Apparatus and Method for Inhibiting the Growth of Microbiological Organisms in Commercial Icemakers and Coolers

Abstract

An apparatus for inhibiting the growth of microbiological organisms in commercial icemakers and coolers by treatment of the air within the device evaporator air space. The apparatus includes a mechanical filtration device, a PCO device, and a UV light device. Air is drawn from the evaporator space, mixed with a small amount of ambient air from around the apparatus, and mechanically filtered to remove particulates. The filtered air is then passed through the PCO device that is activated by the UV light device, where it is treated by the ROS produced by the activated PCO device. A UV light further produces ROS to treat the filtered air stream, which is returned to the internal space of the commercial refrigeration device. Recirculation of the treated air increases residence time. The addition of a small amount of external air with the internal air allows for positive pressurization of the evaporator space.

1 . An apparatus for inhibiting the growth of microbiological organisms in a commercial icemaker or refrigeration device, the apparatus comprising:
 an inlet plenum in fluid communication with a treatment plenum, the inlet plenum accepting air from the evaporator air space of an icemaker or refrigeration device, the inlet plenum further accepting ambient air from the air space surrounding the apparatus, the combined sources of inlet air forming an inlet plenum fluid stream, the treatment plenum comprising a photocatalytic oxidation (PCO) device substantially enshrouding an ultraviolet (UV) light device, the PCO device activated by the UV light device when energized, wherein the UV light device produces an ultraviolet germicidal irradiation (UVGI) effect and causes the production of at least one reactive oxygenation species (ROS) for introduction into the mechanically-filtered fluid stream to produce a treated fluid stream that is subsequently returned to the evaporator air space.   
     
     
         2 . The apparatus of  claim 1 , the apparatus further comprising:
 a recirculation port in the inlet plenum or in the treatment plenum through which at least a portion of the treated fluid stream is recirculated prior to its return to the evaporator air space.   
     
     
         3 . The apparatus of  claim 1 , the apparatus further comprising:
 a mechanical filtration device separating the inlet plenum from the treatment plenum, wherein substantially all of the inlet plenum fluid stream must pass through the mechanical filtration device.   
     
     
         4 . The apparatus of  claim 1 , the apparatus further comprising:
 an air-motive device capable of producing a positive treated fluid stream pressure within the evaporator air space.   
     
     
         5 . The apparatus of  claim 1  wherein at least two ROS are produced, wherein at least one of the ROS is hydrogen peroxide. 
     
     
         6 . The apparatus of  claim 1  wherein the volumetric flow rate of the evaporator air entering the inlet plenum is less than the volumetric flow rate of the treated fluid stream entering the evaporator air space. 
     
     
         7 . The apparatus of  claim 1 , the UV light device comprising an LED light device capable of ultraviolet light generation. 
     
     
         8 . An apparatus for inhibiting the growth of microbiological organisms in a commercial icemaker or refrigeration device, the apparatus comprising:
 an inlet port and an outlet port having a fluid path therebetween, and an air-motive device effecting the flow of air from the inlet port to the outlet port, both ports in fluid communication with the evaporator area air space of an icemaker or refrigeration device, a pretreatment fluid stream comprising the inlet port air stream;   a mechanical filtration device and a photocatalytic oxidation (PCO) device through which substantially all of the pretreatment fluid stream must pass, the PCO device substantially enshrouding an ultraviolet (UV) light device, the PCO device activated by the energized UV light device, wherein the UV light device produces an ultraviolet germicidal irradiation (UVGI) effect and causes the production of at least one reactive oxygenation species (ROS) for introduction into the pretreatment fluid stream, resulting in a treated fluid stream that is moved to the outlet port by the air-motive device; and   a recirculation port through which at least a portion of the treated fluid stream is recirculated to the mechanical filtration device or the PCO device.   
     
     
         9 . The apparatus of  claim 8 , the apparatus further comprising:
 a fresh-air port allowing the entry into the apparatus fluid path of air that is ambient to the exterior of the apparatus housing, the pretreatment fluid stream further comprising the fresh-air port fluid stream.   
     
     
         10 . The apparatus of  claim 8  wherein the air-motive device is capable of producing a positive treated fluid stream pressure within the evaporator air space. 
     
     
         11 . The apparatus of  claim 8  wherein at least two ROS are produced, wherein one of the ROS is hydrogen peroxide. 
     
     
         12 . The apparatus of  claim 8  wherein the volumetric flow rate of the evaporator air drawn from the evaporator air space by the apparatus is less than the volumetric flow rate of the treated fluid stream entering the evaporator air space from the apparatus. 
     
     
         13 . The apparatus of  claim 8 , the UV light device comprising an LED light device capable of ultraviolet light generation. 
     
     
         14 . A method for inhibiting the growth of microbiological organisms in a commercial icemaker or refrigeration device, the method steps comprising:
 removing a portion of the air from the evaporator air space of an icemaker or refrigeration device and mixing the air with air ambient to the exterior of the icemaker or refrigeration device;   treating the filtered air with an ultraviolet (UV) light device and a photocatalytic oxidation (PCO) media activated by the UV light; and   returning the treated air under pressure to the evaporator air space to maintain a positive pressure therein.   
     
     
         15 . The method of  claim 14 , the method steps further comprising:
 causing the production of reactive oxygen species (ROS) for treating microbes present in the evaporator air space.   
     
     
         16 . The method of  claim 14 , the method steps further comprising:
 causing the production of reactive oxygen species (ROS) for treating microbes present in the evaporator air space, wherein the ROS is hydroxyl radicals or hydrogen peroxide.   
     
     
         17 . The method of  claim 14 , the method steps further comprising:
 recirculating a portion of the treated air such that the recirculated portion is treated by the UV light device and PCO media to increase the residence time of the treated air.   
     
     
         18 . The method of  claim 14 , the method steps further comprising:
 recirculating a portion of the treated air such that the recirculated portion is treated by the UV light device and PCO media to control the level of reactive oxygen species present in the treated air.   
     
     
         19 . The method of  claim 14 , the method steps further comprising:
 providing a UV light of sufficient intensity to substantially illuminate the depth of the PCO material.   
     
     
         20 . The method of  claim 14 , the method steps further comprising:
 providing turbulent flow of filtered air through the PCO media and over the UV light device to increase the amount of air contact with the PCO media and UV light device surface.