Freezer storage container with ventilation openings

Abstract

A food storage and shipping container for use in a commercial freezer is provided. The container has improved heat transfer capabilities. The container includes a box and a lid and a plurality of ventilation openings allowing improved convective heat transfer between the freezer atmosphere and food in the container.

Description

FIELD OF THE INVENTION

The invention relates generally to containers for storage and shipment of frozen food stuffs.

BACKGROUND OF THE INVENTION

Containers fabricated from corrugated paperboard to store and ship frozen food are known. For example, it is known to provide a generally rectangular box in which processed chicken is placed for transportation from the chicken processing plant to a freezer facility. While in the box, the chicken is frozen at the freezer facility to a sub-zero degree Fahrenheit temperature, and subsequently shipped to a distribution center.

Known boxes, designated by reference numeral 10 in FIG. 1, typically have two generally parallel opposing longitudinal sides 12 and two generally parallel opposing transverse sides 14. A preferred size for the boxes 10 is approximately 22 inches long by 15 inches wide by 6.5 inches high. However, specific dimensions may vary. The boxes 10 are held closed by bands 16, and are stacked in layers on pallets 20. Standard pallets are 40″ wide by 48″ long, and will accommodate five boxes 10 per layer. Typically, the pallets are stacked with eight layers of boxes 10. The boxes 10 are preferably stacked with a small gap 22 between the boxes 10 on a given layer.

It is highly desirable during the freezing process to allow air to circulate between the boxes, to increase the convective heat transfer between the freezer air and the boxes 10 and the contents of the boxes, and thereby expedite the freezing process. To further enhance convective heat transfer and expedite the freezing process, it is known to insert dividers 30 between the layers of boxes 10. The dividers 30 form a plurality of air channels 32 alternating between spacer members 34 connected to a panel 36. The dividers 30 allow air to circulate between the layers of boxes 10. However, dividers need to be purchased, and the process of inserting and removing the dividers 30 is labor intensive. Furthermore, the dividers 30 must be cleaned on a regular basis, another labor intensive process. Still further, the additional handling of the boxes 10 required when the dividers 30 are used increases the opportunity for and the probability of damage to the box 10 and its contents. It would be desirable to eliminate the need for use of dividers in the freezing process while maintaining or reducing the time required to complete the freezing process.

SUMMARY OF THE INVENTION

In a first aspect, the invention is a food storage and shipping container for use in a freezer. In an assembled state, the container comprises a box generally in the shape of a parallelepiped having first and second longitudinal side wall panels, first and second transverse side wall panels, an open top and a bottom panel. The container further comprises a lid sized and shaped to close the open top. At least four ventilation openings are located in the container to allow air to flow through the box in a first direction substantially perpendicular to the first and second longitudinal side walls and in a second direction substantially perpendicular to the transverse side walls.

In a second aspect, the invention is a food storage and shipping container for use in a freezer. The container comprises a box generally in the shape of a parallelepiped having first and second generally parallel opposite transverse side panels, each with an upper and a lower edge. The box has first and second generally parallel opposite longitudinal side panels, each with an upper and a lower edge. The box includes an opening defined by the upper edge of each of the side panels and a generally flat bottom panel interconnecting the lower edge of each of the side panels. The container further includes a lid sized and shaped to cover the opening. A plurality of ventilation openings in the container are provided, including a first set of openings wherein each opening defines an area lying in a plane substantially perpendicular to the longitudinal side panels and a second set of openings, wherein each opening defines an area lying in a plane substantially perpendicular to the transverse side panels.

In a third aspect, the invention is a food storage and shipping container for use in a freezer comprising: a box having a plurality of side wall panels; a lid; and a ventilation hole located in a side panel.

Preferably, the box is fabricated from wax coated, corrugated paperboard. The container is preferably sufficiently structurally robust to allow at least six fully loaded containers to be stacked one on top of another without damaging the bottom container or its contents. The ventilation openings may be located near the lower edges of the side panels, with at least one ventilation opening located near the lower edge of each of the side panels. A spacer and false bottom may be provided, sized and shaped to fit within the box and supportable by the bottom panel. The spacer has a plurality of passages allowing fluid communication among the container ventilation openings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For the purpose of illustrating the invention, there are shown in the drawings an embodiment of the invention which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

FIG. 1 is a side view of a pallet loaded with a plurality of prior art containers stacked in multiple layers, with a divider inserted between each layer of containers.

FIG. 2 is an exploded perspective view of a container in accordance with a preferred embodiment of the present invention.

FIG. 3 is an end view of the container of FIG. 2.

FIG. 4 is cross-sectional view of the container of FIGS. 2 and 3, taken along line 4-4 of FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, and particularly to FIGS. 2-4, a food storage and shipping container in accordance with the present invention is indicated generally by the reference numeral 100. The container 100 is generally in the shape of a parallelepiped. The container 100 comprises a box 110 and a lid 130 and is provided with a plurality of ventilation openings 140. More particularly, the box 110 includes first and second generally parallel opposite transverse side panels 112, each having a lower edge 114 and an upper edge 116. The box 110 further has first and second generally parallel opposite longitudinal side panels 118, each having a lower edge 120 and an upper edge 122. The box 110 includes an opening 126 defined by the upper edges 116, 122 of the side panels and a generally flat bottom panel 124 interconnecting the lower edges 114, 120 of the side panels.

The lid 130 is sized and shaped to cover the opening 126. In the preferred embodiment illustrated, the lid 130 is fully separable from the box 110. However, the lid 130 could be formed by one or more panels connected to or integral with one or more of the upper edges 116, 122 and pivotable into a position to cover the opening 126.

A plurality of ventilation openings 140 in the container 100 include a first set of openings 142. Each opening 142 defines an area lying in a plane substantially perpendicular to the longitudinal side panels 118. A second set of openings 144 is provided, wherein each opening 144 defines an area lying in a plane substantially perpendicular to the transverse side panels 112. The plurality of ventilation openings 140 thus allow air to flow through the box 110 in a first direction substantially perpendicular to the longitudinal side panels 118 as well as in a second direction substantially perpendicular to the transverse side panels 112.

In the embodiment illustrated, the ventilation openings 140 are located near the lower edges of the side panels, with at least one ventilation opening 140 located near the lower edge 114, 120 of each of the side panels 112, 118. With the ventilation openings located near the bottom of the box 110, it is preferable to also provide a spacer 150 and false bottom 160, as described in detail below, in order to prevent the contents of the container 100 from blocking the ventilation openings 140. Alternatively, the ventilation openings 140 may be located at points on the container 100 remote from the container contents, such that the contents would not block the ventilation openings 140 in that event, the spacer 150 and false bottom 160 may be eliminated.

The ventilation openings 140 are sized to allow sufficient airflow through the container 100 to provide enhanced convective heat transfer, while also maintaining adequate structural strength and integrity of the container 100. In one preferred embodiment, the ventilation openings 140 have a combined area of at least 5 square inches.

Preferably, the box 110 is fabricated from corrugated paperboard, using conventional box manufacturing techniques. A wax coating may be applied to the corrugated paperboard, using conventional techniques. The lid 130 is also preferably fabricated from corrugated paperboard. Other conventional materials having appropriate strength characteristics over the entire temperature range of the box 110 (such as certain polymeric materials or metals) could also be used to fabricate the box 110 and lid 130.

In an embodiment especially suited for storage and shipping of processed chickens, the longitudinal side panels 118 preferably have a length of approximately 22 inches and the transverse side panels 112 each have a length of approximately 15 inches. Accordingly, the lid has an upper surface 132 approximately 22 inches long and 15 inches wide.

When packed with processed chickens, the container 100 will weigh approximately 40 pounds (for a packed density of approximately 32.2 pounds per cubic foot of container space). Preferably, although not necessarily, during freezing, storage, and shipping, the containers 100 are stacked no less than five high, thus imposing a static load of 5*40=200 pounds on each container 100 on the bottom layer. Hence, the container 100 preferably is capable of supporting a static load of at least 200 pounds distributed generally uniformly over substantially the entire upper surface of the lid. Stated otherwise, the container 100 is preferably, although not necessarily, designed to be capable of supporting a load of at least 0.60 pounds per square inch applied uniformly over the lid upper surface 132. Additional structural capacity, allowing the containers 100 to be stacked more than five high, is desirable but not vital.

As indicated above, when the ventilation openings 140 are located near the bottom of the box 110, the container 100 preferably further comprises a spacer 150 and false bottom 160 sized and shaped to fit within the box 110. When installed in the box 110, the spacer 150 rests upon and is supported by the bottom panel 124. The spacer 150 is formed by a plurality of inter-engaging cross members 152 forming a lattice-type structure. Each cross member 152 is provided with a plurality of passages 154 allowing fluid communication among the container ventilation openings 140.

Preferably, the cross members 152 are formed from corrugated paperboard and are pivotable relative to one another to move between a collapsed configuration (not illustrated) and the extended configuration illustrated in FIG. 2.

The false bottom panel 160 is used in conjunction with the spacer 150. The false bottom panel 160 is sized and shaped to fit within the box 110 and is supportable by the spacer 150 and is preferably fabricated from corrugated paperboard. The false bottom panel 160 and spacer 150 function to keep the container contents away from the ventilation openings 140, and thus prevent blockage of the ventilation openings 140 by the container contents.

In use of the preferred embodiment illustrated, the spacer 150 and false bottom 160 are placed in the bottom of the box 110. The container contents (not illustrated) are then deposited in the box 110, and the lid 130 is put on to close the box 110. Preferably, bands are installed on the container 100 to restrain the lid 130 to the box 110. The containers 110 are then shipped to a freezer facility from the processing plant. Preferably, the containers 110 are shipped on a pallet, and, in contrast to existing procedures wherein prior to the freezing process it is necessary to install the dividers 30 between layers of prior art containers 10 (see FIG. 1), the containers 100 may be stacked directly on top of one another.

When placed in a blast freezer (not shown) in their stacked, palletized configuration, the ventilation holes 140 allow warmer air within the containers 100 to circulate with the cooler air of the freezer. The flow can be induced solely by natural convection, or alternatively can be a combination of natural and forced convection, as the freezer may be equipped with one or more fans to help force cooler ambient air through the containers 100.

The operating temperature of the blast freezer is on the order of −25 degrees Fahrenheit. The containers 100 are left in the blast freezer for a period of approximately 48 hours. While in the blast freezer, the temperature of product stored in the containers 100 is reduced from approximately 30 degrees Fahrenheit to approximately −5 to −10 degrees Fahrenheit.

The ventilation holes 140 provide enhanced heat transfer rates when compared to the existing container 10 configuration (even when the dividers 30 are used), as the rate of natural convective heat transfer within the container 100 is substantially increased because warm air within the container 100 comparatively readily flows out of the container 100 through the ventilation openings 140 to be replaced by cooler freezer air. While the conventional dividers 30 promote enhanced convective heat transfer on the exterior of the convention container 10 (at the substantial cost of providing, installing, and removing the dividers 30), enhancing the convective heat transfer on the interior of the container 100 is thought to be particularly effective in reducing the total freeze time required.

The container according to the invention provides substantially improved heat transfer performance and consequently reduces freeze cycle times, while also eliminating the need for use of dividers in the freezing process. The reduced freeze cycle times provide the advantage of reducing the risk of bacterial contamination of the food stored in the container.

While the invention has been described and illustrated with respect to the exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without parting from the spirit and scope of the present invention.

Claims

1. A food storage and shipping container for use in a freezer comprising:

a box generally in the shape of a parallelepiped, having first and second longitudinal side wall panels, first and second transverse side wall panels, an open top and a bottom panel;

a lid sized and shaped to close the open top; and

at least four ventilation openings located in the container to allow air to flow through the box in a first direction substantially perpendicular to the first and second longitudinal side walls and in a second direction substantially perpendicular to the transverse side walls.

2. A food storage and shipping container for use in a freezer comprising:

a box generally in the shape of a parallelepiped, having first and second generally parallel opposite transverse side panels, each with an upper and a lower edge; first and second generally parallel opposite longitudinal side panels, each with an upper and a lower edge; an opening defined by the upper edge of each of the side panels; and a generally flat bottom panel interconnecting the lower edge of each of the side panels;

a lid sized and shaped to cover the opening; and

a plurality of ventilation openings in the container, including a first set of openings wherein each opening defines an area lying in a plane substantially perpendicular to the longitudinal side panels and a second set of openings wherein each opening defines an area lying in a plane substantially perpendicular to the transverse side panels.

3. The container of claim 2 wherein the box is fabricated from corrugated paperboard.

4. The container of claim 3 wherein the corrugated paperboard includes a wax coating.

5. The container of claim 2 wherein the longitudinal side panels each have a length of approximately 22 inches and the transverse side panels each have a length of approximately 15 inches and the lid has an upper surface approximately 22 inches long and 15 inches wide.

6. The container of claim 5 wherein the container is capable of supporting a static load of at least 200 pounds distributed generally uniformly over substantially the entire upper surface of the lid.

7. The container of claim 5 wherein the ventilation openings have a combined area of at least 5 square inches.

8. The container of claim 2, wherein the container is capable of supporting a load of at least 0.60 pounds per square inch applied uniformly over the upper surface of the lid.

9. The container of claim 2, wherein the ventilation openings are located near the lower edges of the side panels, with at least one ventilation opening located near the lower edge of each of the side panels.

10. The container of claim 9 further comprising a spacer sized and shaped to fit within the box and supportable by the bottom panel and having a plurality of passages allowing fluid communication among the container ventilation openings.

11. The container of claim 10, the spacer being formed by a plurality of inter-engaging cross members forming a lattice-type structure.

12. The container of claim 11, wherein the cross members are formed from corrugated paperboard.

13. The container of claim 12, wherein the cross members are movable relative to one another to move between a collapsed configuration and an extended configuration.

14. The container of claim 10 further comprising a false bottom panel sized and shaped to fit within the box and supportable by the spacer.

15. A food storage and shipping container for use in a freezer comprising: a box having a plurality of side walls; a lid; and a ventilation hole located in a side panel.