Abstract:
An apparatus for providing a thermal treatment to a product, such as food, is described. One embodiment of the apparatus includes lime and water contained separately within a sealed reaction vessel. The reaction vessel includes a flexible wall portion that is adjacent to a perforator that can puncture a membrane separating the lime and water. In one embodiment, the perforator is separate from and fee-floating within the water. In another embodiment, the reaction vessel is substantially surrounded by the product. The reaction vessel is hermetically sealed against underpressure or overpressure, permitting use with pressurized food. The reaction vessel can be incorporated into a variety of containers and the reaction vessel and container can be sterilized for packaging food.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/091,704, filed Aug. 25, 2008. The entire contents of the above-listed provisional application are hereby incorporated by reference herein and made part of this specification. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to a self-contained food packaging system, and more particularly an apparatus for heating or cooling, or a container for packaging food including such an apparatus. 
         [0004]    2. Discussion of the Background 
         [0005]    There is a long-standing need for food package systems that can heat or cool the food. Prior art attempts at such systems typically include a chemically reacting mixture in a separate container that is stored within the package. 
         [0006]    While various configurations of chemical systems and container shapes have been proposed, they all suffer from practical problems that have prevented their widespread acceptance. Examples of problems with various prior art configurations include: escape of hot chemicals from the reaction chamber, inefficient heating, devices to activate the chemical reactions that are difficult to use, difficulty in sterilizing the container for use with food, and difficulty in mating the portion having the chemical reacting mixture with a food container. 
         [0007]    Thus there is a need in the art for an apparatus that permits for the easy operation of a heating or cooling device packages with a food container. Such an apparatus should be easy to sterilize and incorporate into a food package, should be able to be packaged with pressurized food, and should be safe to handle. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The present invention overcomes the disadvantages of prior art by providing a self-contained reaction vessel that, depending on the chemical reactants contained therein, heat or cool a food product in contact with the vessel. 
         [0009]    In one embodiment, a reaction vessel is provided, where the reaction vessel includes a sealed container having a reactant and a perforator, where the perforator can be moved by manipulating the reaction vessel to puncture the sealed container. 
         [0010]    In another embodiment, a container and a reaction vessel is provided, where the reaction vessel is situated substantially within the food, where the reaction vessel includes a sealed container having a reactant, and a perforator that can pierce the sealed container. 
         [0011]    In yet another embodiment, a container and a reaction vessel is provided, where the reaction vessel is sealed and is situated substantially within the food, where the reaction vessel generates heat by mixing reactants including water and lime. 
         [0012]    In one embodiment, a reaction vessel for a container is provided that is hermetically sealed against overpressure and underpressure. 
         [0013]    In another embodiment, a container having a reaction vessel for thermally treating food within the container is provided that permits food to be store using aseptic or hermetically treated methods. The container may be used to store, for example and without limitation, coffee, hot chocolate, soups with or without morsels. 
         [0014]    In yet another embodiment, a reaction vessel for thermally treating food is provided that is a self-contained vessel that can be later provided to food packers for incorporation into a container and provided with food. 
         [0015]    These features together with the various ancillary provisions and features which will become apparent to those skilled in the art from the following detailed description, are attained by the reaction vessel for thermally treating food, and container including the same, of the present invention, preferred embodiments thereof being shown with reference to the accompanying drawings, by way of example only, wherein: 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0016]      FIG. 1  is a perspective view of one embodiment of container for thermally conditioning a product; 
           [0017]      FIG. 2A  is a sectional view  2 - 2  of  FIG. 1 ; 
           [0018]      FIG. 2B  is a perspective sectional view  2 - 2  of  FIG. 1 ; 
           [0019]      FIG. 3  is a sectional view  2 - 2  showing detail of one embodiment of a reaction vessel; 
           [0020]      FIG. 4  is a sectional view  2 - 2  showing detail of one embodiment of a perforator; 
           [0021]      FIG. 5  is a top view of the perforator of  FIG. 4 ; and 
           [0022]      FIGS. 6A-6D  are sequential sectional view of an embodiment of the self-heating container in use, where  FIG. 6A  is prior to use,  FIG. 6B  is during activation;  FIG. 6C  is during heating of the product; and  FIG. 6D  is just prior to consumption of the product. 
       
    
    
       [0023]    Reference symbols are used in the Figures to indicate certain components, aspects or features shown therein, with reference symbols common to more than one Figure indicating like components, aspects or features shown therein. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0024]      FIG. 1  is a perspective view of one embodiment of a container  100  for thermally conditioning, that is heating or cooling, a product. The product may be, for example and without limitation, an edible product such as a food, a soup, or a drink, such as a baby formula or tea. The product may also be product that is not edible, such a wax to be used as a hot wax in a cosmetic treatment. 
         [0025]    In the embodiment of  FIG. 1 , container  100  includes a removable lid  101  and an outer body  103 . Outer body  103  is shown as being generally cylindrical, but may, in alternative embodiments, have the shape of a bowl, cup, or tub or other shape as is convenient for utilizing the thermally conditioned product, outer body  103  is transparent, translucent, or opaque, or includes printing or labels on all or part of its surface. 
         [0026]      FIG. 2A  is a sectional view and  FIG. 2B  is a perspective sectional view of one embodiment of a container  100 , which may be generally similar to the embodiment illustrated in  FIG. 1 , except as further detailed below. Where possible, similar elements are identified with identical reference numerals in the depiction of the embodiments of  FIGS. 1 and 2 . 
         [0027]    Container  100  includes a reaction vessel  210  comprising a reaction vessel body  211  and a reaction vessel bottom  213 , and outer body  103  which includes a side  201  that extends from an opening  203  to a bottom  205 . In the embodiment of  FIGS. 2A and 2B , bottom  205  further includes a portion  207  that is adjacent to reaction vessel bottom  213 . 
         [0028]    Reaction vessel  210  is generally interior to outer body  103  and forms a hermetic seal with the outer bottom at a location  209  which is near side  201  and/or bottom  205 . The seal at location  209  can be formed in a number of ways including, but not limited to, a press fit, an adhesive or other joining technique, or thermoforming outer body  103  to a protruding feature on reaction vessel  210 . 
         [0029]    Volume  202  includes the interior of outer body  103  including side  201  from opening  203  to sealing location  209 , not including the volume occupied by reaction vessel  210 . In one embodiment, some or all of volume  202  includes a product P. Locating reaction vessel  210  wholly or substantially within outer body  103  is advantageous, as this allows for efficient heating or cooling of the product contained therein with a minimal amount of heat transfer between the reaction vessel and the container exterior. 
         [0030]    For container  100  that heats product P it is desirable that the product not occupy all volume  202  to accommodate any expansion of the product resulting from heating. It is preferred that internal surface  204  of side  201  and external surface  212  of reaction vessel body  211  is compatible with the edible product—that is, it will not contaminate or be corroded or dissolved by the edible product or any other material occupying volume  202 . Further, it is preferred, but not required that outer surface  212  and/or the inner surface  204  can be sterilized for use with edible products packaged therein. 
         [0031]    Outer body  103  may be formed from a variety of materials selected for their ability to maintain shape, resist moisture or gas permeation, and ability to be sanitized for filling with a food product. Materials selection is well known in the art and may include, but is not limited to, an injection molded polypropylene, a thermoformed polypropylene, or a thermoformed polypropylene/EVOH/polypropylene. The material and thickness may BE chosen for its ability to maintain shape and resist gas permeation. Methods of sanitizing, when required, include, but are not limited to, heating or treating with ozone or other chemicals. 
         [0032]      FIG. 3  is a detailed view of one embodiment of a reaction vessel  210 , which may be generally similar to the embodiments illustrated in  FIGS. 2A and 2B , except as further detailed below. Where possible, similar elements are identified with identical reference numerals in the depiction of the embodiments of  FIGS. 1 ,  2 A,  2 B, and  3 . 
         [0033]    In general, reaction vessel  210  provides thermal conditioning of a product within volume  202 . It is preferred, though not necessary, that reaction vessel  210  be structurally secure to contain the reacts and products within the vessel. Reaction vessel  210  contains the components to produce the necessary chemical reactions to create or absorb heat from product P. In one embodiment, reaction vessel body  211  is a metal can formed from aluminum, tin, or stainless steel, and reaction vessel bottom  213  is a metal piece that is formed with to be flexible when joined to the reaction vessel body. Optionally, varnished aluminum may be used to resist chemical activity with specific products. Reaction vessel body  211  and reaction vessel body  213  are thus, in one embodiment, metal pieces that are sealed along joint  303 . Joint  303  may be a weld, crimped, or adhesive joint. The outer portion of reaction vessel  210  is preferably, thought not necessarily, formed from metal to ensures safe operation, by containing any reactants and reaction products within the reaction vessel, and efficient heat transfer with product P. Metal surfaces are also easily treated to be aseptic when required. 
         [0034]    In one embodiment, reaction vessel  210  is formed of materials with sufficient strength to fully contain heated reactants and products, both during storage of the reactants and during and after reactions are completed. In another embodiment, reaction vessel  210  is sufficiently strong to maintain its shape when packaged in a pressurized container, such as when product P is pressurized. In yet another embodiment, reaction vessel body  211  and reaction vessel bottom  213  are formed from metal sheet having a thickness of approximately 0.2 mm to 0.8 mm. Thus for example, reaction vessel body  211  may be formed by stamping and reaction vessel bottom  213  is formed by stamping and rolling. 
         [0035]    Reaction vessel bottom  213  has a central portion  325  which may move axially towards first compartment  310 . Central portion  325  is adjacent to portion  207  of outer body  103  so that an inward movement of portion  207  will affect the volume of reaction vessel  210 . This motion may be used to activate thermal conditioning, as described subsequently. 
         [0036]    To provide thermal conditioning, reaction vessel  210  may, for example and without limitation, include two or more reactants separated during storage. As shown in  FIG. 3 , reaction vessel body  211  includes a top planar portion  311 , a top cylindrical portion  313 , a flange  321 , and a bottom cylindrical portion  323 . Reaction vessel  210  also includes a membrane  301  and a perforator  330 . Membrane  301  is attached to flange  321 , defining a first compartment  310 , having a volume V 1 , that is bound by top planar portion  311 , top cylindrical portion  313 , and the membrane, and a second compartment  320 , having a volume V 2  that is bound by the membrane, bottom cylindrical portion  323  and reaction vessel bottom  213 . 
         [0037]    In one embodiment membrane  301  is aluminum coated or laminated with polyethylene or polypropylene, and is jointed to flange  321  with an adhesive or by heat or cold seal. 
         [0038]      FIG. 4  is a sectional view  2 - 2  showing detail of one embodiment of perforator  330 , and  FIG. 5  is a top view of the perforator, which may be generally similar to the embodiments illustrated in  FIGS. 2A ,  2 B, and  3  except as further detailed below. Where possible, similar elements are identified with identical reference numerals in the depiction of the embodiments of  FIGS. 1 ,  2 A,  2 B,  3 ,  4  and  5 . 
         [0039]    Perforator  330  is contained within second compartment  320 . In one embodiment, perforator  330  formed from a plastic such as polypropylene and is loosely placed within second compartment  320 . Perforator  330  is adapted to move axially along reaction vessel  210  and pierce membrane  310 . Perforator  330  includes a base  401  having a plurality of holes  403 , and has a central protrusion  405  on one side of the base and guide members  407  and piercing elements  409  on the other side of the base. 
         [0040]    In one embodiment, guide members  407  include one or more portions that extend part or all the way around the circumference of perforator  330 . The purpose of guide members  407  is to prevent perforator  330  from canting while moving towards membrane  301 . In general, piecing elements  409  include one or more elements that extend toward membrane  301 . The purpose of piercing elements  409  is to provide a force to puncture membrane  301 . The plurality of holes  403  provide a way for the contents of second compartment  320  to move to accommodate the motion of perforator  330 , and for the contents of first compartment  310  and second compartment  320  to mix and react once the membrane is punctured. 
         [0041]    In general, perforator  330  is placed within second compartment  320  with central protrusion  405  adjacent portion  325 , guiding members  407  adjacent bottom cylindrical portion  323 , and piercing elements  409  adjacent membrane  310 . To prevent accidental perforation of membrane  301  it is preferred that there be at least several millimeters of space between the piercing elements  409  and membrane  301  or between central protrusion  405  and portion  325 . 
         [0042]    In one embodiment, volume V 1  of first compartment  310  is filled with a first reactant R 1  and volume V 2  of second compartment  320  is filled with a second reactant R 2 . As one example, which is not meant to limit the scope of the present invention, reactant R 1  is quicklime (also know as burnt lime or lime) lime and reactant R 2  is water. Quicklime consists primarily of calcium oxide (CaO) and it reacts with water to forming a hydrate and release heat via: 
         [0000]      CaO+H 2 O         Ca(OH) 2 +(1150 kj/kg of CaO) 
         [0043]    In some embodiments, it is preferred that only a portion of one or more of volume V 1  or V 2  is filled. This is particularly true when the reaction in an enclosed volume generates substantial pressure by heating the reactants and/or products, or by increasing the volume of a liquid or solid within the reaction vessel  210 . In one embodiment, 200 ml of a liquid food is heated from 20° C. to 60° C. with reaction vessel  210  having V 1  of 170 ml provided with 100 g of CaO granulated, and V 2  of 138 ml provided with 100 ml of water. This provides approximately 30% of free space in the unreacted reactant volume for expansion of the reactants and products in reaction vessel  210 . 
         [0044]    In other embodiments, reactants R 1  and R 2  may include a wide variety of compounds that are primarily select for their ability to produce or absorb heat without a large change in volume. Many such reactants are known in the field. The following combinations: calcium chloride and water are another set of reactants that are useful in generating heat. When one or more reactant R 1  or R 2  is a solid it is preferred, though not necessary for the solid to be granular to facilitate mixing and reactions. 
         [0045]    Reaction vessel  210  may be prepared by placing reaction vessel body  310  with top planar portion  311  downwards, filling volume V 1  with lime, sealing membrane  301  against flange  321 , placing perforator  330  in second volume V 1  with piercing elements  409  against the membrane, filling volume V 2  with water, sealing reactor vessel bottom  213  onto the reaction vessel body. Reaction vessel  210  then may be joined to outer body  103 , volume  202  may be filled with product P, and removable lid  101  may be sealed to opening  203 . 
         [0046]    In one embodiment, product P is pressurized when filling volume  202  (as would be the case for a carbonated beverage), and removable lid  101  is sufficiently strong to contain the pressure of the food. 
         [0047]    In another embodiment, product P and container  100  are sterilized separately, and the product is then sealed in the container. In yet another embodiment, container  100  is filled with product P and sealed, and then sterilized. Thus, for example, the container  100  having product P sealed within is sterilized by heating the container. 
         [0048]      FIGS. 6A-6D  are sequential sectional view of an embodiment of container  100  in use, where  FIG. 6A  is prior to use,  FIG. 6B  is during activation;  FIG. 6C  is during heating of the product; and  FIG. 6D  is just prior to consumption of the product. Container  100  of  FIGS. 6A-6D  may be generally similar to the embodiments illustrated in  FIGS. 1 ,  2 A,  2 B,  3 ,  4  and  5  except as further detailed below. Where possible, similar elements are identified with identical reference numerals in the depiction of the embodiments of  FIGS. 1 ,  2 A,  2 B,  3 ,  4  and  5 . 
         [0049]      FIG. 6A  shows container  100  in an upright and stored condition.  FIG. 6B  shows container  100  next turned upside down, with a force applied to portion  207 . As described above, the force of portion  207  causes portion  325  to move inwards, resulting in perforator  330  to translate within second compartment  320  and cause piercing elements  409  to puncture membrane  301 . With container  100  in this configuration, water within what was second compartment  320  drains into what was first compartment  310  and mix and react with the lime therein. Holes  403  permit perforator  330  to move through the water with reduced resistance and permit the water to easily mix with the lime. As the reaction proceeds, heat Q evolves from reaction vessel  210  and heats product P. 
         [0050]      FIG. 6C  shows container  100  righted for continued heating of product P, and  FIG. 6D  shows lid  101  removed so that the product may be consumed. 
         [0051]    Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. 
         [0052]    Similarly, it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. 
         [0053]    Thus, while there has been described what is believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention.