REFRIGERATED CONTAINER

FIELD OF INVENTION

The present invention relates to a refrigerated container.

More particularly, the present invention relates to air flow in a refrigerated container and to directional management/control of the air flow.

BACKGROUND TO INVENTION

Refrigerated transport containers are widely used in industry for the transportation of produce, such as fresh fruit and vegetables. An important aspect for maintaining the freshness of the produce, and in so doing the shelf-life and marketability thereof, is that the temperature within the container must be uniform and constant throughout the container, i.e. with minimal temperature fluctuations.

Many standard refrigerated containers have a cooling unit at one end with a fan for circulating cool air within the container. The circulation normally takes place by blowing the air along passages in the floor of the container (in a "T-bar" floor), letting the air rise up through the fruit, and circling back to the cooling unit near the roof of the container.

When packing a container, the produce is located in ventilated cartons placed on pallets. Due to constraints in packing the container, it is not possible and also not always desirable to pack the pallets flush against the side walls of the container as friction with the side walls may damage the cartons and also heat from the ambient outside environment may be transferred through the walls and damage the produce. A problem that then arises is that the gap between the pallets and the side walls allows the cool air to bypass the cartons and

can created warm pockets of air amongst the cartons. Consequently the produce is not properly cooled and it can spoil.

A further problem that is encountered is that the warm air pockets result in more moisture evaporating from the produce. This reduces the firmness of the produce and leads to weight loss thereof. The evaporated moisture can freeze in the cooling unit when the air is re- circulated, thus lowering the humidity in the container.

Additionally, the warm air pockets require extra cooling and thus lower the efficiency of the cooling unit.

It is an aspect of the invention to suggest a refrigerated container, which will assist in overcoming these problems.

SUMMARY OF INVENTION

According to the invention, a refrigerated shipping container includes a housing; a chamber in the housing, wherein the chamber is adapted to receive produce; a refrigeration unit associated with the container, the refrigeration unit having an air outlet, being adapted to blow air into the chamber, and an air inlet, being adapted to receive air from the chamber; and deflecting means supported by the housing being adapted, in use, to deflect refrigerated air from the air outlet to flow substantially horizontally through the chamber before the air is recycled to the air inlet.

The housing may have opposite first and second end walls wherein the refrigeration unit is provided near the first end wall, the housing further may have at least one duct leading from the air outlet to near the second end wall, each duct being adapted to convey refrigerated air from the air outlet to near the second end wall so that, in use, the air is deflected to flow substantially horizontally from the second end wall towards the first end wall.

The housing may have opposite first and second end walls wherein the refrigeration unit is provided near the first end wall so that, in use, the air is deflected to flow substantially horizontally from the first end wall towards the second end wall, the housing further may have at least one duct leading from near the second end wall to the air inlet, each duct being adapted to convey refrigerated air from near the second end wall to the air inlet.

The container may have a vertical cross-sectional area being smaller than its horizontal cross-sectional area, wherein horizontal air flow in the chamber correspondingly occurs at a higher velocity than vertical air flow.

The produce may be provided in ventilated cartons on pallets within the chamber.

The deflecting means may include at least one flexible curtain extending from the housing into the chamber and contacting against the produce or against the cartons or pallets.

The curtain may be a plastic or canvas sheet.

The deflecting means may be a lining adapted to encase the produce.

The deflecting means may include expansion means provided between the housing and the lining and being adapted to press the lining against the produce.

The expansion means may be inflatable dunnage bags.

The lining may be a plastic or canvas sheet.

Each duct may extend along a roof of the housing.

Each duct may be formed within a floor of the housing.

Each duct may be formed by a "T-bar" floor within the housing that is covered with a sheet, such as a plastic sheet.

Each duct may extend for a length of approximately 75% to 80% across the distance between the first and second first end walls.

Also according to the invention, a refrigerated shipping container includes a chamber; and deflecting means provided within the chamber, the deflecting means being adapted, in use, to deflect refrigerated air to flow in a substantially horizontal direction through the chamber.

Further according to the invention, a method of refrigerating a shipping container including the steps of cooling air in the container; of creating an air flow within the container; and of directing the air flow to travel horizontally within the container.

The method may include the step of locating produce within the container and deflecting the air flow to pass through the produce.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described by way of example with reference to the accompanying schematic drawings.

In the drawings there is shown in:

Figure 1 : A sectional side view of a refrigerated container according to the invention; and

Figure 2: An end view seen along arrow II in Figure 1.

DETAILED DESCRIPTION OF DRAWINGS

Referring to the drawings, a refrigerated container in accordance with the invention, generally indicated by reference numeral 10, is shown.

The container 10 has a substantially rectangular housing 12 having a floor 14, opposite side walls 16,18, opposite end walls 20,22 and a roof 24. The container 10 defines a chamber 26 being adapted to receive produce 28 located in ventilated cartons on a number of pallets. A refrigeration unit 30 is provided near the first end wall 20 for cooling and circulating refrigerated air (indicated by arrows 32) within the chamber 26. An access door is provided in the second end wall 22.

The floor 14 is a conventional T-bar floor having a number of ducts or passages 34 therein that extend from the first end wall 20 to the second end wall 22. The ducts 34 are joined to an air outlet of the refrigeration unit 30 so that cool refrigerated air 32 is conveyed from the refrigeration unit 30 past the produce 28 and released into the chamber 26 near to the second end wall 22. The ducts 34 may terminate at a point between 20% to 25% of the distance from the second end wall 22 to the first end wall 20.

The ducts 34 can alternatively be provided along the side walls 16,18 or the roof 24.

The container 10 further includes deflecting means 36 for ensuring that the refrigerated air 32 flows through the produce 28 and is not able to bypass the produce 28 by flowing along gaps 38 between the produce and the side walls 16,18 or the roof 24. In use, the deflecting means 36 deflects the refrigerated air to flow substantially horizontally through the produce 28 in the chamber 26 from the second end wall 22 towards the first end wall 20 before the air is recycled to the inlet of the refrigeration unit 30.

The deflecting means 36 as shown is a lining 40 for encasing the produce 28 and being pressed against the produce 28 by inflatable dunnage bags 42 to prevent the lining from moving away from the

produce 28 during transportation. The lining 40 encases the entire sides of the produce 28 and a large portion of the top of the produce 28, apart from about 10% to 20% of the top nearest to the refrigeration unit 30.

Alternatively, as the dunnage bags 42 may become damaged or deflate during transit, the deflecting means 36 can be a number of flexible curtains suspended from the roof 24 extending transversely across the chamber 26 between the side walls 16,18. The curtains preferably have a sufficient length so that they contacting against the produce 28 to close off the gap 38 between the produce 28 and the roof 24. The curtains can be provided with weights at their free ends to prevent them from flapping away from the produce 28 during transportation.

Although some refrigerated air may escape from the confines of the produce 28 between adjacent curtains, the air will again be deflected into the produce 28 when the air abuts against the next curtain. This continuous deflection creates a form of air-blanket that will further assist in causing the air 32 to flow within the produce 28.

The lining or curtains can be made of plastic sheet or canvas sheet.

The container 10 has a vertical cross-sectional area being smaller than its horizontal cross-sectional area. Therefore horizontal air flow in the container correspondingly occurs at a higher velocity than vertical air flow, which increases heat transfer between the air and produce 28 located in the chamber 26.

The container 10 can be a shipping container, a reefer container or a road truck trailer.