Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F7/00—Ventilation
  • F24F7/007—Ventilation with forced flow
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F7/00—Ventilation
  • F24F7/003—Ventilation in combination with air cleaning
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2221/00—Details or features not otherwise provided for
  • F24F2221/12—Details or features not otherwise provided for transportable
  • F24F2221/125—Details or features not otherwise provided for transportable mounted on wheels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2221/00—Details or features not otherwise provided for
  • F24F2221/28—Details or features not otherwise provided for using the Coanda effect
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
  • F24F8/10—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
  • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Definitions

• 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.
• 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.
• 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:
• Piston air displacement ventilation systems 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.
• their blown integral wall structure 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.
• Ventilation devices by air displacement by thermal effect stratification are mainly used in air conditioning applications.
• 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.
• 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.
• 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.
• occupancy area 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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".
• 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.
• 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.
• 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 5,616,172 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.
• 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.
• 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.
• 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.
• 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 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].
• Vs average blowing speed
• Va average suction speed
• 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).
• FIG. 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.
• 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.
• 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).
• 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).
• FIGS. 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).
• 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).
• Is blowing incidence
• Ss blowing surface
• C Coanda effect
• 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).
• 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).
• 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,
• 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).
• 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].
• 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).
• 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).
• Vs 2/2 + Ps / p + g * h Va 2/2 + Pa / p + .DELTA.h (Bernouilli with losses).
• 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.
• 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.
• FIG. 5b represents the conditions for digital simulation of the air flow diagrams obtained for a prototype of the independent PLASMAIR TM 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 device (101) is placed against and in the central part of the so-called treatment wall (52).
• K-E the energy model
• 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.
• 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).
• the third column 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.
• the fourth column (not grayed out) relates to the case where the device has been adjusted
• FIG. 6 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).
• 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.
• 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).
• 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).
• 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].
• 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).
• the vertical channeling means (103) is included inside the external envelope (126) of the device (101).
• 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).
• 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).
• 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.
• 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
• the contaminating particles (4) present in the air (A) of the short part (3 a) undergo the decontamination process.
• 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).
• 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.
• 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.
• 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,
• FIGS. 8a to 8d A second advantageous embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIGS. 8a to 8d.
• 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.
• 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 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.
• 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).
• 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].
• 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).
• Vs speed average blowing
• Figure 9a schematically corresponds to the results obtained by numerical simulation when Vs ⁇ 0.79 m / s and Va ⁇ 1.2 * Vs.
• FIG. 10a A second preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIG. 10a.
• 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).
• PV vertical plane of symmetry
• RS blowing ratio
• 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).
• 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.
• a waterproofing coating (of the oilcloth type) is applied externally to the thermowell.
• remove the protective tape Thus, most of this thermowell is covered with an airtight sealing material.
• 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.
• 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.
• a blowing surface Ss
• 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.
• 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).
• PV vertical plane of symmetry
• the side walls (141) of the sucking nozzle (118) are therefore further apart.
• FIGS. 10a, 10b, 12 and 13a, 13b 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).
• Fs parasitic inclined shunt air flow
• a sixth preferred embodiment, recommended by the invention, of the independent airborne decontamination device (101) is shown with reference to FIG. 12.
• 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.
• FIGS. 14a and 14b 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.
• 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.
• 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.
• 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.
• a particularly suitable application concerns airborne decontanaination of health premises, for the protection of patients and hospital staff against the risk of cross-contamination.
• 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.
• Another application concerns civil protection in the context of bio-terrorist attacks.
• 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 ...

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Ventilation (AREA)
• Duct Arrangements (AREA)
• Accommodation For Nursing Or Treatment Tables (AREA)
• Disinfection, Sterilisation Or Deodorisation Of Air (AREA)

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• 2003
  • 2003-09-10 FR FR0310654A patent/FR2859522B1/fr not_active Expired - Fee Related
• 2004
  • 2004-09-10 WO PCT/FR2004/002309 patent/WO2005025711A2/fr not_active Ceased
  • 2004-09-10 CN CNA2004800290992A patent/CN1863584A/zh active Pending
  • 2004-09-10 CA CA002538227A patent/CA2538227A1/en not_active Abandoned
  • 2004-09-10 US US10/571,558 patent/US20070202798A1/en not_active Abandoned
  • 2004-09-10 RU RU2006111437/06A patent/RU2347149C2/ru not_active IP Right Cessation
  • 2004-09-10 JP JP2006525863A patent/JP2007505283A/ja active Pending
  • 2004-09-10 EP EP04787357A patent/EP1670565A2/de not_active Withdrawn

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