BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to the art of icemakers and, more particularly, to a refrigerator icemaker assembly which removes moisture from refrigerator air.
2. Description of the Related Art
In a domestic refrigerator, moisture tends to be attracted to the surface of the evaporator, which is usually the coldest spot in the refrigerator. The frost that forms on the evaporator reduces airflow and impedes the refrigerator heat transfer process. Therefore, refrigerators typically require either manual or automatic removal of frost buildup periodically in order to function properly. One approach to removing frost utilizes an electric heater. However, this type of defrost system is energy intensive and undesirably increases the temperature in the freezer compartment. The use of electric heaters for the purpose of defrosting an evaporator further entails the use of accessories (defrost heater shield, etc.), which adds to the cost of the system and reduces useable space within the refrigerator. Therefore, there is seen to exist a need in the art for an alternative defrost system which is more energy-efficient and avoids the drawbacks associated with electric heater-type defrosting systems.
SUMMARY OF THE INVENTION
The present invention is directed to a refrigerator including an icemaker moisture removal and defrost assembly. The moisture removal and defrost assembly includes an icemaking device having a moisture removal portion including a plurality of longitudinal fins defining a plurality of airflow channels located beneath an ice making cavity. A refrigerator airflow circuit circulates refrigerated air through the airflow channels before flowing across an evaporator. A refrigerant line connects the compressor, condenser, evaporator and icemaking device in series to cool the evaporator and the icemaking device. More specifically, the longitudinal fins of the moisture removal portion are cooled by the refrigerant line and any moisture in the refrigerated air is deposited on the longitudinal fins in the form of ice or frost. Thus, moisture that would otherwise condense on the evaporator is removed from the refrigerated air by the icemaking device.
Defrosting of the longitudinal fins may be performed either by a resistance heater adjacent the ice making cavity that can also be used for ice harvesting, by a hot gas defrost system, or a combination of both. When a hot gas defrost system is employed, hot gas from the condenser is supplied to the refrigerant line, whereby heated refrigerant flows through the icemaking device and melts any frost or ice accumulated on the moisture removal portion of the icemaking device.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an upper perspective view of a refrigerator with a portion cut-away to expose a compartment housing an icemaker moisture removal and defrost assembly of the present invention;
FIG. 2 is a schematic cross-sectional side view of the moisture removal and defrost assembly of FIG. 1;
FIG. 3 illustrates a top cross-sectional view of the moisture removal and defrost assembly of FIG. 1;
FIG. 4 is a top perspective view of a direct contact icemaker employed in connection with the present invention;
FIG. 5 is an exploded bottom perspective view of the icemaker of FIG. 4;
FIG. 6 is an alternative bottom fin arrangement for the icemaker of the present invention;
FIG. 7 is perspective side view of an alternative icemaker according to the present invention including side wall fins;
FIG. 8 illustrates one embodiment of a refrigerated fluid flow system including a hot gas defrost system according to the invention; and
FIG. 9 illustrates a refrigerated fluid flow system of the present invention including an alternative hot gas defrost system.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With initial reference to FIG. 1, a refrigerator, generally indicated at 2, includes a cabinet 4 within which is defined an icemaking compartment 8. As is well known in the art, cabinet 4 includes a freezer compartment 10 selectively accessed through the pivoting of a freezer door 11, and a fresh food compartment 12 (shown in FIG. 3) selectively accessed through the pivoting of a fresh food door 13. As is known in the art and shown in FIG. 2, refrigerator 2 also includes a lower machine compartment 16 housing a condenser 18 and a compressor 20. As depicted, an icemaker moisture removal and defrost assembly 30 in accordance with the present invention is arranged within icemaking compartment 8. In general, moisture removal and defrost assembly 30 includes a direct-contact icemaker or icemaking device 32, an ice bin 34, an evaporator 36 and a fan assembly 38. Among other components which will be discussed in more detail below, direct contact icemaker 32 is shown to include a moisture removal portion 40, a refrigerant loop 42 and a heating element 44.
An airflow circuit within refrigerator 2 is generally indicated at 45 as will now be discussed with reference to FIG. 3. As shown, icemaking compartment 8 is preferably located at an upper portion of freezer compartment 10, which is separated from fresh food compartment 12 by a mullion 46. An air inlet channel 50 extends through a front end portion of mullion 46 and provides an airflow channel from fresh food compartment 12 into icemaking compartment 8. Likewise, an airflow outlet channel 52 extends through a back end portion of mullion 46 and provides an airflow channel from icemaking compartment 8 into fresh food compartment 12. In use, moist refrigerated air from fresh food compartment 12 enters icemaking compartment 8 through air inlet channel 50 and is directed through airflow channels 54 defined by a plurality of longitudinal metal fins 56 extending from the moisture removal portion 40 of icemaker 32. As depicted in FIG. 3, fins 56 are preferably laterally spaced along the bottom of icemaker 32 and extend longitudinally along the bottom of icemaker 32. As the moist refrigerated air passes through airflow channels 54, moisture condenses on metal fins 56 and forms a layer of ice or frost. The now dryer refrigerated air passes out of airflow channels 54 and is directed through evaporator 36 by fan assembly 38, and then out through air outlet channel 52 into fresh food compartment 12.
Direct contact icemaker 32 will now be discussed in more detail with reference to FIGS. 4 and 5. In general, icemaker 32 includes a main body portion 58, an ice making cavity or ice mold 60, an ejector arm 62 rotatably mounted to main body portion 58 for ejecting ice cubes from ice mold 60, and a tray 64 for directing ice ejected from ice mold 60 into ice bin 34 (shown in FIG. 1). A heating system including heating element 44, preferably in the form of a sheathed, electric resistive heating element, may be utilized during an ice harvesting event in order to slightly melt ice formed within ice mold 60 to aid in harvesting of the ice. Advantageously, heating element 44 may also be effectively utilized to defrost moisture removal portion 40. More specifically, when an ice harvest or defrost event is desired, a controller (not shown) activates heating element 44, which then heats both fins 56 to melt ice or frost accumulated thereon, and ice mold 60 to slightly melt any ice formed therein to aid in harvesting the ice.
Mounting brackets 66 may be provided for securing icemaker 32 to a support structure (not shown) or evaporator 36 in icemaking compartment 8. As best seen in FIG. 5, refrigerant loop 42 extends through and is sandwiched between a support portion 68 attached to main body portion 58, and moisture removal portion 40. Moisture removal portion 40 includes the plurality of fins 56 which define airflow channels 54 there between for directing air flow along fins 56. In use, refrigerant loop 42 cools water within ice mold 60 to form ice cubes therein, while also cooling fins 56. As relatively warmer moisture-laden air from fresh food compartment 12 enters icemaking compartment 8 and comes into contact with the cold fins 56, moisture from the air condenses on fins 56 in the form of ice or frost, thereby removing moisture from the air before the air comes into contact with evaporator 36. Therefore, moisture which would otherwise accumulate on evaporator 36 is instead accumulated on fins 56 of icemaker 32.
In another preferred embodiment depicted in FIG. 6, an alternative moisture removal portion 40′ includes offset rows of fins 70-74, wherein each row of fins is offset from the previous row of fins, and define progressively narrower airflow channels 54′. For example, a first row of fins 70 includes eight longitudinal fins, and a second row of fins 71 includes ten fins that are slightly offset laterally from the first row of fins 70, as depicted in FIG. 6. With this configuration, as moisture-laden air advances through progressively narrower channels 54′, there is more surface area (more concentrated fins) for the air to come into contact with. Thus, by the time the refrigerated air from fresh food compartment 12 travels from an inlet side 80 of moisture removal portion 40′ and exits channels 54′ at an outlet side 81 of moisture removal portion 40′, all or most of the moisture in the air is removed from the air by the fins.
In accordance with another embodiment shown in FIG. 7, a direct contact icemaker 32′ includes a set of longitudinal side fins 90 which are spaced along the side of icemaker 32 and define airflow channels 92 there between. With this configuration, side fins 90 provide additional surface area to remove moisture from air traveling through icemaking compartment 8. More specifically, in addition to airflow through channels 54, 54′ of moisture removal portion 40, 40′, refrigerated air from fresh food compartment 12 may also be channeled through side channels 92 from an inlet side 93 of a main body portion 58′ to an outlet side 94 of main body portion 58′.
The manner in which refrigerant is circulated throughout a refrigeration system 100 in accordance with the present invention will now be discussed with reference to FIG. 8. In general, refrigeration system 100 includes a refrigerant line 102 which connects, in series, condenser 18 (including a condenser fan indicated at 104), compressor 20, evaporator 36 and icemaker 32. A first cap tube or expansion device 108 is located along refrigerant line 102 between compressor 20 and evaporator 36. In the preferred embodiment shown, refrigerant line 102 carries cooled refrigerant to evaporator 36 prior to icemaker 32. Due to a pressure drop through evaporator 36, refrigerant carried to icemaker 32 within refrigerant line 102 is cooler than refrigerant entering evaporator 36. However, an optional secondary expansion device 110 may be located between evaporator 36 and icemaker 32 to further cool refrigerant within refrigerant line 102 prior to icemaker 32. In this preferred embodiment, refrigerant loop 42 extending through moisture removal portion 40 of icemaker 32 is part of refrigerant line 102.
A heat exchange portion 120 is positioned along refrigerant line 102 between icemaker 32 and compressor 20 and between condenser 18 and evaporator 36. More specifically, a first portion 122 of refrigerant line 102 carrying cool refrigerant from icemaker 32 to compressor 20 is aligned adjacent a second portion 124 of refrigerant line 102 carrying warm refrigerant from condenser 18 to evaporator 36. Optionally, refrigeration system 100 also includes a hot gas defrost system 130 having a hot gas line 132 fluidly connected to a condenser portion 134 of refrigerant line 102 and a compressor line 136 by a three-way valve 138. In use, when a defrost event is desired, a controller (not shown) opens three-way valve 138 such that hot gas from compressor 20 travels through hot gas line 132 to refrigerant line 102 prior to evaporator 36 to heat refrigerant within refrigerant line 102 flowing through evaporator 36 in order to melt any frost or ice accumulated on evaporator 36.
In an alternative embodiment, rather than utilizing heating element 44, the heating system utilized by icemaker 32 comprises a hot gas defrost system 130′ depicted in FIG. 9. More specifically, hot gas line 132′ connects compressor 20 and refrigerant line 102 prior to icemaker 32 and after evaporator 36. In use, when a defrost event or ice harvesting event is desired for icemaker 32, a controller (not shown) opens three-way valve 138 such that hot gas from compressor 20 travels through hot gas line 132′ to refrigerant line 102 prior to icemaker 32 to heat refrigerant within refrigerant line 102 flowing through refrigerant loop 42 in order to melt any frost or ice accumulated on fins 56 and slightly melt any ice cubes formed within ice mold 60 during an ice harvest event. Alternatively, icemaker 32 may utilize both heating element 44 and hot gas defrost system 130′.
In addition to other advantages referenced above, the present invention provides for about 1.1 cubic feet of additional usable freezer compartment space based on previous side-by-side models due to the ability to use a smaller evaporator in place of a conventional evaporator. Further, the heating systems of the present invention eliminate the need for a conventional evaporator defrost heater.
Although described with reference to preferred embodiments of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, although not shown, it should be understood that refrigerant loop 102 may be reconfigured to carry refrigerant to icemaker 32 before evaporator 36. In general, the invention is only intended to be limited by the scope of the following claims.
Patent Application
20110252816
