AU4514300A - Oxygenation system for transport of live seafood - Google Patents

Description

OXYGENATION SYSTEM FOR TRANSPORT OF LIVE SEAFOOD This invention relates to means for transporting live fish and other marine life intended for human consumption. In particular, the invention relates to an oxygenation system for transporting live seafood by airfreight.

BACKGROUND OF THE INVENTION It is generally appreciated that seafood does not keep for a particularly long time once it is dead, the shelf life of some fish and seafood being as little as a few hours from the time of death, even with adequate refrigeration. Although storage and transportation of seafood has been made possible by freezing seafood once it is killed, there are many markets around the world, particularly those in Asian countries where fresh seafood is greatly preferred over :.:•:frozen seafood. This is particularly so where the seafood is to be eaten raw, as is the case i" for example with Japanese cuisine. In order to maintain the appropriate texture of the seafood and avoid possible contamination and deterioration, it is necessary and indeed essential that the seafood be freshly killed just prior to its preparation for consumption.

15 Although it has previously been known to transport live seafood, particularly fish, in sealed plastic bags contained in polystyrene boxes, this method has not proven to be particularly economical. In this method, plastic bags are filled with clean fresh or sea water as required for the particular species, the fish are added and the bag then sealed after pumping it up with oxygen. It is reasonable to expect that fish will only survive in this environment, particularly in airfreight conditions, for upwards of four to five hours depending on the level of pollution in the water, the general stress induced by the trip and the exhaustion of the oxygen in the bag. Although fish may in fact survive for longer periods, the risk of mortality greatly increases with extended freight times. Thus there is an increased risk of mortality, particularly if fish are freighted over longer distances, or unforeseen circumstances (eg delays) occur during transport.

In addition to the major disadvantage that many of the fish do not survive such transport, it is an extremely inefficient system in so far as the yield of fish to water is concerned. Typical polystyrene boxes have dimensions of around 500 mrnm x 350 mm x 250 mm and generally contain only one or two fish weighing in total only four to five kg. The water content of the polystyrene box is generally around ten kg, the typical ratio of fish to water therefore being in the vicinity of 1:2.

Furthermore, because of potential leakage, it has been generally necessary to use two plastic bags, one inside the other, thereby adding further to the additional costs and hence poor economy.

Therefore, since many potential markets for live seafood, particularly those in South East Asia, are in excess of five hours from major fishing sites (eg in southern waters around Australia), even allowing for express airfreight, it would be extremely advantageous to 10 provide an improved means of airfreight whereby the probability of live fish surviving the trip over a longer period of time is greatly improved and the yield of fish to water is considerably higher. Although such an improved method would also yield significant advantages over shorter distances by virtue of the economies produced by the higher yields, it would be particularly advantageous if a method for transporting live seafood were o 15 available so that those markets which are relatively remote from major fishing areas and which cannot be presently served therefrom, could now be accommodated.

OBJECT OF THE INVENTION o°o The present invention has therefore been conceived out of the need to provide an improved means of transporting live seafood, especially fish, to potential markets remote from the source of capture, by providing a reusable container in co-operation with an oxygenation system capable of transporting such live seafood in an aircraft. At the very least, the invention provides an alternative to known methods of transporting live seafood.

DISCLOSURE OF THE INVENTION According to the present invention, there is provided a container suitable for being airfreighted, comprising one or more compartments for receiving water and live seafood for transport of the live seafood and an oxygenation system for feeding oxygen under pressure to the one or more compartments containing the water and live seafood during such transport, wherein the container is able to resist leakage of water therefrom under normal airfreight conditions.

Preferably, the outer shell of the container is manufactured from suitable water impermeable material, for example, suitable rigid plastics material or metal such as stainless steel and is provided with a removable outer lid, which can be secured to the container to prevent leakage of any water which has escaped from any of the one or more inner compartments.

Where more than one compartment is provided within the container for water and live seafood, such compartments are preferably formed within the container itself, that is to say, any internal walls of such compartments are either integral with or fixedly attached and sealed to the outer walls of the container. Alternatively, water and fish may be placed together in independent containers, eg drums, each locatable within the container.

-In either case, it is preferred that each of the individual compartments or inner containers resist the egress of water therefrom. The one or more compartments for receiving the live fish and water are therefore each ideally covered with one or more suitably sized lids which, at least about their periphery, are sealed thereto. For example, a suitable lip may be i provided about the perimeter of each compartment and covered with a compressible rubber or other suitable material to form a gasket against leakage when a lid is secured thereon.

Securing of the compartment lid may be achieved by any known and convenient means such as bolts and wingnuts.

It will be appreciated that the respective compartments should not in fact be totally sealed (ie made air tight), especially as it is intended that oxygen under pressure be allowed to pass into each compartment. In order that there is no undue pressure build up in each compartment, it should therefore not be totally sealed. In any event, the outer lid of the container will provide a useful secondary seal against any water that does escape from any individual inner compartment as mentioned above.

For example, in one embodiment of the invention, oxygen is provided to each compartment by means of a suitable air line or hose from a tank containing pressurised oxygen. The flow of oxygen need only be minimal to keep the fish alive and is generally restricted by means of a valve located on the oxygen tank itself With advantage, additional restriction may be provided in the air line (eg at T junctions) where a plurality of compartments are fed from a single oxygen cylinder, in order to ensure an even and equal flow into each compartment.

The free end of each air line is preferably inserted into each compartment for water and live fish though a hole in the wall or lid thereof It is generally preferred that this hole be otherwise sealed against the passing of water. The free end of the hose is attached to a so-called air stone, preferably a carbon air stone, capable of evenly dispersing the oxygen into the water in the form of tiny bubbles in order that at least some of the oxygen is thereby dissolved in the water, rather than simply escaping to the atmosphere.

10 It is generally preferred that the oxygenation system be wholly contained within the container itself. To this end, one or more suitable compartments are provided to accommodate at least one oxygen tank or cylinder, containing oxygen under pressure. For example, in one embodiment a divider suitably located across the container provides a large compartment or tank for water and fish and a smaller compartment for a pair of oxygen oo15 tanks, so that a spare tank is available should it be necessary to change from a depleted cylinder at a convenient checking point during transport, eg as the container is about to be loaded into or unloaded from an aircraft. With convenience each tank may be provided with a separate air line into the water/fish containing compartment to facilitate changeover, or simply to provide dual capacity in case one tank should be depleted or otherwise fail.

oeo 20 Alternatively, it may be useful to simply increase the total flow of oxygen by having the valves of both tanks turned on.

It will be readily appreciated that both seawater and pressurised oxygen are both potentially hazardous and dangerous to aircraft. Thus in the embodiment described above, it has been found useful to provide an exhaust air vent in the lid of each water tank to allow for the escape of excess air (ie the oxygen under pressure). This is conveniently achieved by providing a tube leading from a hole, for example, in the centre of the lid of the water tank leading back to the reservoir for the oxygen tanks. Not only does this provide a vent for excess air but also allows any small volume of water which is caused to pass therethrough to be channelled back to and be ultimately contained in the reservoir housing the oxygen tanks. It has been generally determined that the container should not leak if held at 450 to the horizontal for predetermined periods simulating the greatest expected banking of an aircraft during flight. Provided that the water level is kept sufficiently below the lid of the compartment, so that when the container is tipped through such an angle, it will not in fact pass though the air vent, leakage should not occur and any small volumes which do escape will be accommodated in the compartment for the oxygen cylinders.

The container, once it has been used in transporting its contents of live seafood, may be conveniently reused. Furthermore, a container of the type described will with advantage serve to transport other material on its return journey, once it is dried out It has been found that with a container of the type described it is possible to increase the V, 9% 10 fish to water ratio to at least 1:1.2 and to possibly 1:1.1. This represents almost a doubling of the fish to water ratio achievable with currently known methods. Furthermore, in tests ".conducted with a container according to the invention, it has been established that fish transported by this means are able to survive at least 17 hours and it is expected would be able to survive upwards of 30 hours, resulting in significantly longer journeys being 15 available, with less risk of mortality. The advantages of using a system of air freight for live o*o* seafood according to the present invention, lie not only in higher yields and longer time limits before there is a risk of mortality, but the fish arrive live and with an improved quality -primarily arising from a less stressful means of transport.

:*o4o6 0 In a second aspect of the invention, there is provided as an alternative to the foregoing, means for airfreighting live seafood in which one or more discrete containers, suitable for being airfreighted, are each able to receive water and live seafood for transport of the live seafood, each container being able to receive oxygen under pressure from a remote oxygenation source during such transport, and wherein each of the one or more discrete containers is able to resist leakage of water therefrom under normal airfreight conditions essentially as described above.

For example, in smaller aircraft (especially for shorter domestic routes) which are unable to accommodate larger containers, small barrels or drums can be employed in an analogous way to that described above for a larger single container, the main difference being that the smaller barrels are each fed pressurised oxygen from a facility that is not itself contained with such barrels in a single outer container. With convenience each barrel may be provided with a screw on lid with an opening therein through which the air line from the oxygenation tanks may be passed.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention will now be described with reference to the drawings in which: Fig. 1 is a plan view of an example of a container for transporting live seafood, especially fish, according to the present invention, 9* oooo Fig. 2 is a plan view of the lid for the water/fish compartment found in the container illustrated in Fig. 1, and Fig. 3 is a cross sectional side elevation of the embodiment illustrated in Fig. 1.

*o BEST MODE OF CARRYING OUT THE INVENTION Referring generally to Figs 1 to 3, there is illustrated a container, generally referenced 11, for airfreighting live seafood, especially fish. The outer shell of the container 12 is 15 manufactured from suitable water impermeable material, for example, suitable rigid plastics material or metal such as stainless steel. The overall dimensions of the container 11 preferably correspond with preferred sizes of transport containers already in use in airfreighting other materials.

As illustrated, one preferred shape and size of the container 11 is provided in a substantially cubic shape, the container 11 having a length and width of about 1.1 m and a height of approximately 0.9 m and therefore a total cubic capacity of approximately 1 m 3 The container 11 is provided with a removable outer lid (not illustrated), which can be secured to the shell 12 by any suitable known means to prevent leakage from the container 11 of any water escaping from compartments therein.

Across the outer shell 12 of container 11, there is located a rigid wall member 13, which is fixed to and sealed against the shell 12 along its sides and bottom to form a pair of compartments 14 and 15. The larger compartment 14 is able to receive water and live fish or other seafood for transport, whilst the smaller compartment 15 is provided with a shelf 16 having a pair of holes 17 formed therein to receive and support oxygen cylinders (not illustrated).

Compartment 14 for receiving the live fish and water is able to be covered with lid 18, which seats on lip 19 about the upper periphery of the compartment 14. The lip 19 is provided with a rubberised coating (not illustrated) which acts as a gasket against leakage when the lid 18 is clamped down thereon, for example by means of bolts (not illustrated) which pass through corresponding holes 20 in the lip 19 and edge of the lid 18. The bolts may be conveniently secured with wingnuts for easy release. The lid 18 is also provided with an airvent (not illustrated) located in approximately the middle thereof, so that even .when an aircraft transporting the container 11 banks in any direction within normal operating limits, water will not spill out, assuming of course that the compartment 14 is not overfilled, ie is not filled to the brim. Should any water spill it will still be contained within the container 11 as a whole. Leakage from such air vent will also be reduced if a hose is fitted thereto which drained directly to some convenient collection point located within the container 11.

20 Oxygen is provided to the compartment 14 by means of an air line or hose 21, which communicates at one of its ends through the wall 13 and to which is connected the outlet from one or other of the oxygen tanks which may be located in compartment 15 as described above. The other end of hose 21 is attached to a suitable air stone 22. In a container of the size described above, comprising a single compartment 14 for water and live fish, it has been found that the preferred length of air stone 22 is around 600 mm with a diameter of about 40 mm. Two such stones 22 are included, together with their corresponding air feed lines 21, to allow flexibility in having one or other or both operate as required from their respective sources of oxygen.

In order to improve the performance of the air stone 22 it has been found that both ends should be sealed with an impervious material, eg a resin which will also act as a glue to retain a spigot in one of the ends and onto which the hose 21 may be conveniently attached.

By sealing both ends of the air stone 22, the oxygen which is under pressure is forced to permeate only the cylindrical surface, thereby achieving a more even flow therethrough.

A container 11 of the type described above will have an effective capacity of around 750 litres for the stated dimensions. As mentioned before, it has been found that with a container 11 of the type described, it is possible to increase the fish to water ratio to at least 1:1.2 and to possibly 1:1.1, with a yield of up to 250 kg per container for the size of container described. This compares favourably with previous yields of as little as 115 kg for similar sized containers packed with fish in plastic bags in polystyrene boxes. Furthermore, 10 in tests conducted with a container according to the invention, it has been established that 0. 9% fish transported by this means are able to survive at least 17 hours and it is expected would •be able to survive upwards of30 hours.

•The foregoing describes only one particular embodiment of the present invention, and modifications obvious to those skilled in the art can be made thereto without departing from 15 the scope of the present invention.

o*oo

Claims (20)

1. A live seafood transport container suitable for being airfreighted, comprising one or more compartments for receiving water and live seafood and an oxygenation system for feeding oxygen under pressure to the one or more compartments containing the water and live seafood during such transport, wherein the container is able to resist leakage of water therefrom under normal airfreight conditions.

2. A live seafood transport container according to claim 1, in which the outer shell of the container is manufactured from suitable water impermeable material, for example, rigid plastics material or metal such as stainless steel.

3. A live seafood transport container according to claim 1 or claim 2, which is provided with a removable outer lid, which can be secured to the container to prevent leakage of any water which has escaped from any of the one or more inner compartments.

4. A live seafood transport container according to any one of the preceding claims, comprising more than one compartment within the container for water and live seafood, •.15 such compartments being formed within the container itself, to the extent that any internal walls of such compartments are either integral with or fixedly attached and sealed to the outer walls of the container. A live seafood transport container according to any one of claims 1 to 4, wherein water and live seafood are placed together in independent containers such as individual drums, each locatable within the container.

6. A live seafood transport container according to either claim 4 or claim 5, in which each of the individual compartments or inner containers resist the egress of water therefrom.

7. A live seafood transport container according to any one of the preceding claims, in which the one or more compartments for receiving the live seafood and water are each covered with one or more suitably sized lids which, at least about their periphery, are sealed thereto, for example, by means of a suitable lip provided about the perimeter of each such compartment, the lip being covered with a compressible rubber or other suitable material to form a gasket against leakage when a lid is secured thereon.

8. A live seafood transport container according to claim 7, in which securing of each compartment lid is achieved by any convenient means including bolts and wingnuts.

9. A live seafood transport container according to claim 8, in which each respective compartment is not totally sealed or made air tight. A live seafood transport container according to any one of the preceding claims, wherein oxygen is provided to each compartment by means of a suitable air line or hose from a tank containing pressurised oxygen, the flow of oxygen being sufficient to keep the fish alive and being generally restricted by means ofa valve located on the oxygen tank itself

11. A live seafood transport container according to claim 10, wherein additional restriction is provided in the air line or hose, for example at T junctions where a plurality of o*oo compartments are fed from a single oxygen cylinder, in order to ensure an even and equal 15 flow into each compartment. .e

12. A live seafood transport container according to either claim 10 or claim 11, in which the free end of each air line or hose, that is to say the end remote from the oxygen supply, is 9 inserted into each compartment for water and live fish though a hole in the wall or lid thereof

13. A live seafood transport container according to claim 12, in which the hole through which the air line or hose is fed, is otherwise sealed against the passing of water.

14. A live seafood transport container according to any one of claims 10 to 13, wherein the free end of the air line or hose remote from the oxygen supply is attached to a so-called air stone, preferably a carbon air stone, capable of evenly dispersing the oxygen into the water in the form of tiny bubbles in order that at least some of the oxygen is thereby dissolved in the water, rather than simply escaping to the atmosphere. 11 A live seafood transport container according to any one of the preceding claims, in which the oxygenation system is wholly contained within the container itself

16. A live seafood transport container according to claim 15, in which one or more suitable compartments are provided to accommodate at least one oxygen tank or cylinder, containing oxygen under pressure.

17. A live seafood transport container according to claim 16, wherein a divider is located across the container to provide a large compartment or tank for water and live seafood and a smaller compartment for a pair of oxygen tanks, so that a spare tank is available should it be necessary to change from a depleted cylinder at a convenient checking point during transport, for example as the container is about to be loaded into or unloaded from an aircraft.

18. A live seafood transport container according to claim 17, wherein each tank is provided with a separate air line or hose into the compartment containing the water and live seafood to facilitate changeover in case one tank should be depleted or otherwise fail, or to •15 provide dual capacity or to allow an increase in the total flow of oxygen by having the valves of both tanks turned on.

19. A live seafood transport container according to any one of claims 16 to 19, in which there is provided an exhaust air vent in the lid of each water tank to allow for the escape of excess air arising from the infeed of the oxygen under pressure.

20. A live seafood transport container according to claim 19, wherein a tube leads from a hole in the lid of the water tank and leads back to the compartment for the oxygen tanks.

21. A live seafood transport system for airfreighting live seafood in which one or more discrete containers, suitable for being airfreighted, are each able to receive water and live seafood for transport of the live seafood, each container being able to receive oxygen under pressure from a remote oxygenation source during such transport, and wherein each of the 12 one or more discrete containers is able to resist leakage of water therefrom under normal airfreight conditions.

22. A live seafood transport container according to claim 21, in which small barrels or drums are employed as the discrete containers, each barrel being provided with a screw on lid with an opening therein through which an air line or hose from the oxygenation tanks is passed.

23. A live seafood transport container or system for transporting live seafood substantially as described herein in conjunction with the accompanying Figures. o 0 S.. DATED this Seventh day of July 2000 10 JOHN EDWARD FREEDMAN Patent Attorneys for the Applicant WILSON YOUNG oo