Exhaust Hood

Abstract

An exhaust hood having a first fan wheel sucking in and transporting away room air. A second fan wheel sucks in external air and is arranged axially displaced relative to the first fan wheel. Guide vanes are arranged externally about the first and second fan wheels. The guide vanes are embodied as a cavity and form venting passages. A first air flow exiting from the first fan wheel and a second air flow exiting from the second fan wheel are guided past each other, separate from each other, through the guide vanes and are directionally deflected by the guide vanes. Walls of the guide vanes form a surface for heat exchange between the first and second air flows.

1 - 12 . (canceled) 
     
     
         13 . An exhaust hood comprising:
 a first fan wheel sucking in and transporting away room air;   a second fan wheel sucking in external air and arranged axially displaced relative to the first fan wheel;   guide vanes arranged externally about the first and second fan wheels;   wherein the guide vanes are embodied as a cavity and form venting passages;   wherein a first air flow exiting from the first fan wheel and a second air flow exiting from the second fan wheel are guided past each other, separate from each other, through the guide vanes and are directionally deflected by the guide vanes;   wherein walls of the guide vanes form a surface for heat exchange between the first and second air flows.   
     
     
         14 . The exhaust hood according to  claim 13 , wherein:
 the venting passages for the first air flow effecting room air discharge and the venting passages for the second air flow effecting external air supply are arranged annularly externally about the first and second fan wheels;   the venting passages correlated with the first fan wheel have a height that extends into an area of the second fan wheel but have only one opening relative to the first fan wheel;   the venting passages correlated with the second fan wheel have a height that extends into the area of the first fan wheel but have only one opening relative to the second fan wheel.   
     
     
         15 . The exhaust hood according to  claim 13 , further comprising a partition arranged between the first and second fan wheels so that the first and second fan wheels are separated from each other, wherein the partition separates the first and second air flows from each other. 
     
     
         16 . The exhaust hood according to  claim 13 , wherein at least the walls of the venting passages correlated with the first fan wheel have an extension that is curved in radial direction toward the first fan wheel. 
     
     
         17 . The exhaust hood according to  claim 13 , comprising an annular discharge opening having an inner wall, wherein the venting passages correlated with the first fan wheel open into the annular discharge opening, wherein the inner wall of the discharge opening delimits a receiving opening from where the external air sucked in by the second fan wheel is guided to the venting passages correlated with the second fan wheel. 
     
     
         18 . The exhaust hood according to  claim 17 , wherein:
 the first fan wheel sucks in the room air and forces the room air into the venting passages correlated with the first fan wheel, wherein the room air is guided from the venting passages into the discharge opening; and   the second fan wheel sucks in the external air and forces the external air into the venting passages correlated with the second fan wheel, wherein the external air is guided from the venting passages in a direction laterally away from the rotational axis of the fan wheels.   
     
     
         19 . The exhaust hood according to  claim 17 , further comprising a pipe-in-pipe air guiding system connected to the annular discharge opening. 
     
     
         20 . The exhaust hood according to  claim 13 , wherein the venting passages correlated with the first and/or second fan wheels are one or more shaped parts easily removable from the exhaust hood. 
     
     
         21 . The exhaust hood according to  claim 13 , wherein at least one of the first and second fan wheels is a shaped part that is easily removable from the exhaust hood. 
     
     
         22 . The exhaust hood according to  claim 13 , wherein the first and second fan wheels have an at least approximately identical air conveying volume. 
     
     
         23 . The exhaust hood according to  claim 13 , comprising a common shaft on which the first and second fan wheels are arranged. 
     
     
         24 . The exhaust hood according to  claim 13 , comprising a common drive motor wherein the first and second fan wheels are driven by the common drive motor.