Transparent Ice Maker

Abstract

An apparatus and method for producing substantially clear ice in a variety of desired shapes. The apparatus and method in the described embodiments generally provide for an insulated ice mold containing one or more mold cells, each mold cell with an open top, open bottom, and insulated side walls, that is suspended over a liquid water reservoir surrounded and contained in an insulated container. The top surface of the water residing in each mold cell is exposed to freezing air. The insulated walls forming the sides of one or more mold cells act to ensure that each ice shape forms and grows from the top surface, down and towards the bottom of each mold cell. The liquid water reservoir, which contacts the bottom surface of the ice shape, remains in a liquid phase and serves as an impurity sink into which the impurities and gases contained in the freezing water are driven as ice forms downward in the mold cell. The liquid water reservoir acts to arrest ice growth below the bottom of the mold cell, while the water in the mold cells freezes into a solid above the ice-water interface.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. Non-Provisional patent application Ser. No. 14 / 098,046 entitled “TRANSPARENT ICE MAKER” filed on Dec. 5, 2013 and claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 61 / 892,679, filed on Oct. 18, 2013 with the United States Patent & Trademark Office the complete disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates generally to an improved apparatus and method for making clear or transparent ice, and more specifically, to an apparatus and method for making clear or transparent ice in a variety of geometric shapes and which can be implemented in commonly available refrigeration / freezer equipment.[0003]Typical household and commercial refrigeration systems include separate refrigerator and freezing compartments. Ice cubes may be formed manually or automatically in various conventionally known manners uti...

AI Technical Summary

Benefits of technology

[0007]According to one aspect, the present invention provides an apparatus comprising an insulated ice mold form containing one or more mold cells, each mold cell with an open top, open bottom, and formed insulated side walls that is suspended over a liquid water reservoir surrounded and contained in an insulated container. The top water surface of the water residing in each mold cell is exposed to freezing air. The insulated walls forming the sides of one or more mold cells act to ensure that each ice shape forms and grows from the top surface of the ice shape forming within each mold cell, which is in contact with freezing air, down and towards the bottom of each mold cell during the freezing process. The liquid water reservoir, which contacts the bottom surface of the ice shape suspended in a mold cell terminating substantially at or near the ice-water reservoir contact level or interface, serves as an impurity sink into which the impurities and gases contained in the freezing water contained in each mold cell are driven as ice crystals form and ice growth occurs in each cell in a vertical downward direction. Likewise, the liquid water reservoir acts as a heat sink to resist freezing, while the ice shapes in the mold cells are freezing into a solid phase above the ice-reservoir water interface during the ice shape formation process. By leveraging the thermodynamic cooling properties in part resulting from the larger surface area to volume (SA / V) ratio of the individual mold shapes which are in fluid connection with the lower SA / V ratio of the liquid water reservoir the water reservoir remains available in liquid phase for an extended period of time to receive additional impurities and gases as the water in each mold cell transitions into a solid ice shape during the freezing process. The liquid water reservoir acts to substantially arrest additional solid ice shape growth beyond the bottom of the mold cell at or near the ice-water reservoir interface due to the high specific heat property associated with liquid water (the specific heat of water is 1 calorie / gram ° C.), and the substantially reduced surface area to volume ratio between the solid ice shape forming or formed in each mold shape and the liquid water reservoir.

[0008]Once the ice shape has grown to the desired dimension, which generally correlates to the vertical length or depth of the mold cells at or near the ice-water reservoir interface, the ice mold, with ice shapes contained in the one or more mold cells, is easily removed from the insulated container as the presence of the ice-liquid water reservoir interface provides a natural physical separation point between the ice shapes and liquid water reservoir. There is no need for mechanical cutting or thermoelectric separation equipment to separate the ice mold form from the insulated container. The frozen clear ice shapes may then be easily ejected by hand from the individual mold cells and immediately used for cooling purposes or placed in a freezer for storage. The ice mold form may then be replaced in the insulated container, re-filled with liquid water, and replaced in the freezer compartment for the production of additional clear ice.

[0009]According to another embodiment, the present invention provides an apparatus and method for forming clear or transparent ice in a variety of geometric shapes. The insulated ice mold form may be constructed and formed as a single-piece so as to yield clear or transparent ice in cubic, conical, square, spherical, hemi-spherical or other ice shapes as desired. In one embodiment, the insulated single-piece ice mold form is constructed in a cylindrical shape with a hemi-spherical bottom that minimizes surface area to volume (S / V) ratio for an extractable shape from the single-piece ice mold producing clear ice in the contemplated embodiment.

[0010]According to another embodiment, the present invention provides an apparatus and method for forming clear or transparent ice comprising an insert tray with one or more cells formed within the interior region of the insert tray. The insert tray is placed into and surrounded by an insulating jacket both of which are then inserted into an insulated container containing the liquid water reservoir. The insulating jacket surrounds and is in physical contact with the exterior sidewalls of the insert tray and acts to promote the formation of clear or transparent ice shapes within the cell or cells of the insert tray as later described herein. The insert tray may be constructed and formed of one or more pieces and shaped to produce a variety of clear or transparent ice in cubic, conical, square, spherical, hemi-spherical or other ice shapes as desired.

Problems solved by technology

Impurities and gases contained within the water to be frozen are trapped in the solidified ice cube during the freezing process, commonly near the center and / or the bottom surface of the ice cube, due to their inability to escape as a result of the freezing liquid to solid phase change of the ice cube surfaces.

The method and apparatus disclosed in U.S. Pat. No. 6,357,720 is also limited in its ability to produce clear ice cubes in that the gases vented during the freezing process must be diffused through the permeable sidewalls and the mold bottom at a faster rate than the liquid-to-solid phase change rate occurring in the ice mold.

However, the suspended and dissolved solids and liquids in the water freezing in the molds are not removed or liberated and remain in the resulting ice cubes.

Another drawback of these known apparatuses and methods for producing clear ice concerns their requirement of electro-mechanical energy inputs and assemblies, and / or specific construction materials (e.g. air permeable) that may only be formed and produced using technical construction methods and equipment in order to function and produce clear ice.

Moreover, they fail to produce a clear ice product as they are generally focused and drawn to the removal of a specific contaminant, such as gas bubbles or suspended solids, versus the removal of the combination of suspended and dissolved liquids, solids and gases which exist in unfrozen water and prevent the formation of clear ice.

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