US20100024465A1

US20100024465A1 - Air Flow Control Method and System

Info

Publication number: US20100024465A1
Application number: US12/511,501
Authority: US
Inventors: Don Guyomar
Original assignee: Cool Dynamics Refrigeration Pty Ltd; Post Harvest Technology Consultants Pty Ltd
Current assignee: Cool Dynamics Refrigeration Pty Ltd; Post Harvest Technology Consultants Pty Ltd
Priority date: 2008-07-30
Filing date: 2009-07-29
Publication date: 2010-02-04
Also published as: AU2009203064B2; NZ578719A; AU2009203064A1

Abstract

An integrated airflow control facility for force cooling of produce in a cool room (10), including a dedicated storage zone (1) for storage of the produce and a dedicated refrigeration zone (2) separated by a physical divider (34) in which the divider includes one or more integral extraction fans (24) to extract air form the storage zone and direct said air through refrigeration coils (40/42) positioned in said the refrigeration zone for cooling thereof, in which the divider further includes one or more air outlets (44/46) to direct the cooled air exiting the refrigeration zone into the storage zone and in which the storage zone, refrigeration zone and the physical divider are integrated into a single airflow control facility.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Australian Provisional Patent Application No 2008903908 filed on 30 Jul. 2008, the content of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a method and system for air flow control and more particularly relates to a method and system for the control of air flow in cool rooms where a product is required to be force cooled.

BACKGROUND OF THE INVENTION

Produce, such as fruit and vegetables, are force cooled prior to storage and/or transportation. This type of cooling requires cool air to be drawn through the produce, which is usually contained within crates, boxes or cartons and can be stacked on one or more transportation pallets. The storage of the produce is such that it enables air to flow through the sides of the crates (or boxes or cartons) and thus, through the produce within that storage area.
The produce is stacked on one or more transport pallets that can be stacked in a cool room in rows and if necessary on more than one tier or level. At an end opposite an entry to the cool room there is generally located, one or more fans which is used to draw warm air out of the cool room and circulate cool air through the cool room, after introducing cool air down the sides of the cool room. This air is then able to move through the pallets and over the produce in order to force cool the produce or at least maintain it within a predetermined range of temperature.
In existing cool room installations, a refrigeration coil unit is generally installed at the end where the fans are located inside the cool room. That is, the refrigeration coil unit is installed on an interior face of the back wall at a height which is above the fans and above the pallets. Air passing through the refrigeration coil is then cooled and redirected to the sides of the cool room.
With the position of such refrigeration coils, it has the disadvantage of having to allow for the height of the refrigeration coil unit which adds to the overall height of the cool room tiers, as a refrigeration coil unit is required for each tier. Its position on the internal face of the rear wall also limits the amount of pallets or stacks of pallets that can be stored within a cool room having a predefined height. Thus, for example there may be a situation where four tiers can be used for storage instead of three tears where the refrigeration coil is located at a position other than at the upper surface of the internal rear wall.
The present invention seeks to overcome one or more of the above disadvantages by providing an improved air flow control method and system within a cool room that substantially reduces the volume of the air to be cooled and provides improved efficiency in the system of cooling.

SUMMARY OF THE INVENTION

The invention provides an integrated airflow control facility for force cooling of produce in a cool room, said facility comprising a dedicated storage zone for storage of said produce and a dedicated refrigeration zone separated by a physical divider wherein said divider includes one or more integral extraction fan means to extract air form said storage zone and direct said air through refrigeration coil means positioned in said refrigeration zone for cooling thereof, wherein said divider further includes one or more air outlet means to return said cooled air exiting said refrigeration zone into said storage zone and wherein said storage zone, refrigeration zone and said physical divider are integrated into a single airflow control facility.
The outlet means may be formed with or arranged adjacent the refrigeration coil means. Preferably the cooled air directed through the outlet means is directed along the sides of the produce storing zone for subsequent distribution through the produce.
The refrigeration coil means is preferably positioned between the extraction fan and the air outlet.
The produce may be stored in rows of pallets and in one or more tiers, such that at least one row of pallets of produce are in each tier. Preferably in each tier the outlet means comprises one or more outlets with each outlet adapted to have cooled air directed therethrough onto a corresponding row of pallets.
Preferably the area in which the refrigeration coil means, or evaporators, is located is bounded by at least opposed side walls of the cool room, a rear wall of the cool room and the divider (or front plenum wall). The refrigeration coil means may extend wholly or partially between the divider and the rear wall of the cool room and be arranged in any orientation that enables air exiting from the extraction fan means to be cooled. The refrigeration coil means may be one or more separate units that extend upwardly from the floor or downwardly from a ceiling of the cool room. The refrigeration coil means may be at an acute angle with respect to the plane of the divider and the rear wall. Preferably each of the refrigeration coil units are rectangular slabs of coils.
The zone containing the refrigeration coil means may be partitioned such that a refrigeration coil unit, an outlet and one or more extraction fans direct air from the produce storing zone through separate compartments for cooling and redirected through an outlet to cool a row of pallets storing the produce. In this way, the number of rows of pallets to be cooled can be controlled.
For a cool room having more than one tier, each tier may be separated and have separate extraction fan means, refrigeration coil means and outlet means.

BRIEF DESCRIPTION OF THE DRAWINGS AND LEGEND

Legend

1. Storage zone
2. Refrigeration zone
10. Cool room
12. Central frame structure
14. Spacer
16. Spacer
18. Tracks
20. Vertical struts
24. Extraction fan
24A. Upper fan
24B. Lower fan
34. Divider
36. Compartment (plenum)
38. Rear wall
40. Refrigeration coil unit
41. Spacer
42. Refrigeration coil unit
43. Spacer
44. Air outlet
45. Infill walls
46. Air outlet
49. Single wall
51. Refrigeration coil support
60. Spacers
61. Spacers

Preferred embodiments of the invention will hereinafter be described, by way of example only, with reference to the drawings in which:

FIGS. 1A, B and C are respectively plan, side and front views of a two tier cooling assembly used in a cool room according to an embodiment of the invention;

FIGS. 2A and B are respectively side and front views of a single tier cooling assembly used in a cool room according to a further embodiment of the invention;

FIG. 3 is a plan view of a two line single tier cooling assembly according to a further embodiment of the invention;

FIG. 4 shows front, side and plan views of a two tier cooling assembly according to a further embodiment of the invention;

FIGS. 5A, B and C are respectively front, plan and side views of a two tier cooling assembly according to a further embodiment of the invention;

FIGS. 6A, B and C are respectively front, plan and side views of a single or two tier cooling assembly having refrigeration coil units at an angle according to a further embodiment of the invention; and

FIGS. 7A, B and C are respectively front, plan and side views of a single or two tier cooling assembly having horizontally disposed refrigeration coil units according to a further embodiment of the invention.

FIG. 8 is an end perspective view of a two tier cool room with which embodiments of the present invention may be used;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring firstly to FIG. 1A, the invention can be seen to comprise an integrated air flow control facility for forced cooling of produce stored in a cool room 10. The air flow control facility is preferably integrated into the construction of the cool room 10 and comprises discrete and dedicated zones including a storage zone 1 for the storage of produce for cooling where the storage zone 1 generally forms the bulk of the cooling room. The air flow control facility also includes a dedicated and discrete refrigeration zone 2 formed as part of the cool room 10 but specifically separated from the storage zone 1 by virtue of a physical divider 34. The physical divider 34 is provided with one or more integral extraction fans 24 so as to provide for the drawing of air from the storage zone 1 into the refrigeration zone 2 for subsequent passage past refrigeration coil means 40 and 42 positioned within the refrigeration zone 2. The divider 34 further includes one or more outlets 44 and 46 so as to provide for the movement of air cooled by way of the refrigeration coil means to escape for a refrigeration zone and return to the storage zone 1.
The specific separation of the storage zone 1 and refrigeration zone 2 of the air flow control facility of the invention allows the facility to be incorporated into a cool room 10 in such a manner to allow maximum design flexibility and optimisation of the storage zone 1 in contrast to the refrigeration zone 2.
Referring now to FIGS. 1A through to 1C, the rear of the cool room is provided with a divider 34, being an interior wall or front plenum wall, in which is mounted one or more fans 24. A compartment or plenum 36 is formed between the wall 34 and a rear wall 38 of the cool room 10 so as to provide the refrigeration zone 2. A pair of upstanding refrigeration coil units (evaporators) 40 and 42 in the refrigeration zone extend between the front plenum wall and rear wall 38. Air flow through the fans 24 is directed through each of the coil units 40 and 42 to respective outlets 44 and 46 so that the cooled air exiting from each of the units 40 and 42 is directed down the sides of the cool room 10 to then be drawn through the produce stored in pallet stacks positioned in the storage zone 1.
In different embodiments, the coil units 40 and 42 may be at different orientations, such as at an acute angle with respect to the longitudinal axis of the cool room and may not extend entirely from wall 34 to wall 38. Alternatively, the units 40 and 42 may be combined with the respective outlets 44 and 46 as shown in FIG. 4. Alternatively, a partition can exist in the space or compartment 36 extending between walls 34 and 38 so that two compartments are formed. A fan 24 may be used in each compartment to draw air out of the cool room and through a separate coil unit which may be free-standing within the respective compartment or be formed at the outlet 44 or 46. In this manner air flow can be controlled to flow in one compartment and not the other or flow through both compartments at the same time. This would be dependent on the amount of produce that needs to be force cooled. The fan configuration can either be forced draught or induced draught air flow through the units 40 and 42.
Alternatively, a horizontal divider can split the compartment into upper and lower compartments respectively. Each compartment would have its own fan or bank of fans 24 and its own separate outlets which may be combined with respective coil units. Alternatively free-standing coil units can be arranged. Thus the coil units can extend from the floor or from the top of each compartment and need not extend over the entire height from floor to top. Any remaining space between a coil unit and the top (or floor) can be filled in with material in order to more efficiently direct the air to the outlet. The coil units can also extend horizontally across the plenum 36 between the side walls or a portion thereof.
In FIG. 1A air from the produce storing area is returned through fans 24 and directed through vertically-mounted refrigeration coil units 40 and 42 and then through respective outlets 44 and 46 back into the produce storing area. FIG. 1B, a side view corresponding to the plan view of FIG. 1A, shows a two tier assembly where there is an upper fan 24A and a lower fan 24B which direct the air through the refrigeration coil units 40 and 42 and having spacers 41 and 43 above and below the coil units which would be infilled in order to better direct the air through the units 40 and 42.
With reference to FIG. 1C there is shown a front elevation of the two tier system of FIGS. 1A and 1B, in which for each tier there is a extraction fan 24 which directs air through respective refrigeration coil units 40 and 42 which are suspended between the ceiling and floor of the cool room 10. The gaps between the ceiling and each refrigeration coil unit and the gaps between the floor and each refrigeration coil support (51) are all infilled with material in order to direct the air to be cooled through each of the units 40 and 42 and out through outlets 44 and 46.
FIGS. 2A and 2B respectively show side and front elevations of a single tier cool room in which air drawn from the storage zone 1 and directed through fan 24 which is then directed to flow through the vertically-mounted refrigeration coil units 40 and 42 and out through respective outlets 44 and 46 as shown in FIG. 2B. Infill walls 45 close off any gaps through which the air to be cooled can escape and is therefore directed through the coil units 40 and 42.
FIG. 3 shows two side-by-side flow control facilities which include a much larger cool room area all on a single level in which each system operates similar to that disclosed with reference to FIG. 1. The two compartments 36 forming two refrigeration zones 2 are divided by a single wall 49 either side of which is a respective outlet 46 and 46 which returns cooled air back into the main produce storing area. Two or more tiers may be used for this system.
In FIG. 4 there is shown front side and plan views of a further embodiment in which the extraction fans 24 are placed closer to the ceiling and floor within the divider 34 in a two tier system. The side view shows the refrigeration coil units 40 and 42 having a space existing to the ceiling and to the floor and also a space existing between the back wall of the cool room and the units 40 and 42. All of these spaces would be filled in by a suitable material.
With reference to FIGS. 5A, B and C there is shown respectively front, plan and side elevations of a two tier system that has separate split vertical refrigeration coil units 40A and 42A on a second tier and 40B and 42B on a first lower tier. Air from the exhaust fan 24 on each level flows through the refrigeration coil units and out through outlets 44 and 46 back into the main cool room storage area. The mounting of each of the refrigeration coil units on each tier is intermediate the ceiling and floor of each tier. Each of the tiers form respective spacers 60 and 61 which are included in the plenum or compartment 36. Parts of the plenum 36 that are not taken up by the space occupied by spacers 60 and 61 are infilled with material so that the air distribution is directed through the refrigeration coil units and into the discharge outlets 44 and 46.
Referring to FIGS. 6A, B and C, there is shown respectively front, plan and side elevations of a system that is equally applicable to single or dual tiers. It includes in the plenum or compartment 36 forming the refrigeration zone 2 with one embodiment showing refrigeration coil units 40A and 42A either side of fan 24, the units extending at an angle across the compartment between the rear wall and the divider or front wall of the plenum 34 and having a height such that they are disposed between the ceiling and floor of the tier(s). These angles are typically between 45 and 60 degrees but can be at any other suitable angle. Spaces between the first angled refrigeration coil units 40A and 42A and the divider 34, and spaces between the ceiling and the floor and the units would be filled in by suitable material so that air does not go through that gap. In a second embodiment and as an alternative to having coil units 40A and 42A, another pair of refrigeration coil units 40B and 42B are disposed at the sides of the divider 34 and parallel to and adjacent the outlets 44 and 46. This second pair of refrigeration coil units extends from the ceiling to the floor so that the entire outlet is covered by the second set of refrigeration coil units.
In FIGS. 7A, B and C there is shown dual tier system (that can apply to a single tier system) in which a refrigeration coil unit 40 extends horizontally almost across the entire width of the space 36 of the refrigeration zone above a respective fan 24. This is more clearly seen in the plan view of FIG. 7B. It extends from the rear wall to the divider or front wall of the plenum 34 and has a space above and below the refrigeration coil unit 40. Thus air is directed from the fans 24 upwardly and through the coil 40 which is then cooled and expelled through respective side outlets 44 and 46.
With any of the above arrangements, the volume of air that would require to be cooled from the interior of the cool room is much reduced as the space taken up by the refrigerant coil units is not a factor. As such, improved cooling efficiency is achieved as there is not as great a volume of air to be cooled.
The evaporator (refrigeration coil) capacity can be increased by increasing the size of the plenum between the rear wall 38 and front plenum wall 34. The system can be used for multiple forced air cooling blinds adjacent to one another, or in different positions around the cool room walls.
An air flow control facility in accordance with embodiments of the invention may be used in a cool room 10 of the type shown in FIG. 8. The cool room 10 has two tiers and cools produce that is adapted to be held in containers or pallets. In this particular case the produce is banana and the cool room is used to ripen the banana which is held or stored in up to forty-four containers or pallets. The cool room 10 has a central frame structure 12 that separates two rows of stacked pallets (not shown) that are loaded into spaces 14 and 16 of the cool room, typically by fork lift. The lower tier of rows of pallet stacks are placed on the floor of the cool room whilst the upper tier rows of pallet stacks are supported on each side of the cool room 10 on tracks 18 which are carried by vertical struts 20. Similar tracks are carried by the central frame 12 to support the inner edges of the lowermost pallets of the upper tier stacks.
The lower rows of pallet stacks extend to a height less than the height of the tracks 18 so that air flow occurs across the top of the lower stacks. A similar air flow occurs across the top of the upper pallet stacks and an air corridor exists between the opposed pallet stacks. One or more air extraction fans 24 draw air from the air corridor between the opposed pallet stacks, with that air being replaced by air drawn through the sides of the pallet stacks and through the produce contained within the stacks of pallets. Refrigerated air is thus directed horizontally along the face of the cartons/containers being forced air cooled or ripened, minimising the mixing of air leaving the refrigeration coil units or evaporators with room air before coming into contact with the produce.
With a multi-tier configuration, room heights are reduced or at least minimised, as the coil units/evaporators are generally installed or fitted in a vertical plane position and not in a front plenum wall positioned horizontally above the produce pallets that are being cooled or ripened.
With the present invention, the refrigeration evaporator coils are positioned in a vertical plane or horizontal plane between two walls, being a front plenum wall and a rear wall of the cool room, and a ceiling. This creates a space or plenum to allow fans to draw or force (induced draught or forced draught) air through the installed coil units. The air is then discharged from the plenum cavity through an opening or openings, creating a curtain of air along the face of the pallets or cartons, crates or bins being forced air cooled or ripened. The air is then returned to the evaporator/refrigeration coils through holes in the face cartons minimising the mixing of air leaving the coil units with the room air before contacting the produce being cooled or ripened.
The invention in the integrated air flow control facility of the invention provides for the first time the dedicated separation of a storage zone of a cool room and the refrigeration zone so as to maximise the efficiency of both these two zones in a manner not found in any of the prior art. The separation of these two important zones allows maximum efficiency and operation where the refrigeration zone can be specifically engineered for the purposes of maximising efficiency of the cooling function and a storage zone can be engineered in accordance with the different requirements for maximising storage and air flow movement through to produce stored in the cool room. The invention allows cooling air to be directed along the face or surface of the produce or product to be cooled with minimal contact with the storage zone air prior to the cool air being drawn into contact with the produce or products and returned to the cooling evaporators thereby minimising any dilution of the cooling air and maximising the cooling affect.
It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

1. An integrated airflow control facility for force cooling of produce in a cool room, said facility comprising:

a dedicated storage zone for storage of the produce,

a dedicated refrigeration zone,

at least one refrigeration coil in said refrigeration zone,

a physical divider which separates the storage zone and refrigeration zone, said divider including:

at least one integral extraction fan to extract air from said storage zone and direct said air through said at least one refrigeration coil positioned in said refrigeration zone for cooling thereof, and

at least one air outlet to return said cooled air exiting said refrigeration zone into said storage zone, and

wherein said storage zone, refrigeration zone and said physical divider are integrated into a single airflow control facility.

2. A facility according to claim 1, wherein said at least one refrigeration coil is positioned between said at least one extraction fan and said at least one air outlet.

3. A facility according to claim 1, wherein said at least one air outlet is positioned one of at and toward side edges of said divider such that said returned cooled air is directed along sides of said storage zone.

4. A facility according to claim 1, wherein said refrigeration zone is bound by at least opposing side walls of said cool room, a rear wall of said cool room and said divider.

5. A facility according to claim 1, wherein said at least one refrigeration coil extends at least partially between said divider and a rear wall of said cool room.

6. A facility according to claim 5, wherein said at least one refrigeration coil includes at least one separate unit extending between a floor and ceiling of the refrigeration zone of said cool room.

7. A facility according to claim 5, wherein said at least one refrigeration coil is positioned at an acute angle relative to a plane of said divider and said rear wall.

8. A facility according to claim 1, wherein said refrigeration zone is partitioned such that a refrigeration coil unit, an air outlet and at least one extraction fan direct air from said storage zone through separate compartments for cooling and redirecting through said outlet to cool a row of pallets storing said produce.

9. A cool room including a facility according to claim 1.

10. A multi-tiered cool room wherein each tier includes a facility according to claim 1.

11. A cool room according to claim 9, wherein said storage zone includes rows of pallets in at least one tier corresponding to said at least one air outlet.

12. (canceled)

13. (canceled)