System and Method for Rapidly Producing Clear Ice Shapes

RELATED APPLICATIONS

[0001]This application claims the benefit of U.S. Provision Application No. 63/741,852, filed Jan. 4, 2025.

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0002]In general, the present invention relates to systems and methods that are used to produce clear ice. Clear ice is ice that does not contain bubbles or other visible impurities within the matrix of the ice crystals. More particularly, the present invention relates to systems that flow water over an actively cooled surface to cause the water to freeze and create ice.

2. Prior Art Description

[0003]Clear ice is ice that does not contain gas bubbles or other visible impurities within the crystalline structure of the ice. This provides clear ice with the appearance of glass. Currently, there is an increasing demand for clear ice. Clear ice is used by bars to make high-end cocktails, Clear ice is also used by artists to produce ice sculptures.

[0004]Air contains multiple gases, such as nitrogen, oxygen and carbon dioxide that naturally dissolve in water. As the water freezes into ice, the dissolved gasses tend to be expelled either into the remaining water as desolated gasses, or as bubbles trapped in the ice. Very fine bubbles that become trapped in the ice cause the ice to appear as cloudiness. Increasing the freezing rate increases the level of dissolved gasses near the ice forming surface and increases the likelihood the gasses will form into bubbles in the ice. In the prior art, clear ice is typically made by placing an actively cooled surface under a flow of purified water. The flowing water near the ice forming surface flushes away the water with an elevated concentration of dissolved gasses as well as bubbles that have started to form. Without actively flowing water, the process relies on diffusion of the dissolved gasses in the water to avoid concentrations that would result in bubbles. The result is a block of clear ice. However, the most common problem associated with making clear ice is the long time period required to produce a block of clear ice. Introducing flowing water from an external source at any temperature not exactly 0 deg C. will introduce heat to the system and erode the ice. Flowing water erodes and melts ice as it contacts the ice. As such, in order to make clear ice under flowing water, the ice must be created at a rate greater than the ice is being eroded and melted by the flowing water, but not too fast as to trap gas bubbles within the ice.

[0005]Another problem associated with making clear ice is controlling the shape of the clear ice. As ice freezes to a cooled surface, a block of ice is formed that has the same peripheral shape as the cooled surface. If the ice is to be configured into more complex shapes, the ice must be cut, carved, or otherwise shaped after the ice is made. This adds great cost to producing clear ice in complex shapes.

[0006]In the prior art, attempts have been made to produce clear ice into shapes. This is primarily attempted using one of two methods. In a first method, the temperature of the mold is controlled with extreme precision to ensure that the ice forms slowly and does not trap air bubbles. Such prior art systems are exemplified by U.S. Pat. No. 9,651,290, entitled “Thermoelectrically Cooled Mold For Production Of Clear Ice”, and U.S. Pat. No. 9,574,811, entitled “Transparent Ice Maker”. In the second method, water is slowly sprayed onto a cold surface to form ice. The thin layers of ice are applied slowly, therein preventing air bubbles from becoming trapped in the ice.

[0007]Both the first method and the second method used in the prior art rely upon the slow creation of ice to form a shape. The slow production rate of ice makes such prior art systems less than ideal for using in making clear ice on a commercial scale, where rate of production is a determinant of equipment costs and profits.

[0008]In U.S. Pat. No. 9,696,079 to Boarman, entitled “Rotational Ice Maker”, an icemaker is disclosed that rocks the water within a mold by turning the mold 45 degrees in the horizontal plane. The rocking water slowly freezes and fills the mold. The rocking action, however, is incapable of completely filling a round mold or flat-top mold, thus the system creates imperfect shapes.

[0009]A need therefore exists for an improved system and method that can produce clear ice in a more rapid manner. A need also exists for a system and method that can produce clear ice in complex and complete shapes without carving. These needs are met by the present invention as described below.

SUMMARY OF THE INVENTION

[0010]The present invention is an ice making system and its associated method of making clear ice. Clear ice has the appearance of glass, wherein the ice is free of bubbles and other visible imperfections.

[0011]A mold is provided that defines an interior cavity. An open neck leads into the interior cavity and provides a pathway for water to be added into the interior cavity. A coolant system is used to cool at least the lower part of the mold to a temperature below freezing. Water is added to the mold to fill the interior cavity. The water is added through the open neck. Once the mold is full, no new water is added or circulated from an external source. This eliminates water flowing in from an external source and introducing heat that will limeade the ice forming process.

[0012]An agitator or similar device is coupled to the mold. The agitator provides continuous movement to the mold. This causes the water in the interior cavity to continuously move within the mold as the water freezes within the mold. The agitator is controlled to provide adequate water flow and flushing over the entire developing ice surface. Agitation of the water without variation can produce dead zones in the mold where the water does not move significantly. The agitator is varied to avoid any areas of slow moving water within the mold 12 that may otherwise naturally develop. This ensures that adequate levels of water flow over the total ice forming surfaces and flush away dissolved gasses to a level adequate to achieve clear ice.

[0013]As the moving water in the mold freezes, the water freezes from the bottom up. The mold is actively cooled until ice fills the interior cavity of the mold and at least part of the open neck. When the ice is removed from the mold, the ice in the open neck forms an ice nub. The ice nub is removed to leave a clean molded form of clear ice.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]For a better understanding of the present invention, reference is made to the following description of exemplary embodiments thereof, considered in conjunction with the accompanying drawings, in which:

[0015]FIG. 1 is a schematic of an exemplary ice making system illustrating the primary components of the system;

[0016]FIG. 2 is a schematic showing an exemplary embodiment for the mold and the agitator components of the ice making system;

[0017]FIG. 3 shows the mold of FIG. 2 at different stages of operation;

[0018]FIG. 4 shows an ice form removed from the mold and being worked to remove excess ice;

[0019]FIG. 5 shows an alternate embodiment of a mold with active cooling in both the upper and lower sections of the mold; and

[0020]FIG. 6 shows an alternate embodiment of a mold containing multiple cavities and one agitator.

DETAILED DESCRIPTION OF THE DRAWINGS

[0021]Although the present invention system and method can be embodied in many ways, only a few exemplary embodiments are shown. These embodiments are selected in order to set forth some of the best modes contemplated for the invention. The illustrated embodiments, however, are merely exemplary and should not be considered limitations when interpreting the scope of the appended claims.

[0022]Referring to FIG. 1, a conceptual overview of the present invention ice making system 10 is shown. The present invention ice making system 10 includes a mold 12. The mold 12 defines a cavity 14 that is shown as being generally spherical. However, the cavity 14 can have square shapes, polygonal shapes, character shapes, and object shapes. The mold 12 is preferably a two-part mold having a top section 16 and a bottom section 18. Both sections 16, 18 of the mold 12 can be actively cooled. However, in the preferred embodiment, only the bottom section 18 of the mold 12 is actively cooled. The top section 16 of the mold 12 can be the same material as the bottom section 18 of the mold 12. However, the top section 16 of the mold 12 is preferably made from a silicone or a like elastomeric material that has a low rate of thermal conductivity. This ensures that any water introduced into the mold 12 will freeze from the bottom up. The use of an elastomeric material for the top section 16 of the mold 12 also makes the removal of the top section 16 easier. It should also be understood that the use of two-part molds is exemplary and multi-section molds can also be used.

[0023]A cylindrical neck 21 leads into the top of the mold 12. The cylindrical neck 21 is used to introduce water 26 into the cavity 14 of the mold. An optional fill chamber 25 can be provided, wherein water 26 flows into the cylindrical neck 21 and into the mold cavity 14 from the fill chamber 25. The fill chamber 25 can have a lid 27 to prevent spillage of water 26 during operations.

[0024]The ice making system 10 has a programmable controller 24 that runs through the use of operational software 22. The mold 12 is connected to an agitator 20 that is capable of producing constant movement of the water within the mold 12. The operational frequency of the agitator 20 and/or the direction of movement can be controlled by the programmable controller 24.

[0025]Water 26 is prepared and added to the fill chamber 25. Although the water 26 can be added slowly, it is preferred that enough water is added to the fill the chamber 25 all at once and to slightly overfill the mold cavity 14. The excess water 26 partially fills the cylindrical neck 21. During operations, the water 26 may momentarily splash back into the fill chamber 25. This keeps all the water 26 local and avoids the need for new water 26 being introduced from the outside. The arrangement also provides the water with a large area exposed to air. This large exposed surface area, along with agitation, aids in relieving the water 26 of its elevated dissolved gas burden.

[0026]The water 26 can be ordinary tap water but is preferably highly purified water, with dissolved solids removed by distillation, reverse osmosis, or some other means. The water is preferably chilled to near 0 C. Since the water 26 is provided in a volume sufficient to fill the mold cavity 14, no new water with its inherent heat needs to be added. If tap water is used, the water 26 passes through a filter 28 to remove sediments from the water 26. The filtered water 26 is then cooled to approximately one degree centigrade using a precooler 30. The cooled filtered water 26 is provided to the mold 12 in a volume sufficient to fill the mold.

[0027]As water 26 enters the cavity 14 of the mold 12 from the fill chamber 25, the agitator 20 causes the water 26 to swirl and otherwise move within the cavity 14. The speed and/or rotational direction of the agitator 20 is controlled to achieve a high degree of movement within the cavity 14. Such movement of the water 26 promotes adequate flushing over the entire developing ice surface. Controlling the agitator 20 ensures that the water does not create a waterflow pattern within the mold 12 that has areas of no or slow water movement. The purpose of varying the agitator 20 is to ensure that water flows quickly over water/ice interface that develops in the mold 12. One agitator setting may flush one area of the ice surface very well while leaving another area of ice surface relatively undisturbed. If left alone, this undisturbed area will develop cloudy ice. By varying the settings of the agitator 20 a high water flow is developed that flushes the previously under disturbed area.

[0028]The mold 12 is cooled using a coolant system 34. The coolant system 34 can be any system capable of cooling the mold 12 to temperatures below freezing in a controlled manner. The coolant system 34 can cool the mold 12 using Peltier devices, wherein the mold 12 is in direct contact with the Peltier devices. Likewise, the coolant system 34 can be a traditional refrigeration unit that passes refrigerant through the mold 12. However, in the preferred embodiment, the coolant system 34 has a refrigeration unit that cools a heat transfer fluid 36, such as glycol. The heat transfer fluid 36 is then pumped through the mold 12 to lower the temperature of the mold 12.

[0029]Referring to FIG. 2, a functional exemplary embodiment of an ice making system 40 is shown. In this embodiment, there is a mold 42 with a lower section 44 and an upper section 46. The lower section 44 defines a semicircular recess 48 with a maximum diameter D1. The upper section 46 also defines a semicircular recess 50 with a maximum diameter D1. However, the upper section 46 also has an open cylindrical neck 52 that leads vertically into the semicircular recess 50. The cylindrical neck 52 has a second diameter D2 that is between thirty percent and sixty percent of the maximum diameter D1 of the semicircular recesses 48, 50. Such a size is required to achieve adequate motion of water 26 within the cylindrical neck 52, as is later explained. When the mold 42 is closed, the lower semicircular recess 48 and the upper semicircular recess 50 define a spherical cavity 54 with the cylindrical neck 52 extending vertically from the top of the spherical cavity 54. The cylindrical neck 52 leads into a fill chamber 55.

[0030]In this embodiment, only the lower section 44 of the mold 42 is actively cooled. Coolant pathways 56 are formed in the lower section 44 under the lower semicircular recess 48. The coolant pathways 56 are near the curvature of the lower semicircular recess 48. This produces a thin floor 58 in the lower section 44 between the lower semicircular recess 48 and the coolant pathways 56. The thin floor 58 is preferably less than 6 mm thick for plastic materials to ensure rapid heat transfer between the coolant pathways 56 and the spherical cavity 54. However, larger thicknesses can be used when highly thermally conductive material, such as aluminum, is used. What is important is that the coolant can draw heat from the water in the mold 12 in a time efficient manner. The coolant pathways 56 connect to a coolant intake port 60 and a coolant output port 62 so that flow of coolant 64 through the coolant pathways 56 can be constantly maintained.

[0031]In the embodiment of FIG. 2, the agitator 66 is embodied as an electric motor 68 with an eccentric linkage 70. The eccentric linkage 70 attaches a shaft 72 of the electric motor 68 to the bottom center of the lower section 44. The electric motor 68 is a variable speed motor that enables the rotational speed of the shaft 72 and eccentric linkage 70 to be selectively adjusted.

[0032]Referring to FIG. 3 in conjunction with FIG. 2, it will be understood that the lower section 44 of the mold 42 is actively cooled to a temperature below freezing. Water 26 is introduced into the fill chamber 55. The water 26 flows through the cylindrical neck 56 and fills the spherical cavity 54 within the mold 42. The mold 42 is being moved by the agitator 66, therein causing the water 26 to move within the mold 12. As the water 26 moves in the spherical cavity 54, the water 26 begins to freeze against the surface of the mold 42 from the bottom of the mold 42 upward. As the water 26 freezes and ice 74 begins to build up on the interior of the mold 42. As the water 26 freezes to ice 74, the ice 74 cannot hold the gases in solution like water. Initially, the gases are dissolves back into the remaining water 26 next to the ice/water interface. However, the water 26 next to the ice/water interface has an even higher concentration of dissolved gasses. Natural Diffusion tries to spread the concentrated gasses throughout the remaining water 26, but it's a slow process. Eventually the level of dissolved gasses in the water 26 next to the ice/water interface is too great and some gases emerge on the other side of the ice/water interface as bubbles that can get trapped in the ice 74. The liquid water 26 is moving and washes over the ice 74. This flushes away water 26 with an elevated dissolved gas burden caused by the ejection the gasses from the developing ice 74. The moving water 26 flushes the high gas burden water away before it reaches a concentration that will cause the ejected gasses to emerge as bubbles that can be trapped in the forming ice 74.

[0033]As the water 26 freezes, the spherical cavity 54 fills with ice 74 from the bottom to the top. Once the spherical cavity 74 is full, the ice spreads into the cylindrical neck 52. The diameter D2 of the cylindrical neck 52 is large enough to maintain constant movement of water 26 within the cylindrical neck 52 for as long as free flowing water remains. As the water 26 freezes to ice 74, an ice nub 76 is created above the spherical cavity 54. Once the ice nub 76 is formed, the active cooling stops. The mold 42 can then be opened and a clear molded ice form 78 can be removed. To assist in the opening of the mold 42, the coolant can be warmed to a temperature above freezing. This adds heat to the mold 42 and helps the ice form 78 to separate from the mold 42.

[0034]Referring to FIG. 4, it can be seen that the ice nub 76 on the molded ice form 78 is superfluous and needs to be removed in order to perfect the shape of the molded ice form 78. A heated iron 80 is provided. The heated iron 80 has a contact surface 82 that matches the desired shape of the molded ice form 78. The heated iron 80 is caused to contact the molded ice form 78 to melt the ice nub 76. Once the ice nub 76 is removed, the molded ice form 78 is complete. The molded ice form 78 is completely made of clear ice and is ready for use. The molded ice form 78 can be stored in a freezer or any location that is below freezing. Should frost accumulate on the molded ice form 78 during storage, the frost can be rapidly removed by quickly passing the ice form 78 under running water or submersing the ice form 78 in water. The frost will melt leaving the ice form 78 with its crystal clear appearance.

[0035]In the exemplary embodiments thus described, only the lower section of the mold is actively cooled. This is to ensure that the water in the mold freezes starting at the bottom of the mold, wherein the ice progresses upwardly. In larger molds, the top section of the mold can also be actively cooled while maintaining the bottom-to-top freeze profile. Referring to FIG. 5, an alternate mold 83 is shown that has a top section 84 and a bottom section 85. Primary coolant pathways 86 are formed in the bottom section 85 in the manner previously described. In this embodiment, secondary coolant pathways 87 are formed in the top section 84. The secondary coolant pathways 87 cool the lowest parts of the top section 84. In addition, the secondary coolant pathways 87 have less surface area than the primary coolant pathways 86. Lastly, the secondary coolant pathways 87 have separate inputs and outputs so that the volume of coolant flowing through the secondary coolant pathways 87 can be controlled separately. In this manner, the secondary coolant pathways 86 can actively cool the top section 84 of the mold 83 without affecting the bottom-to-top ice formation pattern.

[0036]In the embodiment of the system described, only one mold is shown being agitated by an agitator 20. It should be understood that molds can be formed as multicompartmental trays, wherein each tray is connected to a single agitator. Referring to FIG. 6, such a multicompartment tray 90 is shown. The number of molds 92 on each tray 90 can vary from two to one hundred. Since multiple molds 92 are on each tray, water can be supplied using a single fill chamber 94. The fill chamber 94 can interconnect many molds cavities 92. If water overflows or spills out of any one mold cavity 92, it will flow into another adjacent mold cavity 92. Otherwise, each of the mold cavities 92 forms clear ice in the manner previously described.

[0037]It will be understood that the embodiments of the present invention that are illustrated and described are merely exemplary and that a person skilled in the art can make many variations to those embodiments. All such embodiments are intended to be included within the scope of the present invention as defined by the claims.