Systems and methods for producing ice

Abstract

In accordance with the principals of the present invention, an ice machine, tray, and process for producing high-quality, substantially clear ice is provided. A heat exchanger in the ice machine removes energy from liquid, cooling the liquid from room temperature to freezing temperature, then overcomes the heat of fusion to form ice. The tray containing a liquid is received in a freezing/mixing chamber. The tray includes an energy transfer surface in thermal contact with the heat exchanger to define a liquid/ice boundary layer. The tray further includes at least one freezing cavity having geometry defining surfaces to form the geometry of the ice. An egress area is defined in the tray above the geometry defining surfaces. A mixing mechanism is provided in operative communication with the liquid to create a velocity profile at the liquid/ice boundary layer to create a directional freezing process starting from the energy transfer surface of the tray in thermal contact with the heat exchanger and growing through the freezing cavity up to the egress area. The velocity profile at liquid/ice boundary enables impurities to be washed away during the freezing process, deterring impurities from getting entrapped in the ice. Impurities in the liquid are thereby washed away and concentrate in a pool away from the ice, ultimately in the egress area of the tray to be purged. In addition, in embodiments sensors can be provided to provide various functions selected from the group consisting of, for example, determining ice creation status, determining freezing height, varying ice creation, determining tray presence, detecting freezing/mixing chamber door position, determining liquid level, and combinations thereof.

What is claimed is: 
     
         1 . An ice machine comprising:
 a heat exchanger that removes energy from liquid, cooling the liquid to freezing temperature, then overcoming the heat of fusion to form ice;   a freezing/mixing chamber adapted to receive a tray, the tray containing the liquid;   the tray comprising an energy transfer surface in thermal contact with the heat exchanger to define a liquid/ice boundary layer, at least one freezing cavity having geometry defining surfaces to form the geometry of the ice, and an egress area; and   a mixing mechanism in operative communication with the liquid to create a velocity profile at the liquid/ice boundary layer to create a directional freezing process starting from the energy transfer surface of the tray in thermal contact with the heat exchanger and growing through the freezing cavity up to the egress area;   whereby the velocity profile at liquid/ice boundary enables impurities to be washed away during the freezing process, deterring impurities from getting entrapped in the ice and encouraging impurities to pool away from the ice, ultimately in the egress area of the tray to be purged.   
     
     
         2 . The ice machine of  claim 1  further wherein the liquid comprises water. 
     
     
         3 . The ice machine of  claim 1  further comprising a user interface to enable the user to command the ice machine and the ice machine to communicate to the user, the user interface communicating to the user when the ice is ready. 
     
     
         4 . The ice machine of  claim 1  further wherein the heat exchanger comprises a thermoelectric cooler (TEC) element coupled with an energy transfer surface of the heat exchanger. 
     
     
         5 . The ice machine of  claim 1  further wherein the heat exchanger comprises a cold plate as an energy transfer surface in thermal contact with a heat pump and in thermal contact with the energy transfer surface of the tray, and a heatsink in operative association with the heat pump, with insulation provided in between the heatsink and cold plate. 
     
     
         6 . The ice machine of  claim 5  further wherein the cold plate comprises metal with a pedestal, a base, and side metal walls. 
     
     
         7 . The ice machine of  claim 5  further wherein the cold plate comprises a varying thickness to more evenly distribute energy. 
     
     
         8 . The ice machine of  claim 1  further wherein the freezing/mixing chamber comprises insulative properties that mitigate energy loss through the sides and top. 
     
     
         9 . The ice machine of  claim 1  further wherein the mixing mechanism comprises an impeller integrated into a lid above the freezing/mixing chamber, the impeller moving into the liquid in the egress area of the tray at a fixed position relative to the energy transfer surface when the lid is closed, and out of the liquid when the lid is open. 
     
     
         10 . The ice machine of  claim 1  further wherein operation of the mixing mechanism is varied based on the status of the ice formation. 
     
     
         11 . The ice machine of  claim 1  further wherein the mixing mechanism is contained over a plurality of freezing cavities. 
     
     
         12 . The ice machine of  claim 1  further wherein formed ice is maintained at a pre-determined height by adjusting process parameters. 
     
     
         13 . The ice machine of  claim 1  further whereby the velocity profile at the liquid/ice boundary encourages total dissolved solids (TDS) and total dissolved gasses (TDG) to be washed away and concentrate in a pool ultimately in the egress area of the tray during the freezing process. 
     
     
         14 . The ice machine of  claim 1  whereby the velocity profile at the liquid/ice boundary further encourages crystal growth creating a crystal structure starting from the energy transfer surface of the tray in thermal contact with the heat exchanger and growing through the freezing cavity up to the egress area. 
     
     
         15 . The ice machine of  claim 1  further comprising a sensor providing input into an end time determination for an ice generation cycle. 
     
     
         16 . The ice machine of  claim 1  further comprising a sensor that determines presence of the tray. 
     
     
         17 . The ice machine of  claim 1  further comprising a sensor that determines height of the ice. 
     
     
         18 . The ice machine of  claim 1  further comprising a sensor that detects level of the liquid. 
     
     
         19 . The ice machine of  claim 1  further comprising a sensor that detects position of a door to the freezing/mixing chamber. 
     
     
         20 . A method of ice creation comprising:
 filling a tray with a liquid to a specified height, the specified height being greater than the height of a freezing cavity defined in the tray;   placing the filled tray in a freezing/mixing chamber, thereby placing an energy transfer surface of the tray in thermal contact with a heat exchanger thereby creating a liquid/ice boundary layer;   mixing the liquid thereby creating a velocity profile at the liquid/ice boundary layer;   cooling the liquid via the heat exchanger to freezing temperature, thereby overcoming the heat of fusion to form ice at the liquid/ice boundary layer;   converting the liquid to ice up until a specified height, the velocity profile at the liquid/ice boundary layer thereby reducing impurities from the ice; and   providing at least one sensor, the sensor determining the status of ice creation.   
     
     
         21 . The method of ice creation of  claim 20  further comprising: providing a plurality of sensors at specified heights of the tray filled with a liquid; utilizing the plurality of sensors, monitoring the temperatures at specified heights of the tray; and utilizing the temperatures at specified heights of the tray, determining at what height freezing of the liquid has occurred in the tray. 
     
     
         22 . The method of ice creation of  claim 20  further comprising providing at least one sensor at the heat exchanger, utilizing the sensor at the heat exchanger, monitoring the temperature of the heat exchanger; and utilizing the temperature of the heat exchanger, determining the status of ice creation. 
     
     
         23 . The method of ice creation of  claim 22  further comprising determining an end time for an ice generation cycle by measuring temperature on the hot side of the heat exchanger. 
     
     
         24 . The method of ice creation of  claim 22  further comprising determining an end time for an ice generation cycle by measuring temperature on the cold side of the heat exchanger. 
     
     
         25 . The method of ice creation of  claim 22  further comprising varying the ice creation method based on the status of the ice formation. 
     
     
         26 . The method of ice creation of  claim 25  further comprising varying the mixing based on the status of the ice formation. 
     
     
         27 . The method of ice creation of  claim 25  further comprising varying the cooling based on the status of the ice formation. 
     
     
         28 . The method of ice creation of  claim 20  further comprising providing a sensor to determine the ambient air temperature, and utilizing the ambient air temperature in varying the ice creation method. 
     
     
         29 . The method of ice creation of  claim 28  further comprising providing a sensor at an input of the heat exchanger to determine the ambient air temperature. 
     
     
         30 . The method of ice creation of  claim 20  further comprising providing a sensor that determines presence of the tray. 
     
     
         31 . The ice machine of  claim 30  further wherein the sensor determines the presence of the tray and position of a door to the freezing/mixing chamber. 
     
     
         32 . The method of ice creation of  claim 20  further comprising providing a sensor that detects position of a door to the freezing/mixing chamber. 
     
     
         33 . The method of ice creation of  claim 20  further comprising providing a sensor that determines the level of the liquid. 
     
     
         34 . The method of ice creation of  claim 20  further comprising removing the tray from the freezing/mixing chamber, purging a layer of liquid concentrated with impurities contained above the ice, and removing the ice from the freezing cavity. 
     
     
         35 . The method of ice creation of  claim 20  further comprising placing the filled tray in a freezing/mixing chamber, thereby placing an energy transfer surface of the tray in thermal contact with a cold plate of the heat exchanger, the cold plate in thermal contact with a thermoelectric cooler (TEC) element. 
     
     
         36 . The method of ice creation of  claim 20  further comprising mixing the liquid with an impeller thereby creating a velocity profile at the liquid/ice boundary layer. 
     
     
         37 . The method of ice creation of  claim 20  further comprising once a specified ice height is achieved, controlling the mixing and/or cooling to maintain the height. 
     
     
         38 . The method of ice creation of  claim 37  further comprising prior to removing the tray from the freezing/mixing chamber, reversing polarity of the heat exchanger. 
     
     
         39 . A tray adopted to receive a liquid to be received in a freezing/mixing chamber of an ice machine, the tray comprising:
 a lower wall of the tray defining an energy transfer surface adapted to be in thermal contact with a heat exchanger of the ice machine, the heat exchanger removing energy from the liquid, cooling the liquid to freezing temperature, then overcoming the heat of fusion to form ice at a liquid/ice boundary;   at least one freezing cavity having geometry defining surfaces extending upwardly from the energy transfer surface to form the geometry of the ice, the freezing cavity defined above the energy transfer surface; and   an egress area contained above the freezing cavity, the egress area receiving a mixing mechanism to contact with the liquid in the egress area to create a velocity profile at the liquid/ice boundary layer, thereby creating a directional freezing process starting from the energy transfer surface of the tray in thermal contact with the heat exchanger and growing through the freezing cavity up to the egress area, and which deters impurities from getting entrapped in the ice;   whereby the velocity profile at liquid/ice boundary encourages impurities to be washed away and concentrate in a pool ultimately in the egress area during the freezing process.   
     
     
         40 . The tray of  claim 39  further wherein the egress area is formed above a plurality of freezing cavities. 
     
     
         41 . The tray of  claim 39  further wherein the energy transfer surface is selected from the group consisting of a low thermal conductivity material, a high conductivity material, and combinations thereof. 
     
     
         42 . The tray of  claim 39  further wherein the geometry defining surfaces of the tray are supported by walls of the freezing/mixing chamber of the ice machine to form the geometry of the ice. 
     
     
         43 . The tray of  claim 39  further wherein the freezing cavity and geometry defining surfaces form geometry of ice selected from a group consisting of a single freezing cavity having a cube shape, a single freezing cavity having a cylindrical shape, a single freezing cavity having a rectangular shape, a plurality of freezing cavities having cube shapes, a plurality of freezing cavities having cylindrical shapes, a plurality of freezing cavities having rectangular shapes, and a plurality of freezing cavities having shapes combined thereof. 
     
     
         44 . The tray of  claim 39  further wherein the geometry defining surfaces are shared by multiple freezing cavities. 
     
     
         45 . The tray of  claim 39  further wherein the geometry defining surfaces and the energy transferring surface coincide. 
     
     
         46 . The tray of  claim 39  further comprising a fill line in the egress area. 
     
     
         47 . The tray of  claim 39  further wherein the egress area width is expanded relative to the freezing cavity width. 
     
     
         48 . The tray of  claim 47  further wherein the expanded egress area has angled walls. 
     
     
         49 . The tray of  claim 48  further wherein a bend in the angled walls defines a fill line. 
     
     
         50 . The tray of  claim 39  further wherein the energy transfer surface further defines notches in the freezing cavities. 
     
     
         51 . The tray of  claim 39  further wherein the surfaces of the freezing cavity provide a slight draft. 
     
     
         52 . The tray of  claim 39  further comprising a sensor that determines the ice height. 
     
     
         53 . The tray of  claim 39  further comprising a sensor that detects liquid level. 
     
     
         54 . The tray of  claim 39  further comprising a sensor to notify the ice machine of the presence of the tray.