Abstract:
A produce chamber ( 1 ) is provided to subject produce in a crate ( 7 ) to a controlled atmosphere. The chamber ( 1 ) has at least one inflatable/deflatable balloon seal structure ( 15 ) for sealingly engaging with a side wall of a produce crate ( 7 ) which has at least one opening ( 13 ) in a side wall ( 11 ) thereof. The balloon seal structure ( 15 ) has at least one discharge opening ( 19 ) that aligns with the at least one crate opening ( 13 ). Crates ( 7 ) with produce therein can be loaded in the chamber ( 1 ) with the balloon seal structure ( 15 ) deflated. The balloon seal structure ( 15 ) can then be inflated and controlled atmosphere allowed to circulate through the balloon seal structure ( 15 ) and discharged from the opening ( 19 ) and through the crate opening ( 13 ) to expose the produce to a controlled atmosphere.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a 35 U.S.C. §371 National Phase Entry Application from PCT/AU2009/001300, filed Sep. 30, 2009, and designating the United States, which claims claims benefit of U.S. provisional application No. 61/101,199 filed on Sep. 30, 2008, which is incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to a produce chamber and method for subjecting produce in produce crates to a controlled atmosphere and has particular although not exclusive application for banana ripening. 
     BACKGROUND 
     Produce chambers have been known for subjecting produce in produce crates to controlled atmosphere. Typically, the produce is held in produce crates and controlled atmosphere is introduced into the chamber and allowed to expose the produce in the produce crates to the controlled atmosphere. The produce crates typically have openings in the side walls to allow the controlled atmosphere to reach all of the produce within the crates. Efficient flow of controlled atmosphere through the crates is not always guaranteed. In some cases, produce may escape exposure to the controlled atmosphere because of the way in which the controlled atmosphere is passed to the crates. Further, it is known that crates can be stacked in multiple height tiers within chambers and that a blind or tarp like curtain is placed over each layer to control the way in which the controlled atmosphere passes through the crates in each layer. A typical example of a produce chamber of the latter type is disclosed in our U.S. Pat. No. 5,041,298. 
     STATEMENT OF INVENTION 
     It is desirable that there be a more efficient way to ensure that the controlled atmosphere passes through the produce crates. 
     Therefore according to a first aspect of the invention there is provided a produce chamber for subjecting produce in a produce crate to a controlled atmosphere, said chamber comprising: 
     at least one inflatable/deflatable balloon seal means for sealingly engaging with a side wall of a produce crate, the produce crate having at least one opening in the side wall to allow controlled atmosphere to be introduced to the produce crate, 
     the balloon seal means having at least one atmosphere discharge opening therein to align with the at least one opening in the produce crate when the produce crate is located in the chamber; 
     the balloon seal means being arranged so that when a product crate with produce therein is to be introduced into the chamber, the balloon seal means can be deflated, the produce crate located in the chamber, and then the balloon seal means inflated and controlled atmosphere allowed to discharge into the chamber through the balloon seal means, so that the balloon seal means will inflate and seal against the side wall of the produce crate and so that the controlled atmosphere can be discharged from the at least one discharge opening through the at least one opening in the side wall of the produce crate to expose produce therein to the controlled atmosphere; and 
     an atmosphere circulating means for circulating controlled atmosphere away from the produce crate, 
     wherein the balloon seal means comprises at least two upright extending elongate socks spaced apart by the width of a produce crate so that when a plurality of produce crates are located in the chamber, one sock will engage with side walls of corners of two adjacent produce crates, and wherein each sock comprises at least two discharge openings, each discharge opening being for a respective one of the two adjacent produce crates. 
     In an example, the chamber employs multiple tiers of produce crates without the need to use a blind or tarp-like curtain between each layer. 
     In one example, the plurality of upright elongate socks are positioned adjacent a wall in said chamber, said wall acting as a reactive surface for the upright socks to inflate against and to permit an inflating sealing force to be applied from the upright socks to the side walls of the produce crates. 
     According to a further aspect of the present invention there is provided a method of subjecting produce to a controlled atmosphere in a produce chamber comprising: 
     locating produce in a produce crate in said chamber; 
     inflating an inflatable/deflatable balloon seal means comprising at least two upright extending elongate socks to engage and seal with a side wall of the produce crate, said at least two elongate socks being spaced apart by the width of a produce crate so that when a plurality of produce crates are located in the chamber, one sock will engage with side walls of corners of two adjacent produce crates, and wherein each sock comprises at least two discharge openings, each discharge opening being for a respective one of the two adjacent produce crates; 
     allowing controlled atmosphere to pass into the balloon seal means and through the discharge openings therein and then through an aligned opening in a side wall of said produce crate to expose the produce therein to said controlled atmosphere; 
     circulating controlled atmosphere away from the produce crate; and 
     deflating the balloon seal means to break the seal with the side wall of the produce crate and subsequently removing the produce crate and produce from the chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention can be more clearly ascertained, examples of embodiments of the invention will now be described with reference to the accompanying drawings wherein: 
         FIG. 1  is a diagrammatic perspective view of an example of an embodiment of a produce chamber, 
         FIG. 2  is an end elevation of the produce chamber shown in  FIG. 1  showing inflatable/deflatable balloon seal means in a inflated condition and sealing against produce crates in tiers, 
         FIG. 3  is a view similar to  FIG. 2  but showing the inflatable/deflatable balloon seal means in a deflated condition, 
         FIG. 4  is a plan view of the produce chamber shown in the previous figures, 
         FIG. 5  is a side elevation of the produce chamber shown in previous figures, 
         FIG. 6  is a close-up perspective view of a plenum and an upright extending elongate sock of a balloon seal means showing the way in which they are bonded together and the way in which they can be mounted to wall surfaces within the chamber, 
         FIG. 7  is a top perspective view showing a controlled atmosphere air circulator for use with the chamber shown in the previous figures, and 
         FIG. 8  is a transverse cross sectional view of a part of an upright extending sock of a balloon seal means showing mounting to a wall surface within the produce chamber. 
     
    
    
     DETAILED DESCRIPTION 
     Referring initially to  FIGS. 1-5 , there is shown a produce chamber  1  of generally rectangular configuration with access doors  3  at one end, and a controlled atmosphere circulating means  5  at the other end. In this example, the produce chamber  1  has a width sufficient to enable two rows of produce crates  7  to be placed on the floor  9  directly opposite one another.  FIG. 1  shows that the produce crates  7  can enter the chamber  1  through the open end that is closed by the doors  3 . The chamber  1  has a sufficient height, in this example, to allow two tiers of produce crate  7  to be stacked within the chamber  1 , one above the other.  FIG. 1  does not show the upper tier of crates  7  in order to aid clarity, however,  FIGS. 2 and 3  clearly show the arrangement for two tiers. 
       FIG. 1  shows that the crates  7  have side walls  11  that have at least one opening  13  therein. In this example, there are multiple openings  13  on each opposite side wall  11  of the crates. The end walls of the crates are shown solid but they may contain similar openings  13 . The tops of the crates are open to allow produce to be stacked therein. Typically, the crates can be made from a plastics material or other suitable material such as metal or mesh or wood or even a board material or similar. The produce crates  7  are typically rectangular as shown. 
     Mounted within the chamber  1  is at least one inflatable/deflatable balloon seal means  15 . In the example shown, there are multiple inflatable/deflatable balloon seal means  15 . In the example shown, the inflatable/deflatable balloon seal means  15  comprise multiple upright extending elongate socks. Whilst upright extending socks have been shown, the inflatable/deflatable balloon seal means  15  may comprise other arrangements such as laterally horizontally extending concertina type balloon seal means or similar. The inflatable/deflatable balloon seal means  15  are connected with an upper plenum  17  that is also inflatable/deflatable in a balloon like manner. The socks and the plenums shown are typically manufactured from a synthetic plastics material sheet such as a material known by the trade name Nylon 210. Another suitable material is known by the trade name Cambacon. The sheet is formed into ducts to provide the socks and the plenums. Other suitable materials may be utilised such as rubberised canvas or synthetically treated canvas or similar substitutes such as plastics sheets. Typically, the Nylon 210 sheets are approximately 1 mm in thickness and are thus quite flexible and will naturally assume a deflated condition unless inflated by a controlled atmosphere. Other thicknesses are possible provided they allow the plenums and socks to collapse and to be inflated. 
     In the example, it can be seen that there is inflatable/deflatable balloon seal means  15  at each side wall of the chamber  1  in a first tier, and a similar arrangement in a second tier. The plenums  17  connect with the controlled atmosphere circulating means  5 , as best shown in  FIGS. 4 and 5 . 
     Each of the inflatable/deflatable balloon seal means  15  is spaced apart by the width of a produce crate  7  so that when a plurality of produce crates are located in the chamber  1 , one sock of the inflatable/deflatable balloon seal means  15  will engage with side walls of corners of two adjacent produce crates. This is best shown in  FIG. 4 , and partly shown in  FIG. 5 . 
       FIGS. 2 and 3  show how the inflatable/deflatable balloon seal means  15  can be inflated to engage with side walls  11  of the produce crates  7 .  FIG. 3  shows the inflatable/deflatable balloon seal means  15  and the plenum  17  in a deflated condition and not engaging with any of the side walls  11  of the produce crates  7 . Accordingly, in order to load and/or remove produce crates from the chamber  1 , the inflatable/deflatable balloon seal means  15  and plenums are collapsed which then provides free access and movement of the crates  7 . When the crates  7  are positioned within the chamber  1 , then the inflatable/deflatable balloon seal means  15  and the plenums  17  can be inflated so they will engage with the side walls  11  of the produce crates  7  as shown. The socks that form part of the inflatable/deflatable balloon seal means  15  have at least one discharge opening  19  therein. This is shown only in  FIG. 1  where each sock has multiple discharge openings  19 . The plenums  17  are also shown with discharge openings  19 . When the produce crates  7  are located correctly within the chamber  1 , and the inflatable/deflatable balloon seal means  15  and the plenums  17  inflated, they will engage with the respective side walls  11  of the produce crates and with the upper edge surface of the produce crates respectively. This is diagrammatically shown in  FIGS. 2 and 4 . Because the ducts that form the plenum  17  connect with the controlled atmosphere circulating means  15 , then an atmosphere pressure can be supplied to the plenum  17  and to the inflatable/deflatable balloon seal means  15  by reason of a circulating fan  21  within the controlled atmosphere circulating means  5 . It can be seen that each sock forming the inflatable/deflatable balloon seal means  15  engages with upright corner edges of each of the produce crates  7 , and the discharge openings  19  are such that the controlled atmosphere passes therefrom and into and the aligned openings  13  of the produce crates  7  so that the controlled atmosphere will forcibly pass through the produce crates  7 , and expose the produce therein to the controlled atmosphere. This is diagrammatically shown in  FIGS. 2 and 5  by the flow arrows that show atmosphere flow paths. 
     In the example shown, there are two rows of produce crates  7  within the chamber  1 . The walls within the chamber  1  therefore provide reactive surfaces for the upright socks and plenums to inflate against and to permit an inflating sealing force to be applied from the socks and the plenums  17  to the side walls of the crates  7 . Whilst in the example shown, the walls comprise the walls of the chamber  1  itself, there may be independent wall surfaces provided within the chamber  1  for this purpose. The extreme ends of each of the socks and the plenums are sealed closed so that the controlled atmosphere passes only through the discharge openings  19  into the chamber and through the crates  7 . 
     In the example shown, it can be seen that the there is a right hand side arrangement of inflatable/deflatable balloon seal means  15  and plenum  17 , and a mirror image on the left hand side so rows of produce crates  7  can be held in the chamber positioned relative to each of the side walls. It can also be seen that there is a controlled atmosphere return passage  23  between the faces of the side walls of the produce crates  7  that directly face each other. This is shown in  FIGS. 2 ,  3  and  4 . The controlled atmosphere circulating means  5  has an intake  25  in line with the return passage  23 . Accordingly, in use, the controlled atmosphere is circulated within the chamber  1  by being pressurised by the fan  21  so that it passes up through the ducts that form the plenums  17  and then into the socks that form the inflatable/deflatable balloon seal means  15 . The controlled atmosphere then passes through the discharge openings  19  into the openings  13  in the crates and then through the crates, exposing the produce therein to the controlled atmosphere. The controlled atmosphere then forcibly passes through the crates through openings on the opposite side faces and into the return passage  23  and then back into the controlled atmosphere circulating means  15  as shown by the atmosphere flow arrows. 
       FIG. 3  shows guide means  27  in each of the tiers for correctly locating the crates  7  relative to the inflatable/deflatable balloon seal means  15  and the plenums  17 . The guide means are shown in this example as right angle elongate rails. This is merely one example of a suitable guide means  27 . Typically, the guide means  27  can be built as racking within the chamber  1  and the crates  7  allowed to slide or otherwise move along the guide means  27  to correctly position the crates  7 . End stops (not shown) may be provided at the extreme ends of the guide means  27  to locate the crates  17  at positive stop positions at the end of the chamber  1  adjacent the controlled atmosphere circulating means  5 . 
       FIG. 6  shows a close-up perspective view of the inflatable/deflatable balloon seal means  15  in the form of a sock, connecting with a plenum  17 . The sock is high frequency welded to the plenum  17  along weld line  29 , and a suitable opening is provided in the plenum  17  to allow controlled atmosphere to pass from the plenum  17  into the inflatable/deflatable balloon seal means  15 . Other forms of bonding the socks to the plenums are not excluded. 
       FIG. 6  also shows a fastening system  31  to enable mounting of the inflatable/deflatable balloon seal means  15  and plenums  17  relative to the chamber  1 . Here, elongate ‘C’ connectors similar to yacht sail connectors are bonded to the surfaces of the inflatable/deflatable balloon seal means  15  and the plenum  17 . These may be in short lengths as shown or in continuous lengths.  FIG. 8  shows how the ‘C’ shaped connectors connect with a beaded support  33  that is fastened to the walls within the chamber  1  by a suitable fastening medium or means. Typically, the fastening system  31  and beaded support  33  can be formed of a plastics material. 
       FIG. 7  is a top perspective view of the casing of the controlled atmosphere circulating means  5 . The casing has four outlets  35  to which the ducts of the plenum  17  connect. In this case, there are four outlets being for each of the four plenum ducts. The casing of the controlled atmosphere circulating means  5  contains the intake  25  previously referred to. 
     It should be appreciated that the above example provides a produce chamber for subjecting produce in crates to a controlled atmosphere and dispenses with the need to provide a blind or tarp over each layer as the controlled atmosphere is forcibly directed through the produce crates by reason of the balloon seal means. 
     The controlled atmosphere may be any suitable atmosphere needed for enhancing the keeping/ripening or conditioning of produce. For example, the controlled atmosphere circulating means  5  may be a high humidity air processing apparatus. In other instances, it may be an apparatus that circulates a specialised gas for ripening of the produce such as ripening of bananas. The produce need not necessarily be vegetables or fruit but may be flowers or other similar produce. It is contemplated that the produce will be holdable within the crates  7  so there will be intercites between adjacent products stacked within the crates  7  so that the controlled atmosphere can forcibly freely pass through the crates and the produce to expose substantially all the surfaces of the produce to the controlled atmosphere. 
     Whilst there have been shown two rows of produce crates  7  within the chamber  1 , the arrangement may be such that there is only one crate  7  within the chamber. In another example, there may be multiple rows of crates  7 . Further, whilst there have been shown two tiers of crates  7 , it should be understood that there may be only a single tier, or multiple tiers. Further, it should be appreciated that the inflatable/deflatable balloon seal means may be independently inflated or deflated relative to the passage of the controlled atmosphere. In other words, there may be a separate inflating/deflating circuit, independent of any circulating controlled atmosphere. The disclosed arrangement where the controlled atmosphere actually inflates the inflatable/deflatable balloon seal means  15  provides for a relatively economic system. If any of the socks or plenums  17  should rupture, then they can be economically replaced. 
     These and other modifications may be made without departing from the ambit of the invention the nature of which is to be determined from the foregoing description. 
     It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art in any country. 
     In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.