeds of the portions of the primary air jet on the surface of blowing] to be there lower than the average suction speed (Va) [average speed of the portions of the air flow sucked on the suction surface] [Ns <Va]. The inventors have found, computer modeled and demonstrated by aeraulic measurements on independent airborne decontamination devices of a room implementing this process, that this phenomenon of “parasitic shunt air flow” is greatly reduced or even eliminated, when the means of the invention are implemented.

Brief description of the drawings and figures Figure 1 shows schematically, in side view, the phenomenon of aerosol sedimentation and resuspension in a non-ventilated room. Figure 2 shows schematically, in side view, the distribution of air flows in a ventilated "short" room (without special precautions) by mixing with primary blowing jet attached to the ceiling and suction flow attached to the floor (reproduced from 'after Muller).

Figure 3 shows schematically, in side view, the distribution of air flows in a ventilated "long" room (without special precautions) by mixture of primary blowing jet attached to the ceiling and suction flow attached to the floor (reproduced from 'after Muller). FIG. 4a schematically represents, in side view, the distribution of the air flows obtained by computer simulation of a ventilation device (of the type of that of FIG. 2) operating in a room ventilated by mixing with a primary blowing jet attached to the ceiling and suction flow attached to the floor, according to the teachings of the invention. FIG. 4b schematically represents, in perspective, the distribution of the air flows obtained by computer simulation of a ventilation device (of the type that of FIG. 4a) operating in a ventilated room according to the teachings of the invention and showing a detailed view of the effective lateral suction and blowing surfaces of the ventilation device of FIG. 4a making it possible to appreciate their relative sizes and the average speeds of suction and blowing.

FIG. 5a schematically represents a portion of an animated air stream allowing the analytical demonstration of the advantages implemented by the invention and eliminating the “parasitic inclined shunt air flow”. FIG. 5b schematically represents the conditions for digital simulation of the air flow diagrams obtained for a prototype of the independent airborne decontamination device of the invention. FIG. 5c represents a table of values of the results from the calculation in digital simulation as illustrated in FIG. 5b.

FIG. 5d represents a graphic illustration of the results obtained as presented in FIG. 5c. FIG. 6 schematically represents, in side view, the air flows obtained by computer simulation of an independent decontamination device operating in a room according to the teachings of the invention.

Figures 6a and 6b show in section and in perspective, an enlarged view of the independent decontamination device of the invention. Figure 6c shows a top view of the operation of the device of Figure 6 and a view of the air streams it generates horizontally.

FIG. 6d schematically shows an enlarged side view of the sucking nozzle of the independent decontamination device of FIG. 6 and its action on the contaminating particles in suspension and those located at ground level. FIG. 6e schematically shows, in perspective, a vision of the device of the invention and of its suction stream.

FIG. 7 schematically represents, in side view, the operating principle and the action on the aerosols of a decontamination device operating in a room according to the teachings of the invention. Figures 8a and 8b show in section and in perspective a view of the blowing nozzle of the independent decontamination device of Figure 6 and its position relative to the ceiling.

Figures 8c to 8h show, in side view, the influence of the adjustment of the blowing incidence angle of the device of the invention. Figures 9a and 9b show, in side view, the importance of a recommended variant of the invention relating to the adjustment of the suction and blowing speeds.

FIG. 10a represents in perspective, a detail of a first preferred mode by the invention of embodiment of the blowing nozzle. FIG. 10b represents, in perspective, a detail of a second mode preferred by the invention for producing the blowing nozzle.

Figure 11 shows, in perspective, a detail of a preferred embodiment by the invention of the sucking nozzle.

FIG. 12 represents, in perspective, a preferred mode by the invention of embodiment of the vertical channeling means with reduced thickness. Figures 13a and 13b show, in perspective, a preferred embodiment by the invention of the vertical channeling means with adjustable height. Figures 14a and 14b show, in perspective, a preferred embodiment by the invention of the device of Figure 6 with auxiliary suction nozzle. Figures 15a and 15b show, in perspective, a preferred embodiment by the invention of the device of Figure 6 with expandable blowing nozzle.

Detailed description of the invention

Figure 1 depicts a classic non-ventilated room (3). The ambient air (A) in the room (3) is filled with a multitude of contaminating particles (4) comparable to aerosols which, under the action of their weight and gravity, are by sedimentation effect (5 ) driven at ground level (6). So that the contaminating particles (4) will, with a low vertical rate of sedimentation (5), gradually come to accumulate in a thin lower layer of highly contaminated air (Ce) in contact with the soil (6). If we take stock of the contaminating particles (4) included in room (3), a small portion of the contaminating particles (4), although extremely dangerous for the occupants (1), is present in suspension in the form of contaminating aerosols in suspension (4a) contained inside the volume of the part (3). Another very dense portion of the contaminating particles (4) is, under the effect of gravitation, thermal movements of convection coming from the ground (6) and Brownian movements, accumulated in the form of contaminated aerosols accumulated (4b) under forms a kind of cloud, inside the thin layer of highly contaminated lower air (Ce). Inside this thin, highly contaminated lower air layer (Ce), the concentration of accumulated contaminating aerosols (4b) is asymptotic as it approaches the soil (6). However, most of the contaminating particles (4) present in the part (3) are the adhered particles (4c) which, following their long descent under the effect of gravitation, have adhered to the ground (6) by forces of Van der Waals, originating from interactions between the molecules they contain and the soil (6). The occupancy area (2) is the part of the room (3) where the occupants (1) are usually located. It is normally defined as the space delimited by a surface 50 cm distant from the walls (50) comprising windows (51), and 20 cm distant from the other walls (140). It rises up to 180 cm from the ground (6). The occupants (1), during their movements in the room (3), will generate disturbances and turbulence (7) at ground level (6) and resuspend, by upward disturbance currents (8) , some of the aerosols accumulated contaminants (4b) and adhered particles (4c) located at ground level (6) in the lower part of the occupation zone (2). A phenomenon similar to that leading in meteorology to the formation of powerful cumulonimbus clouds develops on a reduced scale in the room (3). The light rays (53) of the lighting (54) arranged on the ceiling (20) and coming from the window (51) cause an inhomogeneous heating of the ground (6). This results on the ground (6) in powerful upward convection movements (57) which also cause strong resuspension of some of the accumulated contaminating aerosols (4b) and of the adhered particles (4c) located on the ground (6). These contaminating aerosols (4b, 4c) go up in the upper parts of the occupied zone (2) and reach the mouth and the respiratory zones (9) of the occupants (1). So that these contaminating aerosols (4b, 4c) resuspended by these phenomena, increase the content of contaminating aerosols in suspension (4a). They increase the risk of being aspirated by occupants (1) of the room (3) and by the same, the probability of biocontamination of these occupants (1) by airborne biological agents likely to develop different types of diseases (Aspergillosis, pneumonia ...).

The prior art widely uses the ventilation method by mixing with a primary blowing jet (19) attached to the ceiling (20) and suction flow (21) also attached to the floor (6), both by the Coanda effect (C). . Figures 2 and 3 show the implementation of this ventilation method according to the prior art using a fixed ventilation device (65) linked to the building containing the room (3). According to the prior art, a primary air jet (19), previously treated by the fixed ventilation system (65) (heated, cooled, decontaminated, humidified, dehumidified, etc.) is blown into the room (3). through a wall blowing mouth (10) formed in the first vertical said treatment wall (52) and opening into the room (3) by a blowing surface (Ss), located opposite the vertical said treatment wall ( 52), in the vicinity of the ceiling (20). The primary air (19) is directed in a direction of blowing incidence (Is) [average on the blowing surface (Ss) of the mean directions of the portions of the primary blowing jet (19)] oriented in the direction of the ceiling ( 20) (or, usually as shown in Figures 2 and 3, parallel to it) ^ so as to attach by Coanda effect (C) said primary blowing jet (19) on the surface of the ceiling (20). At the same time, a stale suction air flow (21) is sucked in, with a flow equivalent to the primary jet (19), through a suction mouth (11) formed in the vertical wall called treatment (52) and emerging. in the room (3) through a substantially vertical suction surface (Sa), located opposite the same side treatment wall (52), in the vicinity of the floor (6) of the room (3). Thus, at ground level (6), air is sucked (A) through a flared, substantially horizontal suction stream (55), parallel and attached to the ground surface (6) by Coanda effect (C ). The primary air jet (19) is deployed outside of the occupation zone (2), between the envelope (63) of the occupation zone (2) and the attachment wall of the jet ( 19) constituted by the ceiling (20). The primary air jet (19) therefore travels a long way and is mixed with a large amount of ambient air (A) before reaching the occupied zone (2). It is this mixture which causes dilution between the stale air and the fresh air, which leads to air conditioning and decontamination, the object of ventilation. This arrangement is said to be more comfortable thermally for the occupants (1). The fixed ventilation system (65) includes an outdoor air handling unit (73), generally located on the roof of the building. The one shown is a combined supply and return unit used in the usual way in the field of air treatment in recycling. It includes one or more fans of the centrifugal or other type (67) and (71) allowing the setting in motion of the air (A) and the establishment of the aeraulic diagram, a heating coil (70), a filter with air (69) and a mixing box (68) between recycled air and outside fresh air. The air handling unit (73) is connected to a diffusion sheath (72) leading to the wall blowing mouth (10), and thus delivering the previously treated primary jet (19) through the blowing surface (Ss ). The suction duct (66) connects the wall suction mouth (11) to the inlet of the air handling unit (73) to evacuate the flow of contaminated and or contaminated suction air (21) from the piece (3). FIG. 2 describes the aeraulic diagram (reproduced from Muller) obtained, according to the prior art, inside a so-called “short” part (3 a), the length (L) of which is less than about three times its width (1). We end up with an enveloping flow with "a loop" (Bl). It can be seen that according to the prior art (without particular precautions), there appears a “parasitic inclined shunt air flow” (Fs) which rises from the ground (6), and crosses the occupation zone (2) inclined and upwards towards the blowing surface (Ss). It is understood that the “parasitic inclined shunt air flow” (Fs) which rises from the ground (6) causes a resuspension of the contaminating aerosols (4b, 4c) which accumulate and adhere to the ground level (6) with consequences similar to those described with regard to FIG. 1. These contaminants (4b, 4c), during their upward journey, will increase the content of aerosol contaminants in suspension (4a) in the ambient air (A) of the room (3). According to the prior art, the risk of biocontaniination by air is therefore increased in "Short rooms" (3a) ventilated by attached jet mixing (19), due to the existence of this "parasitic inclined shunt air flow" (Fs).

FIG. 3 describes the aeraulic diagram (adapted from Muller) obtained according to the prior art inside a so-called “long” part (3b) whose length (L) is greater than approximately 3 times its width ( 1). It can be seen that there is an aeraulic partitioning of the "long" part (3b) into several air zones (Zl, Z2, Z3, ...). A first "closed" air loop (B1), similar to that obtained in the "short" rooms and shown in FIG. 2, is established in the first zone (Z1). It consists of a primary blowing air jet (19) which follows the ceiling (20), and descends vertically along an inclined branch (77) through the occupancy zone (2) substantially in the central part of the “long” part (3b), before joining horizontally in the vicinity of the ground (6) the suction surface (Sa). Besides the fact that the effect of “parasitic inclined shunt air flow” (Fs) rising from the ground (6) is also present, other “closed” air loops (B2, B3,. ..) in vortex (12a, 12b) develop between the first loop (Bl) and the wall (50) located at the other end of the room (3) in successive areas (Z2, Z3). These “closed” air loops (B2, B3, ...) penetrate inside the occupation zone (2). This second phenomenon is due to the fact that due to the great length (L) of the part (3), the primary blowing jet (19) peels off early in a peeling zone (14) from the ceiling (20). The primary blowing jet (19) is then no longer attached to the ceiling (20) but qualified as free. This also leads to a succession of speed induction effects (30a, 30b, ...) and leads to the formation of secondary vortices (12a, 12b) leading to the creation of "closed" air loops (B2, B3, ...) in the secondary zones (Z2, Z3, ...). Contaminant aerosols in suspension (4a) located in the secondary vortex zones (12a,

12b) “closed” air loops (B2, B3, ...) are trapped and distant from the blowing (Ss) and suction (Sa) surfaces of the fixed ventilation (65) and decontamination system. The contaminating aerosols in suspension (4a) can however be transported between the different "closed" air loops (Bl, B2, B3, ...) via exchange zones (17a, 17b) present at the stationary state in equilibrium state of the part (3). The part (3) is therefore not treated in its entire volume in an optimal manner since the decontamination treatment is slowed down in the evacuation of the aerosol contaminants in suspension (4a). In addition, it is understood that the multiplication of upward movements resulting from air loops (Bl, B2, B3, ....) increases the resuspension of contaminating aerosols (4b, 4c) accumulated and adhered to the ground level (6) and therefore the risk of occupant biocontamination (1) in the occupancy area (2). To reduce the risk of biological contamination by air, it is preferable to implement the ventilation method by mixing with jets attached in "short rooms" (3a). FIGS. 4 a and 4b schematically describe the characteristic means implemented by the method of the invention in a "short" room (3a) to considerably reduce or even eliminate the effect of "inclined air flow parasitic of shunt" ( Fs) described in FIGS. 2 and 3. The method of the invention implements the general principles described in FIG. 2 of a method of ventilation by mixing with a primary blowing jet (19) attached to the ceiling (20) and suction flow. (21) attached to the ground (6) by Coanda effect (C). However, the method of the invention is remarkable in that the average blowing speed (Vs) [the average of the speeds of the portions of the primary air jet on the blowing surface (Ss]] is required to be lower than the average suction speed (Na) [average speed of the portions of the air flow sucked on the suction surface (Sa)] [Ns <Na].

A first analytical demonstration of the advantages of this means, admittedly simple, implemented by the invention, but leading to the effect [with considerable advantages for airborne decontamination (not achieved by the prior art)] of eliminating the " inclined shunt parasitic air flow ”(Fs) can be made using the Bernouilli theorem opposite Figure 5a.

Figure 5a shows a detail of a portion of an animated air stream (vf) in constant motion. It is considered, for the sake of simplification, that air (A) is a perfect incompressible fluid subjected only to the forces of gravity. And we extract from this animated air stream (vf) a minimal portion of moving air (da).

The infinitesimal portion of air (da) belonging to the vein (vf) has: a variable section (s), a variable speed (N), a variable length (dx), a mass (dm), and a local pressure ( P).

Air has a density (p) considered constant. The acceleration of gravity is constant and equal to (g).

As a first approximation, the total mechanical energy Et of infinitesimal portion of air (da) is the sum: of its kinetic energy Ec ≈ Vi dm * V2, of its potential energy of pressure Epr = P * s * dx = P * dm / p, and of its potential energy of gravity Epe = g * z * dm.

The total mechanical energy And of infinitesimal portion of air (da) is in first approximation conserved along any animated fluid vein (vf). So that per unit of mass of air moving along any animated air stream (vf), the expression: V / 2 + P / p + g * z = constant. This is an expression of Bernouilli's theorem, valid in the absence of energy expenditure (which we will take into consideration later) along any animated air stream (vf) in a room (3). Referring to Figure 2, we will demonstrate by "the absurd" leading to the need for the means of the invention, [namely that the average blowing speed (Vs) is less than the average speed of aspiration (Va)] so that the effect of “parasitic inclined shunt air flow” (Fs) is absent from the part (3) described in FIG. 2. In fact, if there was no effect of “Parasitic shunt inclined air flow” (Fs), all the veins coming from the blowing surface (Ss) would join the suction surface (Sa). If we consider the multitude of animated air streams (vf) which join: the blowing surface (Ss) where the average air blowing speed is (Vs), the blowing pressure is (Ps), and where the height is (h) at the suction surface (Sa) where the average air suction speed is (Va), the suction pressure is (Pa), and the height (h) is nothing,

They would all be continuous and not exploded (in several sub-jets) along their length. One could legitimately apply to them the Bernouilli theorem in averaged form on the blowing (Ss) and suction (Sa) surfaces and lead to:

Vs ^2/2 + Ps / p + g * h = Va ^2/2 + Pa / p (average Bernouilli). It seems important to point out that it is the very existence of this non “bursting” of the veins (vf) which makes it possible to implement Bernouilli's theorem in average form. Because in this case, we can consider that any vein (vf) coming from the blowing surface (S s) leads to the suction surface (Sa) and vice versa. This would not be the case if there was a parasitic inclined shunt air flow ”(Fs).

However, it is obvious that the fact that the air is blown into the room (3) by the blowing surface (Ss) and sucked by the suction surface (Sa) requires that Ps> Pa. Let us now suppose that Vs> Go. In this case, it appears that the left member of the equality (Bernouilli average) considered above is strictly greater than the right member of this same equality. We would conclude that the equality imposed by Bernouilli's Theorem would not be verified. We can express this by:

[Absence of the effect of “parasitic inclined shunt air flow” (Fs) of the part (3)], And [Vs> Va]

=> Non respect of the average Bernouilli Theorem on the blowing surfaces

(Ss) and suction (Sa).

The logical mathematical opposite of the above expression requires:

Respect for Bernouilli's Theorem => [Existence of the effect of “shunt parasitic inclined air flow” (Fs) in room (3)], or [Vs <Va].

We have therefore just shown that in a room (3), the means of the invention, namely [Vs <Va], is a necessary condition for the absence of the effect of “inclined air flow parasitic of shunt »(Fs) in room (3). In fact, the condition imposed is more severe. In the permanent flow of the animated air stream (vf), part of the total mechanical energy is dissipated under the effect of external forces such as: friction on the walls of the room (3) and especially due to the induction effect between the primary air jet (19) and the air (A) of the room (3). Between the two ends of the animated air stream (vf) there is dissipation of a friction load loss ΔH. Bernouilli's theorem applied to the animated air stream (vf) and corrected for the influence of the pressure drop then becomes:

Vs ^2/2 + Ps / p + g * h = Va ^2/2 + Pa / p + .DELTA.h (Bernouilli with losses).

It is therefore necessary, in the absence of “inclined shunt stray air flow” (Fs) in the room

(3), that: (Va ² -Vs ² ) / 2 = (Ps - Pa) / p + g * h - ΔH Va ² = Vs ² + 2 * [(Ps - Pa) / p + g * h - .DELTA.h]

Let Va <(Vs ² + 2 * [(Ps - Pa) / p + g * h]) ^1/2

We therefore arrive at the following condition:

Vs <Va <(Vs ² + 2 * [(Ps - Pa) / p + g * h])

If the average suction speed (Va) is lower than the blowing speed (Vs), a “shunt parasitic inclined air flow” (Fs) is established and the Bernouilli theorem is no longer applicable under its medium form. If the average suction speed (Va) is greater than the blowing speed (Vs), the phenomenon of “parasitic inclined shunt air flow” (Fs) weakens and then gradually disappears. And, the more the average suction speed (Va) exceeds the blowing speed (Vs), the more the induction phenomena leading to the mixing of air with the induced primary jet.

(19) develop and consume pressure drop ΔH. Beyond this second limit Va> (Vs ² + 2 * [(Ps - Pa) / p + g * h]), we can estimate that the flow by Coanda effect (C) cannot be established and that we are witnessing a mainly turbulent movement.

This is of course a demonstration with very simplifying hypotheses but which allows us to understand the importance of adjusting the average suction speed

(Va) compared to that of blowing (Vs) and therefore the importance of this yet simple means [Vs <Va] recommended by the invention.

FIG. 4a very schematically represents the results obtained by the inventors, and resulting from the experimentation and the joint use of computer aeraulic simulation tools. It describes the air flow diagram of the air movements (A) in a room (3) similar to that described in FIG. 2, but in which the means of the invention relating to the ratios between average blowing speed (Vs) and average speed d 'aspiration (Va) have been implemented. These results from aeraulic simulation calculations and measurements carried out on prototype devices implementing these means, have made it possible to demonstrate that when the means recommended by the invention are implemented in part (3), that is to say that when it is imposed that the average blowing speed (Vs) [average of the speeds of the portions of the primary air jet (19) on the blowing surface (Ss)] is lower than the average speed of suction (Va) [average of the speeds of the portions of the aspirated air flow (21) on the suction surface (Sa)] [Vs <

Go] then the effect of "shunt parasitic inclined air flow" (Fs) of the prior art as described in relation to FIG. 2 is greatly attenuated (see it is avoided). This effect of "flow of parasitic inclined shunt air (Fs) is mainly due to the induction forces generated by the primary blowing jet (19). By favoring the induction forces generated by the suction flow (21), which are directed towards the ground (6), to the detriment of the induction forces generated by the primary blowing jet (19), the balance of interactions of these two types of moments makes it possible to conserve the flow of aspirated air (21) glued to the ground (6) by the Coanda effect (C). The dilution of the part (3) is closely linked to the air flow used, at the outlet of the blowing surface (Ss) and at the inlet of the suction surface (Sa). It is not a question here of improving the yield of the dilution (which approaches 100%), but rather of improving the decontamination in terms of quality. The “parasitic inclined shunt air flow” (Fs) being eliminated, the aeraulic ascent of contaminating aerosols (4) in the occupied zone (2) does not take place, and therefore, the probability occupants (1) biocontamination is reduced, insofar as these biocontaminants (4) remain mainly confined in the thin lower layer highly contaminated air (Ce) and are not in contact with the occupants' respiratory zones (9) (1).

FIG. 4b represents in perspective the arrangements to be implemented in a room (3) in terms of effective blowing surface (Sse) and effective suction surface (Sae) for implementing in a fixed ventilation system (65) the means of the invention. The wall outlet (10) and suction (11) outlets used in fixed ventilation systems (65) are generally equipped with outlet (60) and suction (61) grids which materialize the outlet surfaces (Ss ) and suction (Sa) but partially block the air flows. These grids (60,61) usually consist of a metal plate provided with a multitude of holes, or a metal frame (81) provided with a plurality of directional strips (83) and / or any other means partially obstructing the corresponding mouth (10,11), while being porous to air. We call effective surface (Sse, Sae) of a grid (60, 61), the surface of the empty virtual grid which would have the same overall aeraulic behavior of the couple [fluid speed (Vs, Va) crossing it / pressure ( Ps, Pa)]. Grids sold commercially are generally accompanied by specifications indicating their effective area. Otherwise it is possible to measure it empirically. In Figure 4b, there is shown the blowing grid (Ss) and a representation of its effective blowing section (Sse). There is also shown the suction grid (Sa) and a representation of its effective suction section (Sae). We understand that it was imposed in the room (3) that the effective blowing surface (Sa) is greater than the effective suction surface (Sa). This allows to achieve that [Vs <Va]. It can be seen that the primary blowing jet (19) coming from the blowing surface (Ss) is perfectly bonded to the ceiling (20) by the Coanda effect (C). The suction line on the floor

(55) of the aspirated air flow (21) is also perfectly bonded to the floor (6) by the Coanda effect (C). No “inclined shunt inclined air flow” (Fs) is present in the room (3). FIG. 5b represents the conditions for digital simulation of the air flow diagrams obtained for a prototype of the independent PLASMAIR ™ airborne decontamination device (101) operating according to the means of the invention in a room (3), this as a function of different effective ratios of supply air (RS). The blowing ratio (RS) is called: the ratio between the effective blowing surface (Sse) and the effective suction surface (Sae). The numerical simulations were carried out under the following conditions:

Workpiece length (L) = 4 m Width of the room (1) = 3m Height of the room (h) = 2.5 m Air flow: Qv = 500 m3 / hour.

The axes (X), (Y), (Z) and the list of the different points (P = PI, P2, ..., P8) of simulations are arranged at 2 cm from the ground (6) as shown in Figure 5b. The quantity calculated numerically (Yvelocity) represents the local digital average of the vertical component of the air speed, taken at each of the points (P = PI, P2, .... P8) distant from (d = dl, d2 , ...., d8) of the front face (165) of the device (101). It is about the average of the vertical component of the speed of the air, in a cubic volume constituted by the meeting of 9 elementary cubic meshes of simulation arranged contiguous and centered on each point P of simulation. The device (101) is placed against and in the central part of the so-called treatment wall (52). We use the energy model called K-E to establish the air movements from the Navier-Stokes equations. Although the regime concerned is turbulent, the state of spatial dimension studied of the movement is much higher than the Kolmogorov scales (description of molecular type) of the fluid particles so that the Navier-Stokes equations apply. In this digital simulation, a smoothing of the movements of the air molecules is implemented. The reliability of the use of this numerical method currently knows no known counterexample, for fluid speeds lower than Mach 13. This is of course the case in this study. The type of mesh chosen is hexagonal due to the simple architecture of the part (3). The number of mesh is 500,000 to cover the piece (3). This number is much higher than the theoretical number of 3000, usually considered sufficient for the validation of this type of study. By the definition of Yvelocity (P), we understand that this parameter, which can be positive or negative, is very significant of the existence of upward or downward movements of air (A) in the room (3).

Thus, if Yvelocity (P) is positive, this means that the air speed in the vicinity of point (P), located two cm above the ground, has an average component tilted upwards. In this case, we deduce that there are mainly updrafts on the ground, in the vicinity of point (P). We can conclude that there is a good chance that a “Parasitic inclined shunt air flow” (Fs) starts from this point. On the contrary, if Yvelocity (P) is negative, it means that the air speed, in the vicinity of point (P), has an average component inclined downwards. We can conclude that there is little chance that a “parasitic inclined shunt air flow” (Fs) starts from this point. The table in FIG. 5c gives the results obtained by this simulation. In this table, the first column designates the simulation point (P = P1, P2, ..., P8). The second column (grayed out) relates to the case where the device (101) has been adjusted so that the blowing ratio (RS = 0.57) [ratio between the effective blowing area (Sse) and the effective suction area (Sae)] is less than 1. That is to say that one is outside the conditions imposed by the invention. We are in the probable conditions for the formation of the “parasitic shunt flux” (Fs) as predicted by the theoretical analysis developed above. The third column (grayed out) corresponds to the case where the device (101) has been adjusted so that the blowing ratio (RS) is equal to 1. This is the limiting case of presence of the “parasitic shunt flux” (Fs ) as predicted by the theoretical analysis developed above.

The second and third columns are grayed out, to better delimit the conditions outside the application of the recommendations of the invention. Finally, the fourth column (not grayed out) relates to the case where the device has been adjusted

(101) so that the blowing ratio (RS = 1.43) is greater than 1. That is to say that one is within the framework of the conditions imposed by the invention. Under the conditions of column 2 where (Va = 0.57 Vs), that is to say (Va <Vs), we see that the local numerical average of the vertical component of the air speed is positive at points (P4) to (P7) distant from the device (101). This means that there is upward movement of air in the portion of the part (3) furthest from the device (101). It can reasonably be concluded that a “parasitic shunt flow” (Fs) rises from the extreme part of the part in the direction of the blowing mouth (110). Under these conditions, the use of the device (101) as an airborne decontamination system is very ineffective due to the presence of updrafts at ground level (6).

Under the conditions of column 3 where (Va = Vs), we also note that the local numerical average of the vertical component of the air speed is positive at points (P5) to (P7), distant from the device (101 ). This means, as previously, that there is upward movement of air in the portion of the part (3) furthest from the device (101). It can be concluded that a “parasitic shunt flow” (Fs) rises from the extreme part of the part (3) in the direction of the blowing mouth (110). Under these conditions, the use of the device (101) as an airborne decontamination system is also very ineffective due to the presence of updrafts at ground level (6). On the other hand, under the conditions of column 4 where (Va = 1.43 Vs), that is to say (Va> Vs), we note on the contrary that the local numerical average of the vertical component of the speed of the air is always negative at all points (PI) to (P8). It can be concluded that no “parasitic shunt flux” (Fs) rises from the part (3). Under these conditions, the use of the device (101) as an airborne decontamination system is very ineffective due to the absence of updrafts at ground level (6).

The capacities of the method of the invention to eliminate the phenomenon of “parasitic inclined shunt air flow” appear more clearly on the diagram of FIG. 5d. This represents, according to each of the 3 blowing ratio conditions (RS) referred to above, the curve of the parameter YvelocityÇP) as a function of the position of the different points (PI, P2, ..., P8) of simulations on the ground (3) in the figure (5b). We can see that, for a given blowing ratio (RS), the existence of a “parasitic inclined shunt air flow” results in an incursion of the Yvelocity curve in the hatched (Yvelocity> 0) zone. This numerical demonstration makes it possible to conclude that the conditions recommended by the invention are effective, namely: (Va> Vs), or, which is equivalent, Effective blowing surface (Sse) greater than Effective suction surface (Sae ), to eliminate the “parasitic shunt flux” (Fs), which was nevertheless considered inevitable by those skilled in the art.

The principles of the method of the invention, making it possible to respond to the faults of the prior art, can be advantageously implemented within the independent PLASMAIR ™ airborne decontamination device (101). An independent mobile airborne decontamination device (101) according to the invention is shown in FIG. 6, installed in a short room (3 a), for implementing therein the ventilation method by mixing with primary blowing jet (19) and flow. suction (21) attached to Coanda double effect (C). The device (101) comprises a vertical channeling means (103) placed vertically. It is intended to be arranged substantially parallel and close to a first vertical treatment wall (52) of the short part (3a) to be treated. The channeling means (103) has a first lower suction end (104), located in the lower part in the vicinity and at a distance from the ground (6) of the short part (3a). The channeling means (103) has a second upper blowing end (105), located more in height. It is intended to be located in the upper part in the vicinity and at a distance from the ceiling (20) of the short room (3a). The device (101) is equipped with a means for setting in motion (106) the air (A). This is disposed inside the vertical channeling means (103). It creates an overpressure (ΔP = Ps - Pa) between the upper blowing end (105) and the lower suction end (104), to allow the movement of air (A) outside. It also ensures the movement of air (Ac, Ad) inside the channeling means (103). A floor surface sucking nozzle (118) (6) extends the channeling means (103) at its lower suction end (104). It is located opposite the floor (6) of the short part (3a). The suction nozzle (118) provides in the vicinity of the ground (6) a suction mouth (111) having a suction surface (Sa). The suction surface (Sa) has a substantially vertical inlet section (109). This suction surface (Sa) is an empty annular space, but for better visualization it is shown in gray. This is shown in developed flattened form in the lower right corner of FIG. 6. It ensures at ground level (6) air suction (A) according to a substantially horizontal, parallel suction stream (55) and glued to the floor (6) by Coanda effect (C). The suction stream (55) appears in more detail in Figure 6e. A ceiling surface blowing nozzle (129) (20) extends the channeling means (103) at its upper blowing end (105). It is intended to be located near the ceiling (20). It spares the upper part of a blowing mouth (110). The blowing mouth (110) has a porous blowing surface (Ss), arranged substantially frontally, bearing laterally on the extreme lateral edges (119a, 119b, 119c, 119d) of the blowing mouth (110). This is shown enlarged in the upper right corner of Figure 6. The blowing mouth (110) ensures through its entire blowing surface (Ss) the production of a primary jet (19) of air (A ), oriented upwards [or horizontally] so as to reach the ceiling (20) [or be parallel to it], to allow the attachment of the primary blowing jet (19) to the ceiling (20) by Coanda effect (VS). A means of decontamination (127) (operating by filtration and / or destruction) of the contaminating particles (4a, 4b, 4c) of the air (A) is located inside the vertical channeling means (103), between the sucking nozzle (118) and the blowing nozzle (129). It partitions internally, on its section (S), the vertical channeling means (103), to force the contaminated air (Ac) to pass through it, between a contaminated upstream area (113) and a downstream area (114) where the air (Ad) is at least partially decontaminated. The decontamination device (101) is characteristic in that in addition the cross section (Sae) (shown in the corner lower right) of the suction surface (Sa) of its suction nozzle (118) is less than the effective section (Sse) (shown in the upper right corner) of the blowing surface (Ss) of the blowing mouth (110). In this way, the average blowing speed (Vs) [average speed of the air jet on the blowing surface (S s)] is lower than the average suction speed (Va) [average flow velocity d air sucked on the suction surface (Sa)] [Vs <Va]. It can be seen with reference to FIG. (6) that the device (101) makes it possible to attach the previously treated primary blowing jet (19) to the surface of the ceiling (20). Then, the primary blowing jet (19) undergoes detachment (14) at the opposite end of the short part (3a) thus allowing said primary jet (19) to flow onto the opposite wall (50). Finally, the primary blowing jet (19) undergoes a return to the ground (6) in order to be attached to it by the Coanda effect (C) and to be taken up in continuity with the suction flow (21) attached to the ground (6). With reference to FIGS. 6 a and 6 b, the interior and exterior elements of the independent airborne decontamination device (101) appear in more detail. The vertical channeling means (103) is included inside the external envelope (126) of the device (101). When the device (101) is in operation, the contaminated air (Ac) coming from the part (3) passes through the sucking nozzle (118) with surface effect on the ground (6), extending the channeling means ( 103) at its lower suction end (104) located opposite the ground (6). There is a suction pressure (Pa). Then the contaminated air (Ac) then passes through a coarse prefilter (120) to be rid of its too bulky airborne elements (131) which can impair the proper functioning of the device (101). The contaminated air (Ac) passes inside an acoustic attenuation system (122) making it possible to avoid the propagation of airborne and solid-state noise. This consists of a plurality of parallel baffles (107, 108) located in two groups on either side of the air movement means (106), making it possible to avoid the propagation of airborne noise and support. The air movement means (106) is preferably a centrifugal type fan. Then the contaminated air (Ac) is forced to pass through the decontamination means (127) where it is at least partially decontaminated. The decontaminated air (Ad) reaches the upper blowing end (105) and is then released through the blowing mouth (110). This decontaminated air (Ad) leaves the device (101) through the blowing mouth (110) where there is a blowing pressure (Ps). The active means of the device (101) can be turned on or off by means of an on and off system (124). The device (101) is equipped with 4 wheels (125) fixed at its bottom. So that the device (101) is mobile. It can be easily moved from one room (3) to another through the door. A system for adjusting the volume flow rate of the device (123) makes it possible to adapt the flow rate according to the needs of decontamination and the size of the part (3). With regard to FIG. 6c, it can be seen that the combined action of the pretreated primary blowing jet (19) attached by Coanda effect (C) and of the suction flow attached to the ground (21) itself attached by Coanda effect (C), makes it possible to encompass the entire area of occupation (2) of the short room (3a). With reference to FIG. 3, it can be seen that the independent mobile airborne decontamination device (101) installed in a short room (3a) and adjusted according to the means fixed by the invention, makes it possible to implement in the room (3a ) ventilation by mixing with a primary blowing jet (19) and suction flow (21) attached to the double Coanda effect (C) and moreover, as has been demonstrated above, to avoid the phenomenon of “flow of 'inclined shunt stray air' (Fs). Referring to Figure 6d, we see that the device (101) according to the invention allows the vicinity of the ground (6) to suck as and when sedimentation (according to the phenomenon described in Figure 1) all contaminating aerosols in suspension (4a) and accumulated contaminating aerosols (4b, 4c) located in close proximity to the ground (6) in the thin lower layer of highly contaminated air (Ce). This takes place via the suction flow (21) attached to the floor (6).

The contaminating aerosols (4a, 4b) located near the suction stream (21) and included in the suction stream (55) are by suction induction effect (las) continuously directed towards the suction stream (21) attached to the ground (6) to be evacuated by the suction mouth (111) and undergo the decontamination process. The device (101) according to the invention leads to a reduction in the quantity of contaminated contaminated particles (4b, 4c) by continuous evacuation of the latter.

One consequence is that the floor (6) gets dirty much less quickly and that consequently the part (3) requires less frequent cleaning. This also leads to a very significant reduction in the effects of re-ascending movements of the contaminated contaminated particles (4b, 4c) (resulting from convective effects, or turbulence, ... of these particles). It also leads to a virtual elimination of the rising effect of contaminated particles sedimented in suspension or accumulated (4b, 4c) usually due to the existence of the phenomenon of “inclined shunt parasitic air flow” (Fs) . With reference to FIG. 7, the overall action of decontamination of a mobile independent airborne decontamination device (101) installed in a short room (3a) has been schematized and adjusted according to the means fixed by the invention. It can be seen that this decontamination action takes place differently on the contaminating particles (4): in the upper portion (Cs) of the part, in the lower portion (Ci) of the part, in the middle portion (Cm) of the room.

The primary blowing jet (19) and the suction flow (21) attached to the Coanda double-acting (C) encompass the entire area of occupation (2) of the short room

(3a). All of the contaminating particles (4) present in the air (A) of the short part (3 a) undergo the decontamination process. In the upper part of the room (Cs), the contaminating particles (4), in the form of contaminating aerosols in suspension (4a) are continuously sucked upwards, by effect of blowing induction (Iss) towards the ceiling (20) inside the primary blowing jet (19). Then they are channeled vertically along the opposite wall (50) before being entrained in the suction air flow (21). In the middle portion (Cm), the contaminating particles (4) are essentially those which come from an emission linked to the occupants of the occupation zone (2). Their concentration is very low. In addition, they are continuously drawn towards the lower portion of the part (Ci) by sedimentation effect (5) of gravity. Finally, in the lower portion of the part (Ci), the contaminating particles (4), in the form of contaminating aerosols in suspension (4a) are continuously sucked down, by suction induction effect (las) in direction of the ground (6) inside the suction air flow (21).

The absence of “parasitic shunt inclined air flow” (Fs), as well as the lower suction induction effect (las) caused by the primary suction jet (21), prevents the ascent of contaminant accumulated aerosols (4b) and adhered particles (4c) from the thin bottom layer of highly contaminated air (Ce) in the room portions (Cs, Cm).

In such a way that the contaminating particles (4) from each portion of the part (Cs, Cm, Ci) are rapidly evacuated in the suction air flow (21) before entering the device (101) under the conditions described in FIG. 6d to be eliminated. Actual decontamination tests carried out on an independent PLASMAIR ™ airborne decontamination device (101) demonstrate its effectiveness in decontaminating a part (3) with performances close to those of a laminar flow at a cost at least ten times less.

A first advantageous embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIGS. 6d, 6e and 8b. According to this variant, the sucking nozzle (118) is of the ground suction type (6). That is to say that the suction mouth (111) has a first so-called lower suction wall (132), either in quasi-contact with the ground (6), or formed by the ground (6) itself. - even as described in Figure 6d. The suction mouth (111) has a second so-called upper suction wall (133), in the shape of a substantially horizontal lip, formed by a portion (134) of the base.

(137) of the suction nozzle (118). So that the vertical suction surface (Sav) is free and constituted by the annular open vertical surface (136) formed between the base (137) of the sucking nozzle (118) and the ground (6). It ensures at ground level (6) a sucking of air according to a vein (55) glued to the ground, coming from a flared planar sector at the end of suction (138) coming from the three other walls (50, 140,

144) of the short part (3a) opposite the vertical treatment wall (52). In addition, the vertical suction surface (Sav) of the floor suction sucking nozzle (118) (6) is unobstructed. So that it has a developed surface equal to its effective suction surface (Sae) as shown in the lower right corner of the figure (8b). It can be seen that the effective suction surface (Sae) is less than the blowing cross section (Sse) of the blowing surface (Ss) of the blowing mouth (110) (as shown in the upper right corner of the Figure 8b). The characteristic arrangement of this first variant makes it possible both to improve the soil effect at the suction level and therefore the decontamination action in the thin lower layer of highly contaminated air (Ce), while at the same time limiting the effect

"Parasitic shunt inclined air flow" (Fs).

A second advantageous embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIGS. 8a to 8d. In Figures 8a and 8b we see that the upper blowing edge (130) is located at a distance from the ground (Ds) of more than 170cm. This is suitable for a room with a standard height of around 250 cm. Respecting this height (Ds) ensures that the air flow diagram as described in FIG. 6 runs smoothly. In FIGS. 8c and 8d, it can be seen that the porous blowing surface (Ss) of the blowing mouth (110) is provided with an orientation means (163) of the blowing air streams (164) constituting the primary blowing jet (19), controlled mechanically using a lever (167). The orientation means (163) allows to adjust the blowing incidence angle (as) of the blowing mouth (110) [average on the blowing surface (Ss) of the angle of the blowing air streams (164) of the primary blown jet (19) with the horizontal plane (H)] so that it is substantially between an angle of 20 ° and 70 °. Figures 8e and 8f show the importance of this second arrangement recommended by the invention. There is shown in side view, on each of them a device (101) placed in a short room (3a) having the characteristics of those described with reference to Figure (5b). The influence of the setting of the blowing incidence angle (as) of its blowing nozzle (110) has been studied by numerical simulation. Figure 8e corresponds to the case where (as = 20 °). Figure 8f corresponds to the case where (as = 70 °). It can be seen that in the recommended adjustment range (20 ° <as <70 °), when the other provisions of the invention are established, then the phenomenon of “shunt parasitic inclined air flow” (Fs) is avoided. Figure 8g corresponds to the case where (as <20 °). Figure 8h corresponds to the case where (as> 70 °). It can be seen that outside of the recommended adjustment range (20 ° <as <70 °), when the other provisions of the invention are established, then the phenomenon of “parasitic inclined shunt air flow” (Fs) appears. When (as> 70 °) we see establishing both a phenomenon of multi-zoning (Zl, Z2) and the appearance of several air loops (Bl, B2) as described in the "long" parts figure 3, as well as the appearance of a “parasitic inclined shunt air flow” (Fs). When (as <20 °) we see the appearance of a “parasitic inclined shunt air flow” (Fs) alone.

A third advantageous embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIG. 9b. The effective blowing section (Sse) of the blowing mouth (110) is at least 20% greater than the effective cross section of the suction surface (Sae) of the sucking nozzle (118). In addition, the volume flow rate (Qv) of the air movement means (106) is adjusted so that the average blowing speed (Vs) [average jet velocity at the outlet of the porous surface of supply air (Ss)] is greater than 0.79 m / s [Vs> 0.79 m / s]. According to these provisions, the average suction speed (Va) [average speed of the air flow sucked on the suction surface at the inlet of the porous suction surface] is at least 20% higher than the speed average blowing (Vs), (Na> 1.2 * Vs). When these particular arrangements of the invention are established, then the phenomenon of “parasitic inclined shunt air flow” (Fs) is avoided. On the contrary, Figure 9a schematically corresponds to the results obtained by numerical simulation when Vs <0.79 m / s and Va <1.2 * Vs. We observe during Numerical simulations that, apart from the threshold values recommended above, we see establishing both a phenomenon of multi-zoning (Zl, Z2) and of several air loops (Bl, B2) as described in the pieces “Long” in FIG. 3 as well as the appearance of a “parasitic inclined shunt air flow” (Fs). The characteristic arrangement of this third variant also makes it possible to limit the effect of

"Parasitic shunt inclined air flow" (Fs).

A second preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIG. 10a. According to this second embodiment, the blowing nozzle (129), on which the porous blowing surface (Ss) bears, is enlarged relative to the average width of the vertical channeling means (103). This widening is measured perpendicular to the vertical plane of symmetry (PV) of the device (101), perpendicular to its front part (165). It is measured parallel to the first vertical treatment wall (52). Thus, the porous blowing surface (Ss) being enlarged, the blowing ratio (RS) increases for an effective suction surface

(Sae) remained constant. The blowing speed (Vs) is greatly reduced compared to the suction speed (Va). The weakening of the effect of "parasitic inclined shunt air flow" is thereby increased. A particular means of implementing this second preferred embodiment is described with reference to FIGS. 15a and 15b. The blowing nozzle (129) has means for enlarging its lateral dimensions (157). This consists of at least one [and preferably two, as described in FIGS. 15a and 15b] cylindrical portion (s) of blown porous blowing (s) (159) arranged laterally by means of pipe (103) and in its upper part. They are placed perpendicular to the vertical plane (PV) of symmetry of the device (101).

The porous flexible blowing cylindrical portions (159) are collapsed vertically when the air movement means (106) is inactive, as described in FIG. 15a. However, they are deployed horizontally under the effect of the pressure (Ps) when the air movement means (106) is active as described in FIG. 15b. Thus they provide a movable blowing surface (Ss) substantially horizontal in the deployed position (161).

The porous flexible blowing cylindrical portions (159) can be manufactured in the form of a thermowell made of a woven, reinforced textile material. The textile material of the thermowell is covered with a protective adhesive strip on a generator. Then a waterproofing coating (of the oilcloth type) is applied externally to the thermowell. Then remove the protective tape. Thus, most of this thermowell is covered with an airtight sealing material. However, a longitudinal range of each porous flexible blowing cylindrical portion (159) is left free of sealing material on a generator so as to allow air to pass. In this way, a porous surface (Spa) is provided on a fraction of the surface of the thermowell placed on a generator. The remaining surface (SE) is sealed on the other fraction. This provides a blowing surface (Ss) which allows the emission of a primary blowing jet (19) along this generator, that is to say parallel to the ceiling (20) when the porous flexible cylindrical portions blower (159) are deployed. One can advantageously use a telescopic stiffening means

(170), one end of which is placed inside the porous flexible cylindrical blowing portion (159) and the other end of which is secured to the vertical channeling means (103). The telescopic stiffening means (170) makes it possible to increase the range of each porous flexible cylindrical blowing portion (159) in deployed mode (161). Preferably, the deployment of this telescopic stiffening means (170) is ensured by the pressure inside the device (101). Its folding can be ensured by a spring.

This leads to a device (101) whose lateral dimensions are small in the inactive position. He can easily walk through a door. On the other hand, in the active position, the blowing surface (Ss) can be deployed over a width substantially equal to that of the part (3). In this way, an enveloping blowing flow is provided which extends over the entire width of the part (3). This results in a much more effective decontamination. A third preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIG. 10b. The porous blowing surface (Ss) comprises a frontal blowing surface (Ssf) extended laterally by two lateral blowing surfaces (Sslg and Ssld) formed on the lateral faces of the blowing nozzle (135) intended to be placed opposite the side walls (140,144) of the room (3). This arrangement makes it possible to increase the effective blowing surface (Sse) and to better treat the lateral zones of the room (3) situated along the lateral walls (140, 144). This also contributes to better elimination of the effect of “parasitic inclined shunt air flow” (Fs). A fourth preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIG. 11. The suction nozzle (118) of the ground suction type is widened at its upper wall (139) relative to the average width of the vertical channeling means (103) which it extends below. This widening is measured perpendicular to the vertical plane of symmetry (PV) of the device (101) perpendicular to its front part (165). The side walls (141) of the sucking nozzle (118) are therefore further apart.

A fifth preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIGS. 10a, 10b, 12 and 13a, 13b. The suction nozzle (118) has a tulip-shaped lower portion (143), placed facing the ground (6). It has also been found by numerical simulation that this arrangement contributes to a better elimination of the effect of “parasitic inclined shunt air flow” (Fs). A sixth preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIG. 12. The mean section of the vertical channeling means (103) in a longitudinal deployment (DL) ( size), taken along the plane of symmetry (PV) of the device (101), less than the longitudinal deployment (DLS) of the sucking nozzle (118). The two dimensions are measured parallel to the vertical plane of symmetry of the device (PV) perpendicular to its front part (165). A seventh preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to Figures 13a and 13b. The vertical channeling means (103) comprises a length-adjustable channeling portion (147). This adjustable pipe portion (147) can in particular be constituted by a bellows (149). Such an arrangement makes it possible to adapt the height of the porous blowing surface (Ss) as a function of the height (h) of the part (3). It follows that the device (101) can respond to the architectural variety of the rooms (3) and thus attach the primary jet (19) to the ceiling (20) by coanda effect in elongated mode (153) as shown in Figure 13b. The narrowing of the height-adjustable channel portion (147) allows the device (101) to pass through a door of the room (3) in retracted mode (151), as shown in FIG. 13 a.

An eighth preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIGS. 14a and 14b. The device (101) comprises an auxiliary suction nozzle (155) formed in the front part of the channeling means (103). The auxiliary suction nozzle (155) is located approximately halfway up (about 1 meter from the ground). The auxiliary suction nozzle (155) opens into the means of pipe (103) upstream of the means for removing contaminating particles (127), in said upstream contaminated area (Ac). This arrangement allows the air decontamination action (A) in the vicinity of the auxiliary suction nozzle (155). An occupant (2) carrying contaminating particles (4) releases contaminating aerosols in suspension (4a). This occupant during a hospitalization, is positioned in a bed in a substantially horizontal manner, his respiratory tracts are thus located approximately 1 m in height. The use of this preferred mode makes it possible, via the auxiliary suction nozzle (155), to directly treat the emissions of contaminating aerosols in suspension (4a) emitted by the occupant in the area (Cm) such as described in figure 7.

Aims and advantages of the invention

The main aim and advantage of the invention is to reduce, or even eliminate, the phenomenon of “parasitic shunt air flow”, considered by the prior art as necessarily associated with the use of a ventilation method by mixture of primary blowing jet attached to the ceiling and suction flow attached to the floor, by Coanda effect.

A second advantage of the invention is to reduce the effects of the upward movement of contaminating particles sedimented in a room. A third advantage of the invention is to aspirate as they settle the aerosols in suspension, and the aerosols accumulated in the thin layer of highly contaminated air located near the ground. A fourth advantage of the invention is to reduce the quantity of contaminating particles adhered to the ground and consequently the cleaning needs of the part.

A fifth advantage of the invention is to reduce the concentration of contaminating aerosols in suspension in the area of occupancy of the occupants of a room. A sixth advantage of the invention is to reduce the occurrence of diseases by biological contamination of airborne origin in a room. A seventh advantage of the invention is to offer a ventilation system by attached jet mixing, presenting performances close to those of a laminar flow in terms of decontamination of a part for a reduced cost of an order of magnitude. . An eighth advantage of the invention is to offer an airborne decontamination system with "high cleanliness" and mobile. A ninth advantage of the invention is to be able to quickly bring into non-equipped places, the means of combating occurrences of biological contamination. This concerns both home medicine, the fight against epidemics, civil protection, pharmaceutical and / or food production ... A tenth advantage of the invention is to offer a mobile device very suitable for capturing and the evacuation of airborne contaminating particles close to the ground and to avoid their resuspension. This particularly concerns hypersensitive subjects (allergies).

An eleventh advantage of the invention is to increase the kinetics of decontamination of a room ventilated by mixing.

Industrial applications of the invention

The invention makes it possible to optimize the process of decontaminating a room and removing its contaminating airborne particles at a lower cost. The invention therefore has industrial applications in any type of closed structure requiring air decontamination. This concerns in a non-exhaustive manner: health, agrifood, research, transport, breeding, pharmacy, schools ... A particularly suitable application concerns airborne decontanaination of health premises, for the protection of patients and hospital staff against the risk of cross-contamination. This concerns protection in hospitals against risks of contagion of SARS type (Severe Acute Respiratory Syndrome) ... Another application concerns the punctual fight against certain consequences of conventional ventilation in professional, public and domestic premises leading to risks of infections by airborne contaminants transmitted by the air conditioning system. This concerns local protection, in a room of a ventilated building, against the problems of allergies and / or cross contamination (sick building syndrom) coming from the air conditioning of the building. One can cite an application in the context of maritime or air passenger transport.

One can also cite an application for industries presenting a local biological risk linked to the production of a contaminating agent. This may be the case in the pharmaceutical and food industries. This also applies to microbiological research laboratories. Another application concerns the protection of high density farms (chicken, pork, etc.) with a view to perpetuating a high health status, in particular in farms where inputs are limited (selection farms).

Another application concerns civil protection in the context of bio-terrorist attacks.

A wider application concerns the limitation of the risks of transmission between customers and / or staff of cafeterias and restaurants.

Another application concerns the prevention of epidemic risks in nurseries, schools and places of small size but of great occupation. Finally, an application concerns the protection of staff and visitors to dental offices and veterinary clinics ...

The scope of the invention should be considered in relation to the claims below and their legal equivalents, more than by the examples given above.

Claims

claims

1) Method of ventilating a room (3) by mixing, with a primary blowing jet (19) attached to the ceiling (20) and suction flow (21) attached to the floor (6), by double coanda effect (C ), of the type according to which a) a primary jet of air (19) previously treated (heated, cooled, decontaminated, humidified, dehumidified, etc.) is blown into the room (3), i) through a blowing surface (Ss), located opposite a side wall (52) said to be of treatment, in the vicinity of the ceiling (20), ii) in a direction of blowing incidence (Is) [average over the blowing surface (Ss) of the mean directions of the portions of the primary jet (19)] oriented towards the ceiling (20) (or parallel to it), so as to attach by said Coanda effect (C) said primary blowing jet (19) on the surface of the ceiling (20), b) a suction air flow (21) is polluted, with a flow equivalent to the primary jet (19), i) this, through a suction surface (Sa) sensitivity slightly vertical, located opposite the same lateral treatment wall (52), in the vicinity of the ground (6) of the room (3), ii) ensuring at ground level (6) a suction of air (A) along a suction stream (55) • substantially horizontal, • parallel and attached to the ground surface (6) by the Coanda effect (C),

This ventilation process being characterized in that in addition: c) the average blowing speed (Vs) is imposed [average of the speeds of the portions of the primary air jet (19) on the blowing surface (Ss)] to be lower than the average suction speed (Va) [average of the speeds of the portions of the suction air flow (21) on the suction surface (Sa)] [Vs <Va]. 2) A method of ventilating a room by mixing, with a primary jet (19) of blowing and suction flow (21) with double coanda effect (C), according to claim 1, characterized in that, in addition, a ) it is required that the effective blowing surface (Sse) be greater than the effective suction surface (Sae). ) Independent device (101) for airborne decontamination of a part (3), for implementing the method according to claim 1 of ventilation by mixing with a primary blowing jet (19) and suction flow (21) attached double Coanda effect (C), this device (101) being of the type constituted by: a) a vertical channeling means (103) arranged vertically [intended to be disposed substantially parallel and close to a first vertical treatment wall (52) of the part (3) to be treated], this channeling means (103) comprising: i) a first lower suction end (104), located in the lower part in the vicinity and at a distance from the ground (6) of the part (3), ii) and a second upper blowing end (105), located more in height, and intended to be located in the upper part in the vicinity and at a distance from the ceiling (20) of the room (3), b) an air setting means (106) (A), arranged inside of the vertical channeling means (103), and creating an overpressure (ΔP) between the upper blowing end (105) and the lower suction end (104), to allow the movement of air to the inside and outside of the channeling means (103), c) a suction nozzle (118) with a surface effect on the ground (6), extending the channeling means (103) at its lower suction end (104 ) located opposite the ground (6) of the part (3), and providing in the vicinity of the ground (6) a suction mouth (111), i) having a suction surface (Sa) with inlet section substantially vertical, ii) and ensuring at the level of the ground (6) a suction of the air (A) according to a suction stream (55) • substantially horizontal, • parallel and glued to the ground (6) by Coanda effect (C ), d) a blowing nozzle (129) with a surface effect on the ceiling (20), extending the channeling means (103) at its upper blowing end (105) [intended to be located close to the ceiling (20)] and providing in the upper part a blowing mouth (110), i) having a porous blowing surface (Ss), disposed substantially frontally, bearing laterally on the extreme lateral edges ( 119a, 119b, 119c, 119d) of the blowing mouth (110), ii) and ensuring through its entire blowing surface (Ss) the production of a primary jet (19) of air, oriented upwards or horizontally [so as to reach the ceiling (20) or be parallel to it], to allow the attachment of the primary blowing jet (19) to the ceiling (20) by Coanda effect (C), e) a means decontamination (127) (by filtration and / or destruction) of the contaminating air particles (A), i) located inside the vertical channeling means (103), between the sucking nozzle (118) and the blowing nozzle (129), ii) internally partitioning, on its section (S), the vertical channeling means (103), to force the contaminated air (Ac) to pass through it, between a contaminated upstream zone (113) and a downstream zone (114) where the air (Ad) is at least partially decontaminated, this decontamination device (101) being characterized in that in addition: f) the cross section (Sae) of the suction surface (Sa) of its suction nozzle (118) is less than the cross section (Sse) of the blowing surface (Ss) of the blowing mouth (110), so that the average blowing speed (Vs) [average speed of the air jet (19) on the blowing surface (Ss)] is lower than the average speed of suction (Va) [average speed of the air flow sucked (21) on the suction surface (Sa)] [Vs <Va]. 4) independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1, ventilation by mixing with primary blowing jet (19) and suction flow attachments (21) with double Coanda effect (C), this device (101) being characterized in that, in addition, in combination: a) on the one hand, its suction nozzle (118) is of the suction type on the ground (3), that is to say of which the suction mouth (111): i) has a first wall of so-called lower suction (132) • either in quasi-contact with the ground (3), • is formed by the ground (3) itself, ii) and has a second so-called upper suction wall (133), formed by a portion (134) of the base (137) of the sucking nozzle (118), iii) so that its vertical suction surface (Sa) is free and constituted by the annular open vertical surface (136) formed between the base (137) of the sucking nozzle (118) and the ground (3), iv) and ensures at ground level (3) a sucking of the air according to a vein (55) glued to the ground (6), coming from a flared end suction planar sector (138) coming from the three other walls (50, 144, 140) of the room (3) opposite the treatment wall (52), b) on the other hand, the vertical surface suction (Sav) from the suction nozzle (118) to suction ground ration (3) is less than the blowing cross section (Sse) of the blowing surface (Ss) of the blowing mouth (110). 5) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by double Coanda effect (C), this device (101) being characterized in that in addition, in combination: a) the upper edge (142) of the porous blowing surface (Ss) is located at a distance of the ground (Ds) of more than 170cm [suitable for a room (3) of standard height (h) of approximately 250 cm], b) and the porous blowing surface (Ss) of the blowing nozzle (110) is provided with orientation means (163) of the blowing air streams (164) constituting the primary blowing jet (19), mechanically adjustable, so that the angle of incidence of blowing (as) of its nozzle supply air (129) [average over the supply surface (Ss) of the angle of the supply air streams of the primary jet with the hor plane izontal] is between an angle of 20 ° and 70 ° relative to the horizontal plane (H). 6) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by double Coanda effect (C), characterized in that, in addition, in combination: a) on the one hand, the effective cross-section of the blowing surface (Sse) of its blowing nozzle (129) as well as its air movement means (106) are dimensioned so that the average blowing speed (Vs) of the blowing nozzle (129) [average of the jet velocities at the outlet of the porous blowing surface (Ss )] is greater than 0.79 m / s [Vs> 0.79 m / s]; b) and on the other hand, the cross section of the blowing surface (Sse) of its blowing mouth (110) is at least 20% greater than the cross section of the suction surface (Sae) of its sucking nozzle (118), so that the average suction speed (Va) [average speed of the suction air flow (21) entering the porous suction surface (Sa)] is greater by minus 20% at the average blowing speed (Vs)] (Va> 1.2 * Vs).

7) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by double Coanda effect (C), characterized in that, in addition, said blowing nozzle (129), on which said porous blowing surface (Ss) is supported, is enlarged relative to the average width of the means of vertical pipe (103) which it extends above, [measured perpendicular to the vertical plane of symmetry (PV) of the device (101) perpendicular to its front part (165)].

8) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by double Coanda effect (C), characterized in that in addition the porous blowing surface (Ss) has a frontal blowing surface (Ssf) extended laterally by lateral blowing surfaces (Sslg and Ssld) formed on the side panels (135) of the blowing nozzle (129) placed opposite the side walls (140, 144) of the room (3).

9) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that, in addition, the suction nozzle (118) is widened at its upper wall (139), relative to the average width of the vertical channeling means (103 ) that it extends below [measured perpendicular to the vertical plane of symmetry (PV) of the device (101) perpendicular to its front part (165)].

10) Independent airborne decontamination device (101) of a part (3) according to claim 4, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by double coanda effect (C), characterized in that, in addition, the sucking nozzle (118) has a tulip-shaped lower portion (143), placed facing the ground (6).

11) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that in addition the mean section of its vertical channeling means (103) to a longitudinal deployment (DL) (size), according to the plane of symmetry (PV) of the device (101), lower than the longitudinal deployment (DLS) of the suction nozzle (118) [both measured parallel to the vertical plane of symmetry (PV) of the device (101) perpendicular to its front part (165)].

12) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that it further comprises an auxiliary suction nozzle (155): a) formed in the front part of the channeling means (103), b) about half -height, (of the order of 1 meter from the ground (6)), c) opening into the channeling means (103), upstream of the means for removing contaminating particles (127), in said upstream contaminated zone (Ac).

13) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that, in addition, its vertical channeling means (103) comprises a portion of channeling adjustable (147) in length (in particular with bellows (149)) to allow adaptation the height of the porous blowing surface (Ss) as a function of the height (h) of the room (3) and the attachment of the primary jet (19) to the ceiling (20) by Coanda effect (C), while allowing the passage of the device (101) through a door of the room (3).

14) Independent airborne decontamination device (101) of a part (3) according to claim 3, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by double-acting Coanda (C), characterized in that, in addition, its blowing nozzle (129) comprises means for enlarging its lateral dimensions (157) ensuring lateral deployment of its blowing surface (Ss) .

15) Independent airborne decontamination device (101) of a part (3) according to claim 14, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that, in addition, its blowing nozzle (129) comprises a means for enlarging its lateral dimensions (157) constituted by at least one [preferably two] ρortion ( s) flexible cylindrical (s) porous blowing (159), a) arranged laterally by means of pipe (103) and in its upper part (105), perpendicular to the vertical plane of symmetry (PV) of the device (101), b) and deploying under the effect of pressure (Ps) by providing a mobile blowing surface (Ss) substantially horizontal in the deployed position (161). 16) Independent airborne decontamination device (101) of a part (3) according to claim 15, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that, in addition, said flexible porous blowing cylindrical portion (159) comprises a) a porous surface (Spa), on a fraction of its surface, to provide a surface of blowing (Ss) and allow the emission of a primary blowing jet (21), b) and a sealed surface (SE) on another fraction.

17) An independent airborne decontamination device (101) of a part (3) according to claim 15, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that it further comprises at least one telescopic stiffening means (170), one end of which is placed inside the porous flexible cylindrical blowing portion (159) and of which the other end is integral with the vertical channeling means (103).

18) Independent airborne decontamination device (101) of a part (3) according to claim 17, for implementing the method according to claim 1 of ventilation by mixing with primary blowing jet (19) and suction flow ( 21) attached by Coanda double effect (C), characterized in that, in addition, the deployment of this telescopic stiffening means (170) is ensured by the pressure inside the device (101). * * *