Exhaust hood with air curtain

Abstract

An exhaust hood captures and contains a thermal plume with a minimum of exhaust air by defining a short-throw planar jet around a protected perimeter. Corner interference is mitigated by various mechanisms including having at least one of adjacent planar jets run only partly along a respective edge such that said first and second curtain jets do not meet at said corner; having a direction of the planar jets proximate corners where they meet being intermediate between respective directions of the jets along respective main portions of the perimeter; or having a direction of the jets of one of the adjacent edges be horizontal while the other is vertical.

1 - 17 . (canceled) 
   
   
       18 . An apparatus for removing cooking effluent from a cooking appliance, the cooking effluent being such as to tend to rise upward by buoyancy effect as a plume, the apparatus comprising:
 an exhaust hood defining a recess with an access positioned above the cooking appliance, the recess having an exhaust vent,   the exhaust hood defining a perimeter with a side edge and a forward edge meeting at a corner,   the exhaust hood being configured to generate a first curtain jet along the forward edge and a second curtain jet along the side edge,   wherein one of the first curtain jet and the second curtain jet is directed in a substantially horizontal direction and the other of the first curtain jet and the second curtain jet is directed substantially downward.   
   
   
       19 . An apparatus as in  claim 18 , wherein the first curtain jet and the second curtain jet are each formed by a series of orifices in the perimeter projecting primary jets which coalesce to form a respective curtain. 
   
   
       20 . An apparatus as in  claim 18 , further comprising a fan configured to feed air from a conditioned space to the exhaust hood forward and side edges such that the first curtain jet and the second curtain jet are formed using the air fed from the conditioned space. 
   
   
       21 . An apparatus as in  claim 18 , wherein one of the first curtain jet and the second curtain jet is fed by a flow of less than 10 ft 3 /min per linear foot of the edges along which the respective jet is formed. 
   
   
       22 . An apparatus as in  claim 18 , wherein the recess has a curved shape. 
   
   
       23 . (canceled) 
   
   
       24 . An apparatus as in  claim 18 , wherein the one of the first curtain jet and the second curtain jet directed in a substantially horizontal direction is directed toward the recess. 
   
   
       25 . An apparatus as in  claim 18 , wherein the first curtain jet is directed in a substantially horizontal direction toward the recess and the second curtain jet is directed substantially downward and away from the recess. 
   
   
       26 . An apparatus for removing cooking effluent from a cooking appliance, the cooking effluent being such as to tend to rise by buoyancy effect as a plume, the apparatus comprising:
 an exhaust hood defining a recess with an access positioned above the cooking appliance, the recess having an exhaust vent,   the exhaust hood defining a perimeter with at least one side edge and a forward edge, the forward edge meeting with each side edge at a respective corner,   the exhaust hood being configured to generate a first curtain jet along the forward edge and a second curtain jet along each side edge;   wherein one of the first curtain jet and the second curtain jet is substantially horizontally directed and the other of the first curtain jet and the second curtain jet is substantially vertically directed.   
   
   
       27 . An apparatus as in  claim 26 , wherein the first curtain jet and the second curtain jet are each formed by a series of orifices in the perimeter projecting primary jets which coalesce to form a respective curtain. 
   
   
       28 . An apparatus as in  claim 26 , further comprising a fan configured to feed air from a conditioned space to the exhaust hood such that the first curtain jet and the second curtain jet are formed using the air fed from the conditioned space. 
   
   
       29 . An apparatus as in  claim 26 , wherein one of the first curtain jet and the second curtain jet is fed by a flow of less than 10 ft 3 /min per linear foot of the edges along which the respective curtain jet is formed. 
   
   
       30 . An apparatus as in  claim 26 , wherein the recess is curved between the forward edge and the exhaust vent. 
   
   
       31 . An apparatus as in  claim 26 , wherein the one of the first curtain jet and the second curtain jet is directed substantially toward the recess. 
   
   
       32 . An apparatus as in  claim 26 , wherein the other of the first curtain jet and the second curtain jet is directed substantially away from the recess. 
   
   
       33 . (canceled) 
   
   
       34 . An apparatus as in  claim 18 , wherein a nozzle arrangement configured to generate the one of the first and second curtain jets faces the recess. 
   
   
       35 . An apparatus as in  claim 26 , wherein a direction of the one of the first and second curtain jets and a direction of the other of the first and second curtain jets are perpendicular to each other. 
   
   
       36 . An apparatus as in  claim 26 , wherein the first curtain jet is substantially horizontally directed and the second curtain jet is substantially vertically directed. 
   
   
       37 . An apparatus for removing cooking effluent from a cooking appliance, the apparatus comprising:
 an exhaust hood defining a recess and a perimeter,   the recess having an access positioned above the cooking appliance and an exhaust vent,   the perimeter including at least one side edge and a forward edge, each side edge meeting the forward edge at a respective corner,   the forward edge being configured to generate a first curtain jet and each side edge being configured to generate a second curtain jet,   wherein one of the first curtain jet and the second curtain jet is directed substantially toward the recess, the other of the first curtain jet and the second curtain jet is directed substantially away from the recess, and the first curtain jet is directed substantially orthogonal to the second curtain jet.   
   
   
       38 . An apparatus as in  claim 37 , wherein the first curtain jet is substantially horizontally directed, and the second curtain jet is substantially vertically directed.