Patent Publication Number: US-2006010791-A1

Title: Method for converting a structure into a disinfestation apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      The present application claims the benefit under any applicable U.S. statute to U.S. Provisional Patent Application No. 60/291,407 filed May 16, 2001, titled PORTABLE HEAT-TREATING DISINFESTATION APPARATUS. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates generally to an apparatus for eradicating pests in commodities, wood products, paper products, machinery, appliances that dispense foods or drinks and packaging materials and, in particular, a portable apparatus for eradicating pests using heat.  
     BACKGROUND OF THE INVENTION  
      Modern transportation means have made it feasible to transport foods, machinery and other commodities from one geographical region to markets in regions on the other side of the world. In addition, equipment that holds foods or drinks, such as vending machines, water-coolers, coffee machines, etc., have a high incident of infestation by cockroaches, other pests and larvae and their eggs. This infestation can be present in any imported, exported or domestic consignment due to the heat, moisture and dark cavities in their design.  
      Wood packing such as pallets, dunnage, crating, packing blocks, drums, cases, load boards, pallet collars, commodities, related and un-related machinery and skids can be present in any imported, exported, or domestic consignment, including consignments which would not normally be the target of phytosanitary inspection. Wood packing is frequently made of non-manufactured, low quality inexpensive raw coniferous and/or non-coniferous wood that may not have undergone sufficient processing time or treatment to remove or kill pests present within raw wood and therefore becomes a pathway for the introduction and spread of pests. Furthermore, wood packing is very often re-used (in that packing received with an imported consignment may be used again to accompany a second consignment). Therefore, the true origin of any piece of wood packing material is difficult to determine and thus its phytosanitary status cannot be ascertained or guaranteed.  
      In all regions of the world, imports of automobiles, machinery, parts and other non-food products are fumigated with Methyl Bromide or Ethylene Dibromide to kill pests hiding within various machinery or packaging. However, these chemicals can damage the ozone layer, and the residue left behind by these chemicals is harmful to people.  
      Heat treatment is an effective method for controlling pests without the drawbacks of fumigation e.g., highly toxic chemicals, airtight fumigation containment, certified pest controller(s), regulation by various state and/or federal agencies, and lengthy treatment/clearing times. Studies have documented that temperatures at or above 120 degrees Fahrenheit for thirty minutes is lethal to insects and pests. (Forbes and Ebling 1987, Sheppard 1984, Quarles 1995, and Zeichner 1998) The NPPO (National Plant Protection Organization) has established requirements for non-manufactured wood packing to manage the pest risk associated with this pathway. The process for establishing import/export requirements for wood packing may be different from that used for commodities moving as consignments. The normal process of undertaking risk analysis to determine if measures are necessary and the strength of such measures are frequently not possible for wood packing material because its origin and phytosanitary status may not be known. For this reason, it has become mandatory to regulate wood packing broadly by applying globally accepted measures that eliminate any presence of the more important regulated pests and significantly reduce the risk for a number of others.  
     SUMMARY OF THE INVENTION  
      Recent laws passed in Canada and in the European Union require that all wood and wood products and packing materials entering their respective countries be treated so as to eradicate pests. This invention embodies a proven treatment method which requires that wood packing be subjected to an elevated temperature (i.e., at least 56° Celsius) for an extended period of time (e.g., at least thirty minutes).  
      Vending machines, water coolers, coffee machines and similar equipment lend themselves to be treated effectively with heat to eliminate pests without damaging the equipment. With the use of heat, no risk of chemical transfer to water or vending products can occur, thus greatly reducing liability. Moreover, there is a commercial need for a portable heat disinfestation apparatus that can eradicate pests and be moved from one location to another. The present invention describes a portable device that eradicates pests by the use of heat and that is relatively quick and easy to manufacture. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and, together with the description, serve to explain the principles of the invention.  
      In the drawings:  
       FIG. 1A  is a side plan view of a portable heat-treating disinfestation apparatus according to the present invention using a remote direct fired heating system;  
       FIG. 1B  is a side plan view of a portable heat-treating disinfestations apparatus utilizing a trailer that can be moved by a tractor unit using a remote direct fired heating system;  
       FIG. 2  is a top view of the portable heat-treating disinfestation apparatus illustrated in  FIG. 1  with the direct fired heating system attached to the rear of the apparatus;  
       FIG. 3  is a rear view of the portable heat-treating disinfestation apparatus illustrated in  FIG. 2 ;  
       FIG. 4A  is a front interior view in one embodiment of the portable heat-treating disinfestation apparatus illustrated in  FIG. 1  (used with a direct fired, electric, or indirect fired heater) with the doors opened;  
       FIG. 4B  is a front view of the portable heat-treating disinfestation apparatus illustrated in  FIG. 1  with the doors closed;  
       FIG. 5A  is a portable heat-treating disinfestation apparatus according to the present invention using an indirect fired system;  
       FIG. 5B  is a side view of the apparatus illustrated in  FIG. 5A  with a set of trailer wheels attached;  
       FIG. 5C  is a side view of another embodiment of the apparatus illustrated in  FIG. 1B  using a remote indirect fired heating system connected to the apparatus with either rigid duct, flexible duct, or a combination of both;  
       FIG. 6A  is an enlarged side view of a typical direct fired heating system capable of being used with the portable heat-treating disinfestation apparatus illustrated in  FIGS. 1A, 1B ,  2 , and  3 ;  
       FIG. 6B  is an enlarged end view of the inlet end of the direct fired heating system illustrated in  FIG. 6A ;  
       FIG. 7  is a side plan view of a portable heat treating disinfestation apparatus according to the present invention using an indirect fired heating system;  
       FIG. 8  is a cross-sectional view of the plenum shown in  FIG. 7 ;  
       FIG. 9A  is a top view of the hypotenuse side that forms the ducts of  FIG. 7 ;  
       FIG. 9B  is a side view of the duct portion illustrated in  FIG. 9A ;  
       FIG. 10  is a front view of an end cap for a duct used in the embodiment of  FIG. 7 ;  
       FIG. 11  is an enlarged cross-sectional view of a longitudinal side wall of the chamber;  
       FIG. 12  is a top cross-sectional view of the embodiment illustrated in  FIG. 7 ;  
       FIG. 13A  is an enlarged front view of the return air baffle of  FIG. 7 ;  
       FIG. 13B  is an enlarged side view of the return air baffle of  FIG. 7 ;  
       FIG. 14A  is an enlarged end view of a T-shaped floor section of  FIG. 14B ;  
       FIG. 14B  is a front interior view of the portable heat-treating disinfestation apparatus illustrated in  FIG. 7  (used with an indirect fired heater) with the doors opened; and  
       FIG. 15  is a side view of a direct fired heating system that becomes an integrated component of the portable heat-treating disinfestation apparatus of  FIGS. 1A, 1B , or  5 C with either rigid duct, flexible duct, or a combination of both. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      For the purpose of this patent, the term “pest” shall be defined as, but not limited to, any unwanted living organism susceptible to eradication by means of heat (e.g., insects, biological organism, mold, fungus, anthrax, etc.)  
      For the purpose of this patent, the term “heater” shall be defined as, but not limited to, any device that has the means to raise/increase the temperature of air or a given substance either directly or indirectly, through conduction, convection, or radiation. The source of heat can be derived from the means of a combustible fossil fuel (e.g., propane, natural gas, heating oil, etc.) electricity, steam, coal, or wood.  
      For the purpose of this patent, the term “products” shall be defined as, but not limited to, non-manufactured wood packing (e.g., pallets, dunnage, crating, packing blocks, cases, load boards, skids, etc.), paper products, appliances that hold and dispense foods or drinks (e.g. vending machines, water coolers, coffee machines), and machinery equipment, and commodities.  
      In describing a preferred embodiment of the invention, specific terminology will be selected for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.  
      Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which a portable disinfestation apparatus utilizing heat, in accordance with the present invention, is generally indicated at  10 .  
      Referring to  FIG. 1A , a chamber  12  that is designed to be movable is set in place. The chamber  12  is preferably insulated in order to conserve energy in bringing the interior of the chamber up to a desired temperature and in maintaining that temperature but may not be insulated in some cases due to use of existing truck body or the like. The chamber  12  may either be of new construction or refurbished (e.g., a former reefer container, an insulated trailer on wheels, etc.).  
      The interior of the chamber  12  may be designed to hold specific goods or commodities. For example, the width of the chamber  12  may accommodate a standard pallet, and/or shelves may depend from the walls to hold certain shipping containers.  
      In a preferred embodiment, the floor of the container may be reinforced to allow a forklift to ingress and egress. This feature will greatly facilitate loading and unloading of the chamber  12 .  
      The chamber  12  preferably has a rectangular shape. This allows the chamber to be shipped conveniently on a flatbed truck, train car, ship or other means of transportation.  
      Referring to  FIGS. 1A, 2 ,  3 ,  4 A and  5 A, the chamber  12  has a flat bottom  14 , opposing parallel first and second endwalls  16  and  18  depending upward along the traverse side of the flat bottom  14 , and opposing parallel third and fourth endwalls  20 ,  22  depending upward along the longitudinal sides of the bottom  14 . A top  24  encloses the structure. A door or a pair of doors  42 ,  44 , are located in the first endwall  16  to provide a means of ingress and egress to the interior of the chamber  12 .  
      An important feature of the present invention is its portability. Forklift pockets may be formed below the chamber  12  to allow a fork-lift to raise the chamber in order to move or reposition the apparatus  10 . In an alternative embodiment, lifting mounts may be produced in the upper four corners of the chamber  12 . The lifting mounts provide a means for an overhead crane, large fork-lift machine or ship&#39;s crane to attach to the chamber  12  in order to lift the chamber.  
      Other preferred embodiments are illustrated in  FIGS. 1B, 5B ,  5 C and  7 . As shown in  FIG. 5B , a plurality of wheels  99  can be attached to the underside of said chamber  12 . (Alternatively, the chamber  12  can be attached to a flatbed trailer or other platform that has wheels  99 .) Attached closer to the end of the chamber  12  opposite the wheels is a stand  92  and a means  97  for pulling the chamber  12 . The stand allows the apparatus  10  to sit without external assistance.  
      As illustrated in  FIGS. 1B, 5B , and  5 C the chamber  12  may be adapted so that it can be easily mounted on, and removed from, a trailer bed  95 . The trailer bed  95  has a plurality of wheels  99  at its back end. At the front end of the trailer bed  95  are a means  97  to allow the trailer/chamber to be pulled by a truck (i.e., a tractor-trailer vehicle) and a stand  92 .  
      Referring to  FIGS. 3 and 4 A, the rear wall  16  of the chamber has an inlet  28  and an outlet  29 . An inlet duct  40 , connects the inlet  28  to a direct fired heater  30 . The outlet  29  is open to the ambient air.  
      In one embodiment a pair of doors  42 ,  44  pivot about hinges that are connected to side walls  20 ,  22 , respectively, as illustrated in  FIG. 4B . The doors  42 ,  44  swing independently of each other and allow ingress and egress to the interior of the chamber  12 .  
      Referring now to  FIGS. 6A and 6B , a typical direct fired heating unit  30  is illustrated. This type of heating unit is usually identified by its elongated cylindrical housing  32 ; however, some direct fired heaters have a rectangular or other polygonal shaped housing. A fan or blower connected to an electric motor and a burner assembly are mounted within the housing  32 . The fan or blower draws air in from the inlet end  34  of the heater  30 , pushes the air through the housing and over the burner assembly and out the outlet end  36  of the housing.  
      In one embodiment the burner assembly is designed to mix oxygen from the air passing by with natural or propane gas. After an igniter ignites the air/gas mixture, the burner assembly ensures a controlled burn as long as gas is delivered to the burner assembly from an external source. Approximately the entire second half of the housing  32  acts as a combustion chamber. As the air passes through the flame at the burner assembly and through the combustion chamber, it is heated to a desired temperature.  
      A control box  38  is mounted on the exterior of the housing  32 . The control box  38  protects electronic circuitry used to control the operation of the heater  30 . Specifically, the electronic circuitry controls the amount of gas delivered to the burner assembly, provides power to the electric fan motor and the starts the igniter.  
      As illustrated in  FIG. 3 , the heater  30  is mounted on the outside of the rear wall  16  of the chamber  12 . Referring now to  FIGS. 6A and 6B , first and second brackets  84 ,  85 , respectively, are used to secure the direct fired heater  30  to the chamber&#39;s end wall  16 .  
      Referring again to  FIGS. 1A, 1B ,  3 ,  6 A and  6 B an input air duct  40 , connects the outlet  36  of the direct fired heater  30  to an inlet  28  in the chamber. In  FIG. 3 , the outlet  29  of the chamber  12  is located proximate the inlet  34  of the heater  30 . This allows the heater to simultaneously draw in fresh air along with some of the relatively hot air being expelled from the interior of the chamber  12 . This method saves energy while ensuring that the air inside of the chamber  12  stays at the desired temperature.  
      Referring now to  FIG. 5C , a portable apparatus  10  utilizes a remote indirect fired heater  32  as illustrated. An input air duct  40 , connects the outlet of the indirect fired heater to the inlet  28  of the chamber  12 . The outlet  29  of the chamber is connected to the inlet of the indirect fired heater  32  through return air duct  41 . This allows the heater to continuously re-circulate the heated air within the chamber thus saving energy and ensuring the air inside the chamber  12  stays at the desired temperature.  
      Referring now to  FIGS. 5A, 5B  and  7 , a portable disinfestation apparatus  10  utilizing an indirect fired heater  50  is illustrated. The two types of disinfestation apparatus are basically the same except that the air in an indirect fired heat system does not come in direct contact with a burning flame. An indirect fired heater  50  is similar to gas-burning heaters found in many commercial buildings.  
      In one embodiment illustrated in  FIGS. 7 and 14 B the indirect fired heater  50  has its output mounted directly over the plenum inlet  60  of the chamber  12 . Ductwork  52  connects the outlet  61  of the chamber  12  to the inlet of the indirect fired heater  50 . (It should be noted that  FIG. 4A  shows the plenum inlet  28  as circular in shape; however, because the general shape and design of the indirect fired heater  50  is different than a direct fired heater  30 , the plenum inlet  60  is usually rectangular when used with an indirect fired heater  50 .  
      The interior of the chamber will now be described. Although the drawings show an indirect fired heating system  50  in connection with the interior details, it would be understood by one skilled in the art that the interior chamber of an apparatus  10  using a direct fired system  30  is substantially identical.  
      A side cut away of the chamber  12  is also illustrated in  FIG. 7 . A plenum  55  is formed on the inside of the back wall  16 . The plenum  55  is substantially rectangular in shape and covers the entire width (i.e., from longitudinal wall  20  to longitudinal wall  22 ). A portion of the ceiling of the chamber forms the top of the plenum  55 . A plenum deck  56  forms the bottom.  
      Two diametrically opposed ducts  51 ,  53  assembled from a pre-determined number of duct sections extend from the plenum  55  substantially the entire length of the chamber  12 . The ducts  51 ,  53  have a triangular cross-section as shown in  FIG. 14B . A portion of the ceiling of the chamber forms the top of each duct  51 ,  53  and a portion of the sidewall of the chamber forms the side of the duct.  
      Referring now to  FIG. 8 , the face  62  of the plenum  55  is illustrated.  FIG. 9A  is a top view of the hypotenuse or long side  64  of a triangular duct section. As illustrated, a plurality of mounting holes  66  is positioned along each edge of the hypotenuse side of the duct section.  FIG. 9B  is a side view of the hypotenuse side  64   6 f the duct section.  
      The bottom portions of the hypotenuse side  64  are attached to the side wall (e.g., preferably with screws, but rivets, spot welding or other means may be used) of the chamber  12 , while the top portion is attached in to the ceiling of the chamber  12 . The hypotenuse side  64  of the duct sections are joined to the upper left and upper right corners of the plenum face  62 . An end cap  71  seals off the end of each duct.  
      Duct end caps  71 , as shown in  FIG. 10 , close off the ends of each duct  51 ,  53 . The end caps  71  abut against the hypotenuse side  64  and are secured by screws through mounting holes  69  to the ceiling and wall of the chamber  12 .  
      The ducts  51 ,  53  serve to distribute the warm air away from the plenum  55  to be evenly distributed to the interior of the chamber  12 .  
      In a preferred embodiment, the walls of the chamber are chamfered to form a plurality of parallel, vertically-oriented channels  77  that extend from the ceiling to the floor of the chamber  12 . The channels  77 , best illustrated in the partial cross-sectional wall view of  FIG. 11 , help to ensure that the warm air does not stay suspended above the products placed inside the chamber. The channels  77  provide a vertical passageway for the air to circulate within the chamber  12 .  
       FIG. 14A  is an enlarged view of a floor portion. As illustrated, this system can utilize external rigid or flexible ducting as means of transport for heated supply air or return air, the floor is comprised of a plurality of T-shaped supports  78  that extend upwards from a base  79 . Referring again to  FIG. 14A , the T-shaped supports  78  define a plurality of channels  88  on the floor of the chamber. The channels  88  provide a horizontal floor-level passage for the air to move within the chamber  12 . The T-shaped supports  78  are made of metal in one embodiment so that they may support the weight of a fork lift or other machinery needed to load product within the chamber.  
      Referring now to  FIGS. 13A and 13B , a return baffle  70  depends from the deck of the plenum. Referring again to  FIG. 7 , the return baffle  70  ensures that only the cooler air near the floor of the chamber is returned to the heater  50 .  
      In practice, the products are placed within the chamber  12 . The doors  40 ,  42  are closed. The heater  50  ignites and the motor in the heater begins to turn the fan. Air is drawn out of the chamber  12  through the outlet  61  and into the heater  50 . The air is heated to a set temperature and is blown through plenum inlet  60  into the plenum  55 . Within plenum  55 , the heated air is divided substantially in two and directed into the ducts.  
      The ducts  51 ,  53  distribute the heated air along the entire longitudinal dimension of the chamber  12 . The gutters  77  direct the heated air downward along the walls of chamber  12 . Since hot air rises, some of the air directed by the gutters  77  moves to the center of the chamber  12 . As the heated air cools, it falls to the floor of the chamber  12 . The T-shaped supports  78  provide channels  88  so that the cooled air can be returned, unobstructed to the return baffle  70  where it will eventually be drawn back through the outlet  61  and into the heater  50 .  
      Although this invention has been described and illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made which clearly fall within the scope of this invention. The present invention is intended to be protected broadly within the spirit and scope of the appended claims.