Abstract:
The present invention is an apparatus and method for providing effective ozonation of water used in ice making equipment for the production of ice cubes and for the ozonation of ice retaining bins located within an ice/beverage dispenser for sanitizing and retarding the growth of microorganisms therein and in the drains associated therewith.

Description:
This application claims benefit to Provisional Application 60/124,058 filed Mar. 12, 1999. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to methods and apparatus for maintaining a sanitary condition in an ice maker and beverage dispenser, and in particular to such methods and apparatus using ozone as a sanitizing agent. 
     BACKGROUND OF THE INVENTION 
     The need to keep ice making and dispensing and beverage dispensing equipment clean over time is well known in the art. It is understood that such equipment can become contaminated with microorganisms, such as, bacteria, yeast, fungi, and mold. Thus, for example, the ice forming evaporator, fluid lines and ice storage area found in such equipment must be periodically cleaned. In the case of beverage dispensers, overflow beverage can promote the growth of microorganisms resulting in the clogging of the drains thereof. 
     Manual cleaning with detergents and sterilizing chemicals can be effective, however, cleaning schedules are not, as a practical matter, always adhered to. In addition, the job may not be done satisfactorily in terms of a thorough cleaning and rinsing of the food contact and drain elements or tubes. Thus, systems have been developed including electronic controls that, in the case of an ice maker, automatically enter the machine into a sanitizing cycle wherein cleaning agents are pumped there through and subsequently rinsed off. Of course, the automatic systems can fail as well, where, for example, the cleaning agent reservoir runs out of cleaner, or the apparatus simply breaks down or fails to operate properly. Moreover, cleaning of the drains thereof is not specifically addressed or provided for in the prior art. 
     The use of ozone (O 3 ) as a sanitizing/oxidizing agent is well known, and especially its use to kill microorganisms in water. In ice machines, ozone has been used wherein a venturi is placed in the water line that runs from the water pump to the water distribution manifold. An ozone generator is connected to the venturi injector so that O 3  can be entrained into the water as it flows there through. Thus, O 3  is carried by the water over the ice making evaporator for providing some bactericidal or bacteriostatic effect. However, there is a need to provide for an ice maker and/or beverage dispenser wherein the ozone generator is an integral part thereof and where the produced ozone can be utilized more effectively so as to maintain a sufficient bacteriostatic condition. Furthermore, the is a need in the prior art to provide for such equipment having an extended life with respect to the ozone generator and to be resistant to any oxidation resulting from the presence of ozone in and around such equipment. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus and method for providing effective ozonation of water used in ice making equipment for the production of ice cubes and for the ozonation of ice retaining bins for sanitizing and retarding the growth of micro-organisms therein and in the drains of beverage dispensing equipment. 
     In one embodiment of the present invention, a combination ice/beverage dispensing machine has an ice maker secured to a top end of a beverage dispenser. The ice maker produces ice that is dropped into and fills an ice retaining bin within the beverage machine. This type of combination is well known in the art and eliminates the need for manual loading of ice into the beverage dispensing machine. 
     As is also known, an ice maker typically includes a refrigeration component section and an ice making section separated by a dividing panel. The refrigeration component section includes a compressor, a condenser and fan and the associated electronics used for the operation thereof. An ice cube forming evaporator is located in the ice making section and includes a water distribution tube and a water receiving tank. As is known in the art, the ice maker as above described, includes a water pump that operates to pump water from a source thereof to the water distribution tube. The water then cascades over the surface of the evaporator. As the evaporator is cooled by operation of the refrigeration components, some of the water flowing there over will freeze thereon. The remainder of the water will flow into the receiving tank to be recycled by the pump to flow repeatedly over the evaporator until ice of a sufficient thickness is formed thereon. The ice is then harvested, typically by hot gas defrosting of the evaporator, causing the ice to melt slightly and slip off the evaporator and drop into the ice retaining bin of the beverage dispenser. 
     As is further understood, the beverage machine includes a plurality of beverage dispensing valves secured along a front surface thereof and includes a drip tray there below. An ice-dispensing chute typically extends from the same front surface and located centrally of the beverage valves. An ice delivering mechanism provides for transfer of ice from the ice retaining bin into the chute, which mechanism is activated when a cup, to be filled with ice, is placed below an open end of the ice chute. Any spillage of ice or beverage is caught by the drip tray and directed down a drain tube connected thereto. The ice bin includes a cold plate for receiving ice from the ice retaining bin for providing heat exchange cooling of the fluid beverage components flowing through individual tubes retained within the cold plate. 
     A merchandising structure is also secured to the front surface of the ice/beverage dispenser at a level thereon above that of the beverage valves. The merchandising structure includes a frame having a merchandising window to which various advertising transparencies can be secured. The transparencies are generally illuminated by means of back lighting thereof wherein a fluorescent bulb is secured to the ice/beverage dispenser front surface behind the transparency. The merchandising structure can be removed to reveal an interior panel. The panel is secured by means of a pivot hinge to the dispenser front surface and includes thereon-electrical sockets for engaging and retaining the fluorescent bulb. The panel can be swung down and open to reveal a component retaining area. An ozone generating device is secured within this component area. An appropriate electrical power supply circuit is retained in the component area and provides the correct power level necessary to operate the ozone generator. The ozone generator includes an air inlet and an air outlet. As is well understood regarding ozone generation in general, oxygen (O 2 .) travels into the inlet so that the high electrical potential of the interior of the generator can result in the production of ozone (O 3 ) from the ambient air. The O 3  then travels out of the generator outlet. In the present invention, an air pump is secured to the inlet of the ozone generator. The outlet is secured to a tube running to the air inlet of a venturi. The venturi is located in the ice making machine in the refrigeration component section, and includes a water inlet and a water outlet. The venturi is fluidly connected in the stream of water running from the pump to the ice maker distribution tube. Thus, the water line running from the outlet of the pump is secured to the inlet of the venturi and the outlet of the venturi is secured to a tube extending to the water distribution tube. 
     In operation, the air pump provides a driving force for the O 3  produced by the ozone generator to flow into the air inlet of the venturi. During the time that ice is being produced, the water pump causes a flow of water through the venturi. Thus, the suction force produced by the venturi effect coupled with the driving force provided by the air pump was found to finely entrain very minute bubbles of the now O 3  rich air into the water. This O 3  rich water then flows into the water distribution tube over the evaporator. It was found that by enriching the O 3  content of the water in this manner using an air pump to provide for such improved mixing thereof, rather than rely on the inherent suction effect of the venturi alone, that sufficient quantities of O 3  would reach the water distribution tube, the evaporator and the receiving tank such that growth of microorganisms thereon was greatly reduced or eliminated. 
     In the above described embodiment a T-fitting can be used wherein a portion of the ozone produced by the generator is directed to a tube that ends at a fitting secured to a top edge of the ice retaining bin of the beverage dispenser. Thus, O 3  laden air is moved by the air pump up to and out of the ice bin fitting. As O 3  molecules are heavier than air, they fall under the force of gravity into the bin. It was found that the microorganism content of the bin and the water drain tube and growth thereon or therein was greatly reduced or eliminated. It was also discovered that such content and growth in the drip tray and associated drain tube was reduced or eliminated. In particular, the clogging type of growth in the drain tubes was not found to re-occur. 
     In the above described embodiment it was found that the bacteriostatic or bactericidal effects of the ozone were maximized in a method of operation wherein the ozone generator and the air pump ran continuously regardless if the ice maker was in an ice making mode or not. When not in the ice making state, i.e. when the water pump was not operating, the O 3  laden air did not mix with the water as well, however it would flow from the venturi in a reverse direction through the water pump into the receiving tank. At the same time it would flow in the “normal” direction from the venturi and up to the water distribution tube. Of course, a larger amount of O 3  would, during non ice making times, also flow into the ice retaining bin, as less would be demanded due to the absence of the suction effect of the venturi. When long ice maker off periods are encountered, a modification can be made to allow the water pump and venturi (along with the generator and air pump that are already energized) to operate when the unit is not making ice. This will permit continued circulation of O 3  containing water over the evaporator as if the ice maker were in an ice making mode. 
     In a second embodiment of the present invention, an ice maker and ice/beverage combination as above described is used, except no venturi is utilized and ozone is moved by the air pump only. In this further embodiment a tube runs directly from the outlet of the ozone generator to a fitting which enters into the water distribution tube that is located at the top perimeter edge of the ice making compartment. In this embodiment the O 3  laden air is more “passively” mixed with the ice making water, than in the first embodiment where a venturi is utilized. However, by using the strategy of also running the ozone generator continuously, it was found that a direct connection to the distribution tube also served to provide for a substantial reduction in microorganisms present or growing on or in the water distribution tube, the evaporator, the receiving tank and the pump and associated tubing. This embodiment was also found to reduce or eliminate the presence of microorganisms in the ice retaining bin and associated drain tubing, as well as in the ice dispensing chute, cold plate drains, drip tray and drain tube thereof. 
     In a third embodiment of the present invention, a beverage machine as above described is used, except no ice machine is secured to the top thereof. In this embodiment an ozone generator and air pump are used to feed a line running to a fitting secured to the top perimeter edge of the ice dispensing hopper. This embodiment was also found to reduce or eliminate the presence of microorganisms in the ice retaining bin and associated drain tube as well as in the ice dispensing chute, drip tray and drain tube thereof. 
     In a fourth embodiment, a drop in type beverage dispenser has an integral ozone generating system located in the tower portion thereof. The ozone is distributed to the ice bin and drip tray portions thereof for providing a germicidal effect therein. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     A further understanding of the structure, function, operation, and objects and advantages of the present invention can be had by referring to the following detailed description that refers to the following figures, wherein: 
     FIG. 1 shows a schematic front plan view of a combination ice maker and ice/beverage dispenser. 
     FIG. 2 shows a schematic side plan view of the dispenser of FIG.  2 . 
     FIG. 3 shows a schematic representation of a first embodiment of the present invention. 
     FIG. 4 shows a schematic representation of a second embodiment of the present invention. 
     FIG. 5 shows an enlarged view of water distribution tube and associated evaporator. 
     FIG. 6 shows a schematic representation of a third embodiment of the present invention. 
     FIG. 7 shows a perspective view of an ice/beverage dispenser of the third embodiment of the present invention. 
     FIG. 8 shows an electrical and fluid schematic of the present invention. 
     FIG. 9 invention shows an enlarged front plan view of the component area of the present invention. 
     FIG. 10 shows an enlarged cross-sectional view of a venturi used in the present. 
     FIG. 11 shows a schematic representation of a front view of a fourth embodiment of the present invention. 
     FIG. 12 shows a schematic representation of a side view of the fourth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As seen by referring to FIGS. 1 and 2, a first embodiment of the present invention includes a combination ice/beverage dispensing machine  10  having an ice maker  12  secured to a top end of a beverage dispenser  14 . Ice maker  12  produces particulate ice, such as cubes, that are dropped into an ice retaining bin  15  within beverage machine  14 . This type of combination  10  is well known in the art and eliminates the need for manual loading of ice into a beverage machine. 
     As is also known, ice maker  12  typically includes a housing  16  defining an interior thereof that is divided by a plate  18  into a refrigeration component section  18   a  and an ice making section  18   b . Refrigeration component section  18   a  includes a compressor  20 , a condenser  22 , a condenser fan  24 , and the associated electronics used for the operation thereof, not shown. An ice cube forming evaporator  26  is located in ice making section  18   b  and includes a water distribution tube or manifold  28  extending along a top end thereof and includes a water receiving tank  30  extending along and beneath a bottom end thereof. As is known in the art, ice maker  12  includes a water pump  32  in refrigeration section  18   a  that operates to pump water from a source thereof and from tank  30  to water distribution tube  28 . The water then cascades over the surface of evaporator  26  after exiting a plurality of holes extending through and along the length of tube  28 . As is well understood, evaporator  26  is cooled by operation of the refrigeration compressor  20 , a condenser  22  and fan  24 , so that some of the water flowing there over will freeze thereon. The remainder of the water will flow into receiving tank  30  to be recycled by pump  32  to flow repeatedly over evaporator  26  until ice of a sufficient thickness is formed thereon. The ice cubes so formed are then harvested and dropped into ice retaining bin  15  of dispenser  14 . 
     As is further understood, dispenser  14  includes a plurality of beverage dispensing valves  34  secured along a front surface  36  thereof and a drip tray  38  there below. An ice dispensing chute  40  typically extends from the same front surface  36  and extends therefrom in between valves  34 . An ice delivering mechanism  42  provides for transfer or lifting of ice from ice retaining bin  14  into an opening, not shown, that leads into chute  40 . As is known, a lever  41  operates a switch for operating mechanism  42  and also opening a door between chute  40  and bin  15  for permitting dispensing of ice into a cup when the cup is pressed against lever  41 . Any spillage of ice or beverage is caught by drip tray  38  and directed down a drain tube  44  connected thereto. Ice bin  15  also includes an opening  46  through which ice can fall onto a cold plate  48 . As is known in the art, cold plate  48  provides for cooling of the beverage liquid components that flow through serpentine coils therein to the valves  34 . Melt water runs down the inclined cold plate  48  into a further drain tube  50  which also drains into driptray  38 . 
     A merchandising structure is also secured to front surface  36  of ice/beverage dispenser  10  at a level thereon above that of beverage valves  34 . The merchandising structure includes a removable frame  52  that extends around and supports a merchandising window  54  to which various product indicating transparencies can be secured on an inner side thereof. The transparencies are generally illuminated by means of back lighting thereof wherein a fluorescent bulb is secured to ice/beverage dispenser front surface behind the transparency. As understood by also referring to FIGS. 7 and 9, a panel  58  is hingedly secured to dispenser front surface  36  and includes thereon electrical sockets  60  for engaging and retaining the fluorescent bulb. After removal of frame  52 , panel  58  can be swung down to reveal a component retaining area  62 . An ozone generating device  64  is secured within this component area, and an appropriate electrical power supply circuit is retained in the component area and to provide the correct power level necessary to operate ozone generator  64 . 
     A seen by also referring to FIG. 3, ozone generator  64  includes an air inlet  64   a  and an air outlet  64   b . As is well understood regarding ozone generation in general, ambient air travels into inlet  64   a  so that the high electrical potential of the interior of generator  64  can result in the production of ozone O 3  from the ambient oxygen O 2  therein. The O 3  enriched air then travels out of outlet  64   b . In the present invention, an air pump  66 , also secured in area  62 , is fluidly connected by a tube  68  to inlet  64   a . As seen by also referring to FIGS. 3 and 10, outlet  64   b  is secured to a tube  70  running to an air inlet  72  of a venturi  74 . Venturi  74  is located in ice making machine  12  in refrigeration component section  18   a , and includes a water inlet  74   a  and a water outlet  74   b . Venturi inlet  74   a  is fluidly connected by a tube  75  to an outlet of pump  32  and outlet  74   b  is fluidly connected by a tube  76  to distribution tube  28 . Pump  32  is fluidly connected to a line  78  extending to receiving tank  30 . A float valve, not shown, in receiving tank  30  is connected by a line  87  to a source of potable water such as a pressurized municipal water supply. A check valve  88  prevents the reverse flow of water to generator  64 . 
     In operation, air pump  66  provides a driving force for the O 3  produced by ozone generator  64  to flow into air inlet  72  of the venturi  74 . During the time that ice is being produced, water pump  32  causes a flow of water through venturi  74 . Thus, the suction force produced by the venturi effect coupled with the driving force provided by pump  66  was found to finely entrain very minute bubbles of the now O 3  rich air into the water to a greater extent than either of the two used separately. It was also found that O 3  was better entrained into the water where venturi  74  was oriented in a horizontal position. This O 3  rich water then flows into water distribution tube  28  and over the evaporator  26 . It was found that by enriching the O 3  content of the water in this manner using air pump  66  to provide for such improved mixing thereof, rather than rely on the inherent suction effect of venturi  74  alone, that sufficient quantities of O 3  would reach water distribution tube  28 , evaporator  26  and receiving tank  30  such that growth of microorganisms thereon was greatly reduced or eliminated. 
     The spraying and cascading of water over evaporator  26  releases some of the ozone entrained therein. As O 3  molecules are heavier than the than the O 2  and nitrogen (N 2 ) forming the primary components of the ambient air, the O 3  falls under the force of gravity into bin  15 . It was found that the microorganism count or level of contamination of bin  15 , cold plate  48  and drain tube  50  was greatly lowered or eliminated relative to non ozone treated equipment. It was also discovered that such content and growth in drip tray  38  and associated drain tube  44  was reduced or eliminated. In particular, the clogging type if growth that can become present in drain tubes  44  and  50  was not found to develop. 
     When not in the ice making state, i.e. when water pump  32 , and the refrigeration system as well, are not operating, the O 3  laden air does not mix with the water as well as the venturi  74  can not create a suction. However, with air pump  66  running it will flow from venturi  74  in a reverse direction through water pump  32  into receiving tank  30 . At the same time it will flow in the “normal” direction from venturi  74  and up to water distribution tube  28 . Of course, a larger amount of O 3  will flow, during such non ice making times, into ice retaining bin  14 , as less would be demanded due to the absence of the suction effect of venturi  74 . In the above described embodiment it was found that the bacteriostatic or bactericidal effects of the ozone were maximized in a method of operation wherein ozone generator  64  and air pump  66  ran continuously, regardless if ice maker  12  was in an ice making mode or not. Ordinarily, when the ice maker is off, the water in the tank  30  is stagnant and growth of microorganisms can be accelerated thereby. That result is due to the fact that refrigeration and water pumping are both shut off when the ice bin is sensed as full of ice. An enhancement of the bacteriostatic or bactericidal effects is accomplished by energizing the water pump and ozonating and cycling the water over evaporator  26  even if bin  15  is sensed as full and the refrigeration components of ice maker  12  are shut off. Thus, the control of the present invention provides for such pump operation even during non-ice making times. However, water must not be permitted to spray from the evaporator into the ice bin below. In ice makers of the type having a curtain that extends closely parallel with the evaporator, it is necessary that it be in the closed position before water cycling over the evaporator occurs. Typically, such ice makers include a switch that indicates if the curtain is closed so that running of the pump  32  can be keyed thereto. For example, a further switch, not shown, can be added to the curtain to indicate a closed condition. This further switch can be used to operate a separate relay that provides power to water circulating pump  32  separately from the refrigeration compressor. Those of skill will understand that the ozone generator  64  and air pump  66  are continuously energized. 
     As seen by referring to FIGS. 4 and 5, a second embodiment  90  of the present invention utilizing ice maker  12  and ice/beverage dispenser  10  is illustrated. As seen specifically in the schematic of FIG. 4, no venturi  74  is used. Instead a line  92  runs directly to distribution tube  28 . As seen in FIG. 5, tube  92  is connected to a fitting  94  secured to tube  28 . A check valve  88  in line  92  serves to prevent flow of water there through back to generator  64 . 
     In the operation of embodiment  90 , the O 3  laden air is more passively mixed with the ice making water than in the first embodiment where a venturi is utilized. However, by using the strategy of also running ozone generator  64  continuously, it was found that a direct connection to distribution tube  28  served to provide for a substantial reduction in microorganisms present or growing on or in tube  28 , evaporator  26 , and receiving tank  30 , as well as with pump  32  and associated tubing. 
     As seen by referring to FIGS. 6 and 7, a third embodiment  100  of the present invention is shown. In this embodiment no ice maker  12  is utilized wherein a full ice bin cover  102  serves to enclose cover ice bin area  15  in place of ice maker  12 . In this embodiment ozone generator  64  is used only to feed a line  104  running to a fitting  105  secured to and extending from a top rim  15   a  of ice bin  15 . Thus, embodiment  100  is only concerned with the delivery of ozone to ice bin  15 . This embodiment was also found to reduce or eliminate the presence of microorganisms in ice retaining bin  15  and associated drain tube  48 , as well as in ice dispensing chute  40 , drip tray  38  and drain tube  50  thereof. 
     An electrical schematic of the present invention is seen in FIG.  8 . This schematic is essentially the same for various embodiments herein. A high voltage transformer  106  provides power to generator  64 . A variable transformer  107  can be used to regulate the ozone output of generator  64 . Thus, in situations where, for example, ice maker  12  is not operating to make ice, a lower O 3  output is acceptable. Therefore, the ice maker control can switch generator  64  to a lower output by means of adjusting the voltage output of transformer  107  down. Conversely, going into the ice making mode wherein pump  32  and compressor  20  are turned on will result in generator  64  being switched to a higher voltage. An indicator light  108  is secured to the exterior of merchandising frame  52  and serves to indicate when generator  64  is operating. Fluorescent light sockets  60  are powered by a starter  109  and a ballast  110 . A transformer  111  provides power to valves  34 . 
     In a particular reduction to practice of the present invention in accordance with the first embodiment described herein, bin  15  has a capacity of approximately 150 pounds, and ice maker  12  has an ice production capacity of 400 pounds per day. Generator  64  is manufactured by Ozotech Inc. of Yreka, Calif. and identified by model number 31249. This model of generator operates on 115 volt less and than ½ ampere of current and has an O 3  output of approximately 60 mg/hr. Venturi  74  is of the type manufactured by Mazzei Injector Corporation, of Bakersfield, Calif. and identified as model number 684K. The air pump is of the type manufactured by Second Nature of Blacksburg Virginia and identified as the Challenger II model having an air output of 1.2 liters/min. The lower voltage of 90 volts selected for the reduced output operation of generator  64  resulted in an output of 30 mg/hr. 
     As seen by referring to FIGS. 11 and 12, a further beverage embodiment of the present invention is shown. A dispenser  120  of the “drop in” type is shown. As is known, such dispensers include an ice bin  122  that is sized to drop into an appropriately sized hole in an existing counter top  123  and be supported in part by a perimeter flange  122   a . A tower housing portion  124  extends there above and includes a plurality of valves  125  secured to an exterior top surface thereof. A drip tray and pan  126  is positioned below the valves  125  and includes a drain and drain line  126   a . The bin  122  includes a cold plate  127 , at the bottom thereof, generally positioned at an angle to allow melted ice to flow therefrom and out a drain and drain line  128 . A plurality of beverage lines  129  extend from cold plate  127  up through housing  124  and connect to valves  125 . A plate  131  is positioned within housing  124  and sealed around its perimeter for creating an interior space  132 . Ozone generator  64  and air pump  66  are located within space  132  and can be secured to plate  131 . Ozone is discharged into a tube system  135  having a tube  136   a  for directing a portion thereof into the beverage drip tray  126  and associated drain and drain line  126   a . Ozone is also directed into a further tube portion  136   b  for moving a portion thereof into the ice storage bin  122  and cold plate  127  and its drain and drain line  128 . 
     In operation, it can be appreciated that the ozone produced by generator  133  is delivered by pump  134  so that it falls into bin  122  and onto cold plate  127  and drain and drain line  128 . Ozone is also delivered into drip tray and pan  126  and its drain and drain line  126   a . A bacteriostatic effect is then provided for in both areas. It has been found that such an approach serves to greatly reduce the growth of microorganisms and the drain blocking associated therewith. Housing  124  can be understood to be somewhat expanded in horizontal width to accommodate generator  64  and pump  66  as well as the electronics associated therewith, not shown, within space  132 . However, that additional width can be on the order of only three to four inches. Panel  132  provides for keeping ozone producing elements and electronics dry through isolation from lines  129  and ice bin  122 . Ozone delivery tubes  136   a  and  136   b  can extend through panel  131  and be sealed around there circumference at the point of passage there through. Internal space  132  is vented to provide for a dry air source.