Device for generating an air wall in an upright refrigerated cabinet

Abstract

A device for generating an air wall in an upright refrigerated cabinet ( 22 ) comprises a primary blower slit for generating a primary air stream ( 30 ) in the frontal opening ( 34 ) of the upright refrigerated cabinet which forms a thermal separation between the low inside temperature and the ambient air of a higher temperature. No mixing occurs between the primary air stream ( 30 ) and the secondary, optionally forced air streams ( 1, 9 ) added thereto. The thereby realized great effective heat resistance achieves that the supply of heat from the ambient air to the interior space of the refrigerated cabinet is considerably limited.

1 . A refrigerated cabinet comprising a device for generating an air wall for thermal separation of the air in a relatively cold first space, i.e. the interior of a refrigerated cabinet, cold room or the like for the purpose of cooled self-service presentation of prepackaged cooled food products, from the air in the relatively warm second space, i.e. the space surrounding the refrigerated cabinet or the cold room, which two spaces are mutually connected via a frontal opening extending in a substantially vertical main plane and having a height of a maximum of 2 m, the device comprising: a primary blower slit connecting to a primary blower unit positioned close to a side of the frontal opening and disposed substantially parallel to the main plane of the frontal opening, which slit extends substantially over the whole relevant dimension of the frontal opening for the purpose of generating an at least more or less flat primary air stream directed at least roughly toward the opposite side of the frontal opening,
 the speed of the air in the primary air stream amounts to 2-30 m/s;   the width of the primary blower slit lies in the range of 5-20 mm, preferably 8-15 mm; and   the length of the blower slit in the direction of the air stream lies in the range of about 50-150 mm.   
     
     
         2 . A device as claimed in  claim 1 , wherein the blower slit is divided into blower channels by partitions extending in the air stream direction. 
     
     
         3 . A device as claimed in  claim 1 , compromising a suction unit positioned on the opposite side of the frontal opening and having a substantially prismatic suction slit extending substantially parallel to the blower slit and having substantially the same length as the primary blower slit, to which suction slit connect suction fan means. 
     
     
         4 . A device as claimed in  claim 3 , wherein the primary blower slit is connected via a duct to the suction slit, in which duct fan means are disposed which are both the primary blower fan means and the suction fan means such that the air wall forms part of a substantially closed circuit. 
     
     
         5 . A device as claimed in  claim 1 , wherein the primary and the entrained secondary air streams move in vertical direction. 
     
     
         6 . A device as claimed in  claim 1 , wherein at least one of the secondary air streams is an entrained air stream. 
     
     
         7 . A device as claimed in  claim 3 , wherein the suction slit has a width and is disposed such that it suctions substantially only the primary air stream Sp. 
     
     
         8 . A device as claimed in  claim 3 , wherein a number of regularly distributed, passive control valves are added to the suction slit for the purpose of equal, constant passing airflows, such that the same airflow passes at each longitudinal position, such that the air in the relevant air stream flows substantially in a straight path at any longitudinal position. 
     
     
         9 . A device as claimed in  claim 1 , wherein the position and direction of the blower slit is adjustable. 
     
     
         10 . A device as claimed in  claim 1 , comprising at least two mutually parallel blower slits. 
     
     
         11 . A device as claimed in  claim 4 , wherein the duct is thermally insulated. 
     
     
         12 . A device as claimed in  claim 1  for operation in cooperation with a refrigerated cabinet and adapted to be added to a refrigerated cabinet. 
     
     
         13 . A device as claimed in  claim 12 , the device being integrated with a refrigerated cabinet. 
     
     
         14 . A device as claimed in  claim 1 , wherein a curved air curtain of said refrigerated cabinet runs, among other ways, according to the Coanda effect relative to the primary air stream. 
     
     
         15 . A device as claimed in  claim 5 , wherein the refrigerated cabinet is provided with a static evaporator serving as cooling element, wherein the interior secondary air stream supplies air to the evaporator. 
     
     
         16 . A device as claimed in  claim 12 , wherein the refrigerated cabinet is provided with an evaporator with a fan, said evaporator with fan placed at a bottom or at top of the refrigerated cabinet. 
     
     
         17 . A device as claimed in  claim 9 , wherein at least two horizontal air blower slits are placed on the underside and the air coming from the air slit placed furthest outward is blown out on the top side in more or less horizontal direction. 
     
     
         18 . A device as claimed in  claim 16 , wherein the air coming from the outermost air blower slit is supplied to the condenser of a cooling installation for cooling thereof such that an increased COP is obtained, for instance an increase from 3 to 8. 
     
     
         19 . A device as claimed in  claim 1  for operation in cooperation with a cold room having an air intake and wherein the created external entrained air stream is drawn in via said cold room air intake and fed back via fan means to a supply distributing box with blower slit such that the relevant air stream forms part of a substantially closed circuit. 
     
     
         20 . A device as claimed in  claim 1 , wherein the air streams are supplied and discharged via at least one air distributing box, which is connected to an associated duct of substantially rectangular cross-sectional form, such that it is possible to place fan means in one box on the one side on the refrigerated cabinet and a cooling unit with a cooling group and an evaporator on the other side.