Abstract:
An improved air sterilization system has unobstructed air passageways from a chamber substantially enclosing a volume of air to the air sterilization assembly unit in which the air sterilization assembly unit has heating elements located within air passageways in the unit to exterminate airborne micro-organisms by applying heat to the continuously flowing airstream, and in which the temperature of air leaving the system is insignificantly higher than the temperature of air entering the system.

Description:
This invention is based upon provisional patent application No. 60/330,048, entitled Refrigerator Air Sterilization Device, filed 17 Oct. 2001; and provisional patent application No. 60/330,050, entitled Room Air Sterilization Device, filed 17 Oct. 2001. The priority date for these provisional patent applications is claimed herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Since the beginning of the refrigeration industry there have been improvements in the preservation of food products and other heat sensitive products. However, the refrigeration systems utilized do not inhibit the formation of fungi and bacteria inside the refrigerators and other cooling chambers. More recently, some refrigerators have presented new interior air circulation systems that improve the refrigeration of food products by maintaining a constant flow of cold air of essentially constant temperature which keeps foods at a desired constant temperature. These systems, however, have the drawback of increasing the incidence of cross contamination between food items when bacteria and spores are transported by air from one food item to another throughout the entire refrigeration chamber. 
     Accordingly, there is a need for an improved air sterilization system which can be utilized with existing and new refrigerators with enhanced airflow and temperature technologies so that bacteria, spores, fungi and smells are reduced without negatively impacting the temperature control quality of the refrigeration or other cooling systems. 
     SUMMARY OF THE INVENTION 
     The invention is generally directed to an improved air sterilization system for refrigerators, multipurpose chambers, and compartments where it is desired that the sterilization system will not significantly affect the air temperature where the air within the chamber is substantially confined. The system may include an air sterilization assembly that is located wholly within the interior of a chamber, or may be attached to the exterior or may have some components located in the interior while others are located outside of the chamber. The system has at least one air sterilization assembly, at least one air entrance and at least one air exhaust. The air entrance and exhaust are located within the interior of the chamber such that interior air will freely enter and exhaust the air sterilization assembly by means of air convection. The unsterilized air enters the assembly, is cleaned, and the sterilized air is returned to the chamber without significantly altering the inside temperature of the chamber. 
     The invention uses intense heat contained within capillaries to effectively kill micro-organisms such as mold, bacteria, and virus. Because the device operates without the release of large quantities of heat into the environment, it is particularly suited for use as part of an air sterilization system for a refrigerator, room, multi purpose chamber or compartment requiring air purification. When used inside a refrigeration chamber, the air sterilization system will reduce the development of smells, bacteria, spores and fungi inside the chamber to preserve and extend the shelf life of food products and stored materials. 
     The air sterilisation device consists of a ceramic core having at least one tube, with at least 2 longitudinal capillaries extending the length of the tube. The capillaries have a diameter between 1 mm and 8 mm and the tube may extend between about 120 mm and 2400 mm in length. In the preferred embodiment, the capillaries are heated with an electrically resistant wire that runs the length of the capillaries. The wire is connected to a power supply. When power runs through the wire, the resistance of the wire generates heat, which is radiated into the air surrounding the wire inside the capillary. The resistant wire is designed to produce heat inside each capillary in excess of 160° Celsius. The heat inside the capillaries generates an upward air stream by heating the air when the ceramic pipe is in a vertical position. The heated air exiting from the upper ends of the capillaries creates a negative pressure at the lower ends of the capillaries which sucks exterior air into the ceramic capillaries and sustains a continuous air circulation through the capillaries. Airborne micro-organisms are exterminated by heat as they pass through the heated capillaries. The continuous airflow generated by air convection assures substantial air sterilisation in a quiet and efficient way and with low power consumption. In the preferred embodiment, the tubes are made of a good quality ceramic or equivalent material that can withstand heat greater then 200° C., and that allows the capillaries to be situated closely together where heat may be exchanged between them. The ceramic core is located within an exterior casing having an air access opening at the bottom. An optional heat exchanger can be used at some distance above the ceramic capillaries, and may have a casing top that is resistant to impact and heat, and that has at least one air outlet that will boost airflow out of the device. In the preferred embodiment, the casing will incorporate the ceramic core and be attached to a wall. 
     Accordingly, it is an object of the invention to reduce airborne micro-organisms and of avoid the formation of smells, fungi, mold and bacteria in food-containing air chambers. 
     It is a second object of the invention to provide an improved sterilization system for refrigerators, incorporating air sterilization assemblies. 
     Another object of the invention is to provide an improved air sterilization system for refrigerators in which air sterilization assemblies including intake and outlet connections pass air in the refrigerator through the air sterilization assembly which kills fungus, bacteria and other airborne micro-organisms through heat. 
     Still a further object of the invention is to provide an improved air sterilization system for refrigerators which utilizes a fan to enhance the air flow through the air sterilizing assembly. 
     Yet still a further object of the invention is to provide an improved air sterilization system in which the air sterilization assembly is coupled to a cooling chamber so that the air from the cooling chamber passes through the sterilization system where the heat inside is used to kill the micro-organisms and the heat does not adversely affect the internal temperature of the cooling chamber. 
     Still another object of the invention is to provide an improved air sterilization system in which the air assembly is coupled to a multi purpose chamber or room for sterilizing the air. 
     Yet another object of the invention is to provide an improved air sterilization system to be attached to automobiles, trains, subway cars, submarines, aircraft, cruise ships, war vessels and other types of vehicles in which the air in a restricted volume is to be purified. 
     Still other objects and advantages of the invention will be apparent from the following description of the preferred embodiments. 
     The invention accordingly comprises the features of construction, combination of elements, arrangement of parts, combination of steps and procedures, all of which will be exemplified in the constructions and processes hereinafter set forth and the scope of the invention will be indicated in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the invention, reference is made to the following description taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a cutaway perspective view of an air sterilization assembly constructed in accordance with a preferred embodiment of the invention; 
         FIG. 2  is a side elevation view of a air sterilizing assembly as in  FIG. 1 , attached through the wall of a refrigerator; 
         FIG. 3  is a cutaway perspective view of an air sterilization assembly constructed in accordance with a preferred embodiment of the invention in which the air sterilization assembly is inside the refrigerator wall; 
         FIG. 4  is a partially cutaway perspective view of an air sterilizing assembly inserted in a wall constructed in accordance with a preferred embodiment of the invention; and 
         FIG. 5  is a cutaway perspective view of an air sterilization assembly attached to the outside surface of a chamber wall, constructed in accordance with another preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference is first made to  FIG. 1  in which an air sterilizing assembly, generally indicated as  100 , constructed in accordance with a preferred embodiment of the invention, is depicted. Air sterilizer assembly  100  has contaminated air entering by air convection at inlet  12 . The air in sequence enters the sterilizing ceramic element  1  of the type shown and described in Applicant&#39;s prior U.S. Pat. No. 5,874,050, which is inserted in an optional insulated element  2 . The hot sterilized air exhausts at the sterilizing element top end  3 . The hot sterilized air is then cooled at optional heat exchanger  8 . Finally the cooled, sterilized air exhausts air sterilizer chamber  10  through outlet  11  back to the refrigerator or chamber. 
     As shown in  FIG. 2 , like referenced elements being represented by like referenced numerals, air sterilization assembly  100  is affixed outside of the wall  20  of the chamber. As shown in  FIG. 2 , the left side of wall  20  is the interior of the chamber compartment. Air inlet  12  is shown open on the inside of the chamber compartment with the flow of air through air sterilization assembly  10  and then back out through exhaust outlet  11  through wall  20  of the chamber. In this way, the heat associated with the sterilization process is applied outside of the chamber wall causing less impact on the interior temperature of the refrigerator. 
     Reference is next made to  FIG. 3  where air sterilization system  200  with air sterilization assembly  10  (not shown) including ceramic element  1  inserted in optional insulated element  2  and optional heat exchanger  8 , all at the inside of the refrigerator corner next to wall  20  is shown. In this case, the air sterilization assembly  10  is placed in an insulated chamber  14  and the air sterilization assembly  10  includes optional contaminated air inputs  12  and  12 A and one exhaust  11 . 
     Reference is next made to  FIG. 4  wherein an air sterilization assembly  300  constructed in accordance with another preferred embodiment of the invention is depicted, like elements being depicted by like referenced numerals. In this case, the air sterilization assembly  300  is placed in a tube  30  in refrigerator wall  20 . One portion of channel  30  serves as air inlet  12 A and another portion as exhaust outlet  11 A. An optional circulation fan  5  is shown in the air channel to assist in improving airflow through the assembly. Although the fan is located above the assembly, its positioning is not critical, and it may be mounted below the sterilization assembly, if desired. The air sterilization assembly  300  again includes an air sterilizing element  1 , an insulating element  2  and a heat exchanger  8 . Though only a single such sterilizing element  1  is shown, it is possible to have multiple elements of this sort in the same refrigerator. 
     In each of these embodiments the electrical connections to the air sterilizing units are not shown. These are conventional connections, such as those of the type already shown in Applicant&#39;s prior U.S. Pat. No. 5,874,050. 
     Reference is next made to  FIG. 5  wherein an air sterilization assembly  400 , constructed in accordance with another preferred embodiment of the invention, is depicted. Air sterilization assembly  400  is one in which contaminated air from the inside of a room wall  20  enters inlet  12 , passes through sterilization assembly main body  10  and exhausts via outlet  11  back to the room. A cooling chamber  17 , receiving cold air from inlet  18  and exhausting via outlet  19  is used to cool the sterilization assembly  400  which in turn will reduce the temperature of the air returning to the inside of the room of side wall  20  so as to minimize the increase in temperature inside the room as a result of the sterilization process. Air sterilization assembly main body  10  is held in place within cooling chamber  17  via attachment means  16  which may be of a conventional nature. The air sterilization assembly  400  may also be held in place by other means. 
     With the use of the new air sterilization system as shown in the various figures, air circulation through the air sterilization assemblies is created by air convection through the use of air sterilizers similar to those used in room air sterilizer devices invented by Applicant in U.S. Pat. No. 5,874,050. The air sterilization technology utilized offers excellent results with exceptional reduction in micro-organisms and improvement in indoor air quality as proven by international laboratories, including INETI—Laboratory of Microbiology in Lisbon, SGS Natec in Hamburg, Universidad Complutense of Madrid, TMC—Technical Micronics Corporation in the United States of America and other tests. These tests show that the sterilization assembly system operates in a highly improved fashion when compared to systems relying on filters, and chemical agents. No air sterilizing or air purifying systems are available up to today for refrigerators and cooling chambers. 
     In other preferred embodiments of the invention the refrigerator or chamber or room would be outfitted with one or more sterilization assemblies. Generally, each of the air sterilization assemblies includes at least one air input and at least one air exhaust outlet connected to the interior of the contained volume so that the air inside said contained volume will freely enter and exhaust each air sterilization assembly. The system can operate either with the natural air convection occurrence caused by air heating at the capillaries of the air sterilizing assembly ceramic element or by a dedicated air flow system associated with the air sterilization assembly. The dedicated air flow system may include a fan to blow air into the air sterilization assembly input port or a fan to pull air from the output port. 
     To minimize the effect of the heat utilized in the air sterilization assembly, the system may include an additional cooling chamber inside or outside of the air sterilization assembly which cools the flow of air coming out of the ceramic core exhaust outlet prior to re-entry into the enclosed air volume such as a chamber, room or refrigerator. 
     In addition to being utilized in refrigerators, cooling and multipurpose chambers and rooms, the air sterilization assembly can be utilized in enclosed volumes and also in connection with cooling or heating systems such as vehicles as automobiles, trains, subway cars, submarines, aircraft, cruise ships, war vessels and other types of vehicles in which there are enclosed volumes which are either cooled, heated or merely include airflow. In these cases, the size and number and location of the air sterilization assemblies incorporated into the system are adaptable based upon the needs of the system, including its volume, airflow, temperature, humidity and other physical characteristics. 
     Accordingly, an improved air sterilization assembly capable of sterilizing a refrigerator or other air contained volume is provided. The air sterilization assembly includes input and exhaust outlets with air flowing through a sterilization chamber where the air is heated to a sufficiently high temperature so as to kill micro-organisms and the output air is cooled either through the use of a heat exchanger and/or a cooling chamber. The air sterilization assembly can be placed either fully inside the room, chamber, compartment, refrigerator or inside or outside its side walls and or a partial or total mixture of said options with direct inlet and outlet connections to the room, chamber, compartment, refrigerator or into channels built into their side walls. 
     It will thus be seen that the objects set forth above, among those made apparent in the proceeding description, are efficiently obtained and, since certain changes may be made in the above constructions and processes without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanied drawings shall be interpreted as illustrative, and not in the limiting sense. 
     It will also be understood that the following Claims are intended to cover all of the generic and specific features of the invention herein described and that all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.