GB2037414A

GB2037414A - Means for handling refrigerated cargo

Info

Publication number: GB2037414A
Application number: GB7941009A
Authority: GB
Original assignee: MARI TERM AB
Current assignee: MARI TERM AB
Priority date: 1978-12-11
Filing date: 1979-11-28
Publication date: 1980-07-09
Also published as: JPS5582273A; FR2443968A1; DE2946301A1; SE7810282L; NL7908467A

Abstract

When transporting refrigerated cargo in conventional cargo ships, stackable container flats (15) having perforated floors (16) are used. The flats are arranged in side by side relationship within the cargo hold adjacent to a mobile cooling unit (22). This includes an air cooling plant (24, 25) and a hopper (26) for a heat insulating cover tarpaulin (27). The latter is, in use, arranged in such a manner, that it will extend over at least the top parts of the flats associated with the cooling unit, and is shaped so as to facilitate an even distribution of the air. The flats may be provided with heat insulated end walls (17) but it is also possible to form the tarpaulin as a hood (41) enclosing a group of flats. An insulated tarpaulin may also be extended below the flats. <IMAGE>

Description

SPECIFICATION Means for handling refrigerated cargo Refrigerated cargo, mainly fruit, is usually transported in specially equipped ships, or in general cargo ships having refrigerated holds. The insulation and the refrigerating machinery means a heavy investment, and it is, on most occasions, difficult to take other types of goods in the refrigerated holds on a return journey.

When there is a shortage of reefer ships or in order to take care of seasonal peaks, it may occasionally be desirable to use other ships than the specially equipped ones. In the first instance cargo requiring a moderate degree of cooling is considered, but on occasions frozen goods may be taken, the requirement being to maintain a constant temperature and to ensure a satisfactory exchange of air.

It will be very expensive to insulate ordinary cargo holds for an occasional refrigerated cargo.

but there are many ships, especially of the Ro-Rotype, which, by the input of moderate costs could be made suitable for the transportation of refrigerated cargo. Instead of insulating the ship, it is possible to insulate the transporting units containing the refrigerated cargo, at least one mobile cooling unit being provided in the ship, which on the one hand ensures the necessary cooling air exchange, but the other hand also provides means for protecting the non-insulated sides of the transport units.

A means for handling refrigerated cargo in a conventional cargo ship according to the invention comprises a number of stackable container flats adapted to receive refrigerated cargo and have a perforated floor permitting the passage air, and a mobile unit comprising an air cooling plant and a hopper for storing a cover tarpaulin of sufficient size to extend over a number of flats arranged side by side at the cooling plant.

The cover tarpaulin may be rolled within the hopper and extend over a number of flats arranged side by side, the end walls and preferably also the floors of the individual flats being heat insulated. The downwardly turned face of the cover tarpaulin may be provided with longitudinally running ledges adapted to hold the tarpaulin spaced from the top layer of the cargo.

The ledges are preferably formed as inflatable tubes having closed ends.

The cover tarpaulin may include a sheet of perforated fabric having such an extension,that it will define at least one passage communicating with the air cooling plant for distribution of air over the cargo. The perforated sheet may be connected to the superimposed layer by means of seams running in the longitudinal direction so as to form parallel air distribution passages within the tarpaulin cover.

The perforated sheet and the superimposed layer are preferably formed so that, with respect to the air pressure available, theat the tpp face of the cover tarpaulin will take up an upwardly vaulted shape.

The mobile unit is preferably provided with hoppers for two tarpaulins extendible in opposite directions, as well as a cooling plant having air outlet conduits, like-wise oppositely directed.

A number of flats may be mounted upon a handling frame member to a common transport unit, the cover tarpaulin being formed like a hood, partly enclosing the transport unit, said hood having at least one air inlet opening in its top part, the mobile unit being mounted in a box structure fitted upon a similar handling frame member, and having upwardly directed air conduits forming parts of side walls in the cover tarpaulin hopper.

The tarpaulin hood is preferably, along its top part, provided with at least one air transfer conduil portion extending across the top part, communicating with the air inlet opening or openings, and at its ends having means for connection to adjacent conduit portions.

It may be advantageous to cover also the surface below the flats with an insulating tarpaulin, and to that end a hopper for an extendible tarpaulin may be fitted below the cooling plant.

The frame members carrying a mobile unit as well as container flats brought together to transport units, are preferably formed so as to guide the return flow of air from the cargo back to the refrigerating plant. The frame shaped member and the container flats with their insulated ends walls are preferably provided with flexible packings, when the big transport units are arranged in rows side by side.

Some embodiments of the invention will be described below, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows schematically a portion of the cargo hold in a Ro-Ro-ship augmented with means constructed in accordance with the invention, Figure 2 shows a cross-section through a cargo unit including two superimposed, loaded conatiner flats, Figure 3 shows a modified embodiment of the cover tarpaulin, Figure 4 shows a transport unit having a hoodlike tarpaulin cover, and Figure 5 shows an arrangement of transport units according to Figure 4, arranged in conjunction with a cooling unit.

In Figure 1 reference 10 denotes the cargo hold of a Ro-Ro-ship. The hold is defined by a double bottom 11, a transverse bulkhead 12 and a deck 13, and is accessible in the longitudinal direction of the ship for trucks and similar vehicles.

The refrigerated cargo is supposed to include fruit packed in boxes or cases 14 of conventional size, making them suitable for manual handling, one by one. These boxes, or cases, are usually dimensioned in such a manner that transport aids, such as standardized containers or container flats, may be used in a rational manner. The boxes and cases are furthermore always designed so as to make possible an air exchange around the fruit.

On the present occasion container flats 15 are used for handling the cargo. A container flat includes a floor 1 6 and two end walls 1 7. The latter may be permanently attached to the floor, or may be designed to be folded down upon the floor during a return journey. In use the end walls are stayed by means of brackets 1 8 or other fittings The construction is sufficiently rigid to permit the stacking of loaded flats on top of each other.

The end walls are heat insulated, and the floor is perforated to permit the passage of cooling air.

The insuiation of the end walls may be fitted permanently, but it is possible occasionally to provide insulating slabs at the end walls of standard flats. The floor may also be heat insulated.

In the embodiment shown, four flats 1 5 are mounted upon a handling frame member 1 9 to form a transport unit. Such a unit may be handled by means of a low trolley, which is slid into the frame, and will lift the same together with the cargo resting thereon. The frame is laterally - as shown in Figure 2-defined by I-beams 20, into the inward channels of which the trolly engages during lifting and transportation. The beams are usually provided with cross stays forming support for the floors 16 of the flats. If there is a cross beam level with the side beams, this cross beam will be provided with air passages. The floors 1 6 of the flats are provided with suitably distributed air passages 21.

A number of such loaded frames 1 9 are located side by side in the hold of the ship, and then a mobile cooling unit 22, likewise mounted upon a handling frame member 23, is introduced by means of a low trolley of the same type as is used for handling the goods.

This cooling unit includes fans 24 and cooling batteries 25 having sufficient capacity to maintain a desired temperature at a predetermined number of transport frames. The cooling unit further includes a hopper 26 for a rolled tarpaulin cover 27, which has sufficient length to extend over the adjacent cargo units, and preferably also over the outward face of the unit remotely located with respect to the cooling unit.

The cover tarpaulin 27 is sufficiently broad to be folded down over the upper longitudinal edges of the end walls, and is provided with means for securement against the latter.

On the present occasion, the intention is to locate further loaded frames at the opposite side of the cooling unit, and the latter is therefore provided with two tarpaulin hoppers 26, as well as two fans and two cooing batteries. The rnoile cooling unit may be connected to the electrical current mains of the ship by means of a temporary cable (not shown).

Air distributing conduits 28 extend upwards from the cooling batteries to the upper level of the mobile unit, and terminate in mouthpieces located below the tarpaulin. This is, at its downward face, provided with longitudinally running ledges 29, which, in use, will hold the tarpaulin in spaced relationship with respect to the cargo. The ledges are preferably formed as tubes, being closed at their ends remote from the cooling unit. The tubes may be inflated by means of air from fans 24, or from special compressors (not shown), which supply air at a higher pressure than fans 24.

In such a manner air distribution passages 30 are formed between the cover tarpaulin 27 and the top layer of boxes in the cargo units, and as each individual box will permit a passage of air, and as there are always small clearances between the boxes, the air introduced will be forced downwards, and end walls 17 being impermeable and the cover 27 extending downwards along the outward face of the outermost cargo unit.

Figure 3 shows a loaded flat having a cover tarpaulin 27a of a somewhat modified design. The tarpaulin includes an outer permeable sheet 31, an insulating layer 32 and an inner sheet 33 of perforated fabric. The latter is, basically, broader than the outer sheet and is sewn, or welded to the insulating layer by longitudinally extending seams 34, in such a manner that pockets for air passages 35 will be formed.

The floors 1 6a of the flats are, as mentioned above, perforated so air can pass downwardly from an upper flat to a lower flat through openings 21, and from a lower flat down into the longitudinally running passage, which is formed by the cargo carrying frames 19, which communicate with each other. The returning air will pass into frame 23 carrying the cooling unit 22 and is drawn in by fans 24. Possible low temperature in the air may in this manner be saved.

As the end walls 1 7 are insulated, a spreading of the tarpaulin cover will result in a satisfactory encapsulation of the cargo. The floors 1 6 of the flats may be insulated, but, as half the number of flats will be superimposed upon other flats, and the floors of the lower flats are passed over by the return flowing air, insulation is not as important at the floors as at the end walls.

Figure 4 shows a cargo unit comprising superimposed flats 1 5 mounted upon a frame transport member 1 6. Each flat is, as in the previous embodiment, provided with a perforated floor. The cargo consists here of boxes 40 stacked upon load pallets. It is presupposed that each cargo unit shall comprise four flats and it is here covered by a tarpaulin 41, formed as a hood to enclose the four sides of the cargo unit as well as its top. The top portion 42 of the hood is provided with two longitudinally extending air conduit members 43, which communicate with the space below the tarpaulin 41 by way of openings 44.

Figure 5 shows a portion of a cargo hold in a ship, where a number of cargo units according to Figure 4 are located adjacent to a cooling unit 45.

This is, as in the previous embodiment, located upon a handling frame 46. On this occasion the cooling plant will not require more space than that occupied by a loaded flat. On top of the cooling plant there is a space 48 serving as storage hopper for the tarpaulin hoods, when not in use.

This hopper is defined by two parallel side walls 49 and preferably at least one end wall 50. Two air conduit members 51 are provided at each side wall 49, being connected to the cooling plant and extending to the upper level of hopper 48. The conduit members 43 at the adjcent tarpaulin hood are connectible to conduit members 51 by sleeves 53, and similar sleeves 54 are provided to interconnect conduit members 43 at abutting hoods.

The end of the conduit member furthermost away from the cooling plant is closed by a plug 55.

In order to facilitate the handling, frame 46 has the same dimensions as the cargo frames 20, which means that there will be a space for mounting two flats to one side of the cooling plant and the hopper. Those two flats will have to be covered by a hood of suitable size. The cooling plant 45 and hopper 48 may be formed as separate units. On such occasion air conduit members 51 at the hopper walls will be provided with means for attachment to the conduitsyvithin the cooling plant.

With handling frames 20 containing side beams interconnected by raised cross beams, and where thus the transverse ends of the beams are open, it will be necessary, temporarily to close the end of the outermost frame by means of members 56, so a collecting and return flow passage is obtained below the flats, for the air having passed through the cargo.

To facilitate accessibility within the hold it may be advantageous to dimension air conduit members 51, 43 in such a manner that one conduit will have sufficient capacity to serve all connected cargo units. Either of the conduits may then be plugged.

Also in this embodiment a perforated sheet 60 is provided beneath the tarpaulin proper. This sheet is attached along its perimeter 61.

Independently of which of the two supply conduits 43 is temproarily in use, an even distribution of the air in the space 62 below the tarpaulin proper is obtained.

The perforations in the sheet will be selected in relation to the air pressure available so the outward layer of the tarpaulin obtains an outwardly vaulted shape, which facilitates the flow of moisture, and of rain, during an occasional erection on a quay awaiting loading. This will of course also apply to the embodiment according to Figures 1-3.

When the invention is used in ships having a non-insulated deck in the hold it may be profitable to protect the area below the flats, in the first hand in order to reduce heat losses, but also to prevent possible condensate moisture to run over the deck.

Especially on occasions when the upper cover tarpaulin is formed as hoods according to Figures 4 and 5, the cooling plant 52 may be arranged in an upper space, so a hopper for a rolled tarpaulin may be arranged below said space, whereby a heat insulation may be provided also below the flats. When the handling frames 20 are open at both ends it is possible to pull the tarpaulin down to the close at least a substantial part of the gap between the beam ends.

In an export port lacking cold storages it is possible to prepare a ship's load upon the quay by arranging loaded frames and cooling units in the manner indicated in Figures 1 and 5. When the ship arrives the cargo units and the cooling units are transferred to the ship, step by step.

The reverse procedure will of course be applicable when unloading a ship in a port, lacking cold storages, or when the latter are already filled up.

Many ships are so broad that it is possible to arrange a number of rows of flats side by side. The number of cargo units, which can be connected to a cooling unit, is a question of design, and the number of cooling units with a given capacity will be determined by the size of the ship, but also in view of possible need to differentiate the cargo with respect to content and port ofunloading.

The components may be modified. On certain occasions it may be preferable to design the cooling unit in such a manner that cargo units can be connected to one side thereof only, and instead of rolling the tarpaulin it will be possible to fold the tarpaulin into hopper 26, the breadth of which preferably is selected so the width of a fold will be a function of the breadth of the flat.

So called Ro-Ro-ships are now used in many shipping trades and the arrangement makes it possible to provide cooling plants to be used during the season when it is required to handle refrigerated goods.

An integration with land based transport facilities is a simple matter if the individual container flat units are provided with insulated covers extending over the top and longitudinal sides of the unit. Most trucks and open railway cars will receive a unit in size corresponding to a 'standard ISO-unit.

Claims

1. Means for handling refrigerated cargo in a conventional cargo ship wherein there are provided a number of stackable container flats adapted to receive refrigerated cargo and have a perforated floor permitting the passage of air, and a mobile unit comprising an air cooling plant and a hopper for storing a cover tarpaulin of sufficient size to extend over a number of flats arranged side by side at the cooling plant.

2. A means according to claim 1, wherein the cover tarpaulin is heat insulated.

3. A means according to either of claims 1 or 2, wherein the cover tarpaulin is adapted to be rolled within the hopper, and to extend over a number of flats arranged side by side, the end walls of the individual flats being heat insulated.

4. A means according to claim 3 wherein the floors of the flats are also heat insulated.

5. A means according to claim 3, wherein the downwardly turned face of the cover tarpaulin is provided with longitudinally running ledges adapted to hold the tarpaulin spaced from the top layer of the cargo.

6. A means according to claim 5, wherein the ledges are formed as infiatible tubes having closed ends.

7. A means according to claim 5, wherein the mobile unit is provided with hoppers for two tarpaulins extentible in opposite directions, as well as a cooling plant having air outlet conduits, likewise oppositely directed.

8. A means according to either of claims 1 or 2, where a number of flats are mounted upon a handling frame member to a common transport unit, the cover tarpaulin being formed like a hood, partly enclosing the transport unit, said hood having at least one air inlet opening in its top part, the mobile unit being mounted in a box structure fitted upon a similar handling frame member, and having upwardly directed air conduits forming parts of side walls in the cover tarpaulin hopper.

9. A means according to claim 8, wherein the tarpaulin hood, along its top part is provided with at least one air transfer conduit portion extending across the top part, communicating with the at least one air inlet opening, and at its ends having means for connection to adjacent conduit portions.

10. A means according to any one of the preceding claims, wherein the cover tarpaulin includes a heat insulating layer and below that a sheet of perforated fabric having such an extension, that it will define at least one passage communicating with the air cooling plant for distributibn of air over the cargo.

11. A means according to claim 10, as adapted for an arrangement according to claim 3, wherein the perforated sheet is connected to the superimposed layer by means of seams running in the longitudinal direction so as to form parallel air distribution passages within the tarpaulin cover.

12. A means according to either of claims 10 or 11, wherein spaces between the perforated sheet and the superimposed layer are formed so that, with respect to the air pressure available, the top face of the cover tarpaulin will take up an upwardly vaulted shape.

13. A means according to any one of the preceding claims, wherein the cover tarpaulin is mounted in a hopper below the cooling plant so as to permit extension to cover the deck below the container flats.

14. A means according to any qne of the preceding claims, in which a number of flats are mounted upon handling frame members to form transport units, the frame members being formed to guide the return flow of air from the flats back to the unit, the frame members at their corners being provided with packing members to reduce air leakage.

1 5. Means for handling refrigerated cargo in a conventional cargo ship substantially as hereinbefore described with reference to and as shown in the accompanying drawings.