Method And A Device For Ventilation And Airborne Decontamination By Mixing Using Blow And Suction Flows Attached By The Coanda Effect

Abstract

A device ( 101 ) for airborne decontamination of a room ( 3 ) by mixing using a blown jet ( 19 ) and a suction flow ( 21 ) that are attached by the Coanda effect (C). Vertical trunk means ( 103 ) have a bottom suction end ( 104 ) and a top blow end ( 105 ). Drive means ( 106 ) set the air (A) into motion inside and outside the trunk means. An intake nozzle ( 118 ) provides a vertical suction surface (Sa) serving to suck in the air (A) as a suction stream ( 55 ) parallel to the floor ( 6 ) and attached thereto by the Coanda effect (C). A blow nozzle ( 129 ) using the surface effect at the ceiling ( 20 ) presents a frontal porous blow surface (Ss). It produces a primary jet ( 19 ) of air that is attached to the ceiling ( 20 ) by the Coanda effect (C). Decontamination means ( 127 ) decontaminate the air (A). The effective area (Sae) of the suction surface (Sa) is less than the effective area (Sse) of the blow surface (Ss). This serves to eliminate the “interfering shunt air flow” that is usually associated with attached air blow ventilation systems.

1 - 16 . (canceled)  
   
   
       17 . A method of ventilating a room ( 3 ) by mixing, using a blown primary jet ( 19 ) attached to the ceiling ( 20 ), and a suction flow ( 21 ) attached to the floor ( 6 ), both by the Coanda effect (C), the method being of the type comprising: 
 a) blowing a primary jet of air ( 19 ) that has previously been treated into the room ( 3 ); 
 i) through a blow surface (Ss) situated in register with a treatment side wall ( 52 ) in the vicinity of the ceiling ( 20 ); and  
 ii) in a blow direction of incidence (Is) oriented towards the ceiling ( 20 ) in such a manner as to cause said blown primary jet ( 19 ) to become attached to the surface of the ceiling ( 20 ) by the Coanda effect (C); and then  
   b) sucking in a vitiated suction air flow ( 21 ) at a flow rate equivalent to that of the primary jet ( 19 ): 
 i) through a substantially suction surface (Sa) situated in register with the same treatment side wall ( 52 ) in the vicinity of the floor ( 6 ) of the room ( 3 ); and  
 ii) ensuring that a suction stream of air (A) is sucked-in in the vicinity of the floor ( 6 ), which stream ( 55 ) is: 
 substantially horizontal; and  
 parallel to the surface of the floor ( 6 );  
 
   the ventilation method being characterized further, in combination:    c) firstly, by ensuring that the mean blow velocity (Vs) is less than the mean suction velocity (Va); and    d) secondly, by the vitiated sucked-in air flow ( 21 ) being sucked in through a suction surface (Sa) presenting a bottom suction wall ( 132 ) in physical contact with the floor ( 6 ) of the room ( 3 ), such that the suction stream ( 55 ) of sucked-in air (A) is attached to the surface of the floor ( 6 ) by the Coanda effect (C) in register with and facing the suction surface (Sa).    
   
   
       18 . An independent airborne decontamination device ( 101 ) for a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction flow ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being of the type comprising: 
 a) vertical trunk means ( 103 ) disposed vertically, said trunk means ( 103 ) comprising: 
 i) a suction bottom first end ( 104 ) situated in the bottom portion thereof close to and separated from the floor ( 6 ) of the room ( 3 ); and  
 ii) a blow top second end ( 105 ) situated higher up to be situated in the top portion of the room ( 3 ) close to and spaced apart from the ceiling ( 20 );  
   b) drive means ( 106 ) for setting the air (A) into motion, the drive means being disposed inside the vertical trunk means ( 103 ) and establishing a positive pressure (ΔP) between the blow top end ( 105 ) and the suction bottom end ( 104 ) so as to enable air to move inside and outside the trunk means ( 103 );    c) a surface effect intake nozzle ( 118 ) at the floor ( 6 ) extending the suction bottom end ( 104 ) of the trunk means ( 103 ) where it faces the floor ( 6 ) of the room ( 3 ), while leaving a suction opening ( 111 ) in the vicinity of the floor ( 6 ), the opening: 
 i) presenting a suction surface (Sa) of substantially vertical inlet suction; and  
 ii) providing suction of the air (A) in a suction stream ( 55 ) at the level of the floor ( 6 ), the stream being: 
 substantially horizontal; and  
 parallel to the floor ( 6 );  
 
   d) a surface effect blow nozzle ( 129 ) at the ceiling ( 20 ) extending the blow top end ( 105 ) of the trunk means ( 103 ) and forming a blow outlet ( 110 ) at its top portion, the outlet: 
 i) presenting a porous blow surface (Ss) disposed substantially frontally bearing laterally against the extreme side edges ( 119   a ,  119   b ,  119   c ,  119   d ) of the blow outlet ( 110 ); and  
 ii) producing a primary jet ( 19 ) of air through the entire blow surface (Ss), the jet being oriented upwards or horizontally, in order to enable the blown primary jet ( 19 ) to be attached to the ceiling ( 20 ) by the Coanda effect (C); and  
   e) decontamination means ( 127 ) for decontaminating contaminating particles in the air (A) (by filtering and/or destroying them), the decontamination means: 
 i) being situated inside the vertical trunk means ( 103 ) between the intake nozzle ( 118 ) and the blow nozzle ( 129 ); and  
 ii) internally partitioning the vertical trunk means ( 103 ) across its section (S) so as to constrain the contaminated air (Ac) to pass therethrough between a contaminated upstream zone ( 113 ) and a downstream zone ( 114 ) in which the air (Ad) is decontaminated at least in part;  
   the decontamination device (O 1 ) being characterized in that further, in combination:    f) firstly, its intake nozzle ( 118 ) is of the suction type at the floor ( 6 ), i.e. having a suction inlet ( 111 ) that: 
 i) possesses a bottom, first suction wall ( 132 ) that is formed by the floor ( 6 ) itself;  
 ii) and possesses a top, second suction wall ( 133 ) formed by a portion ( 134 ) of the base ( 137 ) of the intake nozzle ( 118 );  
 iii) such that its vertical suction surface (Sa) is free and constituted by an annular open vertical surface portion ( 136 ) formed between the base ( 137 ) of the intake nozzle ( 118 ) and the floor ( 6 ), and serves to suck in air at the level of the floor ( 6 ) in a stream ( 55 ) that is attached to the floor ( 6 ) by the Coanda effect, and coming from a plane sector ( 138 ) tapering towards the suction and coming from the other three walls ( 50 ,  144 ,  140 ) of the room ( 3 ) opposite from the treatment wall ( 52 ); and  
   g) secondly, the vertical suction surface (Sav) of the suction intake nozzle ( 118 ) at the floor ( 3 ) is less than the effective blow surface (Sse) of the blow surface (Ss) of the blow outlet ( 110 ), so that the mean blow velocity (Vs) is less than the mean suction velocity (Va).    
   
   
       19 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction flow ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, in combination: 
 a) the top edge ( 142 ) of the porous blow surface (Ss) is situated at a distance (Ds) above the floor of more than 170 cm; and    b) the porous blow surface (Ss) of the blow nozzle ( 110 ) is provided with mechanically adjustable director means ( 163 ) for directing the blown air streams ( 164 ) making up the blown primary jet ( 19 ), to cause the blow angle of incidence (αs) from the blow nozzle ( 129 ) to lie in the range 20° to 70° relative to the horizontal plane (H).    
   
   
       20 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, in combination: 
 a) firstly, the effective area (Sse) of the blow surface of its blow nozzle ( 129 ) and its air drive means ( 106 ) are dimensioned in such a manner that the mean blow velocity (Vs) of the blow nozzle ( 129 ) is greater than 0.79 m/s; and    b) secondly, the effective area (Sse) of the blow surface of its blow outlet ( 110 ) is at least 20% greater than the effective area (Sae) of the suction surface of its intake nozzle ( 118 ), in such a manner that the mean suction velocity (Va) is at least 20% greater than the mean blow velocity (Vs).    
   
   
       21 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, said blow nozzle ( 129 ) against which said porous blow surface (Ss) bears is wider than the mean width of the vertical trunk means ( 103 ) that it extends upwards.  
   
   
       22 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, the porous blow surface (Ss) has a front blow surface (Ssf) extended laterally by lateral blow surfaces (Sslg and Ssld) formed on the side walls ( 135 ) of the blow nozzle ( 129 ) placed facing the side walls ( 140 ,  144 ) of the room ( 3 ).  
   
   
       23 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, the intake nozzle ( 118 ) is enlarged at its top wall ( 139 ) to be wider than the mean width of the vertical trunk means ( 103 ) that it extends downwards.  
   
   
       24 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, the intake nozzle ( 118 ) includes a tulip-shaped flare bottom portion ( 143 ) placed in register with the floor ( 6 ).  
   
   
       25 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, the mean section of its vertical trunk means ( 103 ) has a longitudinal extent (DL) (bulk) in the plane of symmetry (PV) of the device ( 101 ) that is less than the longitudinal extent (DLS) of the intake nozzle ( 118 ).  
   
   
       26 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, it includes an auxiliary intake nozzle ( 155 ): 
 a) arranged in the front portion of the trunk means ( 103 );    b) about halfway up (about 1 meter from the floor ( 6 )); and    c) opening out into the trunk means ( 103 ) into said upstream contaminated zone (Ac) upstream from the means ( 127 ) for eliminating contaminating particles.    
   
   
       27 . An independent device (O 1 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, its vertical trunk means ( 103 ) includes a trunk portion ( 147 ) that is adjustable in length (in particular by means of a bellows ( 149 )) to enable the height of the porous blow surface (Ss) to be adapted as a function of the height (h) of the room ( 3 ), so that the primary jet ( 19 ) attaches to the ceiling ( 20 ) by the Coanda effect (C), while still enabling the device ( 101 ) to pass through a door of the room ( 3 ).  
   
   
       28 . An independent device ( 101 ) according to  claim 18  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, its blow nozzle ( 129 ) includes means ( 157 ) for enlarging its lateral dimensions enabling its blow surface (Ss) to be extended laterally.  
   
   
       29 . An independent device ( 101 ) according to  claim 28  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, its blow nozzle ( 129 ) includes means ( 157 ) for enlarging its lateral dimensions constituted by at least one (and preferably two) porous flexible cylindrical blow portions ( 159 ), 
 a) disposed laterally relative to the trunk means ( 103 ) at the top portion thereof ( 105 ), perpendicularly to the vertical plane of symmetry (PV) of the device ( 101 ); and    b) deployable under the effect of the pressure (Ps) so as to provide a mobile flow surface (Ss) that is substantially horizontal in the deployed position ( 161 ).    
   
   
       30 . An independent device ( 101 ) according to  claim 29  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, said porous flexible cylindrical blow portion ( 159 ) comprises: 
 a) a porous surface (Spa) over a fraction of its surface for forming a blow surface (Ss) and enabling a blown primary jet ( 21 ) to be emitted; and    b) a leakproof surface (SE) over another fraction of its surface.    
   
   
       31 . An independent device ( 101 ) according to  claim 29  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, it includes at least one telescopic stiffening means ( 170 ) having one end placed inside the porous flexible cylindrical blow portion ( 159 ) and having its other end secured to the vertical trunk means ( 103 ).  
   
   
       32 . An independent device ( 101 ) according to  claim 31  for airborne decontamination of a room ( 3 ) for ventilating by mixing using a blown primary jet ( 19 ) and a suction stream ( 21 ) both attached by the Coanda effect (C), the device ( 101 ) being characterized in that further, the deployment of said telescopic stiffener means ( 170 ) is performed by the pressure inside the device ( 101 ).