Abstract:
A cryogen injection apparatus for injecting a cryogenic substance into a blender, includes at least one nozzle constructed for being in fluid communication with an interior of the blender; and an electric heat sink member in contact with the at least one nozzle for electrically heating said nozzle. A related method is also provided.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present embodiments relate to bottom injection of cryogen into mixers for cooling and more particularly, to nozzle apparatus that introduce cryogen substances into food products for chilling and/or freezing same, and which apparatus are not clogged from use of the cryogenic substance. 
         [0002]    The bottom injection of cryogen into mixers for cooling food products, for example, are known. Such known bottom injection nozzles for cryogenic substances, such as for example liquid nitrogen (LIN), encounter difficulties when being used with wet products which are drawn into an orifice of the nozzle in communication with the food processing equipment, whereupon the wet food product is frozen upon exposure to the cryogen. When such a situation occurs, the nozzle orifice will become restricted and eventually clogged. Unfortunately, it is extremely difficult to clear the nozzle, frequently requiring disassembly of same, and no further cooling cryogenic substance can be delivered to the mixer for chilling until the clog is removed. 
         [0003]    Existing nozzle structure contributes to this deficiency. That is, known nozzles are made from either thick stainless steel, which transfers a large amount of heat from the mixture or blender wall and thereafter remains cold after an injection cycle of the cryogen until the mixing is complete. This type of stainless steel nozzle contributes to the clogging situation when the cryogenic substance, such as LIN for example, is exposed to the wet product in the blender or mixer. 
         [0004]    Other nozzles are manufactured with a teflon sleeve which reduces the amount of heat transfer from the blender wall to the nozzle, but such nozzles are susceptible to migration of the food product between the sleeve and the housing and will therefore crack the nozzle due to thermal expansion and contraction from the cryogenic substance. 
       SUMMARY OF THE INVENTION 
       [0005]    There is therefore provided an electrically heated bottom injection nozzle apparatus which consists of a cryogen injection apparatus for injecting a cryogenic substance into a blender, including at least one nozzle constructed for being in fluid communication with an interior of the blender; and an electric heat sink member in contact with the at least one nozzle for electrically heating said nozzle. 
         [0006]    There is also provided herein a method for electrically heating a bottom injection nozzle to eliminate clogging of the nozzle, which includes providing an electric heat sink to said injection nozzle upon conclusion of injecting the cryogenic substance to the blender and transmitting power to the electric heat sink for warming the injection nozzle. 
         [0007]    In summary, the present embodiments include a low thermal mass straight bore nozzle with an integrated heating system which provides for rapid thawing of the nozzle and therefore, clearing of any product within the nozzle between injection cycles of the cryogen, such as liquid nitrogen (LIN). The construction of the nozzle embodiment eliminates the possibility of cracking of the nozzle because there are no internal sleeves used which could permit thermal expansion and contraction of any frozen food product or condensate between the nozzle body and the thermal sleeve. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    For a more complete understanding of the present invention, reference may be had to the following description of exemplary embodiments considered in connection with the accompanying drawing Figures, of which: 
           [0009]      FIG. 1  shows a perspective view of the cryogen injection nozzle embodiment of the present invention; and 
           [0010]      FIG. 2 . shows a side view partially in cross-section of the embodiment of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    Before explaining the inventive embodiments in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. 
         [0012]    Referring to  FIGS. 1-2 , an electrically heated injection nozzle apparatus of the present invention is shown generally at  10  mounted to a wall  12  of a blender or mixer (not shown) in which food product (not shown) is disposed for being chilled. While food product is referred to for being treated by the injection nozzle  10 , it is understood that other types of products can be treated with the present injection nozzle embodiment. The apparatus  10  is shown mounted near or at a bottom region  13  of the blender wall  12 . 
         [0013]    The injection nozzle apparatus  10  or apparatus consists of a nozzle or nozzle portion  14  for introducing a cryogen such as for example LIN represented by the arrow  15  through the nozzle into the blender; a heat sink member  16 ; and an enclosure  18  or housing. 
         [0014]    The nozzle  14  can be either a straight bore stainless steel tube or a machined steel tube with an expanding bore, wherein a diameter of the bore increases along the flow path in the direction of the wall  12 . The nozzle  14  is constructed from a material that has a low thermal mass. 
         [0015]    The heat sink member  16  is used to transfer heat to the blender wall  12  and the nozzle  14 . The heat sink member  16  is constructed with a first heat sink portion  20  for the blender wall and a second heat sink portion  22  for the nozzle  14 . The first and second heat sink portions  20 ,  22  may also be formed as an integral unit. The heat sink member  16  is used for transferring heat into the blender wall  12  and to the nozzle  14 . As shown in  FIGS. 1-2 , the heat sink member  16 , which includes the first and second heat sink portions  20 ,  22 , can be constructed from copper, and the second portion  22  surrounds and is in direct contact with a substantial area of the nozzle  14 . The first heat sink portion  20  is in direct contact with the blender wall  12 . 
         [0016]    Electric cartridge heaters  24  are mounted to or embedded in the heat sink member  16  and connected to a conduit connection  26  at a sidewall of the enclosure  18 . Usually, such sidewall will be at or near a bottom  25  of the enclosure  18 . Electrical connectors  27  interconnect the heat sink member  16  with the conduit connection  26 . The conduit connection  26  is wired to a semi-conductor controlled rectifier (SCR)  28  as shown in  FIG. 2 , which conducts the electrical current to the heat sink member  16 . Electric power  30  shown in  FIG. 2  is provided to the SCR  28 . A controller or a proportional-integral-derivative controller (PID controller)  32  is connected to the SCR  28  and receives input  34  for defrosting or thawing with the apparatus  10 . That is, the electric cartridge heaters  24  are powered by the SCR  28  and the PID controller  32 , so that the power can be regulated to defrost or thaw the blender wall  12  and the nozzle  14  in a select amount of time. For example, rapid defrost would mean that increased power will be applied to the heat sink member  16 , while a permissible longer duration of defrost will require less power. 
         [0017]    A thermocouple  36  is positioned at an exterior surface of the first heat sink portion  20  as shown in  FIG. 2 . The thermocouple  36  can be mounted in a cavity  21  of the portion  20  such that the thermocouple is in facing contact with the wall  12  when the enclosure  18  is mounted to the blender wall. The thermocouple  36  will shut down or stop the defrost operation of the apparatus  10  when a desired set point temperature is reached, which can be for example above 32° F. or 0° C. 
         [0018]    The second heat sink portion  22  is sized and shaped with a bore  40  therethrough which is constructed to receive the nozzle  14  to be extended through the second heat sink portion and the blender wall  12  for opening into the blender. The enclosure  18  is provided with a cylindrical portion  19  extending therefrom and having an open end to which a cap  42  is removably mounted. 
         [0019]    The enclosure  18  or housing is constructed and arranged to protect the nozzle  14 , heat sink member  16  and the electrical cartridge heaters  24  from external impacts and water sprays that may occur in a production facility where the blender is being used. As shown in  FIGS. 1-2 , the enclosure  18  includes an internal space  38  or chamber of sufficient volume to support the first and second heat sink portions  20 ,  22 , the nozzle  14 , and the electric cartridge heaters  24  therein. The enclosure  18  has a sidewall at least a portion of which is open-sided at  44 , such that the first heat sink portion  20  functions as a sidewall portion for the enclosure. The thermocouple  36  as shown in  FIG. 2  is positioned for contacting the wall  12  as discussed above, and covered as well when the enclosure  18  is mounted or seated against the wall shown generally at  44 . The enclosure  18  is contoured so that the sidewall will fit flush with an exterior surface on the blender wall  12  as shown in particular in  FIG. 2  An alternate embodiment of the apparatus  10  provides the nozzle  14 , the heat sink member  16 , the enclosure  18  with conduit connection  26 , and the thermocouple  36  as an integral unit. 
         [0020]    The nozzle portion  14  may be constructed from stainless steel; the heat sink member  16  may be constructed from copper or any other highly conductive material, and the enclosure  18  or housing may be constructed from stainless steel or plastic. 
         [0021]    The injection nozzle apparatus  10  of the embodiment showing in  FIGS. 1-2  permits the nozzle  14  to be easily cleaned, because the only elements of the nozzle exposed to an interior of the blender is an interior of the nozzle. Therefore, hot water or other cleaning solutions can be sprayed through the nozzle portion  14  for easy cleaning without having to disassemble the injection nozzle  10 . 
         [0022]    In operation with the actual blender (not shown), a batch of food product, such as for example ground meat with ingredients therein, is placed in the blender which is started such that internal blades (not shown) of the blender mix the food product and ingredients. It is required to chill the meat during the blending operation and therefore, cryogen such as liquid nitrogen (LIN) is injected into the blender through the injection nozzle  14 . That is, the LIN  15  is injected through the nozzle  14  during which heat is transferred from the wall  12  via conduction with the nozzle  14  which also has its temperature reduced to a temperature substantially similar to that of the LIN. Minimal heat is transferred between the wall  12  and the nozzle  14  due to a low thermal mass of the nozzle portion. When a desired, reduced temperature of the meat is obtained, injection of the LIN  15  is stopped and the meat is removed from the blender. The controller  32  actuates the SCR  28  for delivering power to the electric cartridge header  24  mounted or imbedded in the heat sink member  16  to warm the first and second heat sink portions  20 ,  22  to effectively warm and thaw the blender wall  12  and the nozzle  14 . Any frozen meat or water trapped within and clogging the nozzle portion  14  is warmed and the nozzle  14  can be blown out with a high pressure nitrogen gas prior to the next operating batch being disposed in the blender. The high pressure nitrogen gas will easily discharge any matter from the nozzle into the blender. Since nitrogen is used to dislodge any material in the nozzle  14 , and the next batch will be of similar composition of meat and other ingredients, there is no contamination of the next batch of the product being processed in the blender. The construction of the injection nozzle apparatus  10  permits clean-in-place (CIP) of the nozzle portion  14  without removal or disassembly of the apparatus. 
         [0023]    It will be understood that the embodiments described herein are merely exemplary, and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as described and claimed herein. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired result.