Abstract:
The present invention includes an ice and beverage dispenser having an icemaker associated therewith. The icemaker has a refrigeration system that includes a compressor, a condenser and an evaporator. A refrigerant line exiting the condenser is routed through a drip tray of the dispenser before returning to an expansion valve for release of refrigerant into the evaporator. The refrigerant exiting the condenser is at a temperature of from about 100° to 140° F. and provides sufficient heat energy, as it passes through the drip tray, to melt any ice in the drip tray. The additional cooling of the refrigerant as it melts the ice prior to expansion of the refrigerant into the evaporator improves the cooling performance and efficiency of the refrigeration system.

Description:
[0001]    This application claims benefit of provisional application Serial No. 60/469,515, filed May 9, 2003. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to ice and beverage dispensing equipment, and more specifically to such equipment having a capability to prevent ice buildup on and in a drip tray thereof.  
         BACKGROUND OF THE INVENTION  
         [0003]    Combination ice and beverage dispensing machines typically have several beverage dispensing valves and a single ice dispensing chute positioned on the dispenser above a drip tray. Such dispensers also include an ice retaining bin having an ice dispensing mechanism for delivering ice on demand to and through the ice dispense chute. The drip tray serves as a platform on which a receptacle, such as a cup, can be placed as it is being filled with beverage and ice. The drip tray support surface or cup rest usually comprises a wire grate with spacing between the wires to allow any spilled beverage to flow through the grate to a lower drain.  
           [0004]    The accumulation of ice in the drip tray of an ice/beverage dispenser is an ever present problem in the beverage dispensing industry. Since a cup is often hand held during dispensing, and particularly when being filled with ice, it is not always necessary that the drip tray grate provide a cup rest in the area directly below the ice dispensing chute. Thus, the grate wire spacing below the ice chute can be increased or eliminated to permit any spilled ice particles to fall directly into the drip tray and not build up on the grate. The inherent volume of the drip tray below the cup rest grate can often accommodate enough ice during casual use of the dispenser that buildup of ice above the level of the grate is not a problem. However, during periods of high use sufficient ice can spill into the drip tray faster than the ice can melt, such that a significant volume of ice can accumulate in the tray and extend up above the cup rest surface of the grate. A buildup of ice in this manner can interfere with physical placement of a cup below the ice dispensing chute and will eventually lead to ice falling from the drip tray onto the floor area surrounding the dispenser. Thus, in addition to making use of the dispenser more difficult, drip tray ice buildup can result in the floor area around the dispenser becoming wet and having particles of ice thereon, which presents cleanliness and safety hazard problems.  
           [0005]    Attempts have been made to prevent ice buildup on and in drip trays. Other than simply manually removing the ice, one approach has been to pour hot water into the drip tray to melt residual ice. However, this type of task is not something that is regularly scheduled and may not be timely performed. It also is possible that a buildup of ice can happen quickly enough that its presence may not be appreciated before a dangerous condition develops. Electrical resistive heating elements have been used to melt accumulated drip tray ice, but the cost of using such elements can be high if separate temperature sensing and control means are used to maintain and operate the heating elements within a predetermined temperature range, and where no controls are used in order to reduce initial costs, the heating element simply runs continuously, wasting power when heating is not required. Also, should such control mechanisms fail, the heating elements can possibly reach temperatures above what would be practical or safe for standard plastic drip trays.  
           [0006]    Another approach to controlling an accumulation of drip tray ice is described in U.S. Pat. No. 6,107,607, issued Aug. 22, 2000 to Thaddeus M. Jablonski, the present inventor, assigned to the assignee of the present invention and the teachings of which are specifically incorporated herein by reference. According to said patent, the drip tray is rid of ice through an electrical heating element placed in the tray and having a positive temperature coefficient. In this manner, when ice is present in the tray the element is cooled, causing its electrical resistance to decrease and an increased current to flow through the element to heat the element and melt the ice. This approach works well, is less expensive to implement and generally uses less energy than conventional heating elements placed in drip trays, but it nevertheless requires the use of further energy.  
           [0007]    Accordingly, it would be desirable to have a way of eliminating or minimizing drip tray ice buildup problems in a manner that does not require manual intervention or the use of additional energy and that is safe, reliable and of relatively low cost.  
         OBJECTS OF THE INVENTION  
         [0008]    An object of the present invention is to provide a safe and reliable system for preventing an accumulation of ice in a drip tray of an ice and beverage dispenser.  
           [0009]    Another object is to provide such a system in which an accumulation of ice in the drip tray is prevented by melting any ice as may enter the drip tray.  
           [0010]    A further object is to provide such a system in which heat absorbed by ice in the drip tray as it is melted increases the operating efficiency of an icemaker associated with the ice and beverage dispenser.  
         SUMMARY OF THE INVENTION  
         [0011]    In accordance with the present invention, apparatus for making and dispensing ice comprises an ice dispenser having an ice dispensing chute and a sink below the chute; and an icemaker for making and delivering ice to the ice dispenser and having a high pressure refrigerant line, a portion of which refrigeration line extends within the ice dispenser sink to melt any ice in the sink.  
           [0012]    In a preferred embodiment of the invention, an ice/beverage dispenser having a drip tray is associated with an icemaker. The icemaker includes a refrigeration system having a compressor, a condenser, an expansion valve and an evaporator. A high pressure refrigerant line extends from an outlet from the compressor to an inlet to the condenser and a further refrigerant line extends from an outlet from the condenser to an expansion valve for releasing high pressure refrigerant into an inlet to the evaporator, which refrigerant then expands and causes cooling of the evaporator. In the present invention, the refrigerant line exiting the condenser outlet does not extend directly to the expansion valve, but instead is routed through the ice/beverage dispenser drip tray before returning to the expansion valve. Refrigerant exiting the condenser has been “cooled,” but remains “warm” at a temperature of from about 100° to 140° F., and the heat energy of this refrigerant is used, as it passes through the drip tray, to melt any ice in the drip tray. As a side benefit, in the process of transferring heat energy to the ice, the refrigerant is further cooled prior to expansion of the refrigerant into the evaporator, which improves the cooling performance and operating efficiency of the refrigeration system.  
           [0013]    The invention also contemplates a method of eliminating ice from a sink of an ice dispenser that is associated with an icemaker for making and delivering ice to the ice dispenser and that has a high pressure refrigerant line. The method comprising the step of thermally coupling a portion of the refrigerant line to ice in the sink.  
           [0014]    In a preferred practice of the method, ice is eliminated from a drip tray of an ice and beverage dispenser that has an associated icemaker that makes ice for dispensing by the dispenser. The icemaker is of a type that utilizes a compressor, a condenser, an evaporator and an expansion valve having an inlet coupled to high pressure refrigerant at an outlet from the condenser and an outlet coupled to an inlet to the evaporator. To melt ice in the drip tray, the method comprises the step of thermally coupling the high pressure refrigerant to the ice.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view of an icemaker and an ice and beverage dispenser that embody the teachings of the present invention;  
         [0016]    [0016]FIG. 2 is a schematic representation of the icemaker and the ice and beverage dispenser;  
         [0017]    [0017]FIG. 3 is a top plan view of a heated drip tray of the ice and beverage dispenser, and  
         [0018]    [0018]FIG. 4 is a cross-sectional view of another embodiment of heated drip tray. 
     
    
     DETAILED DESCRIPTION  
       [0019]    The present invention is adapted for use with an ice and beverage dispenser having an associated icemaker as shown in FIG. 1 and indicated generally at  10 . The dispenser  10  is adapted to rest on a countertop  11  or other suitable surface and includes an upper ice making portion or icemaker  12  having an external housing  13  and a lower ice and beverage dispensing portion or ice/beverage dispenser  14  having an external housing  16 . The icemaker  12  includes a refrigeration system including a compressor  18 , a condenser  20  and an ice making evaporator  22 . The ice/beverage dispenser  14  includes a merchandising cover  24 , an ice dispensing chute  26 , a splash panel  27  and a plurality of post-mix beverage dispensing valves  28 .  
         [0020]    Referring also to FIG. 2, a drip tray or sink, indicated generally at  29 , is at the lower front of the ice/beverage dispenser  14  and is positioned below the ice dispensing chute  26  and the beverage dispensing valves  28 . The drip tray  29  includes a removable cup rest or metal grate  30  resting on an upper perimeter edge  31  of perimeter walls  32  of the drip tray. A drip tray volume or interior space  33  is defined within the drip tray  29  below the grate  30 , within the perimeter walls  32  and above a bottom drain surface  34  of the drip tray. The bottom drain surface  34  serves to direct waste fluids as may enter the drip tray to a drain  35 . As is conventional, the drip tray can be a rigid plastic structure and include foam insulation material  36  (FIG. 4)  
         [0021]    In use of the dispenser  10 , ice dispensed from the ice dispensing chute  26  that does not enter a receptacle or cup can accumulate in the interior  33  of the trip tray  29  and on the drip tray top grate  30 . So that an accumulation of such ice can be eliminated before it presents problems, according to the present invention a readily available source of heat from the icemaker  12  is used to melt any ice as may enter the drip tray  29  or rest on its grate  30 . This source of heat from the icemaker is the “heat-of-rejection” produced at the condenser  20 , which heat is rejected as “waste” heat in operation of the icemaker in order to cool the evaporator  22  to make ice. The condenser  20  typically operates at a temperature in the range of from about 110° to 140° F., and this heat energy can be tapped and delivered to the drip tray or sink area to melt any ice as may accumulate in the drip tray  29  and/or on its grate  30 . A typical 500 pound per day icemaker rejects over about 11,000 Btu per hour during ice making cycles, only a small portion of which heat need be utilized to effectively melt any accumulation of such ice. This may be accomplished by routing a high pressure refrigerant line that exits the condenser  20  into the interior  33  of the drip tray  29  or to a heat sink located in the drip tray interior, so that a safe and effective supply of heat will be delivered to the drip tray interior to melt any ice accumulated therein. Under the circumstance where no ice is present in the drip tray, temperatures in the drip tray will not rise excessively and will remain at safe levels. A side benefit realized by directing evaporator heat to the drip tray is that a small performance gain will be realized by the icemaker in the melting of ice as a result of additional sub-cooling of the high pressure refrigerant when the refrigerant gives up heat to melt ice in the ice tray.  
         [0022]    As best seen in FIG. 2, the refrigeration system of the icemaker  12  includes a low pressure refrigerant line  37  extending between an outlet from the evaporator  22  and an inlet to the compressor  18  and a high pressure refrigerant line  38  extending from an outlet from the compressor to an inlet to the condenser  20 . Another high pressure refrigerant line  40  extends between an outlet from the condenser  20  and an expansion valve  42  coupled to an inlet to the evaporator  22 . However, unlike the situation that exists in a conventional icemaker where a high pressure refrigerant line at an outlet from a condenser would lead directly to an expansion valve, according to the invention the high pressure refrigerant line  40  is routed from the condenser outlet first downward through and within the housing  16  of the ice/beverage dispenser  14  to a lower front end of the housing where the line exits forward from the housing into the interior space  33  of the drip tray  29 . As also seen in FIG. 3, the refrigerant line  40  includes a tortuously configured portion, such as a serpentine portion  40   a,  that is located and extends in a plane within the interior space  33  of the drip tray  29 . Beyond or downstream from (with respect to the direction of refrigerant flow) its serpentine portion  40   a , the refrigerant line  40  extends rearward back into the ice/beverage dispenser housing  16  and then returns upward through and within the housing to the expansion valve  42  of the icemaker  12 . As is apparent and will be more fully described, in operation of the icemaker  12  the serpentine portion  40   a  of the high pressure refrigerant line  40  will be warm and the heat provided by the serpentine portion within the drip tray will melt ice in the drip tray and on its grate.  
         [0023]    The drip tray grate  30  is preferably made of stainless steel for heat conductivity, strength, resistance to rust and appearance, and is in heat exchange relationship with the serpentine line portion  40   a  of the high pressure refrigerant line  40  within the interior  33  of the drip tray  29 . Various thermally conductive heat exchange support/connecting structures  44  can be removably placed within the interior  33  of the drip tray  29  to provide for retention of the refrigerant line serpentine portion  40   a  in a fixed position within the drip tray and in heat exchange relationship with the grate  30 . To provide satisfactory heat exchange relationship and good thermal conductivity between the grate  30  and the refrigerant line portion  40   a , the support structures  44  are advantageously made of a suitable heat conducting material, such as aluminum or stainless steel. As seen in FIG. 2, further thermal mass and ice melting capability can be provided in the drip tray  29  by a metal plate or liner  46  extending on and along the drip tray bottom drain surface  34 , which plate is placed in thermal contact with the high pressure refrigerant line serpentine portion  40   a  by means of thermal connectors  44  extending between the plate and the serpentine line portion. In an alternative arrangement shown in FIG. 4, the refrigerant line serpentine portion  40   a  can be positioned below the metal plate or liner  46 , between the plate and the drip tray bottom drain surface  34 , so that it is more protected from accidental mechanical damage. In this alternative embodiment, removable thermal connectors  44  may be used to provide thermal connection between the plate  46  and the grate  30  as the plate is heated by the refrigerant line serpentine portion  40   a.    
         [0024]    In operation of the invention, when the icemaker  12  operates to make ice, hot high pressure refrigerant flows through the refrigerant line  38  from the outlet from the compressor  18  to the inlet to the condenser  20 . As is understood, the hot refrigerant is cooled by the operation of condenser  20 , but the refrigerant as it leaves the condenser and flows through the refrigerant line  40  will still be warm. This warm refrigerant flows through the refrigerant line  40  to and through the refrigerant line serpentine portion  40   a  within the interior  33  of the drip tray  29 , where the warm refrigerant gives up heat energy to melt any ice in the drip tray or as may be resting on the drip tray grate  30 . Melting of ice within the drip tray and on its grate will be enhanced to the extent that there is suitable thermal mass with which the high pressure refrigerant line serpentine portion  40   a  is in thermal contact, such as the grate  30 , the metal connectors  44  and the metal liner  46 .  
         [0025]    An additional benefit to melting ice in the drip tray  29  through use of warm refrigerant exiting the condenser  20  of the icemaker  12  is that the heat exchange process will result in high pressure refrigerant in the refrigerant line  40  being further cooled before it reaches and passes through the expansion valve  42  into the evaporator  22 , which will improve the cooling ability and efficiency of the of the icemaker. Consequently, in the process of advantageously using warm refrigerant to melt and eliminate the problems associated with an accumulation of waste ice in the drip tray  29 , the capacity of the waste ice to absorb heat from the refrigerant beneficially results in improvements in icemaker operating efficiency.  
         [0026]    While embodiments of the invention have been described in detail, various modifications and other embodiments thereof may be devised by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.