Clear ice making systems and methods

Abstract

A method of making clear ice includes circulating a refrigerant through a refrigerant loop. A portion of the refrigerant loop is in contact with a mold body. Thus, the refrigerant chills the mold body. The method also includes spraying a first volume of liquid water into a mold cavity of the mold body. As a result, a first volume of ice is formed in the mold cavity. The method also includes spraying a second volume of liquid water into the mold cavity after the first volume of ice has formed. Thus, a portion of the first volume of ice is melted and a second volume of ice is formed in mold cavity. The clear ice includes an unmelted portion of the first volume of ice and the second volume of ice.

What is claimed is: 
     
         1 . A method of making clear ice, comprising the steps of:
 circulating a refrigerant through a secondary cooling loop, wherein a portion of the secondary cooling loop is in contact with a mold body, whereby the refrigerant chills the mold body;   spraying a first volume of liquid water into a mold cavity of the mold body, whereby a first volume of ice is formed in the mold cavity; and   spraying a second volume of liquid water into the mold cavity after the first volume of ice has formed, whereby a first portion of the first volume of ice is melted and a second volume of ice is formed in mold cavity,   wherein the clear ice comprises a second, unmelted portion of the first volume of ice and the second volume of ice.   
     
     
         2 . The method of  claim 1 , wherein the refrigerant is circulated through the secondary cooling loop at a first subfreezing temperature while spraying the first volume of liquid water and the refrigerant is circulated through the secondary cooling loop at a second subfreezing temperature less than the first subfreezing temperature while spraying the second volume of liquid water. 
     
     
         3 . The method of  claim 1 , wherein the refrigerant is circulated through the secondary cooling loop by a refrigerant pump, wherein the step of circulating the refrigerant through the secondary cooling loop comprises circulating the refrigerant through the secondary cooling loop at a first speed while spraying the first volume of liquid water and circulating the refrigerant through the secondary cooling loop at a second speed different from the first speed while spraying the second volume of liquid water. 
     
     
         4 . The method of  claim 1 , wherein circulating the refrigerant through the secondary cooling loop comprises circulating the refrigerant through a heat exchanger coupled to the secondary cooling loop, thereby cooling the refrigerant as the refrigerant passes through the heat exchanger. 
     
     
         5 . The method of  claim 4 , wherein the heat exchanger is in thermal communication with a primary cooling loop, the primary cooling loop comprising a compressor, the method further comprising operating the compressor at a first speed while spraying the first volume of liquid water and operating the compressor at a second speed different from the first speed while spraying the second volume of liquid water. 
     
     
         6 . The method of  claim 1 , wherein the mold cavity is a first mold cavity of the mold body, the mold body further comprising a second mold cavity, wherein the first volume of liquid water is the only liquid water supplied to the mold body during the step of spraying the first volume of liquid water and is sprayed only into the first mold cavity, and wherein the second volume of liquid water is the only liquid water supplied to the mold body during the step of spraying the second volume of liquid water and is sprayed only into the first mold cavity. 
     
     
         7 . The method of  claim 6 , wherein the first volume of water is sprayed only into the first mold cavity and the second volume of water is sprayed only into the first mold cavity when in an energy saving mode. 
     
     
         8 . The method of  claim 6 , further comprising determining that a demand for ice is low before spraying the first volume of liquid water and before spraying the second volume of liquid water. 
     
     
         9 . The method of  claim 1 , wherein the first volume of liquid water and the second volume of liquid water are sprayed from a nozzle positioned below the mold body, whereby a portion of the first volume of liquid water that does not form the first volume of ice drains out of the mold cavity by gravity, and whereby a portion of the second volume of liquid water that does not form the second volume of ice drains out of the mold cavity by gravity. 
     
     
         10 . An ice making assembly operable to generate clear ice, the ice making assembly comprising:
 a secondary cooling loop;   a mold body comprising a mold cavity, the mold body in contact with and in conductive thermal communication with a portion of the secondary cooling loop, whereby circulating refrigerant through the secondary cooling loop chills the mold body;   a water pump coupled to a nozzle, the nozzle positioned proximate to and aligned with the mold cavity whereby the nozzle is configured to direct a spray of liquid water into the mold cavity; and   a controller, the controller in operative communication with the water pump, the controller configured to: 
 activate the water pump to spray a first volume of liquid water into a mold cavity of the mold body, whereby a first volume of ice is formed in the mold cavity; and 
 activate the water pump to spray a second volume of liquid water into the mold cavity after the first volume of ice has formed, whereby a first portion of the first volume of ice is melted and a second volume of ice is formed in the mold cavity, 
 wherein the clear ice comprises a second, unmelted portion of the first volume of ice and the second volume of ice. 
   
     
     
         11 . The ice making assembly of  claim 10 , further comprising a refrigerant pump coupled to the secondary cooling loop and in operative communication with the controller, wherein the controller is further configured to operate the refrigerant pump at a first speed while spraying the first volume of liquid water and to operate the refrigerant pump at a second speed different from the first speed while spraying the second volume of liquid water. 
     
     
         12 . The ice making assembly of  claim 10 , further comprising a heat exchanger coupled to the secondary cooling loop, the heat exchanger operable to cool refrigerant circulating in the secondary cooling loop as the refrigerant passes through the heat exchanger. 
     
     
         13 . The ice making assembly of  claim 12 , wherein the heat exchanger is in thermal communication with a primary cooling loop, the primary cooling loop comprising a compressor, and wherein the controller is further configured to operate the compressor at a first speed while spraying the first volume of liquid water and to operate the compressor at a second speed different from the first speed while spraying the second volume of liquid water. 
     
     
         14 . The ice making assembly of  claim 10 , wherein the mold cavity is a first mold cavity of the mold body, the mold cavity further comprising a second mold cavity, wherein the controller is configured to activate the water pump to spray only the first volume of liquid water and only into the first mold cavity, and wherein the controller is configured to activate the water pump to spray only the second volume of liquid water and only into the first mold cavity. 
     
     
         15 . The ice making assembly of  claim 14 , wherein the controller is configured to spray the first volume of liquid water only into the first mold cavity and the second volume of water only into the first mold cavity in response to an energy saving mode input. 
     
     
         16 . The ice making assembly of  claim 14 , wherein the controller is further configured to determine that a demand for ice is low before spraying the first volume of liquid water and before spraying the second volume of liquid water. 
     
     
         17 . The ice making assembly of  claim 10 , further comprising a nozzle positioned below the mold body, wherein activating the water pump causes the first volume of liquid water and the second volume of liquid water to be sprayed from the nozzle whereby a portion of the first volume of liquid water that does not form the first volume of ice drains out of the mold cavity by gravity, and whereby a portion of the second volume of liquid water that does not form the second volume of ice drains out of the mold cavity by gravity.