WO1994010849A1

WO1994010849A1 - Apparatus for forced air cooling of produce

Info

Publication number: WO1994010849A1
Application number: PCT/US1993/010957
Authority: WO
Inventors: James Still
Original assignee: James Still
Priority date: 1992-11-13
Filing date: 1993-11-12
Publication date: 1994-05-26
Also published as: CA2149019C; CA2149019A1

Abstract

A novel integrated pressure cooling system for produce employing, inter alia, a multiplicity of pressurization units (4), low-velocity cooling coils and adjustable horizontal and vertical sealing means (24), together providing for uniform air flow through individual, compartmentalized pallets stacks (8).

Description

APPARATUS FOR FORCED-AIR COOLING OF PRODUCE Technical Field The subject invention relates to the controlled ripening of fresh produce, in general, and to the forced-air or pressure cooling of bananas, in particular. The same devices and methods can also be successfully applied to other foods and non-food items which might benefit by controlled air and temperature applications. Background Art It is a well-known fact to those involved in the industry of produce management that the market life of produce is a function of time and temperature; the degree of ripening and subsequent deterioration of fruits and vegetables is related directly to the duration and intensity of heat exposure. Thus, effective protection of the produce is dependant upon efficient means of temperature control from harvest through final distribution. Delivery of produce to market, such that suitable shelf life may be accomplished, requires precise regulation of ripening time by importers and wholesale distributors. Several methods of regulating produce ripening times exist and are described in detail in an article authored by F.G. Mitchell, Rene Guillou and R.A. Parsons entitled Commercial Cooling of Fruits and Vegetables, University of California, Agricultural Publications, Berkeley, CA, 1972. One such method is forced-air or pressure cooling. Produce can be air- cooled rapidly by producing a dif-ference in air pressure on opposite sides of the containers in which the fruits or vegetables are shipped. Cooled air passes across this pressure gradient carrying away produce heat and thereby regulating the tempera-ture and, more specifically, the ripening rate of the produce to which the air is exposed. To facilitate this process, special ripening rooms, or chambers as they are sometimes referred, must be constructed. To date, several designs have been suggested, each having in common a floor, ceiling and front, rear and side walls. These rooms are of suitable dimensions to enclose two spaced rows of the palletized produce containers which, in some instances, are stacked in two or more tiers to maximize space. U.S. Patent No. 4,824,685 to Bianco, issued April 25, 1989, teaches one such design. In Bianco, a two-tiered chamber is described whereby the two rows are spaced apart from one another to define an interstitial volume between the rows which substantially forms a low-pressure plenum. There is also sufficient spacing between the chamber ceiling and walls and the inserted palletized produce to define an interstitial volume which forms a high-pressure air plenum. This is a commonly used configuration and is further provided with an interior false wall structure arranged within the chamber which supports an air- handling unit closely adjacent the ceiling of the chamber to provide a source of controlled pressurized air flow and a plurality of high performance exhaust blowers to draw air out of the low pressure plenum. In this manner, the above- described air pressure differential is created. Most current pressurized chambers, like that of Bianco, use rear-of-room evacuation or suction fans and a single, rear-of-room air-handling unit. These systems, by their very nature, cannot provide uniform climate control to individual palletized stacks, some of which are further from the unit than others. Downstream stacks (stacks furthest from the unit) receive lower air pressure and, therefore, demand increases in air unit output to compensate. Regardless, the net result is uneven cooling which cannot be satisfactorily avoided with this configuration. Prior art systems normally utilize a tarp arrangement placed over the top and end of a spacing between the two rows of pallets to produce a closed low- pressure plenum area and to separate same from the high-pressure air space. Large fans are utilized to produce a pressure differential between the tarp-sealed plenum and the high-pressure air space on the opposite sides of the stacked pallets. The air introduced by the air-handling unit is forced by the pressure differential between the high-pressure air space and the low-pressure plenum to flow through openings formed in the sides of the boxes, around the produce contained therein, and into the low pressure plenum to be exhausted by the same fans. In this manner, a forced air circulation is caused to flow uniformly throughout the produce load in the chamber to thereby uniformly control the temperature of the produce with a minimal temperature differential throughout the produce load. The temperature and the air rate of the air introduced into the chamber by the air-handling unit may be controlled in an attempt to achieve a desired ripening rate for the produce. These prior art methods have various shortcomings which has left the effectiveness of such present room designs with much to be desired. Lack of uniformity in air flow through the palletized boxes is the major concern by users of the prior art room designs. It would be appreciated that the air flow transmitted through the vents within the boxes containing the produce which are palletized would not be uniform because of what is essentially a point source pressure introduction from an air-handling unit located on one end of the room as shown, for example, in Fig. 1 of the Bianco, Patent No. 4,824,685. As can be seen in this example, air-handling unit which provides a plurality of fans within a singular air control device provides pressurization from one of the longitudinal ends of the produce ripening room as disclosed in the referenced prior art patent. Though there is more than one fan to provide air flow in the air-handling unit, the fans are essentially a point source of air pressurization, given the larger dimensions of the room compared to the spacing of each individual fan within the air-handling unit. Accordingly, prior art designs with such air-handling units provide an uneven air flow through the palletized boxes which is dependent on a location of a particular palletized box in relation to the air-handling unit. One could appreciate that the pressure drop across the outside of the palletized boxes and the formed interstitial area, referred to as the low-pressure plenum, would vary as a function of the distance of a particular box from the air-handling unit. It is clear that a significant need exists for a solution that addresses the wide variation and air flow through boxed and palletized produce in a ripening room. The existing art in ripening room design does not assure that the air flow will be as uniform as possible in every single produce box stored and being cured therein. With wide variations in air flow given the actual location of a particular box of produce in such an existing ripening room, the user of the room cannot adequately plan or control the rate of ripening of the produce in a uniform and efficient manner. The present art does not provide for an adequate design which allows non-uniform loading of produce in a ripening room. While advancements have been made in improving air flow, temperature and humidity control, little progress has been achieved in developing a comprehensive solution that provides for virtually uniform air flow through palletized produce boxes. Accurate control of temperature and humidity, and therefore the ripening process, requires uniform pressurization across the stacked, palletized produce containers so that the air flow is uniform through the boxes regardless of where the box is located in the ripening room. The subject invention completely obviates all of the shortcomings of the above-described prior art by providing a novel integrated pressure cooling system for produce employing, inter alia, a multiplicity of pressurizing fan units, low-velocity cooling coils and adjustable vertical and horizontal sealing means together providing for uniform air flow through individual, compartmentalized pallet stacks. Disclosure of Invention The subject invention more specifically relates to a substantially improved method for controlling the ripening environment of produce, such as fruits and vegetables and the like. Rather than use the essentially point-source application of a fluid pressure to create an air flow through the palletized boxes containing the produce, the disclosed invention provides a significant improvement by using a plurality of pressure-inducing fans placed around the peripheral area of the ripening room. The present invention describes a structure which provides improved air flow sealing to provide a constant pressure differential as measured across the width of the palletized produce boxes. The present invention substantially increases the control over the ripening process for a given amount of produce. The ripening system of the invention generally comprises a cooling chamber having a floor and ceiling and front, rear and side walls being of suitable dimensions to enclose at least one multiple-tiered rows of unitized and palletized produce, such as fruits and vegetables. As in the prior art systems, the two rows of palletized produce are spaced apart from one another to define an interstitial volume between the rows which substantially forms a low-pressure plenum. There is sufficient space within this low-pressure plenum to allow inspection and access of the produce by a worker. There is also sufficient spacing between the chamber ceiling and walls and the inserted palletized produce to create an interstitial volume which forms the high-pressure air plenum which is defined by an apron-like pressurization shelf to which the plurality of pressurization fan units are affixed. An important feature in the present invention is the reduction in need for an interior false wall structure arranged within the chamber, as set forth in the prior art, because of the application of positive pressure about the peripheral of the room and the apron-like shelf to be described. Accordingly, there is no requirement for tarp-like structures or other devices which must be used to seal the interstitial area within the two palletized rows of the prior art to create the low-pressure plenum area. The temperature control within the ripening room utilizes an air-handling unit which may be placed more liberally than those found in the prior art because of the lack of need of the interior false wall. Specifically, air-handling units which are situated along the longitudinal axis of the ripening room may be used, allowing for more even temperature distribution. The air-handling unit is utilized to provide temperature control and, pursuant to the various different embodiments available, because of the improvements in the disclosed room, the air-handling unit may be placed at the end of the room in a singular location or distributed about the room either down the longitudinal axis or in other combinations, as will be more fully described in the detailed description to follow. A further improvement in the disclosed invention is the incorporation of floating sealing strips used in conjunction with the shelf unit containing the plurality of pressurizing fans. The unique application of gasket material provides for greater improved uniformity of air flow through the produce. Sealing strips are also used in a vertical fashion to provide for sealing between the stacks of palletized boxes resulting in a reduction in air pressure loss between the pressure plenums which would otherwise occur due to leakage between the boxes containing the produce, as opposed to directing the desired air flow through the boxes themselves. With the use of slidable sealing doors to close off the longitudinal end of the high-pressure plenums, along with baseboard-level curbs, sealing any leakage through the access slots in the standard pallets utilized to stack the product, a substantially sealed plenum is formed which provides for more uniform and more carefully-controlled air flow through the produce boxes. The present invention allows a non-uniform number of pallets to be stacked on either side of the longitudinal axis of the ripening room without loss of effectiveness. For example, it would be possible to stack a longer length, and therefore larger number of pallets, on one side of the ripening room disclosed while having only one or two pallets on the opposite side and still provide for an even pressurization of the two outer high-pressure plenums. The enclosed disclosure illustrates a slidable sealing door to be used to seal off the high-pressure plenum at any point desired, thereby creating what is essentially a floating end wall for the high-pressure plenum area. The present disclosure also provides for a multi-tiered stack system which allows the same invention to be used with a multiple layer of two or more stacked pallets. Also, because of the unique design disclosed, it is not necessary that any air-handling unit be affixed to a false wall pursuant to the disclosures found in the prior art. Therefore, it is possible to use air-handling units that provide cooling or heating coils down the longitudinal axis of the room, preferably on the top of the room, providing for a more even temperature distribution throughout the room. It is also possible to combine the cooling unit and pressurization fans into a single device in a useful alteration of the preferred embodiment, as will be more fully described in the detailed description and the drawings to follow. It is, therefore, a primary objective of the subject invention to provide a novel, integrated pressure cooling system for produce employing, inter alia, a multiplicity of pressurization fan units, low- velocity cooling coils and adjustable horizontal and vertical sealing means together providing for uniform air flow through individual, compartmentalized pallet stacks. Another object of the subject invention is independent control over individual palletized stack locals or stations without interruption to surrounding stations. It is also an object of the present invention to provide a system that is energy and cost efficient. It is another object of the present invention to provide a system devoid of unsanitary and cumbersome sealing means. Still another object of the present invention is to provide a system which easily accommodates visual and mechanical inspection and monitoring of produce. Yet another object of the present invention is to provide a system with baseboard level pallet guide means for easy positioning of same. It is yet another object of the present invention to provide for a means to allow controlled air flow across a single row of palletized produce boxes. Yet another object of the present invention is to provide a means to allow open, unsealed produce box tops by utilizing a floating sealing device by balancing air flows through the closure of various produce box openings. Other objects and advantages of the present invention will be apparent upon reference to the accompanying description when taken in conjunction with the following drawings. Brief Description of the Drawings FIG. 1 is a side view of the single-layer ripening room; FIG. 2 is a plan view of the preferred embodiment illustrating the peripheral fan placements; FIG. 3 is an end view of the single-tiered ripening room; FIG. 4 is a plan view of the ripening room showing an embodiment utilizing linearally-distributed cooling coils; FIG. 5 is an end view showing a variation of the preferred embodiment with a two-tiered stacking system for the pallets; FIG. 6 is a plan view of a two-tiered ripening room illustrating longitudinal, center-mounted cooling coils; FIG. 7 is a side view of a two-tiered stacking system for the pallets illustrating longitudinal, center-mounted cooling coils; FIG. 8 is an end view of the single-tiered ripening room illustrating longitudinal, center-mounted cooling coils; FIG. 9 is a side view of a single-tiered ripening room illustrating longitudinal, center-mounted cooling coils; FIG. 10 is a view of the high pressure plenum sealing door; FIG. 11 is a view of the high pressure plenum sealing door further illustrating its placement between the upper shelf and lower curb of the ripening room; FIG. 12 is a view illustrating the pivoting, slidable sealing door for the high pressure plenum illustrating the door's slidable track; FIG. 13 is a view of the ripening room from outside of the slidable access door illustrating the pluricity of pressurization fans on their mounting shelf, as well as the vertical and horizontal sealing strips; FIG. 14 is a view of the ripening room from the opposite end of the slidable, sealing access door further illustrating, and showing a close-up view of, the plurality of fans, along with their mounting shelf and the vertical and horizontal sealing strips; FIG. 15 is an end view of ripening room from a location opposite the access door, illustrating the relationship of the vertical and horizontal sealing means, the lower bumper strip, longitudinally located cooling coils; FIG. 16 is a plan view showing that alteration of the present in-vention whereby the pallet rows are disposed in an angled configuration; FIG. 17 is an end view of the ripening room showing an alteration of the preferred embodiment utilizing fluid pressure manifolds to introduce the circulating fluid from a central pressurization unit; FIG. 18 is a plan view of the ripening room illustrating an alteration of the preferred embodiment whereby there is a pluricity of palletized stacks and interstitial low volume areas; and FIG. 19 is an end view of variations of the preferred embodiment demonstrating the improved sealing means for air flow restriction. Detailed Description of the Invention And Best Mode For Carrying Out The Invention Referring now to the various drawings and, specifically, FIG. 1, illustrated therein is a ripening room apparatus according to the disclosed invention, generally indicated by the numeral 2. In a similar fashion, only generally speaking, to the prior art, the room is conventional in its shape and design in that is it formed by a ceiling, floor and four walls. The front wall is a slidable door panel. The walls, front panel and ceiling are insulated to form a generally gas-tight chamber for the treatment of various produce, such as fruits and vegetables. The overall dimensions of the ripening room are suitable to house one, two, or more one or multi-tiered rows of palletized produce and may be, by way of example only, approximately a height of 12 feet, a width of 12 feet, and a length of 42 feet. There is a suitable entrance way at one end of the room, allowing a forklift or other lifting apparatus to place the pallet stacks 8 within room 2. The palletized produce 8 comprises a plurality of protective boxes 32 to unitize and protect the produce. Protective boxes 32 are stacked on pallets 30 for easy handling during the insertion and removal of the produce load to and from the ripening room 2. Each pallet 30 may be 40" x 48", with 48 protective boxes 32 stacked thereon. Pursuant to the invention, and in accord with the common design of the protective boxes 32 in the trade, each of the protective boxes 32 include side openings 34 which line up with the similar openings in the adjacent boxes on a particular palletized stack 8. As such, the openings 34 facilitate air flow through the boxes 32 in that the commonality of location of openings 34 and boxes 32 provide for continuity from the side of pallet stack 8 adjacent to an outer wall to the inner space defined between two rows of palletized produce, as will be more fully described. It will be appreciated, by reviewing the plan view of FIG. 2 that the two rows of pallet stacks 8 form an interstitial volume between the two rows of the palletized stack 8. By viewing FIG. 3, the shape and definition of the interstitial area creating a low-pressure plenum can be more fully appreciated. The high-pressure air space 16 can be seen in FIG. 3 to be formed by an area defined by side wall 40 and one edge of pallet stack 8. The lower boundary of the high-pressure air space 16 is defined by curb 28 and the upper end is defined by the peripheral fan shelf 12. As can be seen, fans 10 by operating in a direction providing for an increase in pressure from top to bottom which provides air flow into space 16, there would be a pressure gradient from the ambient room area, defined as the low-pressure plenum or space 18, and air space 16. The fluid within this high-pressure area 16 would normally seek to equalize its pressure by flowing to a lower pressure area 18 if it is provided unrestricted flow. In the present invention, such pressure equalization path is across the stack 8 through the box side openings 34 located on boxes 32. As can be shown by the illustrative arrows found in the drawings, and continuing to refer, in particular, to FIG. 3, it will be appreciated that the fluid (air in the preferred embodiment), in space 16 will flow through the boxes as described, finally arriving at the low-pressure area 18. Accordingly, the fluid moving as described would eventually communicate with fan 10 at the intake or low pressure end, and be recirculated by continuously moving from the high- pressure space 16 to low-pressure space 18, thereby allowing a continuous flow of air through the protective boxes 32. In the prior art, high- and low-pressure spaces creating pressure gradients across the stacked boxes containing produce have been developed, but in a non-uniform fashion. By using a point-source pressurization system, usually a series of fans at the end of one room attached to a false wall, the high- and low-pressure spaces created did not provide for uniform air flow across the length of the stacks of produce. It can be appreciated that there would be a higher volume of air flow through the produce boxes at the end of a ripening room which contains the pressurization fans. If one were to assume that the produce boxes are unitized and have a generally equal flow resistance across the box through the openings in the boxes, a greater amount of air volume would flow through the boxes between the high-pressure and low- pressure plenums defined by boxes at the end of the room closer to the pressure source. A variation of the disclosed invention provides a technique for allowing more uniform flow of air volume through produce boxes by varying the size of the plenums formed by the rows of stacked produce. Resistance to air flow in a returned closed-circuit air circulation system is related to the dimensions of the plenum introducing the air to and from the pressurizing fan system. Accordingly, by introducing a continuously variable width between the stacked pallets, as illustrated in FIG. 16, it will be appreciated that the fluid pressure across the protective boxes may be adjusted so as to equalize the air flow through the palletized boxes located at the opposite end of the point source fans, as opposed to the air flow closer to the fan location in which a wider plenum described by angled stacks of pallets provide for a slightly reduced pressure differential across the boxes located therein, ultimately allowing for an equal air flow volume through the palletized boxes located at the far end of a ripening room when compared to boxes located close in to the fans providing the pressurizing sources. Also, it is possible to add vent stripes to existing tarp covers and louvers in air handlers to increase the isolation between the high- pressure areas and low-pressure areas within the ripening rooms. Air leakage and back flow through both the air-handling fans and tarps used in the existing art can be minimized through the use of the methods disclosed in the present invention. This method of ripening room configuration is beneficial in retrofitting existing rooms. It can be appreciated that the air flow would be in reverse of that shown in FIG. 16 in ripening rooms of the existing art in that the fan within the air handler shown would be supplying air flow in the opposite direction. The air would be drawn through the palletized stack 8, in a direction whereby the flow would be towards the center of the room from the outer peripheral area through to the return flow in the air-handling unit 4. It would be appreciated that utilizing the reverse flow technique found in existing ripening rooms, a tarp or other pressure area sealing means would be required to seal off the interstitial area between the non-parallel pallet stacks 8. Returning now to FIG. 3, it would be appreciated that in order to maintain the high-pressure plenum 16, there must be shields sufficient to provide containment of the high-pressure space 16. By providing seals in every location other than those adjacent to the pallet stack 8, the high-pressure within 16 would seek to equalize in the low-pressure area 18 by flowing through the palletized boxes and the box openings 34, as opposed to communicating directly with the low-pressure area 18, without being caused to flow through the protective boxes 32. Horizontal gasket air seal 24 provides a means to improve the air flow through the boxes 32, as well as prevent air flow leakage from the high- to low-pressure areas. In the preferred embodiment, seal 24 is a continuous strip of pliable pvc material running the length of room 2, affixed at the top to shelf 12. It can be seen from FIGS. 11 and 12 that seal 24 prevents air flow from traveling over the boxes 32 since the top of the pallet stack 8 does not normally reach the height of shelf 12. In such a fashion, the air pressure within space 16 creates a pressure gradient across seal 24. Seal 24 is held firmly against box 32 located at the top of stack 8 immediately adjacent to seal 24. It is important to note that seal 24 should extend downward from shelf 12 only to the extent necessary to cover the side of the top boxes on stack 8, as shown in FIGS. 11 and 12, so that the side openings 34 within the top box are sealed from air flow. This is to prevent the low resistance air flow path presented by the openings in the top boxes from exhausting a large volume of air, thereby reducing the pressure within space 16 enough to provide an uneven air flow across the lower boxes in stack 8. One would appreciate, while observing stack 8 in FIG. 3 and the other figures, that the air flow through side openings 34 contained on the top boxes of stack 8 present a low resistance air flow path between the high- pressure area 16 and low-pressure area 18. Experience has shown, and consideration of the fluid dynamics involved would confirm, that the resistance presented by a shorter air path would consume much of the air flow, indicating a much lower volume of air flow across the boxes at the bottom of stack 8 as compared to those on top. For this reason, and as has been found desirable, sealing the top rows of boxes alone allows air flow through said top boxes only through the protective boxes immediately below the top rack of the palletized stack 8. The air flow arrows within FIG. 3 illustrate the air flow therein. The sealing means for the top area of top boxes can be of an adjustable type so as to roll or unroll the horizontal gasket air seal 24 to allow adjustment as to the number of box openings which are covered by the seal. Moving now to a feature of the present invention, vertical and removable seal 26 is illustrated in detail in FIGS. 10 and 11. This removable strip is used to seal the vertical end of the high pressure air space 16 which is present in the preferred embodiment of room 2. As can be seen from the figures, the vertical seal 26 fits snugly between shelf 12 and curb 28. Further, the longitudinal ends of seal 26 fit between the outer wall of room 2 and the edge of the stack 8. Since a tight air seal requires a snug fit providing for little or no fluid leakage, it will be appreciated that a gasket-like material must be applied about the peripheral of seal 26. The material used in the preferred embodiment is a pliable pvc plastic which is looped over itself in a bumper-like fashion creating a pliable sealing means about the contact edge of seal 26. It will be appreciated from FIGS. 10 and 11 that seal 26 may be force-fitted and friction-held in the area provided such as to cause a pressure seal at the end of air space 16. It can be seen that the slidable seal 26 fits on the outer edge of horizontal gasket air seal 24, thereby assuring a firm and proper fit between protective boxes 32 located in pallet stack 8. In the normal course of operation, the protective boxes 32 do not always fit vertically or sit square or true on the pallet 30. With the methods disclosed, the friction-fit seal 26 is pliable enough to cause the gasket edging to fit within any irregularities in the size or location of boxes 32 in stack 8. It will also be appreciated that the gasket material deforms in an outward direction when pressure is applied to the handle shown in FIG. 10 and 11 attached to the face of seal 26. An inward, normally and firmly applied force to seal 26 in its intended resting location will cause the gasket material to be bowed in the outward direction, thereby causing a hysteresis effect in the force necessary to withdraw the seal 26. Accordingly, seal 26 is fairly effortless to install in position, but requires considerable force to withdraw, thereby assuring that the pressurization of area 16 does not cause a blow-out of seal 26. In a similar fashion, it is also possible to present a slidable, adjustable end seal 26 using a sliding track and a frame covered with pvc plastic. Turning now to FIG. 12, it can be appreciated that the frame-like rack shown parallel to stack 8 can be adjusted by running along the longitudinal axis of room 2 on the track. At any point desired, the seal 26, which pivots upon a heel affixing it to an upper and lower track located at the curb 28, seal 26 can be rotated to be friction-fit against boxes 32 on stack 8. It can be appreciated that the frame would be wider than required to simply fill the space between the outer wall and the pallet stack 8. In such a fashion, the frame seal 26 would be open in the inward direction, away from the direction of the free end of high pressure space 16. Accordingly, upon the pressurization of space 16, seal 26 attempts to expand, thereby pressing the edge of seal 26 in contact with pallet stack 8 causing a firm fit. The frame-like device used for seal 26 shown in FIG. 12 is likewise covered with pvc material affixed in a bow-like fashion along the peripheral edge of seal 26 allowing a firm fit where it contacts the boxes 32. Also as can be seen in FIG. 12, in this embodiment of seal 26, the frame is likewise located on the outer edge of horizontal seal 24, thereby assuring that the fit against the top box 32 is equally firm and fluid tight. Turning now to yet another embodiment of the present invention, it will be observed in FIG. 17 that the ripening room 2 may be configured such that air handler 4 can be used to introduce fluid pressurization into high pressure area 16 through manifold 20. In such a fashion, one could appreciate that it is possible to pressurize high pressure area 16 without the use of a plurality of fans 10 as shown in the first described embodiment. In the instant embodiment, the manifold 20 may consist of a singular manifold on each side of room 2 which would pressurize the entire length of area 16. Also, it is possible to develop manifold 20 in a fashion which would allow it to be divided into two or more ducts, thereby introducing pressurized fluid in area 16 at more than one location in each of the high pressure air spaces 16. In either configuration, the present advantage is that it is possible to utilize the improvement disclosed by the present invention by retro-fitting existing rooms that may have air-handling units which can be adapted to provide for the air flow in the ripening process such as described earlier. The basic configuration, in general, provides for introduction of pressurized fluid within air space 16 regardless of the source of the pressurization. Pressurization may be by use of peripheral fans as earlier disclosed or the introduction of pressurized fluid through a pressurization source external of the fan shelf 12 as shown in the earlier figures. Though not disclosed specifically in the figures, one could appreciate that it is possible to integrate the air-handling units, particularly as configured in FIGS. 4, 5 and 6, as well as some of the other figures, such that the air- handling units which provide cooling or heating of the air could be integrated into a unit which would also provide the fluid pressurization used to drive the present system. It will be obvious to one skilled in the art that the integration of a cooling unit with the fan may be placed along each side of ripening room 2 at a location equivalent to the peripheral fan shelf 12, thereby providing, simultaneously and in an integrated unit, the fluid pressurization required to provide high pressure in space 12, as well as the air temperature control normally handled by a separate air handler unit as disclosed in the figures. Other variations and specific adaptations of the ripening room 2 is disclosed in Addendum 1 and entitled "Auto-Ripe" and is attached hereto and incorporated in this specification by reference. Yet another advantage of the disclosed ripening room can be observed and appreciated by the plan view shown in FIG. 18. With the use of the high pressure air space 16, it can be appreciated that the ripening room can be configured such that there are multiple high pressure air spaces and that they may consist or be configured in the middle of a multi-isled ripening room allowing for at least three, and ultimately an indefinite number, of pallet stacks 8 to be located in a particular room. A large, warehouse-like ripening room may conceivably be comprised of many rows of stacks 8 situated between areas 16 formed in multiple parallel rows. Even as disclosed in FIG. 18, it would be appreciated that additional stacks 8 may be located to the far left side of room 2 and the far right side, thereby providing for six (6) rows of pallet stacks 8 without increasing the number of fans 10 and shelves 12 to define high pressure air space 16. Yet another improvement for the sealing means utilized in the present invention are shown in FIG. 19. It will be appreciated that the horizontal gasket air seal 24 shown in the earlier figures can be modified to allow for an adjustable seal which contains a rolling mechanism to be drawn down across the appropriate edge of protective box 32 such as to function as an effective air seal with an adjustable length. The construction of rolling seal 50 is much like that of a vertical rolling blind commonly found in window treatments. Rolling seal end weight 54 allows the seal 50 to remain in position even though it is not fixed to protective box 32. As in the earlier-described invention, the air flow through the boxes creates pressure against the seal 50 holding it firmly in position. It is also possible to use seal 50 in conventional ripening room design since weight 54 can be sufficient enough to maintain the position of rolling seal 50, even though the air flow is reversed as traveling from the center of the room toward the outer peripheral walls. In like fashion, the existing designs of ripening rooms may be improved utilizing top seal flap 52. It would be appreciated from FIG. 19 that seal 52 may be affixed to shelf 12 or any other convenient location such as to allow a seal to be created which takes the place of exiting tarp designs in the existing art. Through use of a flap 52, which can be constructed of pliable foam or some other air-tight material, it is possible to seal the top of the boxes without the use of a tarp, thereby eliminating the problems involved in the prior art which requires a tarp to be drawn across the tops of protective boxes in order to create an enclosed interstitial volume. Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein, but rather any variations which would be obvious or otherwise apparent to one skilled in the art reviewing the disclosure set forth herein are intended to be within the purview of the invention claimed.

Claims

We claim: 1. An apparatus for controlled, pressurized ripening of fresh produce, which comprises: a. a chamber having a ceiling and front, rear and side walls; b. a structure arranged within said chamber to position and support at least one row of palletized produce, each row including palletized produce being spaced apart by a frame structure to define and interstitial volume there between, and said row being further spaced by said frame structure from the walls and ceilings of said chamber to define a fluid circulation space about said palletized produce; c. sealing means to seal said interstitial volume from said fluid circulation space; d. said frame structure including sealing members to seal said vertical space between the palletized produce from the fluid circulation there through; and e. fluid control means to introduce pressurized fluid into said interstitial volume and to introduce a controlled fluid flow into said fluid circulation space; whereby to create a pressure differential between said interstitial space and said fluid circulation space such that said introduced controlled fluid is forced to flow uniformly through said palletized produce.