Pulsed liquid-gas entrained cryogen flow generator

Abstract

An apparatus for providing a liquid-gas entrained cryogen mixture onto a food product includes a first pipe through which is provided a flow of liquid cryogen; a second pipe through which is provided a flow of gaseous cryogen, the second pipe in fluid communication with the first pipe at a mixing region; and a pulsing valve disposed at an interior of the second pipe upstream of the mixing region, the pulsing valve adapted for releasing the gaseous cryogen into the liquid cryogen at select intervals of time to provide a pulsating flow of the liquid-gas entrained cryogen mixture downstream of the mixing region for contacting the food product. A related method is also provided.

What is claimed is: 
     
         1 . An apparatus for providing a liquid-gas entrained cryogen mixture onto a food product, comprising:
 a first pipe through which is provided a flow of liquid cryogen;   a second pipe through which is provided a flow of gaseous cryogen, the second pipe in fluid communication with the first pipe at a mixing region; and   a pulsing valve disposed at an interior of the second pipe upstream of the mixing region, the pulsing valve adapted for releasing the gaseous cryogen into the liquid cryogen at select intervals of time to provide a pulsating flow of the liquid-gas entrained cryogen mixture downstream of the mixing region for contacting the food product.   
     
     
         2 . The apparatus of  claim 1 , wherein the pulsing valve is constructed and arranged within the second pipe for rotational movement therein. 
     
     
         3 . The apparatus of  claim 2 , wherein the pulsing valve comprises:
 an axle spanning an internal diameter of the second pipe and rotatably mounted therein;   a planar member mounted to the axle and having a surface area substantially similar to a cross-sectional diameter of the second pipe; and   a motor operatively connected to the axle for rotation of said axle and the planar member mounted thereto.   
     
     
         4 . The apparatus of  claim 3 , wherein the planar member comprises a circular disc. 
     
     
         5 . The apparatus of  claim 1 , further comprising an on/off valve disposed within the second pipe upstream of the pulsing valve. 
     
     
         6 . The apparatus of  claim 5 , further comprising a modulating valve disposed within the second pipe upstream of the on/off valve. 
     
     
         7 . The apparatus of  claim 1 , further comprising a modulating valve disposed within the second pipe upstream of the pulsing valve. 
     
     
         8 . The apparatus of  claim 1 , further comprising a control valve disposed within the first pipe upstream of the mixing region. 
     
     
         9 . The apparatus of  claim 8 , further comprising a back flow preventer disposed within the first pipe upstream of the control valve. 
     
     
         10 . The apparatus of  claim 1 , further comprising a back flow preventer disposed within the first pipe upstream of the mixing region. 
     
     
         11 . The apparatus of  claim 8 , further comprising a spray bar in fluid communication with the first pipe and disposed in a space at which the food product is present. 
     
     
         12 . The apparatus of  claim 11 , wherein the spray bar comprises at least one opening through which the pulsating flow of the liquid-gas entrained cryogen mixture flows for contacting the food product. 
     
     
         13 . The apparatus of  claim 12 , wherein the spray bar further comprises a nozzle mounted in the at least one opening. 
     
     
         14 . The apparatus of  claim 11 , wherein the spray bar comprises a plurality of sections in fluid communication with the first pipe, each one of the plurality of sections including a plurality of openings through which the pulsating flow of the liquid-gas entrained cryogen mixture flows to contact the food product. 
     
     
         15 . The apparatus of  claim 1 , wherein the liquid cryogen comprises a liquid selected from the group consisting of liquid nitrogen (LIN) and liquid carbon dioxide, and the gaseous cryogen comprises a gas selected from the group consisting of nitrogen (N 2 ) and carbon dioxide (CO 2 ). 
     
     
         16 . A method of providing a flow of a liquid-gas entrained cryogen mixture onto a food product, comprising:
 providing a first flow of liquid cryogen to the food product;   providing a second flow of a gaseous cryogen for contacting the first flow at a mixing region of the first and second flows; and   repetitively interrupting the second flow upstream of the mixing region to provide a pulsating flow of the gaseous cryogen into the liquid cryogen for providing a pulsating flow of a liquid-gas entrained cryogen mixture to the food product.   
     
     
         17 . The method of  claim 16 , further comprising directing the pulsating flow to a spray bar for distributing said pulsating flow to the food product. 
     
     
         18 . The method of  claim 17 , wherein the distributing comprises a plurality of pulsating flows from the spray bar. 
     
     
         19 . The method of  claim 16 , further comprising preventing the first flow from reversing direction away from the mixing region. 
     
     
         20 . The method of  claim 16 , further comprising controlling an amount of each of the first and second flows to the mixing region. 
     
     
         21 . The method of  claim 16 , further comprising separating the pulsating flow of the liquid-gas entrained cryogen mixture into a plurality of discrete flows to the food product. 
     
     
         22 . The method of  claim 16 , wherein the providing the first flow is a 30 psig, and the providing the second flow is at 200 psig. 
     
     
         23 . The method of  claim 16 , wherein the liquid cryogen comprises a liquid selected from the group consisting of LIN and liquid CO 2 , and the gaseous cryogen comprises a gas selected from the group consisting of N 2  and CO 2 .