Thermal Insulation of Shipping Containers

Abstract

A liner (22) for a shipping container is disclosed which includes a roof panel (28), an end panel (30) and side wall panels (26). Cords (24) are attached to the liner in the viscinity of the end wall panel (30) and extend through loops along the top edges of the wall panels (26). Hooks, carried by the parts of the cords (24) between the loops, are provided for attaching the cords to sets of lashing points of the shipping container. The cords can be anchored and then tensioned, in a temporary manner, to pull the top edges of the side wall panels (26) towards the lashing points to facilitate cargo loading. When the cords (24) are permitted to become slack, the roof panel (28) drops down onto the loaded cargo.

Description

FIELD OF THE INVENTION

This invention relates to the thermal insulation of shipping containers.

BACKGROUND TO THE INVENTION

Since the advent of “containerisation” as a shipping concept, some products such as grain, iron ore, coal and oil are still transported “loose” in the holds of the transporting vessels, with most other commodities travelling in shipping containers.

Refrigerated shipping containers are used for products such as fruit and other perishable items that require a temperature controlled climate. Non-refrigerated shipping containers are used for other products which are not temperature sensitive and consequently do not have to be regulated or maintained within a specific temperature range. Other products, such as wines, are far less sensitive to temperature than would require them to be refrigerated, but nonetheless should be protected from extremes of temperature (both hot and cold).

To reduce the range of temperature fluctuations inside a shipping container it has been proposed that the container should be fitted with a liner which restricts heat transfer between the air space containing the cargo and the ambient air. A prior art system is disclosed in U.S. patent specification No. 7416091 published on 26 Aug. 2008.

One object of the present invention is to provide an improved shipping container liner and an improved method of lining a shipping container.

It is common practice to transport liquids in flexible tanks which are large bladders that fit inside standard shipping containers.

Some products, such as molasses, solidify during transit and cannot be pumped from the flexible tank in which they are transported until softened. A conventional way of softening the tank's contents is to provide a means of heating the tank from the outside. Typically the contents of the tank are heated until they are soft enough to allow them to be pumped from the bladder. To reduce the time taken to soften the contents of the flexible tank prior to pumping, and to minimize the energy required for this purpose, the present invention provides means for reducing heat losses from the shipping container.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the present invention there is provided a liner for a shipping container, the liner comprising;

• • a roof panel;
  • two side wall panels extending downward from the roof panel;
  • an end wall panel;
  • cords anchored to the liner adjacent said end wall panel;
  • loops at intervals along the length of the liner in proximity to the zones where the side wall panels intersect the roof panel, said cords passing through said loops;
  • hooks on said cords and attachable to lashing points along the container close to the intersection between its sidewalls and its roof;
  • and means for temporarily tensioning the cords to pull the top edges of the side wall panels up towards the lashing points.

The liner can include means for temporarily attaching the roof panel of the liner to the roof of the shipping container. In one form the attaching means comprises magnets spaced apart along the roof panel. In another form the attaching means comprises hook and loop material, pieces of said material being attached to the top surface of the roof panel.

The liner can further include pull cords attached to the roof panel for pulling the roof panel down to release the roof panel from the roof of the shipping container.

In the preferred form said means for temporarily tensioning the cords comprises an element to which the end of the cord is tied, and a guideway through which a part of said cord remote from said end passes.

Hooks can be attached to said cords adjacent said ends for attaching the cords to fixed elements.

Said guideway can be a slot in the element which slot opens through an edge of the element. Alternatively said guideway can be a hole in said element.

The liner can include a flap which closes the end of the liner, there being a sliding clasp fastener for securing the edges of the flap to the remainder of the liner, the sliding clasp fastener including two sliding clasps which can be secured together to prevent opening of the container.

Said flap can be an extension of the roof panel. In another form said flap is constituted by a separate panel, one of the stringers of the sliding clasp fastener extending around the periphery of the panel.

According to another aspect of the invention there is provided a method of heat insulating a shipping container which comprises;

• • providing a liner having a roof panel, an end wall panel and two side wall panels with cords extending from the vicinity of the end wall panel along the liner through loops provided where the roof panel joins the side wall panels;
  • attaching the cords to sets of lashing points provided where the roof of the shipping container joins its side walls;
  • temporarily anchoring and tensioning said cords to pull the top edges of the side wall panels up towards the lashing points;
  • loading cargo into the liner; and
  • slackening the cords so that the roof panel of the liner drops down into the cargo.

The method can include the step of temporarily attaching the roof panel of the liner to the roof of the container prior to loading the cargo, and releasing the temporarily attachments to permit the roof panel to drop down onto the cargo.

According to a further aspect of the present invention there is provided a jacket for minimising heat loss from a shipping container, the jacket comprising a roof panel, two elongate side wall panels extending downward from the roof panel, an end wall panel spanning between said side wall panels at one end thereof, and a second end wall panel configured to provide access to the inside of the shipping container, the jacket being sized so that it can fit over the shipping container with the side wall panels extending downward adjacent to the outside surfaces of the elongate side walls of the shipping container, the end wall panels extending down adjacent to the outside surfaces of end walls of the shipping container and the roof panel of the jacket extending across the roof of the container, there being means for ensuring that there is an air gap between the jacket and the container.

According to still further aspect of the present invention there is provided a method of unloading a flexible tank which has solidified material in it which method comprises fitting a jacket as defined in the preceding paragraph over the shipping container which has the flexible tank in it, and heating the flexible tank to soften the material in the tank.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

FIGS. 1 to 18 illustrates the construction and fitting of a liner to a shipping container;

FIG. 19 illustrates the closure of a front panel of the liner;

FIG. 20 illustrates the opening of the front panel; and

FIG. 21 illustrates a jacket for a shipping container.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of the inside of a shipping container 10 having a floor 12, a front end wall 14, side walls 16 and a roof 18. Expansion bolts 20 (FIG. 2) are fitted one at the top right hand side of the container 10 and one at the top left hand side of the container 10. The bolts 20 are adjacent the front end wall 14 in the positions indicated by the arrows in FIG. 1. Each bolt 20 is fitted horizontally between two upright surfaces of the container, such as between the flanges of a vertical column or between the side wall and a column, and then expanded to fix it in place.

The liner 22 (FIG. 3) is then placed on the floor 12 of the container 10 in a folded condition. It is subsequently unfolded (see FIG. 4).

Cords 24 (FIG. 5) extend the full length of the liner where the side wall panels 26 (best seen in FIG. 15) of the liner 22 are connected to the roof panel 28. The liner also has an end wall panel 30 and a bottom panel 32 (see FIG. 18).

Each cord 24 (FIG. 5) passes through loops 34 attached to, or incorporated in, the edges of the liner and plastic or metal hooks 36 are attached to the cords 24. Each hook, as best seen in FIG. 5, is s-shaped and the cord is pressed into the smaller of the two almost closed loops which constitute the hook. In another form the hooks can be snap hooks which include a spring loaded element which can be displaced inwardly with respect to the remainder of the hook. One end of each cord 24 is fixed at 38 (FIG. 15) to the liner 22 where the end wall panel 30 joins the side wall panels 26. The cords 24 are of greater length than the liner 22.

The loops 34, which can be of a textile fabric, can alternatively be in the form of synthetic plastic material rings which are sewn to the liner 22.

There are sets of loops 34 along the length of the liner on each side thereof, each cord 24 passing through all the loops 34 on a respective side of the liner. Between each adjacent pair of loops 34 the cord 24 is secured to one of the hooks 36 (see FIG. 5). Along the length of the container 10 there are lashing points 40 (see FIGS. 6 and 7) with which the hooks 36 are engaged. Once the hooks 36 are engaged with the lashing points 40, the liner hangs as shown in FIGS. 8, 9, 10 and 11.

If snap hooks are used, the spring loaded elements of the hooks are pressed against the lashing points to displace the elements inwardly and allow the hooks to engage with the lashing points.

Expansion bolts 42 are then fitted close to the container's roof 18 at the door end of the container (FIG. 12) and the cords 24 passed around them so that the part of each cord 24 that emerges from the last loop 34 on that side is high up in the container.

The end of one of the cords 24 is shown in FIG. 13. The hook designated 44 is attached to the cord 24 by pressing the cord 24 into the smaller of the two loops of the hook through the gap between the end of the smaller loop and the centre part of the hook. The end of the cord 24 is fastened to a “dogbone” 46. The cord 24 also passes through a hole 48 in the dogbone 46.

The end hooks 44 are attached to suitable fixings 50 within the container 10 (FIG. 14) and close to its floor. In conventional shipping containers there is a vertically extending recess in each long wall immediately inside the door opening. One of these recesses can be seen in FIG. 14 and it will be noted that the fixing 50 shown spans this recess.

The dogbones 46 are slid upwards (FIG. 15) so as to pull the cords 24 taut. This lifts the top edges of the side wall panels 26 of the liner towards the lashing points, and the entire liner 22 to the position shown in FIG. 15. This ensures that the roof panel 28 of the liner 22 is close to the roof 18 and walls 16 of the shipping container 10. Consequently the space within the liner into which the cargo is loaded is as large as possible and not obstructed by the liner.

The holes 48 in the dogbones 46 can be replaced by keyhole shaped slots which are open at an edge of the dogbone and the hooks 44 can be omitted. In this form the end of the cord with the dogbone attached is passed behind the fitting 50. The parts of the cords 24 spanning between the bolts 42 and the fittings 50 are pressed into the keyhole shaped slots through their open ends. The dogbones can be slid up the cords 24 to tension the cords.

The liner includes a flap 52 (FIGS. 16 and 17) for closing the open end. In the illustrated form the flap is an extension of the roof panel 28. The panel 52 can be rolled up to permit access to the liner's interior. The flap 52 has loops 54 which may be hooked for this purpose over suitable projections 56 on the container 10. The liner 22 is now as shown in FIG. 18 and ready for loading.

After the cargo has been loaded, the flap 52 is allowed to drop down. Once the cargo is in place the cords 24 are slackened, and the liner drops down until its roof panel 28 is resting on the cargo. There is thus an air gap between the walls 16 and roof 18 of the container 10 on the one hand and the liner 22 on the other hand.

The liner is made from material which has suitable thermal insulation properties. For example, it can comprise two sheets of heavy duty aluminum foil with a layer of woven material between them, the three layers being laminated together. The woven material is preferably plastic and plastics such as polyester and polypropylene can be used. Closure of the flap 52 ensures that the liner 22 also provides a contamination barrier and a moisture barrier separating the cargo within the liner 22 from the space between the liner 22 and the shipping container 10.

In the form illustrated in FIG. 19, the top edge of the flap 52 is attached to, or is an integral extension of, the roof panel 28. One stringer 56 of a sliding clasp fastener 58 is attached to the vertical edges and bottom edge of the flap 52. The other stringer 60 of the sliding clasp fastener 58 is attached to the vertical edges of the side wall panels 28 and to the free edge of the bottom panel 32.

Two sliding clasps 62 are provided which, to permit access to be had to the interior of the liner 22, are slid apart and moved across the bottom panel 32 and then up the side wall panels 26 to positions adjacent the junctions between the top wall panel 28 and the upper edges of the side wall panels 26. The panel 52 can then be rolled up as described.

To close the liner 22, the clasps 62 are returned to the position shown in FIG. 19 and the elongate element 64 of a seal 66 passed through holes 68 in the sliding clasps 62.

As shown in FIG. 20 the liner 22 can only be entered if the element 64 is cut to enable the clasps 62 to be slid apart as described above.

When this form of liner 22 is used, a ramp should be employed over the stringer 60 so that fork lift trucks carrying cargo into the container 10 cannot contact and damage the stringer 56. Such a ramp, even if there is no stringer 60, protects the bottom panel 32 of the liner 22.

In a further form the flap 52 is constituted by an entirely separate panel. In this form the stringer 56 extends around the entire periphery of the panel. The stringer 60 extends along the free edges of the roof panel 28, side wall panels 26 and bottom panel 32.

In FIGS. 10, 11 and 15 four magnets 70 are shown which are spaced apart along the roof panel 28. The number of magnets 70 can be increased or decreased in dependence on the length of the liner 22 and of the container 10. The magnets can be sewn into pockets of the liner 22.

Pull cords 72 (FIG. 15) are sewn to the roof panel 28 of the liner 22 and hang down inside the liner. There can be, for example, between three and six pull cords 72 spaced apart along the length of the liner.

Preferably pockets are provided into which the magnets 70 are sewn. The end of a pull cord 72 can be sewn into each pocket.

As the cords 24 are tightened to pull the roof panel 28 upwardly towards the metal roof 18 of the container, the magnets 70 are attracted to the metal roof 18 of the container. This prevents the roof panel 28 of the liner from drooping down along its centre line and obstructing free passage of the cargo bearing pallets into the liner.

The first pallets loaded are placed against the end wall panel 30 of the liner. Before the cord 72 which is closest to the panel 30 is rendered inaccessible by the load in the liner, it is pulled down to separate the magnet 70 from the container's roof 18. The end part of the liner thus falls down onto the load. Each cord 72 is pulled in turn before it becomes inaccessible whereby the roof panel 28 of the liner is progressively released from the roof 18 of the shipping container 10.

Because of the height of the roof 18 of the container 10 above its floor it assists if a pole is provided with each liner to push the roof panel 28 of the liner up towards the roof 18 of the shipping container so that the magnets 70 are attracted to the container roof.

The magnets 70 can be replaced by the “hook and loop” fastening material which is widely referred to as “Velcro”. More specifically, pieces of “Velcro” are adhered to the downwardly facing surface of the roof 18 of the shipping container 10 and pieces of the other “Velcro” component are secured to the upper face of the roof panel 18 of the liner. Cords as described above are provided to pull the roof panel 18 of the liner down and a pole as described above is used to push the roof panel 18 up so that the “Velcro” pieces are joined prior to loading of the liner.

Referring now to FIG. 21, the jacket 100 illustrated comprises a roof 102, elongate side walls 104, a closed end wall 106, and an panel wall 108 which is configurated so that access can be had to the container which is inside the jacket. For this purpose the panel 108 can comprise two flaps 110 with releasable fastening means 112 (such as “Velcro” strips) for securing the flaps 110 together.

The roof and walls of the jacket are made from material which has suitable thermal insulation properties. For example two layers of heavy duty aluminium foil laminated to opposite sides of a woven synthetic plastics material layer can be used.

The jacket is sized so that it will fit over a standard ISO shipping container whilst maintaining an air gap between the inside of the jacket and the outside of the container. The jacket is used to minimise heat losses whilst the contents of a flexible tank inside the ISO container are being heated to soften the material in the tank so that it can be pumped out.

The requisite air gap can be obtained by providing blocks or strips of heat insulating material on the underside of the roof of the jacket. Blocks or strips can also be provided on the inside faces of the walls of the jacket. However, these latter blocks or strips can be omitted if the width and length of the roof panel results in the walls hanging down at locations which are spaced outwards from the walls of the shipping container.

Claims

1. A liner for a shipping container, the liner comprising; a roof panel;two side wall panels extending downward from the roof panel;an end wall panel;cords anchored to the liner adjacent said end wall panel;loops at intervals along the length of the liner in proximity to the zones where the side wall panels intersect the roof panel, said cords passing through said loops;hooks on said cords and attachable to lashing points along the container close to the intersection between its sidewalls and its roof; andmeans for temporarily tensioning the cords to pull the top edges of the sidewall panels up towards the lashing points.

2. A liner as claimed in claim 1 and including means for temporarily attaching the roof panel of the liner to the roof of the shipping container.

3. A liner as claimed in claim 2, wherein the attaching means comprises magnets spaced apart along the roof panel.

4. A liner as claimed in claim 2, wherein the attaching means comprises hook and loop material, pieces of said material being attached to the top surface of the roof panel.

5. A liner as claimed in claim 2, 3 or 4 and including pull cords attached to the roof panel for pulling the roof panel down to release the roof panel from the roof of the shipping container.

6. A liner as claimed in any preceding claim, wherein said means for temporarily tensioning the cords comprises an element to which the end of the cord is tied, and a guideway through which a part of said cord remote from said end passes.

7. A liner as claimed in claim 6 and including hooks attached to said cords adjacent said ends for attaching the cords to fixed elements.

8. A liner as claimed in claim 6, wherein said guideway is a slot in the element which slot opens through an edge of the element.

9. A liner as claimed in claim 7, wherein said guideway is a hole in said element.

10. A liner as claimed in any preceding claim and including a flap which closes the end of the liner, there being a sliding clasp fastener for securing the edges of the flap to the remainder of the liner, the sliding clasp fastener including two sliding clasps which can be secured together to prevent opening of the container.

11. A liner as claimed in claim 10, wherein said flap is an extension of the roof panel.

12. A liner as claimed in claim 10, wherein said flap is constituted by a separate panel, one of the stringers of the sliding clasp fastener extending around the periphery of the panel.

13. A method of heat insulating a shipping container which comprises; providing a liner having a roof panel, an end wall panel and two side wall panels with cords extending from the vicinity of the end wall panel along the liner through loops provided where the roof panel joins the side wall panels;attaching the cords to sets of lashing points provided where the roof of the shipping container joins its side walls;temporarily anchoring and tensioning said cords to pull the top edges of the side wall panels up towards the lashing points;loading cargo into the liner; andslackening the cords so that the roof panel of the liner drops down into the cargo.

14. A method as claimed in claim 13, and including the step of temporarily attaching the roof panel of the liner to the roof of the container prior to loading the cargo, and releasing the temporarily attachments to permit the roof panel to drop down onto the cargo.

15. A jacket for minimising heat loss from a shipping container, the jacket comprising a roof panel, two elongate side wall panels extending downward from the roof panel, an end wall panel spanning between said side wall panels at one end thereof, and a second end wall panel configured to provide access to the inside of the shipping container, the jacket being sized so that it can fit over the shipping container with the side wall panels extending downward adjacent to the outside surfaces of the elongate side walls of the shipping container, the end wall panels extending down adjacent to the outside surfaces of end walls of the shipping container and the roof panel of the jacket extending across the roof of the container, there being means for ensuring that there is an air gap between the jacket and the container.

16. A method of unloading a flexible tank which has solidified material in it which method comprises fitting a jacket as defined in claim 15 over the shipping container which has the flexible tank in it, and heating the flexible tank to soften the material in the tank.