AU740946B3 - Method and apparatus for shipping super frozen materials - Google Patents

Description

I

Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT (original) r Name of Applicant: Actual Inventor: Address for Service: Invention Title: Coldwave Systems LLC Eric B Graham MADDERNS, 1st Floor, 64 Hindmarsh Square, Adelaide, South Australia, Australia METHOD AND APPARATUS FOR SHIPPING SUPER FROZEN MATERIALS The following statement is a full description of this invention, including the best method of performing it known to us.

I' 4 Field of Invention This invention relates to a method and apparatus for shipping, storing and freezing perishable materials in self-contained shipping containers which maintain the perishable material below Background Information Freezing and Storage Commercial fishing is a worldwide enterprise generating billions of dollars in sales on an annual basis. With modern shipping and storage technology, fish caught nearly anywhere in the world can be efficiently frozen and subsequently transported to almost any market in the world for consumption thereof.

Particular products however, do not lend themselves to conventional freezing and shipping methods. In particular, fish intended for consumption in an uncooked or raw state such as sushi, generally cannot be frozen using conventional equipment, without adversely affecting the quality, i.e. colour and taste thereof. For this reason, fish intended for use as sushi generally must be caught locally so it can be brought to market relatively quickly without freezing. This necessity has tended to limit the supply of fish available for sushi to effectively increase the price thereof relative to frozen fish. This phenomenon tends to produce a relatively large disparity between the price of sushi-grade fish and non-sushi grade frozen) fish in the marketplace.

In a recent attempt to address this disparity, some commercial fishing enterprises have harvested fish, such as tuna and the like, in areas of the world where there is little local demand for sushi-grade product (and thus a substantially lower market value therefor), and transported the product at cryogenic super-cooled) temperatures of less that -40'C to the sushi markets. It has been found that at these temperatures tuna and the like maintain suitable freshness for sushi purposes to thus retain the relatively high quality and premium prices associated with sushi-grade product. To achieve this, specialised equipment has been required at the point of freezing (a local fishing port) and/or purpose modified ships have been required for bulk or containerised transport.

It is an object of the present invention to provide a method that overcomes at least some of the above mentioned problems.

Summary of the Invention In a first aspect of the present invention, a method is provided for freezing and storing fish at a super-frozen temperature of less than or equal to about -50°C, to preserve the fish at sushi-quality. The method includes the steps of: providing a modular, portable apparatus including: one or more containers; a refrigeration system disposed integrally with the one or more containers, the refrigeration system being adapted to freeze product disposed within the apparatus to the super-frozen temperature; the portable apparatus adapted for being shipped to a destination for deployment at the destination to freeze and store fish at the super-frozen 15 temperature, and for being subsequently re-shipped to another destination for re-deployment; S* the one or more containers having a first section adapted for freezing the fish and a second section adapted for storing the fish at the super-frozen temperature; loading the fish into the first section and retaining the fish therein until the S fish reaches the super-frozen temperature; and transferring the fish from the first section to the second section, wherein the fish are maintained at the super-frozen temperature in a substantially preserved state suitable for subsequent consumption as sushi.

A second aspect of the present invention includes a method for providing sushi-quality fish harvested at a first location, to a distinct second location. The method includes the steps of: providing a portable, modular freezer adapted to freeze fish to a superfrozen temperature of less than or equal to about transporting the modular freezer to the first location; loading the harvested fish into the modular freezer and retaining the fish within the modular freezer until the fish reaches the super-frozen temperature; providing a modular shipping container adapted to maintain the fish at the super-frozen temperature; transferring the fish from the modular freezer to the modular shipping container; and shipping the modular shipping container to the second location, wherein the fish are provided at the second location at the super-frozen temperature in a substantially preserved state suitable for use as sushi.

Brief Description of the Drawings d a dFig. 1 shows a roof section of a container with additional insulation, a vent door and a C02 distribution system.

Fig. 2 shows the wall section of a standard ISO shipping container with 15 standard insulation value, and the additional insulation which, when added, will create the super insulated container's insulative value. Standard r-value of a shipping container is in the range of 15 to 20. The super container shown in this figure has rvalues of 30 or more.

Fig. 3 shows a section of super freezer/storage container with super insulated walls, a freezer section and a storage section, a cryogenic liquid supply tank, thermostatic valves for the temperature controlled flow of the cryogenic liquid, an *electric control panel to turn the system on and off and set the desired interior air temperature, fans 25 for increased heat transfer during the freezing process and temperature probes to read the air temperature inside the two sections.

Preferred Embodiment Description Herein we describe a specific embodiment which is the preferred embodiment. While the invention is susceptible to various modifications and alternative forms, this specific and preferred embodiment is shown by way of the drawings and the detailed description herein described. It should be understood, however, that there is no intent to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Referring to Figure. 1, a super freezer/storage apparatus is constructed beginning with a commercially available insulated ISO shipping container built with or designed to support a mechanical refrigeration unit The refrigeration unit was removed from the nose 1. The nose 1 was closed and insulated with 8" to 10" of polyurethane insulation foam 2. Four inches of polyurethane foam insulation was added to the bottom side 3 of the container, between and around the cross members, the walls and ceiling 4 on the inside of the container and the doors 5 of the container.

.oo..i Additional closure gaskets were added around the seal of the doors 6 after the insulation was added to insure a proper seal. A hinged vent door 7 which automatically opens when the pressure inside the container increases. The vent door 15 7 releases the pressure as the cryogenic liquid is added and as the cryogenic liquid sublimates. This was installed in the nose 1 of the container about one inch down from the top of the container box. A cryogenic liquid spray header was installed. The spray head is known as a Transnow CO 2 sprayhead 8 and is the subject of U.S. Pat.

No. 4,640,460. The sprayhead was installed in the roof of the super insulated container and connected to a valve 9 on the outside of the container where the liquid

CO

2 line 10 is connected. The said Transnow CO 2 spray head has properties and S advantages such that it provides the greatest ration of liquid CO 2 to solid CO 2 product, thus operating at highest available efficiency and reducing the refrigeration cost. It should be understood that there is no intention to limit the scope of the invention to use with a Transnow CO 2 spray head, any cryogenic liquid distribution system or solid dry ice could be used as well.

A key feature of the super freezer/storage apparatus is the increased r-value of its walls. Figure. 2 is a cross section of the container wall showing the additional insulation 11.

Figure 3 shows a cross-section and key features of the freezing and storage container. This container is a standard ISO insulated container to which has been added a vent door 12, at least one interior wall 13 and connecting door 14 and foam insulation 15 is added to all walls and doors such to form super-insulated walls and doors increasing the r-value. A cryogenic temperature control system is added consisting of refrigerant piping 16, temperature probes 17, thermostatic valves 18, an electric control panel 19, and cryogenic storage facility Operation The product or material to be frozen is loaded into a freezing section of the freezing and storage super-insulated container which has been pre-cooled to -60 0 C. It is allowed to cool to ambient temperature and is thus transformed into the superfrozen state. The super-frozen product or material is then transferred to a storage S section of the container to await transfer.

The product or material to be shipped is pre-frozen in the super-frozen state is transferred from the storage container and loaded into the super insulated container which has been precooled to -60 0 C. The loading proceeds in the same manner in that they are loaded into a standard shipping container. In most cases the products are bulk loaded by hand, one on top of the other. The amount of product that should be e' loaded is also a factor of how long the shipping time will be and the amount of CO 2 solid is needed. However, once the pre-frozen product or material has been loaded into the super insulated container, this super insulated container provides an atmosphere in which the CO 2 is distributed and surrounds the frozen products inside the super insulated container. As the CO 2 is being distributed a large amount of pressure is being blown into the container box. The effect is something like a blizzard with very high winds. Thus the CO 2 snow will fill air pockets and crevices, although the majority of the snow will be piled on top of the products. Once the product is loaded into the super insulated container and injected with the C0 2 the super insulated container will be handled the same way all other dry cargo shipping containers are handled. This is in distinction to frozen shipping containers which require monitoring and electrical power hookups. Before injecting the CO2, a calculation is performed to determine the amount of CO 2 that will be required to maintain the super frozen state of the product or material until it arrives at its destination or until additional CO 2 can be added to the super insulated container.

This calculation is based upon the insulative value of the super insulated container, the amount (weight) of pre-frozen products or materials which will be loaded, the relative heat factor of the products or materials and the amount of time the product will be in transit. The super insulated container can be loaded onto a truck chassis and transported to the point of departure such as a ship port, rail yard or other transportation depot. It is then taken off of the truck and put into a holding area awaiting loading onto the ship, train or other conveyance. From the moment the super insulated container is loaded onto the conveyance until its arrival at the ooooo destination, no special monitoring or handling is required by the shipper or the S.shipping line.

15 When the container arrives at its destination, the interior temperature of the super insulated container can be tested and, if necessary, additional CO 2 can be added to provide extra storage time. The products can also be unloaded at this point and placed in cold storage at the destination.

i.: Other Embodiments •.This system can be used also with standard frozen products, for example in areas where there is currently no refrigerated shipping service available, but dry container service is available. Further, shipping costs can be often reduced by shipping the container of the subject invention at the dry shipping rate whereas other types of frozen shipping containers require frozen shipping rates.

There are a variety of insulation types which could be used in place of or in addition to polyurethane foam. Any insulation system which raises the r-value of the container above the 15-20 range constituents an additional embodiment of the invention.

Finally, the shipping container could also be used for storage, the storage and freezing container could be also used for shipping and a system comprising a combination of the storage and freezing container and the shipping container are all additional embodiments of the invention.

EXAMPLE 1 Freezing and Storage Container To the super freezer/storage apparatus described above and shown in Fig. 3 were added five 1 hp fans were added to the rear area and the spray header was separated into two sections. Two temperature probes were added (one in each compartment) to monitor the air temperature. The temperature probes were connected to an electric switch box which allows the desired air temperature to be set i inside each compartment. The switches and probes are connected to valves which open and close based on desired temperature setting and the actual air temperature inside each compartment.

Fresh tuna fish were loaded onto racks and the racks were placed inside the freezing section of the container. The doors were closed and the fans and nitrogen supply switches were turned on. Wire temperature probes were placed inside the core meat of the fish. When core temperature reaches around -50°C. everything is turned off and the doors of the container were opened and nitrogen gas was allowed to escape. The fish were taken off the racks and glazed by dipping in water for a few .i seconds. The glazed fish were then loaded into the super insulated storage area.

EXAMPLE 2 Shipping container A super insulated shipping container was constructed and pre-frozen tuna were shipped in it from Italy to Japan, arriving in Japan in perfect super frozen state.

Details of this example follow.

A standard 40 foot insulated shipping ISO container was purchased from Transnow CO 2 The container was modified by building a standard two by four stud wall with a plywood exterior and poly-foam was injected through the plywood and between the two by fours The ceiling and undercarriage was then sprayed with polyfoam adding about 4 inches to all surfaces. The container was then shipped to Italy.

There the container was used for freezing and storing tuna during a two month production and gathering period. About 5 metric tons of tuna loins were produced and frozen during that time. The air temperature and the core temperature of the fish was monitored each day. As the temperature rose above -60'C more CO 2 was added, such that product was consistently below -50°C. Optimal results were achieved by periodic additions of large amounts of CO 2 When the container was fully loaded with tuna loins and ready to ship approximately 22 Metric Tons of liquid CO 2 was added and the whole container was shipped to Japan on the NYK Line, bill of lading number NYKS577080998, on the vessel Osaka Bay. Transit time was 28 days. The .oo.oi overall time between the last injection of CO 2 until opening the door of the container in Japan was 36 days. When the center door leading to the super insulated storage compartment was opened there was a large block of frozen CO 2 snow inside the compartment. The temperature of that snow was found to be -85°C. The fish had a core temperature of -60 0

C.

Advantageously, a preferred embodiment of the present invention enables shipments as small as an individual ISO shipping container (up to approximately metric tons) at a sustained temperature of approximately -50 to -60 0 C. Moreover, such shipments may be advantageously shipped as dry rather than "reefer" .i containers which enable substantial savings in shipping costs. Additional advantages associated with this technique, include elimination of pollution generated by diesel operated mechanical refrigeration systems, and substantial elimination of opportunities for mechanical breakdown, human error and the need for servicing before, after and en-route. Moreover, capital equipment costs are substantially reduced due to the lack of necessity for expensive mechanical refrigeration systems and generator sets, etc. Lost shipments due to equipment failure and human error) may be substantially reduced relative to mechanically refrigerated units.

Accordingly it can be seen that the instant invention provides a method and apparatus for freezing, storing and shipping super frozen materials or products such as tuna fish in a self contained system that maintains the material or product in a super frozen state for long periods of time.

Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention.

Various other embodiments and ramifications are possible within it's scope.

Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.

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Claims (3)

1. A method for freezing and storing fish at a super-frozen temperature of less than or equal to about to preserve the fish at sushi-quality, the method comprising the steps of: providing a modular, portable apparatus comprising: one or more containers; a refrigeration system disposed integrally with said one or more containers, said refrigeration system being adapted to freeze product disposed within said apparatus to the super-frozen temperature; said portable apparatus adapted for being shipped to a destination for .0000: ~deployment at the destination to freeze and store fish at the super-frozen temperature, and for being subsequently reshipped to an other destination for re-deployment; 15 the one or more containers having a first section adapted for freezing the fish and a second section adapted for storing the fish at the super-frozen temperature; loading the fish into the first section and retaining the fish therein until the fish reaches the super-frozen temperature; and transferring the fish from the first section to the second section, wherein the fish are maintained at the super-frozen temperature in a substantially preserved state suitable for subsequent consumption as sushi.

2. The method of claim 1, wherein the container further comprises: a control system to regulate the temperature during the freezing and during the storing processes.

3. The method of claim 1, further comprising the step of glazing the fish with water after said freezing step Dated this 23rd day of May, 2001 COLD WAVE SYSTEMS L.L.C. By its Patent Attorney's MADDERNS 0:6, to *too .9 :0*9# to 9 0. to