Abstract:
Apparatus for aiding in the ripening of produce that includes a sealed container having a refrigeration unit for supplying conditioned air for cooling produce stored in a container. A gas generator is arranged to mix a ripening gas with conditioned air within the container. A fresh air exchanger is integrated into the refrigeration unit for venting conditioned air from the container to ambient and exchanging the vented air with outside fresh air. The fresh air exchanger is automatically operated by a controller which coordinates the cycling of the gas generator with the exchange of fresh air so that the ripening process can be closely regulated.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to apparatus for aiding in the ripening of perishable produce under tightly controlled conditions. 
     BACKGROUND OF TO THE INVENTION 
     In U.S. Pat. No. 6,012,384 to Badalament, there is described an air tight mobile container for storing perishable goods that ripen exothermically. A refrigeration system is arranged to provide conditioned air to the container. Blowers are employed to direct the conditioned air through the inside of the container and to force the air through air permeable bins in which the perishable produce is stored. The conditioned air controls the pulp temperature of the goods to promote uniform ripening of the entire cargo. Oftentimes, the produce is placed in a ripening chamber prior to being loaded into the mobile container and treated with a ripening gas that is dispensed into the chamber to promote a more even ripening of the produce. The produce can, in most cases, spend twenty four hours or longer in the ripening chamber. Considerable time is consumed loading and unloading the ripening chamber. In addition, the extensive handling of the produce during the loading and unloading of the goods can adversely effect the ripening process as well as cause physical harm to the produce. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to improve mobile containers for transporting perishable goods. 
     It is a further object of the present invention to reduce the amount of time needed to ship freshly picked, perishable produce. 
     It is a still further object of the present invention to reduce the amount of handling needed when shipping a cargo of perishable goods. 
     Another object of the present invention is to promote the ripening of produce as the product is being transported to a market place. 
     These and other objects of the present invention are attained by a mobile container having a refrigeration unit for providing conditioned air to the container. Blowers are arranged inside the container to force the conditioned air into thermal contact with the produce. 
     A gas generator adds a ripening gas to the conditioned air which promotes ripening of the produce. A fresh air exchanger system is integrated into the refrigeration unit. The fresh air unit contains a damper door that is automatically controlled so that the air which includes the ripening gas is exhausted from the container into the surrounding ambient and fresh outside air is exchanged for the air vented to the outside. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     For a further understanding of these and other objects of the invention, reference will be made to the following detailed description of the invention which is to be read in connection with the accompanying drawing, wherein: 
     FIG. 1 is a side elevation illustrating a mobile container embodying the teachings of the present invention; 
     FIG. 2 is a sectional view taken along lines  2 — 2  in FIG. 1; 
     FIG. 3 is an enlarged perspective view of a fresh air exchanger unit employed in the practice of the invention; 
     FIG. 4 is a side elevation of the fresh air exchanger unit; and 
     FIG. 5 is a top view of the fresh air exchanger unit. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to FIGS. 1 and 2, there is illustrated a mobile container, generally referenced  10 , that embodies the teachings of the present invention. The container includes a pair of opposed sidewalls  12  and  13 , a pair of opposed end walls  14  and  15 , a top wall  16  and bottom wall  17 . Although not shown, the container is sealed to prevent internal air from escaping to the surrounding ambient. The back wall is furnished with doors (not shown) to permit cargo to be loaded into the container bay. A partition  20  is mounted in the front of the container to establish a mixing chamber  22 . A refrigeration unit  23  is mounted on the front wall of the container. The refrigeration unit contains an evaporator  27  that is arranged to discharge conditioned air directly into the mixing chamber. 
     The present container is provided with wheels  19 — 19  and is designed to serve as a mobile ripening room for certain fruits and vegetables. In certain applications, the produce is stored in a dormant state and a gas is introduced into the conditioned air within the mixing chamber to aid in the ripening process. To this end, a gas generator  28  (FIG. 2) is mounted in the mixing chamber for introducing a ripening gas into the container to modify the container atmosphere for a given period of time until the produce being treated reaches a desired stage of ripeness. The gas flow is then terminated and, as will be explained in greater detail below, the gas is purged from the container to prevent further ripening of the goods. 
     A series of blowers  29 — 29  are mounted in stacks within the mixing chamber. A first stack  30  containing four blowers is placed adjacent the curbside wall  12  of the container while a second stack  31  of four blowers is similarly stacked adjacent to the roadside sidewall  13  of the container. The first stack of blowers is arranged to draw air from the mixing chamber and direct the air toward the rear of the container along a curbside supply air plenum generally referenced  35 . The second stack of blowers is arranged to draw air from the mixing chamber and direct the air along a roadside supply plenum generally referenced  37 . Each plenum is located adjacent to a side wall of the container and extends back from the front wall of the container towards the rear wall. Each plenum further includes a back closure wall  40  that is repositionable along the length of plenum so that the length of the plenum may be selectively adjusted depending upon the load. 
     Bins or boxes  43 — 43  which contain perishable goods are stacked in two parallel rows against the air penetratable wall of each supply air plenum. The boxes, are air penetratable so that conditioned air can move freely through the boxes. The two rows of boxes are spaced apart as illustrated in FIG. 1 to establish a return isle  44  that runs down the center of the container. An opening  45  is contained in partition  20  that extends from the floor of the container to the top wall of the container. The opening is coaxially aligned along the central axis of the container so that air can move freely from the return isle through the opening into the mixing chamber. 
     As indicated by the arrows in FIG. 2, conditioned air is introduced from the refrigeration unit into the mixing chamber. The blowers, in turn, draw the air from the mixing chamber and move a high volume of air down each of the supply air plenums. The supply air plenums which are closed by the back walls  40 , thus become pressurized. Accordingly, the pressurized supply air is forced through the air penetratable boxes into heat transfer relation with the goods stored in the boxes wherein the goods are conductively cooled at a desired rate. Upon passing through the boxes, the air enters the return isle and, under the influence of the blowers, is drawn into the mixing chamber where some air is recirculated over the evaporator coils of the refrigeration unit and the remaining air is mixed with conditioned air from the refrigeration unit. 
     The flow of air through the mixing chamber is rather turbulent due to the action of the blowers and the flow of conditioned air entering from the evaporator. As a result, the ripening gas produced by the gas generator  28  is thoroughly mixed with the conditioned air before reaching the produce. It is important to purge the gas from the trailer upon termination of the ripening cycle in order to control the ripening process and prevent over ripening of the produce. A fresh air exchanger unit generally referenced  50  is integrated into the refrigeration unit which serves to efficiently vent the gas filled conditioned air to ambient and exchange vented air for fresh outside air. 
     Referring now to FIGS. 3-5, the fresh air exchanger unit  50  is supported upon a bracket  52  that is mounted inside the refrigeration unit. The bracket is provided with a vertically disposed mounting flange  53  that is fastened by screws  54  to a vertical column  55  that forms part of the container&#39;s superstructure. The bracket contains a top shelf  57  and a pair of spaced apart arms  58  and  59  that are integral with the shelf and which extends downwardly from the shelf. An electrically driven rotary actuator  60  is mounted upon the outside of arm  58 . The actuator includes a drive shaft  63  that is adapted to pass through a clearance hole formed in the arm  58 . The drive shaft is coupled to one end of an elongated driven shaft  65 . The opposite end of the driven shaft is supported in a bearing  66  mounted in the opposing arm  57  so that the control shaft rotates about the vertical axis  68  of the actuator  60 . A damper door  70  is connected to the driven shaft  65  by a pair of side plates  72  and  73  so that the damper door turns with the driven shaft. A pair of cylindrical connectors  75  and  76  are mounted upon the top surface of the bracket shelf  57 . 
     As best illustrated in FIG. 5, a pair of metering ports  78  and  79  are passed through the shelf so that they open inside the connectors  75  and  76 , respectively. The actuator  60  is adapted to turn the door through about 45° C. of rotation. The damper door is, in turn, arranged to move between a closed position as shown in FIG. 4 wherein the door closes the two metering ports and an open position wherein the ports are fully opened to the surrounding ambient. A gasket  71  is placed between the door and the metering ports at closure to prevent air from passing through the ports when the door is closed. A pair of hoses  80  and  81  (FIGS. 2 and 3) are secured at one end to the connectors by clamps  83  and the opposite ends of the hoses are run into the evaporation section of the refrigeration unit. A first hose  80  is connected to the high pressure side of the evaporator section  27  while a second hose  81  is connected to the low pressure side of the evaporator section. Accordingly, when the damper door is opened, air from the high pressure side of the evaporator is forced out of the container and exhausted to the surrounding ambient while at the same time fresh ambient air is drawn into the low pressure side of the evaporator to replace the air that is being exhausted. 
     The fresh air exchanger is arranged to act in association with the ripening gas generator  28 , through means of a controller  90 . The gas generator is initiated by starting a programmable timer  91  situated in the controller (FIG.  4 ). At this time, the damper door is automatically closed by the actuator  60  and no container air is being exchanged for ambient air. The damper door remains closed until the timer cycles out at which time the gas generator is cycled off and the damper door is opened and will remain open until another ripening cycle is initiated. 
     While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.