WO1996012645A1

WO1996012645A1 - System for handling of fresh fish by transport and/or storage

Info

Publication number: WO1996012645A1
Application number: PCT/NO1995/000192
Authority: WO
Inventors: Christian Corneliussen
Original assignee: Christian Corneliussen
Priority date: 1994-10-19
Filing date: 1995-10-18
Publication date: 1996-05-02
Also published as: NO943964D0; AU3817895A

Abstract

A method and system for handling fresh fish during shipment and storage, wherein the fish are packed in cases and stacked on a pallet (3), and where the cases (1) preferably have gas vents for the supply of carbon dioxide gas or carbon dioxide containing gas (19; 24; 25), and wherein the cases in each stack optionally are defined on two sides by gas channelling elements (4), and wherein said stack of cases with optional gas channelling elements is enveloped by a gas bag (14) which is open at the bottom and at the top has a gas vent (15).

Description

_System for handling of fresh fish by transport and/or storage

The present invention relates to a method of handling fresh fish during shipment and/or storage, wherein the fish are packed in cases and stacked on a pallet, and wherein the cases optionally have gas vents. The invention also relates to a gas channelling element for conducting gas into the respective layers in a stack of foodstuff cases, where the cases have gas vents, where against at least two sides of the stacks of cases there is placed such an element, and where the stack of cases and elements are enveloped by a gas bag. Furthermore, the invention relates to a stackable case for refrigerated, fresh fish, where the case has a storage space wherein in each end wall there are gas vents, so that carbon dioxide gas or carbon dioxide containing gas can pass through the storage volume of the case, and where the bottom of the case preferably is liquid-tight.

Lastly, the invention also relates to a means for the emission of carbon dioxide containing gas into a cold-storage chamber where fresh fish is stored.

The present invention relates to a further development of the invention which is disclosed in Norwegian Patent Application No. 932832.

When packing fresh fish in a conventional manner, especially for export, the fish are normally slaughtered and packed on the same day as the transportation leaves the slaughterhouse. This means that the production or slaughter can be irregular, often with several shifts on some weekdays, whilst on other days, e.g., Fridays, there is no slaughter at all. This method is due to the short "life time" of fish in a fresh condition (6-8 days from slaughter). The duration of transportation is estimated to be 2 to 4 days when hauling to countries abroad. The fish is normally transported in a refrigerated truck where the cold-storage chamber is supplied with cooled air.

In this known method, fresh fish is packed in monoplast or corrugated cardboard cases having a maximum weight of about 30 kg. Of this, the weight of the fish accounts for about 22 kg, and the weight of flake 7 to 8 kg. Some 18 to 26 cases are packed per pallet and everything is palletised.

A major disadvantage of this known method is that to complete the same load the transport truck often loads up at several production plants, thereby creating conditions for possible transfer of infection from one plant to another. This is a major veterinary- medical problem.

German authorities are planning to introduce requirements for the transportation of fresh fish which call for the means of transport to be equipped so that they collect the melt water from the flake ice (about 7 to 8 tonnes per vehicle). With today's technique, this melt water runs out of the vehicle during transportation, thus representing substantial pollution of the environment and a potential source of infection.

If regulations as suggested are put into effect, this will entail considerable investments per truck, which in turn will mean additional costs for the consumers. Thus, one of the objects of the present invention is to increase the storage life of fresh fish substantially, preferably to more than twice today^'s normal storage life. A further object of the invention is to avoid spillage of waste water from haulage trucks, thereby also avoiding the possible transportation of infection from one fish farm to another via such vehicles. It is also an object to achieve cost-related improvements. Additional objects of the invention are to increase the net weight of fish by as much as 20% per case, reduce transportation costs of fresh fish by as much as 20%, and spread the fish slaughtering process evenly throughout the entire working week.

According to the invention, the method mentioned by way of introduction is characterised by the following steps:

that a downwardly open gas bag is drawn down over the stack of cases, optionally prior to the positioning of the bag a gas channelling element being placed on at least two sides of the stack of cases, thereby defining the stack of cases over which the bag is drawn, so that the bag opening is roughly level with the top surface of the pallet; that carbon dioxide gas or carbon dioxide containing gas is supplied to the inside of the gas bag either via a gas supply hose connected to a connection piece in the top of the gas bag and caused to flow down and out via the open bottom of the gas bag, or_. via the open bottom of the gas bag and caused to flow upward and out via a vent, e.g., a connection piece in the top of the gas bag; that the gas is caused to flow into each layer of the stack of cases and out therefrom, possibly via said optionally provided gas channelling elements; that at least one of the following parameters of the gas is measured and regulated: temperature, flow rate, moisture content, carbon dioxide content; and that the stack of cases, optionally equipped in addition with said gas channelling elements, enveloped by the gas bag, is subjected to a pressure difference between the upper side and the underside of the gas bag in order to cause forced, regulated gas flow through the bag and layers of the stack.

According to additional features of the method, the stack of cases, optionally with the addition of the gas channelling elements, and the enveloping gas bag are bound with straps, tape, cling film, shrink film, or similar. Prior to the cases being stacked, a small amount of crushed ice or flake ice, e.g.. 1 to 2 kg, can, in a known way per se, be placed in each case.

According to yet another embodiment of the method, the stack of cases, optionally equipped in addition with gas channelling elements, enveloped by the gas bag. may be subjected to a pressure difference between the upper side and the underside of the gas bag in order to cause a forced, regulated gas stream to flow through the bag and the layers of the stack.

In order to cause the fresh fish to retain a certain degree of moisture, it is preferable that the gas is moistened by means of the ice in the cases, or with externally supplied water.

According to yet another embodiment of the method, at least two adjacent rows of gas bag furnished stacks of cases, optionally equipped with gas channelling elements, are placed in a cold storage chamber, there being placed in connection with the adjacent rows at least one horizontal gas supply hose having laterally directed gas outlet nozzles or orifices, the hose being placed so that it extends some distance up the gas bag over the top of the pallet and some distance below the top of the pallet, optionally right down to the bottom of the pallet.

The gas may, e.g., be supplied in that air, optionally is a cooled state, is caused to flow over a supply of dry ice placed in the cold storage chamber.

The method makes it possible for one or more of said stacks of cases, optionally with accompanying gas channelling elements, and gas bag to be placed in a cold storage chamber where the gas is caused to circulate by means of refrigerating and/or circulation equipment provided in connection with the cold storage chamber. Gas supply pipes may be connected to said refrigerating/circulation equipment and detachably mounted in the ceiling of the cold storage chamber, said gas supply pipes being designed for connection to said gas supply hoses.

The gas channelling element mentioned above is characterised, according to the invention, in that the element consists of double-layered corrugated cardboard having a first airtight cardboard sheet, a second perforated cardboard sheet and a third perforated cardboard sheet, and in that between said first and second sheet and between said second and third sheet, respectively, there is located a perforated, corrugated spacer of cardboard or kraft paper, and in that said double-layered corrugated cardboard is airtight along two side edges and one end edge thereof.

The stackable case mentioned above is characterised according to the invention in that the gas vents are elongate, preferably rectangular. It is of advantage if the case, internally and externally, is octagonal. Two separate, liquid-collecting wells may be provided at the respective ends of the case and each extends substantially in an arch between the longitudinal sides of the case, and upwardly open drainage channels in the bottom of the case opening into said wells.

The case may optionally be made of solid cardboard, the lid of the case being designed in the same way as the case, i.e., as an inverted case, the vertical parts of the lid being intended to rest against the outside of the case, and being equipped with corresponding adjacent gas vents.

The aforementioned means for the emission of carbon dioxide containing gas into the cold storage chamber where the fresh fish is stored, is characterised according to the invention by a tank containing dry ice, where air under pressure is conducted into the tank via a valve, and where the tank has an outlet which is connected to downwardly open gas bags in which stacks of cases containing fresh fish are stored.

The invention will now be described in more detail with reference to the accompanying drawings, which illustrate preferred embodiments of the invention but which are not intended to be a definition of the limits of the invention.

Figure 1 shows a stack of cases on a pallet, and also gas channelling elements. Figure la shows a section of a gas channelling element.

Figure 2 illustrates a first practical embodiment of the method, according to the invention. Figure 3 shows a variant of the embodiment in Fig. 2.

Figure 4 shows a detail of the embodiments in Figs. 2 and 3.

Figure 4a shows a section of Fig. 4.

Figure 5 shows the flow of gas through the stack of cases where this is provided with gas channelling elements and a gas bag drawn thereover.

Figures 5a and 5b show a section of Fig. 5.

Figure 6 is an schematic illustration of the section VI-VI in Fig. 5.

Figure 7 shows an alternative embodiment of what is illustrated in Fig. 2

Figure 8 illustrates a modification of the embodiment in Fig. 3 and also a modification of the solution in Fig. 7.

Figure 9 is an end view of the embodiments in Figs. 7 and 8.

Figure 10 illustrates a practical arrangement of the methodics illustrated in Figs. 7 to 9.

Figure 1 1 shows the gas flow route through a stack of cases with gas channelling panels and gas bag according to the embodiment in Figs. 7-10.

Figures 1 1 a and 1 1 b show a section of Fig. 1 1.

Figure 12 shows the section XII-XII in Fig. 11.

Figure 13 shows a stackable case with lid. according to the invention.

Figure 14 is a top plan view of a case without a lid,. Figure 15 shows the section XV-XV in Fig. 14.

Figure 16 shows the case in Fig. 13 from below.

Figure 17 shows a modification of the embodiment in Figs. 7 and 8

Figure 18 is an end view of the embodiment in Fig. 17.

Figure 1 illustrates a stack of cases 1 where the cases are provided with gas vents 2 in the corners or end walls of each case. The stack of cases 1 is placed on a pallet 3, e.g.. a Europallet. Gas channelling elements 4 are provided on two sides of the stack of cases. Although the embodiment illustrated and described in Figs. 1 - 12 makes use of gas channelling elements, it is also conceivable, especially in the instances when gas is supplied via the top of the gas bag, to forgo the use of gas channelling elements. This is shown and explained in detail in connection with Figs. 17 and 18. The use of case embodiments other than those shown and described is also conceivable, e.g.. cases that do not have a liquid-tight bottom, which perhaps do not have wells/channels, or which do not have gas vents.

The gas channelling element 4 shall ensure that gas is conducted into the storage chambers in the cases 1 in each layer of cases in the stack. For this purpose, the gas channelling element consists of a double-layered corrugated cardboard having a first airtight cardboard sheet 5, a second cardboard sheet 6 having perforations 7, and also a third cardboard sheet 8 having perforations 9. Between the first sheet 6 and the second sheet 5 there is located a corrugated cardboard or kraft paper spacer 10, provided with perforations 1 1. The spacer 10 is preferably glued to said sheets 5 and 6. In a similar manner, a second corrugated cardboard or kraft paper spacer 12, provided with perforations 13, is located between the sheets 6 and 8. As can be seen more clearly from the illustration in Fig. 5, the double-layered corrugated cardboard is airtight along two side edges and one end edge thereof, so that gas can only flow through the one open end edge and through the perforations in the corrugated cardboard. This is illustrated in more detail in Fig. 5 where a downwardly open gas bag 14 is drawn down over the outside of the stack of cases and the said gas channelling elements. As can be seen from Fig. 5, and the enlarged sections in Figs. 5a and 5b, in the illustrated embodiment, gas will be transported from the underside of the stack of cases, up through openings in the pallet 3, so that gas will flow up through the channelling element 4', through the gas vents 2 in the cases 1 , through the storage chambers in the cases, and out through the gas vents at the opposite end of each case. The transfer of gas will also take place between adjacent gas vents, as can be seen in more detail in Fig. 6. Gas will thus flow up via the downwardly open edge of the gas channelling element 4', and will pass out via the gas channelling element 4" which is closed at the bottom but open at the top. The gas bag 14 is provided at the top with a gas emission vent or connection piece 15. The present solution allows gas to flow in a controlled, forced manner through the contents of the stack of cases, in that a pressure difference is created between the underside of the stack and the upper side thereof.

In Fig. 2, the solution according to Figs 1, la and Figs 5, 5a, 5b and Fig. 6 is shown in connection with a truck equipped with a cold storage chamber.

Fig. 2 shows how the method according to the invention can be used in connection with a truck 16. The truck is equipped with a cold storage chamber 17 and has refrigerating equipment 18 located on the outside of the cold storage chamber for circulating and cooling the atmosphere inside the cold storage chamber 17. A tank 19 containing liquid carbon dioxide is also connected to the circulation and refrigerating system 18. Carbon dioxide is conducted according to need from the tank 19 to the cold storage chamber 17 via a supply pipe 20. The supply from the tank 19 can be shut off by means of a controlled valve 21. In the illustrated embodiment the cooled, carbon dioxide containing air or gas for the cold storage chamber is passed out through an outlet 22 down by the floor of the cold storage chamber 17, whence it is passed along the floor of the cold storage chamber in order to be able to penetrate up into the stack of cases from the underside thereof via the free space in the pallet 3 and the openings in the surface of the pallet, the gas rising along one of the gas channelling elements, passing through each layer of cases and out of the gas bag through a vent 15 uppermost therein, via the gas channelling element which is at the opposite side of the stack of cases, as is explained and shown in connection with Figs. 1, la, 5, 5a. 5b and 6 above.

In certain instances, it may be desirable to forgo the mounting of carbon dioxide tanks on the outside of the cold storage chamber 17. In instances such as, for example, when the truck 16 is only occasionally used for the transport of fresh fish, the installation of a carbon dioxide generator may be perceived as unnecessary or unnecessarily expensive. In such instances, a tank 23 containing a body 24 of dry ice may be placed inside the cold storage chamber 17. As described in the case of the embodiment in Fig. 2, the cooling air is conducted to the stacks of cases from the underside thereof, as is shown and described in connection with Figs. 5 - 6, and also in connection with Fig. 2. The air exiting the gas bags is, with the aid of the circulation equipment of the refrigerating equipment 18, conducted back in a cooled state via an outlet pipe 25 and via a valve 26 either to the dry ice tank or directly out via a channel 27 to the underside of the stacks of cases. The position of the valve 26 is dependent upon the carbon dioxide content of the cold storage chamber 17 and the fall of temperature caused by the carbon dioxide from the dry ice 24.

It will thus be understood that in connection with the refrigerating and circulation equipment 18 it will be expedient to measure at least one of the parameters of the cold storage chamber gas, e.g., its temperature, flow rate, moisture content and/or carbon dioxide content. The equipment 18 will be capable of regulating these parameters in relation to pre-set values, optionally with the aid of valve 21 and valve 26, respectively.

In order to ensure that the gas which circulates back to the cold storage chamber 17 reaches all the stacks of cases in the cold storage chamber, according to the invention it will be expedient to provide in the cold storage chamber 17 at least two adjacent rows of gas bag furnished stacks of cases which have the previously mentioned gas channelling elements 4. Between the adjacent rows, for example, rows 28 and 29 as shown in Fig. 4, there is placed, according to a preferred embodiment of the invention, a horizontal gas supply hose 30 which along the length thereof is provided on both sides with laterally directed gas outlet nozzles 31 or orifices. The hose in its non-inflated form will have a cross-sectional dimension that is smaller than the space between the adjacent rows 28 and 29 of stacks of cases. When the hose 30 is supplied with gas pressure caused by the circulation part (fans) of the equipment 18, the hose will expand especially in the transverse direction and lie in contact with the outside of the bags 14 which envelop the stacks of cases in the rows 28 and 29. The hose 30 will preferably extend right down to the floor of the cold storage chamber, so that the orifices 31 open approximately midway between the underside and the upper side of the pallet 3. In this way, an efficient supply of gas to the underside of the stacks of cases and directly into the gas channelling element 4' which is open toward the underside is secured.

Fig. 7 shows a truck 16 provided with a cold storage chamber 17 and refrigerating and circulation equipment 18, as has been described in connection with the embodiment in Figs. 2 and 3. Similarly, the equipment 18 is capable of being connected to a liquid carbon dioxide tank 19. In the embodiment which can be seen in Fig. 7 and which will be better understood with reference to Figs. 11 - 12, the gas coolant circulates in the opposite way, i.e., from the top of the gas bag towards the bottom thereof via said gas channelling elements. The cooling air from the equipment 18 is conducted to the inside of the gas bag via a gas supply pipe 32 which has a number of connection pieces 33 along the length thereof and where these connection pieces 33 by means of a connector 34 and gas supply hose 35 and a connector 36 can be connected to a connection piece 15 which is located uppermost on the gas bag 14, as has been explained in connection with Fig. 5. The connection pieces 15 and 33. and also the connectors 34 and 36. may be of the rapid coupling type, such as are known from, e.g., garden watering equipment. The gas supply pipe 32 may to advantage be suspended from the ceiling 1 T of the cold storage chamber 17, by means of any appropriate suspension means 32', e.g., chains, rubber straps or similar. As will be seen, the gas which has flowed out through the gas bag and the various layers in the stack of cases will exit at the bottom of the stack, pass out via open spaces in the upper part of the pallet 3, and out via the space between the upper side and underside of the pallet and because of negative pressure be drawn out to the equipment 18 via the duct 22. The valve 21 in connection to the carbon dioxide tank 19 can be regulated depending on the desired carbon dioxide content in the gas which flows through the cold storage chamber 17.

The mode of operation of the solution shown in Fig. 8 shall only be explained in respect of the differences that are present in relation to the embodiment in Fig. 7. As will be seen on a comparison with the embodiment in Fig. 3, there is also in this instance a dry ice tank, here indicated by means of the reference numeral 46. The dry ice tank 46 PCI7NO95/00192 2645

contains a body of dry ice 47 and gas is supplied thereto via gas pipe 48. A valve or a damper 37 regulates how much of this gas circulating through the system shall also pass through the dry ice tank 46 in order to be supplied with carbon dioxide from the dry ice 47. Carbon dioxide from the dry ice 47 is conducted out of the tank 46 via an outlet pipe 38 which forms a connection to the supply pipe 32.

As explained in connection with Figs. 2 and 3. the equipment 18 may contain means for measuring at least one of the parameters of the gas, e.g., temperature, flow rate, moisture content and carbon dioxide content, these parameters being regulated in relation to pre-set or desired values. The gas exiting the bottom of the stacks of cases is conducted via the channel 22 to the circulation and/or refrigerating equipment 18. If, for example, it is found that the gas circulating through the system has sufficient carbon dioxide content, the valve 37 will be adjusted so that no gas passes through the dry ice tank 46.

If it is desirable to add moisture to the gas circulating through the system, the use of condensation water from the optional heat exchanger which is in the equipment may be considered. Moreover, it will always be a matter of course to put a small amount of crushed ice or flake ice in each case where fish is stored to ensure the most even refrigeration possible and a certain maintenance of moisture in each case. The amount of water which thus at all times will be in each case will also help to moisten the gas which passes through the layers of the stack of cases.

As is shown in Fig. 9, there is no need for the said supply hose 30 which is shown and described in connection with Figs. 4 and 4a, as the gas exiting on the underside of the stacks of cases is on the negative pressure side of the bag. The circulation equipment in the unit 18 will consequently only have one task, that it to draw in gas via the duct 22. The problem complex is thus rather different than that shown and described in connection with Figs. 2 - 4a.

Fig. 10 shows how a person 39 will easily be able connect the gas supply pipe 32 to each individual gas bag 14 as the cold storage chamber is filled up. In order to ensure that the gas bag does not slide off the stack of cases it will expedient to bind the gas bag with straps, tape or, for example, cling film 40, optionally shrink film or similar.

In Figs 1 1, 1 1a and 1 lb it is shown how the gas flows through the layers of the stack of cases via the supply hose 35, connection 15, 36 and into the gas bag 14. As the gas channelling elements 4' and 4" are positioned in the same way as shown and explained in connection with Fig. 5, the gas flowing via the hose 35 will first pass along the element 4" and exit at different levels in the height of the stack of cases, and thence pass via the various layers of the stack of cases, as outlined in FigJ2, in order subsequently to pass out via the gas channelling element 4' and to the underside of the stack of cases, as can be seen in Fig. 1 la.

In Fig. 13, a case is illustrated which is deemed to be particularly suitable for use in connection with the present invention as described in connection with Figs 1 - 12.

In the illustrated embodiment, the case 1 is provided with a lid 1 ', and the lid 1 ' engages with stabilising ribs 1 " along the top edge of the case 1. In the corners or end wall portion, the case is provided with gas vents 2. The bottom of the case is liquid-tight and is provided with upwardly open drainage channels 41 which end in a liquid collecting well 42. As can better be seen from Fig. 14, there are two separate wells 42' and 42" with associated drainage channels 41 ' and 41 ". As is evident from the cross-section XV-XV in Fig. 14, the drainage channels gradually increase in depth as they approach the well 42. Fig. 16 shows how the underside of the case is equipped with stacking grooves 43 which match stacking ribs 44 on the upper side of the lid 1 '. At the end of the case 1 on the underside thereof there is a recess which serves as a carrying grip for lifting the case.

In an alternative, but not illustrated embodiment, it is conceivable that the bottom of the case is made liquid-tight and is manufactured from solid cardboard, said case having an internal and external octagonal shape, as is shown in Fig. 13. The lid of the case, which is also made of solid cardboard, will be shaped in a corresponding fashion, i.e.. like an inverted case, so that the vertical portions of the lid lie against the outside of the case. Gas vents are provided in both the lid of the case and the case itself, and they may be. for example, elongate, preferably rectangular, as is shown in connection with Fig. 13.

In Fig. 17. it is shown how the stacks of cases 49, without gas channelling elements and covered with a downwardly open gas bag 14 is supplied with carbon dioxide gas or carbon dioxide containing gas via gas supply pipe 32, connection pieces 33, hoses 35 (see Fig. 10) and connectors 34 and 36. Inwards along the length of the cold storage chamber the stacks of cases are placed close to one another, see Fig. 18, just as they are placed close to one another in the transverse direction, so that on each side gaps there are 50 and 51 between the wall of the cold storage chamber 17 and the adjacent stack of cases, it being an option to place gas proofing hoses 52, 53 in these gaps in order to cause the gas to flow forward after having passed out through the bottom of the pallets. The hoses 52, 53 may optionally be supplied with openings for the extraction of gas which flows out through the bottom of the pallets.

As shown and explained in connection with Figs 3 and 4, it is perhaps conceivable that the hoses 52, 53 , provided with orifices laterally, could be supplied with gas under pressure which thus is caused to flow up through the bag 14 and around the cases enveloped thereby, so that the direction of flow in reality is the opposite of that shown in Figs 17 and 18.

Claims

a t e n t c l a i m s

1.

A method of handling fresh fish for shipment and/or storage, where the fish are packed in cases (1) and stacked on a pallet (3), and where the cases in the ends or in the comers thereof optionally have gas vents (2), characterised by the following steps: that a downwardly open gas bag (14) is drawn down over the stack of cases, optionally prior to the positioning of the bag a gas channelling element (4) being placed on at least two sides of the stack of cases, thereby defining the stack of cases over which the bag is drawn, so that the bag opening is roughly level with the top surface of the pallet; that carbon dioxide gas or carbon dioxide containing gas is supplied to the inside of the gas bag either via a gas supply hose connected to a connection piece in the top of the gas bag and caused to flow down and out via the open bottom of the gas bag, oj; via the open bottom of the gas bag and caused to flow upward and out via a vent, e.g.. a connection piece in the top of the gas bag; that the gas is caused to flow into each layer of the stack of cases and out therefrom, possibly via said optionally provided gas channelling elements; that at least one of the following parameters of the gas is measured and regulated: temperature, flow rate, moisture content, carbon dioxide content; and that the stack of cases, optionally equipped in addition with said gas channelling elements, enveloped by the gas bag, is subjected to a pressure difference between the upper side and the underside of the gas bag in order to cause forced, regulated gas flow through the bag and layers of the stack.

2.

A method according to Claim 1, characterised in that the stack of cases, optionally with the addition of the gas channelling elements, and the enveloping gas bag are bound with straps, tape, cling film, shrink film, or similar.

3.

A method of Claim 1 or 2, characterised in that prior to placing the cases in a stack, a small amount of crushed ice or flake ice, e.g., 1 to 2 kg, can, in a known way per se, be placed in each case.

4.

A method according to one or more of the preceding claims, characterised in that the gas is moistened either by means of ice which is placed in the cases or by means of external moistening of the gas with water.

5.

A method according to one or more of Claims 1 to 4, characterised in that in a cold storage chamber (17) there are placed at least two adjacent rows (28,29) of stacks of cases provided with gas bags and optionally provided with gas channelling elements (4). and that in connection with the adjacent rows at least one horizontal gas supply hose (30;52.53) is supplied having laterally directed gas outlet nozzles or orifices, said hose being positioned so that it extends some distance up the gas bag over the top of the pallet (3) and some distance below the top of the pallet, optionally right down to the bottom of the pallet.

6.

A method according to Claim 5, characterised in that the gas is supplied in that air, optionally in a cooled state, is made to flow over a supply of dry ice (24) placed in the cold storage chamber.

7.

A method according to one or more of the preceding claims, characterised in that one or more of said stacks of cases, optionally with accompanying gas channelling elements, and gas bag are placed in a cold storage chamber (17). the gas being caused to circulate by means of refrigerating and or circulation equipment (18,19,20.21) provided in connection with the cold storage chamber, and that gas supply pipes (32) are connected to said refrigerating and/or circulation equipment and detachably mounted in the ceiling (17') of the cold storage chamber, said gas supply pipes being designed for connection to gas supply hoses.

8.

A gas channelling element (4) for conducting gas into the respective layers in a stack of foodstuff cases (1), wherein the cases in the respective ends of comers thereof have gas vents (2), wherein against at least two sides of the stack of cases there is placed a said element, and wherein the stack of cases is enveloped by a gas bag (14), characterised in that the element consists of double-layered corrugated cardboard having - a first airtight cardboard sheet (5), - a second perforated cardboard sheet (6,7), and

- a third perforated cardboard sheet (8,9), between the said first and second layer, and between said second and third layer, respectively, there being provided a perforated, corrugated spacer (10J 1J2J3) of cardboard or kraft paper, and in that said double-layered corrugated cardboard is airtight along two side edges and one end edge thereof.

9.

A stackable case (1) for refrigerated, fresh fish, wherein the case has a storage chamber where in each end wall there are gas vents (2), so that carbon dioxide gas or carbon dioxide containing gas can pass through the storage volume of the case, and wherein the bottom of the case is preferably liquid-tight, characterised in that the gas apertures are elongate, preferably rectangular.

10.

A stackable case as disclosed in Claim 9, characterised in that the case externally and internally is octagonal.

11. A stackable case as disclosed in Claim 9, characterised by two separate liquid collecting wells (42'. 42") which are provided at respective ends of the case and each of which extends essentially as an arch between the longitudinal sides of the case, upwardly open drainage channels (41 ',41 ") in the bottom of the case opening into said wells.

12.

A stackable case as disclosed in Claim 9 or 10, characterised in that the case is made of solid cardboard, that the lid of the case is designed in a similar way as the case, i.e., like an inverted case, the vertical part of the lid being intended to rest against the outside of the case, and being equipped with corresponding adjacent gas vents.

13.

A device for the emission of carbon dioxide containing gas to a cold storage chamber (17) where fresh fish is stored, characterised by a tank (23) containing dry ice (24), wherein air under pressure is conducted into the tank (23) via a valve (26), and wherein the tank has an outlet which is in communication with downwardly open gas bags in which stacks (28, 29) of cases containing fresh fish are stored.