Draining the sump of an ice maker to prevent growth of harmful biological material

Abstract

An ice maker having a refrigeration system, a water system and a control system. The refrigeration system includes an ice formation device. The water system supplies water to the ice formation device, and includes a water reservoir (e.g., a sump or float chamber) for holding water to be formed into ice and a discharge valve in fluid communication with the water reservoir. The control system includes an ice level sensor adapted to sense the ice level in an ice storage bin, and a controller adapted to cause water to drain from the water reservoir when the ice storage bin is full. Substantially or all of the water remaining in the water reservoir is drained such that while the ice maker is not making ice the water reservoir is empty of water. This reduces or prevents the growth of harmful bacteria, parasites, organisms, and/or other biological material in the water reservoir.

What is claimed: 
     
         1 . An ice maker for forming ice, the ice maker comprising:
 (i) a refrigeration system comprising a compressor and an ice formation device;   (ii) a water system for supplying water to the ice formation device, the water system comprising a water reservoir adapted to hold water to be formed into ice and a discharge valve in fluid communication with the water reservoir; and   (iii) a control system comprising an ice level sensor adapted to sense whether an ice storage bin is full of ice, and a controller adapted to cause the discharge valve to open to allow water to drain from the water reservoir based upon an indication from the ice level sensor that the ice storage bin is full of ice.   
     
     
         2 . The ice maker of  claim 1 , wherein the ice formation device comprises:
 an ice making chamber; and   an auger within the ice making chamber for removing ice formed in the ice making chamber.   
     
     
         3 . The ice maker of  claim 2 , wherein opening the discharge valve is further adapted to allow water to drain from the ice making chamber based upon an indication from the ice level sensor that the ice storage bin is full of ice. 
     
     
         4 . The ice maker of  claim 1 , wherein the ice formation device comprises an evaporator and a freeze plate thermally coupled to the evaporator, and wherein the water system further comprises a water pump, wherein the water reservoir, the discharge valve, and the water pump are in fluid communication. 
     
     
         5 . The ice maker of  claim 4 , wherein the controller is further adapted to cause the water pump to pump water out of the water reservoir through the discharge valve. 
     
     
         6 . A method of controlling an ice maker, the ice maker comprising (i) a refrigeration system comprising a compressor and an ice formation device, (ii) a water system for supplying water to the ice formation device, the water system comprising a water reservoir adapted to hold water to be formed into ice and a discharge valve in fluid communication with the water reservoir, and (iii) a control system comprising an ice level sensor adapted to sense whether an ice storage bin is full of ice and a controller adapted to control the operation of the refrigeration system and the water system, the method comprising:
 receiving, by the controller, an indication from the ice level sensor that the ice storage bin is full of ice;   causing, by the controller, the compressor to turn off; and   causing, by the controller, the discharge valve to open to drain water from the water reservoir.   
     
     
         7 . The method of  claim 6 , wherein the refrigeration system further comprises a heat rejecting heat exchanger, and wherein the compressor, the heat rejecting heat exchanger, and the ice formation device are in fluid communication by one or more refrigerant lines. 
     
     
         8 . The method of  claim 6 , wherein the water system further comprises a water pump, wherein the water reservoir, the discharge valve, and the water pump are in fluid communication. 
     
     
         9 . The method of  claim 8 , further comprising:
 causing, by the controller, the water pump to turn on to pump water from the water reservoir through the discharge valve.   
     
     
         10 . The method of  claim 6 , further comprising causing, by the controller, the discharge valve to close when the water reservoir is empty. 
     
     
         11 . The method of  claim 6 , wherein the control system further comprises a water level sensor adapted to sense a water level in the water reservoir, wherein the method further comprises:
 receiving, by the controller, an indication from the water level sensor that the water reservoir is empty; and   causing, by the controller, the discharge valve to close after receiving, by the controller, the indication from the water level sensor that the water reservoir is empty.   
     
     
         12 . The method of  claim 6 , further comprising keeping, by the controller, the discharge valve open for a period of time to empty the water reservoir. 
     
     
         13 . The method of  claim 12 , wherein the period of time is from about 30 seconds to about 5 minutes. 
     
     
         14 . The method of  claim 6 , further comprising the steps of:
 receiving, by the controller, an indication from the ice level sensor that the ice storage bin is not full of ice; and   causing, by the controller, the compressor to turn on.   
     
     
         15 . The method of  claim 6 , wherein the ice formation device comprises an ice making chamber, and wherein the step of opening the discharge valve causes water to drain from the ice making chamber. 
     
     
         16 . A method of controlling an ice maker, the ice maker comprising (i) a refrigeration system comprising a compressor and an ice formation device, (ii) a water system for supplying water to the ice formation device, the water system comprising a water reservoir adapted to hold water to be formed into ice and a discharge valve in fluid communication with the water reservoir, and (iii) a control system comprising an ice level sensor adapted to sense whether an ice storage bin is full of ice, a water level sensor adapted to sense a water level in the water reservoir, and a controller adapted to control the operation of the refrigeration system and the water system, the method comprising:
 receiving, by the controller, an indication from the ice level sensor that the ice storage bin is full of ice;   causing, by the controller, the discharge valve to open to drain water from the water reservoir;   receiving, by the controller, an indication from the water level sensor that the water reservoir is empty; and   causing, by the controller, the discharge valve to close after receiving, by the controller, the indication from the water level sensor that the water reservoir is empty.   
     
     
         17 . The method of  claim 16 , wherein the water system further comprises a water pump, wherein the discharge valve and the water pump are in fluid communication. 
     
     
         18 . The method of  claim 17 , further comprising:
 causing, by the controller, the water pump to turn on to pump water from the water reservoir through the discharge valve.   
     
     
         19 . The method of  claim 16 , further comprising the step of:
 causing, by the controller, the compressor to turn off after receiving, by the controller, the indication from the ice level sensor that the ice storage bin is full.   
     
     
         20 . The method of  claim 16 , further comprising the steps of:
 receiving, by the controller, an indication from the ice level sensor that the ice storage bin is not full of ice; and   causing, by the controller, the compressor to turn on to resume the making of ice.