Abstract:
The invention is directed to a produce chamber having an outer housing with a first panel, a second panel, and a base plate inter-dispersed between both panels. A door is placed between both panels to deposit and remove produce. Positioned within the first panel is a refrigeration system, which includes both ammonium absorption (AAF) system and a Peltier thermoelectric plate (TE) system. The AAF system includes a contact plate which communicates with a series of ducts having a first and second channel. The first channel circulates ammonia, while the second draws and then cools outside air for introduction into the produce chamber. The TE system is positioned proximate the contact plate to afford additional cooling, which has a plurality of parallel thermoelectric plates. A digital controller operates both the AAAF and TEC systems. Such controller also operates a scrubber, which includes zeolite powder, to remove ethylene.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an electric powered chamber to store fruits, vegetables and other food items at regulated temperatures. More specifically, the invention teaches a portable kitchen countertop electric that uses combination of ammonium absorption (AAF) and Peltier effect thermoelectric refrigeration (TE) to efficiently cool produce to allow longer storage for later consumption. 
       BACKGROUND OF INVENTION 
       [0002]    Fruits and vegetables have long been an important component of the human diet. Based upon their various nutrients and antitoxins, consumption of fresh produce helps provide important vitamins and nutrients to the human body. For example, fruits are typically high in fiber, water, vitamin C, and phytochemicals necessary for proper long-term cellular health and disease prevention. 
         [0003]    Regular consumption of fruit is associated with reduced risks of cancer, cardiovascular disease (especially coronary heart disease), stroke, Alzheimer disease, cataracts, and some of the functional declines associated with aging. Diets that include a sufficient amount of potassium from fruits and vegetables also help reduce the chance of developing kidney stones and may help reduce the effects of bone-loss. Fruits are also low in calories which would help lower ones calorie intake as part of a weight loss diet. 
         [0004]    Both fruits and vegetables ripen after they are removed from their associated plants and stalks. Such ripening often helps change the characteristics of the produce, including the sweetening of the fruit as well as changes in texture and firmness. Consumption of fruits and vegetables at the optimal point in the ripening process helps maximize not only taste and enjoyment of these foods, but also their health benefits. Ripening is the natural result of ethylene released by the produce. Maintaining most fruits and vegetables in an efficient cold chain after harvest helps extends and ensures shelf life—by reducing release of ethylene. However, storage of produce in an isolated area without refrigeration causes build up of ethylene and faster ripening (and resulting rotting) of fruit. 
         [0005]    Due to the costs and life spans of harvested fruits and vegetables, there have been many devices developed to address storage to maintain this cold chain. One such example is U.S. Pat. No. 4,845,958 entitled “Method of and Apparatus for Preserving Perishable Goods” to Senda. The apparatus taught by Senda relates to a refrigerated housing that includes a humidifier and a compression system to cool the housing. The device also uses an ethyl alcohol spray to help odorize the ripening produce. 
         [0006]    A second concept for preserving ripening produce is U.S. Pat. No. 5,661,979 entitled “Self-contained Refrigeration Device for Fruit” to Deboer. The Deboer patent teaches a self contained refrigeration unit that uses thermo-electric (TE) chips, as well as a heat sink to dissipate the heat generated by the TEC chips—to afford a cooled container which maintains the fruit. A double headed fan facilitates airflow throughout the assembly, to help remove ethylene through a vent tower. 
         [0007]    Yet a third example of a system for preserving fruit and vegetables is U.S. Pat. No. 5,782,094 entitled “Refrigerated Countertop Snack Container” to Freeman. Akin to Daboer, Freeman uses a Peltier effect thermoelectric element (instead of a compressor) to cool a refrigeration container. Such container is insulated and includes a series of air outlet and intake vents to aide in circulating air about the various snacks in order to reduce ethylene build up. The device further uses a series of fins to aide in circulation, as well as related baffles. 
         [0008]    As shown by the foregoing references, there are certain limitations in current counter-top style devices used to maintain fruits and vegetables. First, these devices are limited to using the Peltier effect (or traditional vapor compression systems) in combination with airflow to ward off the effects of build up. Second, current designs are largely inefficient and consume large levels of energy. Lastly, most of these designs fail to provide effective treatment of the ethylene which is the root of rotting and spoilage of the produce. Accordingly, there is a need in the art of produce storage for an energy efficient and robust chamber for use with fresh fruits and vegetables. 
       SUMMARY OF THE INVENTION 
       [0009]    The forgoing invention solves many of the limitations found in current produce storage devices. The invention is directed to a produce chamber capable of storing and maintaining a variety of fruits and vegetables at a controlled temperature, humidity and level of ethylene concentration. Such produce chamber may be configured to be a countertop appliance, and optionally can be modular such that they can be stacked for use in retail establishments like a grocer. Such stacking allows compact display of various produce allowing optimum ripeness and freshness. Additionally, the produce chamber is scalable so that a single unit could be designed to work as a countertop appliance and much larger single units could be designed for grocery stores. 
         [0010]    Such produce chamber comprises an outer housing having a first panel, a second panel, and a base plate inter-dispersed between both the first and second panels. The first panel includes a circular disk having a ring, a first wall, and a flat bottom portion which mirrors the width of the base plate. Preferably, such first panel may also include a series of vents capable of cooling the refrigeration system. Positioned between both panels is a door (which may translucent) having a handle. Through use of a top hinge, the door is capable of opening to allow placement and removal of produce. A two-part refrigeration system may be positioned within the first panel. Such refrigeration system may include combination of both an ammonium absorption (AAF) system and a Peltier effect thermoelectric (TE) system. 
         [0011]    The ammonium absorption (AAF) system includes an self contained ammonia water solution and a heat source. It has no moving parts and only requires a heat source to make the system work. The system has ammonia, a boiler, condenser, evaporator, storage tank, and an absorber. The evaporator sits on the inside of the unit and a fan directs air over it to cool the product chamber, and the balance of the system is located on the outside of the unit. 
         [0012]    The Peltier effect thermoelectric (TE) can be used as the refrigeration system for the produce chamber. Such thermoelectric (TE) system may include a plurality of thermoelectric modules in parallel relation to one another, laying side by side, or in series relation, stacked on top of one another. These modules have a heat sink on each side of them and a fan on each heat sink to improve their efficiency. The side of the plate that gets cool and its heat sink and fan are substantially inside the produce chamber, and the hot side of the plate and its heat sink and fan are substantially outside of the produce chamber. The produce chamber can use an AAF, a TE, or a combination of AAF and TE refrigeration systems to cool the air inside of the unit. 
         [0013]    Apart from the refrigeration system, the first panel may also include a scrubber capable of removing ethylene and a humidity regulator to prevent premature ripeness of the produce. Such scrubber may include a quantity of crystalline zeolite powder for purposes of removing ethylene from the air within the produce chamber. The last component of the produce chamber is a digital controller capable of operating the refrigeration system, as well as the scrubber sufficient to remove ethylene from the chamber. The controller may also read the humidity and the internal temperature. The controller may include a digital read out, which displays this information and provides updates to the user (U). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    For a fuller understanding of the invention, reference is made to the following detailed description, taken in connection with the accompanying drawings illustrating various embodiments of the present invention, in which: 
           [0015]      FIG. 1  is a perspective view of the produce chamber; 
           [0016]      FIG. 2  is a right side view of the produce chamber; 
           [0017]      FIG. 3  is a left side view of the produce chamber; 
           [0018]      FIG. 4  is front view of the produce chamber; 
           [0019]      FIG. 5  is an exploded view of the components of the produce chamber; 
           [0020]      FIG. 6  is a perspective view of the refrigeration system within the produce chamber; and 
           [0021]      FIG. 7  illustrates the preferred thermoelectric plate (TE) used within the produce chamber. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
         [0023]    As illustrated in  FIGS. 1-6 , the invention is directed to a produce chamber  100  used to store fruits, vegetables other related perishable foods to ensure ripeness. The produce chamber  100  helps regulate the temperature and humidity of fruits and vegetables and to ensure regulated and reduced levels of ethylene. In doing so, the produce chamber  100  helps maintain the proper ripeness of this produce after purchase from the store. While the invention contemplates a design for use on a kitchen countertop, the underlying technology can be used in related units, including produce chambers  100  that are stackable (i.e., for use as displays at grocers to maintain fruits and vegetables), and produce chamber  100  that are equal in size to current grocery store refrigeration units. 
         [0024]    As shown in  FIG. 5 , the components  101  of the produce chamber  100  comprises an outer housing  200 , a door  300  maintained by the outer housing  200 , a refrigeration system  400  and a controller  500  to help regulate temperature, humidity and ethylene concentration. In addition, the invention contemplates placement of a series of perforated trays  600  and a hook  630  within the outer housing  200  which help hold and maintain the stored produce. Other additional and related components  101  will be known and understood by those of ordinary skill in the art upon review of the figures and this disclosure. 
       The Outer Housing 
       [0025]      FIGS. 1 through 5  illustrate, by way of example, one embodiment contemplated by the invention for the outer housing  200 . First turning to  FIG. 1 , the outer housing  200  may include a first side panel  210 , a second side panel  220  and a base plate  230  (shown in greater detail in  FIG. 5 ). The side panels  210  and  220  are essentially parallel to one another in order to form two respective ends of the produce chamber  100 . The base plate  230  is inter-dispersed between both side panels  210  and  220 . Combination of these panels  210  and  220 , as well as the base plate  230  function as the outer casing of the outer housing  200 . This provides a rigid shell for the outer housing  200  in order to protect the integrity of the stored fruits and vegetables. What is more, such rigid shell further serves as a platform in which the various interior components  101  (shown in  FIG. 5 ) are maintained and held within the produce chamber  100 . 
         [0026]      FIG. 2  further illustrates one preferred shape, structure and configuration for the first side panel  210 . The first side panel  210  not only functions as part of the rigid outer housing  200 , but also maintains two primary components  101  of the produce chamber  100 . As shown in  FIG. 2  (as well as  FIG. 5 ), the first side panel  210  has a sufficient shape to house both the refrigeration system  400  and the controller  500 . The first panel  210  further allows for the separation of the cold and hot sides of the refrigeration system  400  as well as to cool the various components  101  housed by the first panel  210 . Moreover, this allows circulation of cooled and humidity controlled air inside the produce chamber  100  for purposes of removing ethylene. 
         [0027]    As shown in both  FIG. 1  and  FIG. 2 , the first panel  210  is preferably a circular disk  211  having an essentially flat bottom portion  212 . The bottom portion  212  illustrated in  FIG. 2  mirrors the width of the base plate  230  (shown in  FIG. 4 ). As also shown in  FIG. 5 , the base plate  230  perpendicularly engages the first flat wall  213  of the first side panel  210 . This allows the bottom portion  212 , and accordingly the entire produce chamber  100 , to rest on a flat surface like a kitchen countertop—or alternatively a display counter (such as in a grocery store). 
         [0028]    Turning back to  FIG. 1  (and also to  FIG. 4 ), the structure of the first panel  210  also includes a first ring  214  (in addition to the first flat wall  213  and the bottom portion  212 ). The first ring  214  is essentially circular, conforming to the shape of the bottom portion  212 . Moreover, the first ring  214  has a sufficient wall thickness so as to house and maintain the various components  101 —which may include both the refrigeration system  400  and the controller  500 . 
         [0029]    As shown in both  FIG. 1  and  FIG. 2 , both the first flat wall  213  and the first ring  214  may include a series of vents  216 . As shown, these vents  216  preferably include a side vent  217 , a panel vent  218  and a fan vent  219 . As shown in greater detail in  FIG. 5 , the primary function of the side vent  217  and the panel vent  218  is to allow the hot side heat sink fan  482  (shown in  FIG. 7 ) to pull ambient air in through the side vent  217  and the panel vent  218 , move it across the hot side heat sink  481  and then push the now hot air out through fan vent  219  so as to remove heat from the refrigeration system  400 . The secondary purpose is to pull ambient air in through the side vent  217  and panel vent  218  to cool the controller  500 . 
         [0030]    Both  FIG. 3  and  FIG. 5  illustrate, by way of example, the structure, positioning and features of the second panel  220 . As shown, the second panel  220  mirrors the size and dimension of the first panel  210 . Furthermore, the second panel  220  comprises a circular disk  221  having a second flat wall  223 , a second flat bottom portion  222 , and a second ring  224  of similar construction compared to the first panel  210 . Such bottom portion  222  mirrors the width of the base plate  230  (again shown in  FIG. 1  and  FIG. 5 ). 
         [0031]    Further shown in  FIG. 1 , this second panel  220  is essentially in parallel relation to the first panel  210 . However, the second panel  220  does not include a set of vents  216  nor does it maintain any portion of the refrigeration system  400  or the controller  500 . 
         [0032]      FIG. 5  illustrates, by way of example, the structure and features of the base plate  230 . As shown, the base plate  230  preferably includes a front raised edge  231 , a bottom panel  232 , a back raised edge  233  and a divider groove  234 . The front raised edge helps engage and creating a sealing relationship with the door  300 . Similarly, the back raised edge  233  both meets and connects to the back panel  350 . The divider groove  235  is a slit that has a sufficient length and depth so as to engage and maintain one or more perforated trays  600 . 
       The Door and Back Panel 
       [0033]    Both  FIG. 4  and  FIG. 5  illustrate, by way of example, the structure and characteristics of both the door  300  (which optionally may be translucent) and the back panel  350  which, along with the outer housing  200 , form the exterior of the produce chamber  100 . First turning to  FIG. 4 , the door  300  includes a first edge  301 , a corresponding second edge  302 , a top edge  303  and a corresponding bottom edge  304 . Moreover, at least a portion of the door  300  is preferably transparent and accordingly “see through”—such that a user (U) may be able to view the condition and quantity of fruits and vegetables within the produce chamber  100 . Preferably, a handle  340  is positioned proximate the bottom edge  304  of the door  300 . The handle  340  helps make it easier to lift up and open the door  300  to retrieve (or alternative store) produce. 
         [0034]    As shown in  FIG. 5 , the first edge  301  of the door  300  is preferably arced. This curvature should be substantially same as that of the first ring  214  of the first panel  210 . Likewise, the second edge  302  should have curve that mirrors that of the second ring  224  of the second panel  220 . Accordingly, when the door  300  is shut, a seal  310  forms between the first edge  301  and the first ring  214  (and correspondingly, the second edge  302  and the second ring  224 ). In addition, the bottom edge  304  forms a bottom seal  320  with the front raised edge  231  of the base plate  230 . 
         [0035]      FIG. 5  further illustrates, by way of example, the salient components  101  of the back panel  350 . As shown, the back panel  350  includes a first edge  351 , a corresponding second edge  352 , a top edge  353 , and a bottom edge  354 . The first edge  351  is sufficiently curved to match the shape of the first panel  210 , while the second edge  352  is likewise arced to mirror the diameter of the second panel  220 . As further shown, the bottom edge  354  forms a bottom seal  360  with the back raised edge  233  of the bottom plate  230 . 
         [0036]    A top hinge  390  connects the top edge  301  of the door  300  with the top edge  351  of the back panel  350 . As shown, the top hinge  390  allows the door  300  to swivel open and expose the various fruits and vegetables within the produce chamber  100 . Optionally, the back panel  350  may include an insulating layer  380 . This insulating layer can be sandwiched between the back panel  350  and an interior panel  385 . Such insulating layer  380  increases the efficiency of the system and reduces the need for the refrigeration system  400  to constantly run to provide cooled air within the produce chamber  100 . 
       Perforated Trays 
       [0037]      FIG. 5  further illustrates, by way of example, the positioning and orientation of the perforated trays  600  within the produce chamber  100 . As shown, the perforated trays  600  preferably include a horizontal tray  610  and a corresponding vertical tray  620 . Both trays  610  and  620  include a plurality of holes  601  to allow air to circulate. This helps ensure the reduction of ethylene within the produce chamber  100 , as well as a regulated internal temperature monitored by the controller  500 . 
         [0038]    As further shown in  FIG. 6 , the horizontal tray  610  is maintained through a slit  611  found within the second panel  220 . In contrast, the vertical tray  620  is maintained by both the horizontal tray  610  as well as the divider groove  234  located on the base plate  230 . Optionally, a hook  630  can be affixed to the top hinge  390  sufficient to hold and maintain bananas and similar fruits within the produce chamber  100 . 
       The Refrigeration System 
       [0039]    Both  FIG. 5  and  FIG. 6  illustrate, by way of example, one embodiment of the refrigeration system  400 . While several refrigeration systems  400  are capable of being used within the produce chamber  100 , the invention specifically contemplates combination of both an ammonium absorption (AAF) system  410  as well as a Peltier effect thermoelectric (TE) system  450 . While  FIG. 5  illustrates this two-part refrigeration system  400 , the invention also teaches use of just a single AAF system  410  without need for the TE system  450  or use of a single TE system  450  without the need for an AAF system  410 . 
         [0040]    Both  FIG. 5  and  FIG. 7  illustrate a TE system  450  generally comprised of a thermoelectric (TE) module  460  which is comprised of a cold side plate  470  and a hot side plate  480  and corresponding cold side heat sink  471  and cold side heat sink fan  472  and hot side heat sink  481  and hot side heat sink fan  482 . When electricity is applied to the TE module  460  the cold side plate  470  cools down and the hot side plate  480  heats up. A cold side heat sink  471  is thermally coupled to the cold side plate  470  which allows heat to be efficiently transferred from the inside of the produce chamber  100  to the cold side plate  470 . A cold side heat sink fan  472  increases the efficiency of the entire system. The cold side heat sink fan  472  also works to keep the air within the produce chamber  100  moving through the zeolite filter  491 . 
         [0041]    As further shown in  FIG. 7 , the heat that is being absorbed by the cold side plate  470  is being transferred to the hot side plate  480 . This heat is transferred through the thermally coupled hot side heat sink  481  which located outside of the produce chamber  100 . The hot side heat sink fan  482  is used to efficiently remove the heat from the hot side heat sink  481 . This heat is vented out through the fan vent  219 . 
         [0042]      FIG. 5  illustrates a AAF system  410  comprised of a boiler  420 , ammonia  421 , a condenser  422 , an evaporator  423 , a storage tank  424 , and an absorber  425 . A concentrated ammonia solution  421  is heated in the boiler  420  and driven off as vapor. The pressurized ammonia  421  gas is then liquefied in a condenser  422 . Supplied with hydrogen, it evaporates in the evaporator  423  and extracts heat from the storage container  424 . The ammonia  421  gas then enters the absorber  425  where it is reabsorbed in a weak solution of ammonia  421 . Finally, the saturated solution flows back to the boiler  420  where the whole cycle starts again. 
         [0043]      FIG. 6  illustrates one arrangement for the various components  101  of the two-part refrigeration system. Since the TE system  450  cools the produce chamber  100  by extracting heat from it. This heat must ultimately be removed from the entire produce chamber  100 . In turn, the AAF system  410  starts by heating ammonia  421  in the boiler  420 . The boiler  420  can be heated by any number of means; all that matters is that heat is provided to the boiler  420 . The invention specifically contemplates combination of both a TE system  450  and an AAF system  410 , wherein the heat from the TE system  450  hot side heat sink  481 , (which is normally wasted energy that must be removed from the produce chamber  100 ), be used to heat the AAF system  410  boiler  420 . By using what would normally be wasted heat from the TE system  450  to drive the AAF system  410 , the overall efficiency of the produce chamber  100  is dramatically increased. 
       The Controller and Scrubber 
       [0044]    The controller  500  is best illustrated in  FIG. 5 . There are three primary functions of the controller  500  contemplated by the invention. First, the controller  500  constantly monitors the temperature and humidity within the produce chamber  100 . Such information may be displayed by a digital readout  510  positioned and located on the first panel  210 . Second, the controller  500  operates the refrigeration system  400 . Such operation may include determining when to turn on the AAF system  410  and/or the TE system  450 . 
         [0045]    As a third duty, the controller  500  can also opt to circulate already cooled air within the produce chamber through a scrubber  490 —for purposes of removing toxins such as ethylene which may lead to premature ripening of the fruits and vegetables contained within the produce chamber  100 . Although a variety of scrubbers  490  known to those of ordinary skill may be used, the invention specifically contemplated use of a zeolite filter  491 . Such zeolite filter  491  should include a sufficient amount of a crystalline zeolite powder  492  capable of removing ethylene from the air within the produce chamber  100 .