Device and Method for Chilling or Deep-Freezing Food Products by Impacting Jets

Abstract

The invention proposes a device for chilling or deep-freezing by impacting jets which consists of a tunnel comprising a moving belt, at least one plate and preferably at least two plates located parallel to each other on either side of said moving belt, at least one plate, and preferably both plates, being provided with through-holes, and at least one means for injecting a cold fluid, said tunnel having a zone under pressure P 1 and a zone under pressure P 2 , the pressure P 1 being greater than the pressure P 2 , characterized in that it includes means for varying the pressure in the zone under pressure P 1 and/or means for cooling the plate or plates down to a temperature below about −80 DEG C, preferably below −90 DEG C and more preferably still below −100 DEG C and for maintaining that temperature; and a method for chilling or deep-freezing food products by impacting jets.

1 - 13 . (canceled) 
     
     
         14 . A device for chilling food products by impacting jets comprising a tunnel comprising
 a moving belt,   at least a first plate located opposite, above or alternatively beneath, said moving belt and provided with through-holes, said first plate being provided with through-holes,   at least one means for circulating a cold fluid, wherein:
 said tunnel being adapted to maintain a zone under pressure P 1  above said first plate when said first plate is located above said moving belt or and/or beneath said first plate when said first plate is located below said moving belt; 
 said tunnel being adapted to maintain and a zone under pressure P 2  between said first plate and the moving belt, P 1  being greater than P 2 ; and 
   a means for varying P 1  and/or a means for cooling said at least a first plate down to a temperature below about −80° C. and for maintaining that temperature.   
     
     
         15 . The device of  claim 14 , wherein the cold fluid is a cryogenic fluid is selected from the group consisting of nitrogen, carbon dioxide, oxygen, air, and mixtures thereof. 
     
     
         16 . The device of  claim 14 , wherein the chilling device is a deep-freezing device. 
     
     
         17 . The device of  claim 14 , wherein the means for cooling said at least a first plate is selected from the group consisting of a heat-exchange circuit attached to the plate, a plate/heat exchanger, a cold fluid bath, and combinations thereof. 
     
     
         18 . The device of  claim 17 , wherein the cryogenic fluid passing through the heat exchanger is taken from the circuit for supplying the chilling machinery. 
     
     
         19 . The device of  claim 14 , wherein the means for varying the pressure is selected from the group consisting of frequency inverters and pressurized storage tanks. 
     
     
         20 . The device of  claim 14 , wherein the circulation means is a centrifugal fan driven by a motor. 
     
     
         21 . The device of  claim 14 , wherein the means for cooling the fluid is the means for cooling the plate. 
     
     
         22 . A method for chilling food products by impacting jets, in which
 a fluid is cooled,   a pressure P 1  is applied to the fluid,   the fluid is forced to pass through holes in a plate and to impact the food product to be chilled, wherein the temperature of the plate is maintained at a temperature below about −80° C. and/or P 1  is varied over time.   
     
     
         23 . The method of  claim 22 , wherein the cold fluid is a cryogenic fluid is selected from the group consisting of nitrogen, carbon dioxide, oxygen, air, and mixtures thereof. 
     
     
         24 . The method of  claim 22 , wherein the chilling method is a deep-freezing method. 
     
     
         25 . The method of  claim 22 , wherein the variation in pressure is a notched sequence, the amplitude of which is a pressure difference ΔP between a normal operating value and a selected set value that is lower or greater than the normal value, said pressure difference ΔP lying between 10 and 1000 Pa and the time for which the variation in pressure is applied Δt lies between 1 and 60 s. 
     
     
         26 . The device of  claim 14 , wherein:
 said at least a first plate comprises first plate located above said moving belt and a second plate located below said moving belt;   each of said first and second plates are provided with through-holes;   the zone under pressure P 1  is above said first plate or below said second plate; and   the zone under pressure P 2  is between said first plate and said moving belt or between said second plate and said moving belt.   
     
     
         27 . The device of  claim 14 , wherein said means for cooling said at least a first plate down to a temperature below about −80° C. is adapted to cool said at least a first plate down to a temperature below −90° C. 
     
     
         28 . The device of  claim 14 , wherein said means for cooling said at least a first plate down to a temperature below about −80° C. is adapted to cool said at least a first plate down to a temperature below −100° C. 
     
     
         29 . The method of  claim 22 , wherein the temperature of the plate is maintained at a temperature below about −90° C. 
     
     
         30 . The method of  claim 22 , wherein the temperature of the plate is maintained at a temperature below about −100° C. 
     
     
         31 . The method of  claim 25 , wherein said pressure difference ΔP lies between 200 and 800 Pa. 
     
     
         32 . The method of  claim 25 , wherein said pressure difference ΔP lies between 400 and 600 Pa. 
     
     
         33 . The method of  claim 25 , wherein the time for which the variation in pressure is applied Δt lies between 2 and 30 s. 
     
     
         34 . The method of  claim 25 , wherein the time for which the variation in pressure is applied Δt lies between 5 and 15 s.