Patent Publication Number: US-11644228-B2

Title: Ice making system for creating clear ice and associated method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of and claims the benefit of priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 16/935,703 filed Jul. 22, 2020, entitled Ice Making System for Creating Clear Ice and Associated Method, incorporated by reference in its entirety herein 
    
    
     FIELD OF THE INVENTION 
     The present subject matter relates generally to clear ice making systems for appliances, and more particularly, to a dual refrigerant system with various adjustable elements for controlling the cooling capacity of the ice making system. 
     BACKGROUND OF THE INVENTION 
     Certain refrigerator appliances include an icemaker. To produce ice, liquid water is directed to the icemaker and frozen. A variety of methods exist for freezing the water. In some systems a glycol refrigerant is used to cool the chamber in which the icemaker resides and a secondary refrigerant system is used to cool the glycol refrigerant. 
     Such a dual refrigerant system has certain drawbacks. For example, additional components are required for a second refrigerant system, raising overall operating costs. Some systems turn off elements of the refrigerant systems when there is no demand for ice to allay such costs. However, doing so may lead to the complication of glycol freezing in the refrigerant system, making it unable to flow when ice is required. In addition, such dual refrigerant systems have a high cooling capacity, leading to fast formation of ice. In forming ice quickly, impurities are trapped in the ice, leading it to have a cloudy or opaque appearance which may be undesirable to users who generally prefer clear ice. 
     Accordingly, an ice making assembly for a refrigerator appliance with a heat exchanger heater for warming the glycol refrigerant prior to initiation of a cooling cycle is desirable. In addition, an ice making assembly for a refrigerator appliance with features for controlling the cooling capacity of the ice making system would also be useful. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In a first example embodiment, an ice making assembly for generating clear ice is provided. The ice making assembly includes an ice holding chamber, a water distribution manifold for providing water to the ice making assembly from a domestic supply, a mold body, a heat exchanger, a first sealed refrigerant system, a second sealed refrigerant system, and a heat exchanger heater. The mold body defines a plurality of ice cavities and is in fluid communication with the water distribution manifold. The heat exchanger has a first inlet in fluid communication with a first outlet and a second inlet in fluid communication with a second outlet. The first sealed refrigerant system includes a pump for cyclically circulating a first refrigerant through a refrigerant manifold. The refrigerant manifold is connected to the first inlet of the heat exchanger and the first outlet of the heat exchanger. At least a portion of the refrigerant manifold is adjacent to the ice holding chamber for removing heat from the ice holding chamber. The second sealed refrigerant system cyclically circulates a second refrigerant through a compressor, the second inlet of the heat exchanger, and the second outlet of the heat exchanger for removing heat from the first refrigerant. The heat exchanger heater is at least partially contained with the heat exchanger for providing heat to the first refrigerant. 
     In a second example embodiment, a method of making clear ice is provided. The method includes detecting a demand for ice, activating a heat exchanger heater for heating a first refrigerant, and monitoring heat exchanger heater usage data. The method also includes activating a pump based on the heat exchanger heater usage data, such that the pump circulates the first refrigerant through a first sealed refrigerant system to remove heat from an ice holding chamber. The method further includes delivering water to a mold body from a water distribution manifold, detecting that demand for ice is satisfied, and deactivating the pump. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. 
         FIG.  1    provides a perspective view of a refrigerator appliance according to an exemplary embodiment of the present subject matter. 
         FIG.  2    provides a perspective view of a door of the exemplary refrigerator appliance of  FIG.  1   . 
         FIG.  3    provides an exploded perspective view of an ice making assembly in accordance with certain aspects of the present disclosure. 
         FIG.  4    provides schematic view of an exemplary ice making system in accordance with the present subject matter. 
         FIG.  5    provides a flow chart of steps in an exemplary method in accordance with the present subject matter. 
         FIG.  6    provides a flow chart of further steps in an exemplary method in accordance with the present subject matter. 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention. 
     DETAILED DESCRIPTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
       FIG.  1    provides a perspective view of a refrigerator appliance  100  according to an exemplary embodiment of the present subject matter. Refrigerator appliance  100  includes a cabinet or housing  120  that extends between a top portion  101  and a bottom portion  102  along a vertical direction V. Housing  120  defines chilled chambers for receipt of food items for storage. In particular, housing  120  defines a fresh food chamber  122  positioned at or adjacent top portion  101  of housing  120  and a freezer chamber  124  arranged at or adjacent bottom portion  102  of housing  120 . As such, refrigerator appliance  100  is generally referred to as a “bottom mount refrigerator.” It is recognized, however, that the benefits of the present disclosure apply to other types and styles of refrigerator appliances such as, e.g., a top mount refrigerator appliance or a side-by-side style refrigerator appliance, as well as stand-alone ice makers. Consequently, the description set forth herein is for illustrative purposes only and is not intended to be limiting in any aspect to any particular appliance or chilled chamber configuration. 
     Refrigerator doors  128  are rotatably hinged to an edge of housing  120  for selectively accessing fresh food chamber  122 . In addition, a freezer door  130  is arranged below refrigerator doors  128  for selectively accessing freezer chamber  124 . Freezer door  130  is coupled to a freezer drawer (not shown) slidably mounted within freezer chamber  124 . Refrigerator doors  128  and freezer door  130  are shown in a closed configuration in  FIG.  1   . 
     Refrigerator appliance  100  also includes a dispensing assembly  140  for dispensing liquid water and/or ice. Dispensing assembly  140  includes a dispenser  142  positioned on or mounted to an exterior portion of refrigerator appliance  100 , e.g., on one of doors  128 . Dispenser  142  includes a discharging outlet  144  for accessing ice and liquid water. An actuating mechanism  146 , shown as a paddle, is mounted below discharging outlet  144  for operating dispenser  142 . In alternative exemplary embodiments, any suitable actuating mechanism may be used to operate dispenser  142 . For example, dispenser  142  can include a sensor (such as an ultrasonic sensor) or a button rather than the paddle. A user interface panel  148  is provided for controlling the mode of operation. For example, user interface panel  148  includes a plurality of user inputs (not labeled), such as a water dispensing button and an ice-dispensing button, for selecting a desired mode of operation such as crushed or non-crushed ice. 
     Discharging outlet  144  and actuating mechanism  146  are an external part of dispenser  142  and are mounted in a dispenser recess  150 . Dispenser recess  150  is positioned at a predetermined elevation convenient for a user to access ice or water and enabling the user to access ice without the need to bend-over and without the need to open doors  128 . In the exemplary embodiment, dispenser recess  150  is positioned at a level that approximates the chest level of a user. 
       FIG.  2    provides a perspective view of a door of refrigerator doors  128 .  FIG.  3    provides a partial, elevation view of refrigerator door  128  with an access door  166  shown in an open position. Refrigerator appliance  100  includes a sub-compartment  162  defined on refrigerator door  128 . Sub-compartment  162  is often referred to as an “icebox.” Sub-compartment  162  is positioned on refrigerator door  128  at or adjacent fresh food chamber  122 . Thus, sub-compartment  162  may extend into fresh food chamber  122  when refrigerator door  128  is in the closed position. Access door  166  is hinged to refrigerator door  128 . Access door  166  permits selective access to sub-compartment  162 . Any manner of suitable latch  168  is configured with sub-compartment  162  to maintain access door  166  in a closed position. As an example, latch  168  may be actuated by a consumer in order to open access door  166  for providing access into sub-compartment  162 . Access door  166  can also assist with insulating sub-compartment  162 . 
     As may be seen in  FIG.  3   , refrigerator appliance  100  includes an icemaker or ice making assembly  160 . It will be understood that while described in the context of refrigerator appliance  100 , ice making assembly  160  can be used in any suitable refrigerator appliance or as a stand-alone icemaker. Thus, e.g., in alternative exemplary embodiments, ice making assembly  160  may be positioned at and mounted to other portions of housing  120 , such as within various ice holding chambers including freezer chamber  124  or sub-compartment  162  or may be fixed to a wall of housing  120  within fresh food chamber  122  rather than on refrigerator door  128 . 
     In  FIG.  3   , ice making assembly  160  is positioned or disposed within sub-compartment  162 . Thus, ice is supplied to dispenser recess  150  ( FIG.  1   ) from the ice making assembly  160 . Chilled air generated by passing air from a sealed system (not pictured) across a refrigerant manifold  366  ( FIG.  4   ) of refrigerator appliance  100 , as discussed in greater detail below, may be directed into ice making assembly  160  in order to cool components of ice making assembly  160 . In particular, an evaporator  332 , e.g., positioned at or within fresh food chamber  122  or freezer chamber  124 , is configured for generating cooled or chilled air for the fresh food chamber  122  and/or freezer chamber  124 . A supply conduit  180 , e.g., defined by or positioned within housing  120 , extends between evaporator  332  and components of ice making assembly  160  in order to cool components of ice making assembly  160  and assist ice formation by ice making assembly  160 . In alternative embodiments, ice making assembly  160  may employ a direct cooling system. A first sealed refrigerant system  360  may be circulated through a refrigerant manifold  366  ( FIG.  4   ), as further described herein. Refrigerant manifold may be integrated into or be situated in close proximity to a mold body  200  of ice making assembly  160 , thereby effecting a direct transfer of heat from mold body  200  to a refrigerant of first sealed refrigerant system  360 . 
     As illustrated in  FIG.  3   , ice making assembly  160  in accordance with an embodiment of the present disclosure is illustrated. The ice making assembly  160  comprises a body or ice tray  190  including mold body  200  for receiving water and freezing the water to ice. As shown, the ice tray  102  includes seven substantially identical ice forming compartments; although, it should be appreciated that more or less than seven ice forming compartments can be provided. It should also be appreciated that while one exemplary type of ice maker is illustrated (a so-called crescent cube variety of ice maker), any suitable ice maker including a twist tray type, can be utilized in connection with the present disclosure. In the illustrated embodiment, each compartment of mold body  200  includes a first side surface  202 , a second side surface  204 , and an arcuate bottom surface  206  interposed between first side surface  202  and second side surface  204 . Partition walls  208  are disposed between each of the compartments, the partitions walls at least partially defining first side surface  202  and second side surface  204 . The partition walls  208  extend transversely across the ice tray  190  to define the ice forming compartments in which ice pieces (not shown) are formed. Each partition wall  208  includes a recessed upper edge portion  210  through which water flows successively through each compartment of mold body  200  to fill the ice tray  190  with water. A water filling operation of ice tray  190  may be based on a set time. 
     Water is provided to compartments of mold body  200  through a channel or water distribution manifold  240  ( FIG.  6   ). Water distribution manifold  240  may include one or more outlets (not pictured). Liquid water within water distribution manifold  240  can flow out of outlets to introduce water to the compartments of mold body  200 . Due to chilled air within chilled air duct (not pictured), water is chilled to or below the freezing temperature of water such that liquid water flowing within compartments of mold body  200  can freeze and form ice cubes. 
     As shown in  FIG.  3   , a sheathed electrical resistance heating element or ice formation heater  382  (further detailed below) is mounted to a lower portion  214  of the ice tray  190 . The heater can be press-fit, stacked, and/or clamped into lower portion  214  of ice tray  190 . Ice formation heater  382  is configured to heat mold body  200  when a harvest cycle is executed to slightly melt the ice and release the ice from the compartments of mold body  200 . 
     An ice ejector or rake  216  is rotatably connected to ice tray  190 . Ice ejector  216  includes an axle or shaft  218  and a plurality of ejector members  220  located in a common plane tangent to axle  218 , one ejector member  220  for each compartment of mold body  200 . Axle  218  is concentric about the longitudinal axis of rotation of ice ejector  216 . To rotatably mount ice ejector  216  to ice tray  190 , a first end section  222  of ice ejector  216  is positioned adjacent an opening  224  located at a first end portion  226  of ice tray  190 . A second end section  228  of ice ejector  190  is positioned in an arcuate recess  230  located on a second end portion  232  of ice tray  190 . In the illustrated embodiment, ejector members  220  are triangular shaped projections  234  and are configured to extend from axle  218  into the compartments of mold body  200  when ice ejector  216  is rotated. It is within the scope of the present disclosure for ejector members  220  to be fingers, shafts, or other structures extending radially beyond the outer walls of axle  218 . Ice ejector  2216  is rotatable relative to ice tray  214  from a closed first position to a second ice harvesting position and back to the closed position. Rotation of ice ejector  216  causes ejector members  220  to advance into the compartments of mold body  200  whereby ice located in each compartment is urged in an ejection path of movement out of the ice forming compartment. 
       FIG.  4    provides a schematic view of certain components of an embodiment of ice making assembly  160 . The ice making assembly  160  of  FIG.  4    includes a heat exchanger  350 . Heat exchanger  350  may include a first inlet  352  in fluid communication with a first outlet  354  and a second inlet  356  in fluid communication with second outlet  358 . Ice making assembly  160  may employ a first sealed refrigerant system  360  for facilitating the freezing of ice in ice cavities  210  in an ice holding chamber such as freezer chamber  124  or ice collector  256 . First sealed refrigerant system  360  employs a pump  362  to cyclically circulate a first refrigerant  364  through a refrigerant manifold  366 . In the preferred embodiment of  FIG.  4   , the first refrigerant is glycol, though other common refrigerants may be employed. Refrigerant manifold  366  may be connected to first outlet  354  of heat exchanger  350  and extend through cabinet  120 . At least a portion of refrigerant manifold  366  may be adjacent to freezer chamber  124  or ice collector  256 , which may contain mold body  200 . As previously described, air may be passed across this adjacent portion of refrigerant manifold  366  chilling the air prior to its introduction into the ice collection chamber. As shown in the embodiment of  FIG.  4   , refrigerant manifold  366  then continues, next connecting to pump  362 , and finally connecting to first inlet  352  of heat exchanger  350 , completing the first sealed refrigerant system loop. In other embodiments, the configuration of components may differ. For example, pump  362  may be located between first outlet  354  and mold body  200  to achieve the same purpose. 
     During each cycle of first sealed refrigerant system  360 , first refrigerant  364  is heated and must be cooled prior to the next cycle. This may be accomplished by cyclically circulating a second refrigerant  371  in a second sealed refrigerant system  370  through heat exchanger  350 . Second sealed refrigerant system  370  cycles second refrigerant  371  from second outlet  356  to a compressor  372 , which heats second refrigerant  371  and drives it through second sealed refrigerant system  370 . Second refrigerant  371  then passes through a condenser (not pictured), which converts the heated gaseous second refrigerant  371  to a liquid, and an expansion device (not pictured), which cools and reduces the pressure of second refrigerant  371 . Second sealed refrigerant system  370  then cycles second refrigerant  371  into second inlet  358  of heat exchanger  350 . The cooled second refrigerant  371  of second sealed refrigerant system  370  has a temperature higher than that of first refrigerant  364 , enabling heat to transfer from first sealed refrigerant system  360  to second sealed refrigerant system  370 . 
     While the features of ice making assembly  160  described above contribute to the formation of ice in mold body  200  generally, the production of clear ice requires that the cooling capacity of ice making assembly be reduced and controlled to slow the rate of ice formation and to thus remove impurities from the ice. Certain elements described above may be controlled for this purpose. For example, compressor  372  may be a variable speed compressor. During operation of ice making assembly  160 , power to variable speed compressor  372  may be reduced, resulting in reduced heat transfer between first sealed refrigerant system  360  and second sealed refrigerant system  370 . By controlling the level of power provided to variable speed compressor  372 , this rate of heat transfer may be controlled, thus enabling selective warming of first refrigerant  364 . A warmer first refrigerant  364  may reduce the amount of heat transfer from water in mold body  200  and thus may slow the rate of ice formation in mold body  200 . 
     Similarly, pump  362  of ice making system  160  may be a variable speed pump. By reducing power to variable speed pump  362 , the rate of flow of first refrigerant  364  through refrigerant manifold  366  may be reduced. A reduction in the flow rate of first refrigerant  364  may also reduce the rate of heat transfer from water in mold body  200  and thus slow the rate of ice formation in mold body  200 . One or more temperature sensors  390  may be at least partially contained within refrigerant manifold  366  to determine the temperature of first refrigerant  364  at one or more locations in its cycle. This temperature information may be used to determine the power requirements of compressor  372 , pump  362 , or other control elements addressed below. 
     Additional control elements may be optionally included in ice making system  160  to slow the rate of ice formation to enable the formation of clear ice. For example, an ice formation heater  382  may be attached to, integral with, or in close proximity to mold body  200 . Operation of ice formation heater  382  provides heat to water introduced to mold body  200 , again slowing the rate of ice formation. Alternatively, or in addition, the ice formation rate on mold body  200  may be reduced by pre-heating the water provided to mold body  200  by water distribution manifold  240 . This may be accomplished by use of a water heater  384  position upstream of mold body  200  and water distribution manifold  240 . Water heater  384  may include a water heater outlet  386  connected to a pipe, hose, or other similar means of conveying fluid, which delivers warm water to water distribution manifold  240 . Here, warm water should be understood as water at a temperature above 75° F. 
     Further, ice making system  160  may optionally include a fluid control valve  388  positioned upstream of water distribution manifold  240 . To the extent that fluid control valve  388  is employed in combination with water heater  384 , fluid control valve  388  may be positioned between water distribution manifold  240  and water heater  384  to control the rate of water flow into mold body  200 . By partially closing fluid control valve  388 , the flow rate of water to water distribution manifold  240  is reduced, thus reducing the flow rate of water to mold body  200 . This, in turn, reduces the rate at which ice is formed, aiding in the formation of clear ice. 
     Heat exchanger  350  of ice making system  160  may further include a heat exchanger heater  380 , as shown in the schematic drawing of  FIG.  4   . Heat exchanger heater  380  may be at least partially contained within heat exchanger  350  so as to provide heat to first refrigerant  364 . This may serve multiple purposes. First, heat exchanger heater  380  may be employed to control the rate of ice formation by heating first refrigerant  364  to reduce the rate of heat transfer from water in mold body  200 . Second, when used in combination with one or more of variable speed compressor  372  and/or variable speed pump  362 , heat exchanger heater  380  may be employed to ensure that first refrigerant  364  does not freeze or to melt first refrigerant  364  if it does freeze. This may be necessary, in one example, if pump  362  is disabled or receives a reduction of power such that second sealed refrigerant system  370  cools first refrigerant  364  beyond its freezing point. In such circumstances, heat exchanger heater  380  would provide heat to first refrigerant  364  to attain or maintain a temperature above its freezing point. In some embodiments, operation of heat exchanger heater  380  may be at least partially dependent on the output of the temperature sensor or sensors  390 . For example, heat exchanger heater  380  may, in some embodiments, only be activated when the temperature of first refrigerant  364  drops below a threshold level above the freezing point to ensure that first refrigerant  364  does not freeze. Of course, other circumstances and inputs, such as activation of pump  362 , may also or instead act as triggers to turn on heat exchanger heater  380 . 
     Now that the construction of refrigerator appliance  100  and ice making assembly  160  have been presented according to exemplary embodiments, an exemplary method  400  of making clear ice will be described. Although the discussion below refers to exemplary method  400  of making clear ice by controlling a variety of elements of ice making assembly  160 , one skilled in the art will appreciate that each of the steps may be performed individually or in combination with the other method steps described herein. 
     As shown in  FIGS.  5 - 6   , method  400  begins with the step  402  of detecting a demand for ice. This detection step may take the form of an input generated by lowering of a hinged lever bar (not pictured) in ice collector  256 . The structure and function of hinged levers are understood by those of ordinary skill in the art and, as such, are not specifically illustrated or described in further detail herein for the sake of brevity and clarity. Hinged lever bar may rest on top of ice collected in ice collector  256 . As ice from ice collector  256  is used, the height of the combined ice lowers, causing the hinged lever bar to rotate about its hinge. Detection of this rotation, in a conventional manner, beyond a given threshold triggers an output that is detected by ice making system  160 . Alternatively, or in addition, a user interaction with user interface panel  148  may also trigger a detection by ice making system with the scope of this step. 
     Upon detection of a demand for ice, method  400  then includes step  404  activation of heat exchanger heater  380  to heat first refrigerant  364  as previously described. Following activation of heat exchanger heater  380 , the next step  406  is monitoring heat exchanger heater usage data. Heat exchanger heater usage data may include any data relating to operation of heat exchanger heater  380  or its effects. For example, in one embodiment, heat exchanger heater usage data may include the length of time that heat exchanger heater  380  is operational. In another embodiment, heat exchanger heater usage data may include the temperature of first refrigerant  364 . Other embodiments may include a combination of this or other heat exchanger heater usage data. 
     After monitoring heat exchanger heater usage data, the next step  408  is activating pump  362  based on heat exchanger heater usage data. For example, when heat exchanger heater usage data is the length of time that heat exchanger heater  380  is operation, pump  362  is activated upon the expiration of a fixed length of time. That fixed length of time is determined based on how long heat exchanger heater  380  requires to melt frozen first refrigerant  364 , which may vary depending on the type of refrigerant used and the physical arrangement of elements in ice making system  160 . For embodiments in which heat exchanger heater usage data is the temperature of first refrigerant  364 , pump  362  is activated upon first refrigerant  364  reaching a temperature appropriate for the desired cooling capacity of ice making system  160 . 
     Method  400  may further include the step  410  of delivering water to mold body  200  in the ice holding chamber (e.g., freezer chamber  124  or ice collector  256 ) from water distribution manifold  240 . The water introduced to mold body  200  transfers heat to first refrigerant  364  as previously described, thus enabling the formation of clear ice under the controls set forth herein. Following the formation of additional clear ice, the next step  412  in method  400  is detecting that demand for ice is satisfied. This detection step may take the form of an input generated by lifting of a hinged lever bar (not pictured) in ice collector  256 . Once enough ice has accumulated in ice collector  256 , the height of the combined ice raises causing hinged lever bar to rotate about its hinge. Detection of this rotation, in a conventional manner, beyond a given threshold triggers an output that is detected by ice making system  160 . Based on that output, pump  362  is deactivated in step  414 , preventing further flow of first refrigerant  364  through refrigerant manifold  366 . 
     In some embodiments, such as that shown in  FIG.  6   , method  400  may further include step  416  of adjusting the speed of variable speed compressor  372 . As previously described, compressor  372  drives refrigerant through second sealed refrigerant system  370 , enabling heat transfer from first sealed refrigerant system  360 . By adjusting the power delivered to variable speed compressor  372 , the speed of compressor  372  may be controlled. By adjusting the speed of compressor  372 , the rate of heat transfer from in first sealed refrigerant system  360  to second sealed refrigerant system  370  may be raised or lowered to achieve a desired cooling capacity for ice making system  160  as first sealed refrigerant system  360  passes in proximity to second sealed refrigerant system  370  as they circulate first refrigerant  364  and second refrigerant  371  through heat exchanger  350 . 
     In the alternative, or in addition, method  400  may also include the step  418  of adjusting the speed of pump  362  following its activation. The speed of pump  362  may be adjusted by adjusting the power delivered to pump  362 . Raising the power delivered to pump  362  raises the speed of pump  362 , increasing the flow rate of first refrigerant  364  through refrigerant manifold  366  and increasing the cooling capacity of ice making system  160 . In contrast, lowering the power delivered to pump  362  lowers the speed of pump  362 , decreasing the flow rate of first refrigerant  365  through refrigerant manifold  366  and decreasing the cooling capacity of ice making system  160 . 
     Other embodiments of method  400  may limit the cooling capacity of ice making system  160  by altering properties of the water introduced to mold body  200 . For example, in one embodiment, method  400  may include the step  420  of activating ice formation heater  382 . As described above, ice formation heater  382  may be attached to, integral with, or in close proximity to mold body  200 . Upon activation, ice formation heater  382  may transfer heat to water and ice on mold body  200 , slowing the rate of ice formation and decreasing the cooling capacity of ice making system  160 . In another embodiment, method  400  may include the step  422  of activating a water heater in fluid communication with the water distribution manifold  240  to provide war water to mold body  200 . In yet another embodiment, method  400  may include the step  424  of adjusting fluid control valve  388 , which is positioned upstream of water distribution manifold  240 . In so doing, the flow rate of water to water distribution manifold  240  is reduced, slowing the rate of ice formation. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.