Material handling system and method

Abstract

A system for forming blocks of frozen material comprising: a heat exchange module comprising a conduit for receiving material to be frozen, the conduit having an internal wall defining an internal recess and an external wall spaced from the internal wall to define a space for receiving a heat exchange fluid; a material supply unit for supplying a flow of material to be frozen into the internal recess of the conduit; a controller for controlling the delivery of the heat exchange fluid to the heat exchange module to cause the material present in the internal recess to freeze; and an extractor for extracting the block of frozen material from the conduit; wherein, the internal recess of the conduit is configured such that at least a portion of an upper or lower surface of the block of frozen material is formed to have a non-planar surface along its length.

Description

[0001] MATERIAL HANDLING SYSTEM AND METHOD

[0002] RELATED APPLICATIONS

[0003] The present application claims priority from Australian Provisional Patent Application No. 2024903690 filed 11 November 2024, the entire contents of which are incorporated herein by reference.

[0004] FIELD OF INVENTION

[0005] The present invention relates generally to a system and method for handling frozen material, and in particular, to a system and method for handling frozen blocks of material.

[0006] BACKGROUND ART

[0007] In a variety of industries, particularly food processing facilities for human and animal consumption, there is a constant need to receive and process raw organic material into a form where it is capable of being stored and further processed. The most convenient means to process such material is to freeze the material in a form that can be transported and stored in a convenient maimer, and which preserves the integrity of the materials.

[0008] A variety of freezing systems have been developed whereby material, such as liquids, solids and a combination thereof, are received and frozen for storage or further processing. The material to be processed may take a variety of forms, from an organic material, such as meat or other products, as well as any liquid product, such as fruit juice or fruit / vegetable pulp, as well as milk and water.

[0009] Plate freezers are one type of freezing system that has been successful in achieving such chilling / freezing of product into a block for further handling. Plate freezers generally comprise a plurality of refrigerated plates mounted within a frame to define a space therebetween, into which the material is delivered to be frozen. A refrigerant is delivered to the plates such that the plates act as evaporators to absorb heat energy from the material thereby rapidly freezing the organic material located therebetween. Once frozen the refrigerant circuit is able to be reversed to provide warm gas or liquid to the plates to defrost the contact zone between the frozen product and the plate surface to facilitate removal of the frozen product from the plates. In most commercially available plate freezing devices, it is desirable that the material to be frozen is able to be quickly loaded into the space formed between the plates and that the resultant frozen material can then be quickly removed as required. In such devices the material is frozen in a rectangular block form, which is a shape defined by the space formed between the substantially flat plates that form the frozen block of material. Thus, the formed blocks of material typically comprise slat or level surfaces and edges with sharply defined comers.

[0010] The convenience of forming a substantially rectangular block of frozen material is that it can be easily stacked on a pallet or conveyor for storage or further processing. As the blocks are frozen to around -15°C and can weigh up to 70 Kgs, the formed blocks have a tendency to stick or adhere together when stacked for storage. This occurs when the blocks are stacked in a vertical maimer, as the exposed surfaces of a frozen block are in direct contact with the exposed surfaces of an adjacent frozen block. Such contact between surfaces along an area where the frozen blocks may have undergone some degree of melting during handling, will result in any melted region of the blocks re-freezing when stacked or otherwise positioned against an adjacent block. This re-freezing at the interface between the blocks will cause the blocks to adhere together at their interface. As a result, when the blocks in the vertical stack are in contact along their entire surfaces, they can become very difficult to separate, often requiring an axe or cutting saw to separate the blocks and break the adhesion forces at their interface. To address this, in some circumstances, the blocks may be stacked with a plastic sheet, or “slip sheet”, applied between each layer of blocks to avoid direct block-block contact for an easier separation of blocks for processing. However, such an arrangement adds additional cost to the palletising process and stacking time, and results in additional waste plastic material being created and introduces risk of foreign objects becoming embedded within the product.

[0011] As such, handling of a stack of blocks of frozen material can be dangerous when there is a need to separate individual blocks. Further, if the blocks are to be processed through a grinder, if multiple blocks become stuck together this can cause an undue force on the grinding equipment which can destroy the equipment and create significant financial costs as well as lost processing time.

[0012] Additionally, during the plate freezing process, it is possible that the blocks may not be fully frozen to the core and some blocks may have a soft centre, being located the furthest from the contact surface of the plate freezer. In such situations, when the blocks are stacked onto a pallet to be stored in a freezer, the blocvks can cause a thermal barrier resulting in minimal opportunity for the cold air present in the freezer to reach the centre of the blocks in the storage stack to enable further freezing of these blocks during storage. This can lead to a potential quality hazard due to the softer core region of the blocks at the centre of the pallet, and a safety risk if these pallets are stacked in multiple vertical blocks which can result in the blocks becoming unstable due to compression of the softer centre of the blocks. As such, there is a need to create a means to allow for the continued transfer of cold energy from the refrigerated air of the freezer storage to the centre of the pallet of stored blocks to allow the core of the blocks to continue to freeze and harden during the storage period.

[0013] Another issue with handling frozen blocks of material is that when the blocks are to be used for further processing, it is often required to increase the temperature of the blocks from a storage temperature of -18°C, to a higher temperature of around -2°C to -5 °C to soften the blocks to minimise potential damage to the further processing equipment. This process is often referred to as tempering. In this regard, in order to temper whole pallets of blocks of plate frozen material, the entire pallet of blocks may need to reside in a -5 °C environment for up to 2 weeks in order to ensure that the core of blocks present in the pallet has equalised with the tempering temperature of the environment. This is largely due to the fact that the stacked blocks may form a solid mass with minimal opportunity for the centrally positioned blocks to be exposed to the higher temperatures. Such an increased storage time can have significant negative impact on the processing time for the material and additional costs in awaiting the tempering of the blocks.

[0014] Thus, there is a need to provide a system and method for forming frozen blocks of material in a maimer that overcomes at least some of problems associated with handling and stacking such blocks in a manner where individual blocks may stick together and become difficult and dangerous to handle. There is also a need to provide a system for facilitating air flow between blocks in a stack of blocks when the stack of blocks are stored in a controlled environment to ensure the blocks can be maintained at a desired temperature in accordance with the environment.

[0015] The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the above prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

[0016] SUMMARY OF THE INVENTION

[0017] Accordingly, in one aspect of the invention there is provided a system for forming blocks of frozen material comprising: a heat exchange module comprising a conduit for receiving material to be frozen, the conduit having an internal wall defining an internal recess and an external wall spaced from the internal wall to define a space for receiving a heat exchange fluid; a material supply unit for supplying a flow of material to be frozen into the internal recess of the conduit; a controller for controlling the delivery of the heat exchange fluid to the heat exchange module to cause the material present in the internal recess to freeze to form a block of frozen material; and an extractor for extracting the block of frozen material from the conduit; wherein, the internal recess of the conduit is configured such that at least a portion of an upper or lower surface of the block of frozen material is formed to have a non-planar surface along its length.

[0018] In an embodiment of the invention, either an upper surface or a lower surface of the internal wall of the conduit has a non-planar surface to form the block of frozen material having the non-planar surface along its length.

[0019] In another embodiment of the invention, both the upper surface and the lower surface of the internal wall of the conduit has a non-planar surface to form the block of frozen material having the non-planar surface along its length.

[0020] The non-planar surface of the upper surface and / or lower surface of the internal wall of the conduit may be at least partially convex in a direction orthogonal to a longitudinal axis of the conduit.

[0021] The non-planar surface of the upper surface and / or lower surface of the internal wall of the conduit may be at least partially concave in a direction orthogonal to a longitudinal axis of the conduit.

[0022] The non-planar surface of the upper surface and / or lower surface of the internal wall of the conduit may have a ridge extending longitudinally along opposing sides of the conduit.

[0023] The internal recess of the conduit may be configured such that ends of the internal recess have a substantially rectangular cross-sectional configuration with at least one comer of the substantially rectangular cross-sectional configuration being curved such that upper or lower surface of the block of frozen material is formed to have at least one curved comer extending along its length.

[0024] Accordingly, in another aspect of the invention there is provided a block of frozen material comprising: an elongate body of frozen material formed by passing the material into a conduit and freezing the material within the conduit to form a block, said block having an upper surface, a lower surface extending between opposing ends; wherein at least a portion of the upper or lower surface of the block is formed to have a non-planar surface along its length such that a plurality of said blocks can be stacked in a vertical arrangement and surfaces of adjacent blocks in said stack contact at distinct points along their adjacent surfaces.

[0025] In one embodiment of this aspect of the invention, both the upper surface and the lower surface of the block have a non-planar surface formed along its length.

[0026] The upper surface and / or lower surface of the block may be at least partially convex in a direction orthogonal to a longitudinal axis of the block.

[0027] The upper surface and / or lower surface of the block may be at least partially concave in a direction orthogonal to a longitudinal axis of the block.

[0028] The upper surface and / or lower surface of the block may have a ridge extending longitudinally along opposing sides of the block.

[0029] The upper surface and / or lower surface of the block may have at least one curved comer extending longitudinally along at least one side of the block.

[0030] In another aspect of the present invention, there is provided a stack of frozen blocks, wherein when the frozen blocks are configured such that when the frozen blocks are stacked in rows of vertically stacked blocks, a gap is formed between adjacent blocks.

[0031] The gap may provide a path for air to flow between blocks in the stack of blocks.

[0032] The gap may provide a leverage point to separate blocks in the stack of blocks.

[0033] In another aspect of the present invention there is provided a conduit for forming frozen blocks of material comprising: an extruded metal body configured to form an internal space having a substantially rectangular cross-section wherein at least one of an upper and / or a lower inner surface of the internal space is non-planar.

[0034] BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The invention may be better understood from the following non-limiting description of preferred embodiments, in which:

[0036] Fig. 1 is a side view of a material freezing system in accordance with an embodiment of the present invention;

[0037] Fig. 2 is a perspective end view of a heat exchange module of the material freezing system of Fig. 1 in accordance with one embodiment; Fig. 3 is an end view of the heat exchange module of Fig. 2;

[0038] Fig. 4 is a perspective view of a partial stack of frozen blocks formed from the heat exchange module of Fig, 2;

[0039] Fig. 5 is a perspective view of a multi-stack of frozen blocks formed from the heat exchange module of Fig. 2;

[0040] Fig. 6 is an end view of a frozen block member formed by a heat exchange module in accordance with another embodiment of the present invention;

[0041] Fig. 7 is an end view of a frozen block member formed by a heat exchange module in accordance with yet another embodiment of the present invention;

[0042] Fig. 8 is a perspective view of a vertical stack of blocks as shown in Fig. 6;

[0043] Fig. 9 is a front end view of a frozen block member in accordance with another embodiment of the present invention in a partial vertical stack;

[0044] Fig. 10 is a perspective view of the partial vertical stack of frozen block members of Fig. 9;

[0045] Fig. 11 is an end view of a frozen block member in accordance with yet another embodiment of the present invention;

[0046] Fig. 12 and Fig. 13 show alternative vertical stacks of frozen block members in accordance with the frozen block member of Fig. 11; and

[0047] Fig. 14 and Fig. 15 show an alternative vertical stack of frozen block members and an end view of a frozen block member in accordance with yet another embodiment of the present invention.

[0048] DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0049] The present invention will be described below in relation to its application for use in creating frozen blocks of organic material, such as animal protein matter in the form of animal viscera and offal for use in pet food production. However, it will be appreciated that the present invention could be equally employed in processing a variety of other matter, such as fish for pet food, fruit and vegetable pulp, water (block ice), beef trimmings, chicken, mechanically deboned meat (MDM), dairy products as well as waste organic products that require chilling prior to disposal or further processing. Further, the apparatus of the present invention could be used to form frozen or partially frozen blocks of material as may be required. The present invention will also be described below in relation to a material freezing system developed by the present applicant and disclosed in the present Applicant’s co-pending International PCT Patent Application No. PCT / AU2023 / 051339, the entire contents of which are incorporated herein by reference. Such a material freezing system comprises at least one conduit having an inlet for receiving the material by way of a pump that applies a positive pressure to the material to facilitate flow of the material into the conduit and out of the conduit. The conduit receives the material to be frozen such that the material is stored within the conduit for a predetermined period of time, during which time a refrigerant is delivered to the conduit to freeze the materials present therein. The conduit has an internal wall in communication with the material present therein and one or more spaces are provided between the internal wall and an external wall of the conduit to receive the refrigerant to apply a low temperature to the material to at least partially freeze the material within the conduit. The one or more spaces formed between the inner wall and the outer wall of the conduit may also selectively receive a defrost fluid, which may be a liquid or gas, to defrost the material at an interface between the material and the internal wall, such that the pump may be activated to push the defrosted frozen material from the conduit via an outlet thereof where the frozen material is able to be sectioned into blocks of material for storage and / or further processing.

[0050] However, it will be appreciated that the present invention will also be applicable for use with more conventional block freezer systems comprising a plurality of refrigerated plates mounted within a frame to define a space therebetween, into which the material is delivered to be frozen. Such a conventional plate freezer system also produces blocks of material for storage and / or further processing.

[0051] Irrespective of the type of system employed to form the frozen block of material, most frozen blocks of material are created in the form of a conventional rectangular block having substantially flat or planar, upper and lower surfaces and edges, forming substantially right-angled comers. Plate frozen blocks of material are frozen in the cavities formed by plates of aluminium with a hollow serpentine cavity in which a refrigerant flows. Such systems create a block freezing material that forms rectangular frozen blocks with perfectly flat or planar surfaces on the upper and lower surfaces, as well as on the connecting edge surfaces. During formation and prior to ejection of the frozen blocks from the plate freezer, the blocks are defrosted with a hot fluid, gas or liquid, replacing the refrigerant creating a slight thawing of the material at the surface of the block in contact with the plates, so that the product releases its adhesion force with the aluminium plate surface caused during freezing. This defrost cycle can create a slight melt on the surface of the flat area of the block that can be up to 2mm thick. Once the blocks are removed from plates and stacked on top of each other, the melted region can re-freeze such that the vertically stacked blocks can become adhered together at their interface.

[0052] To address this problem, the system and method of the present invention has been proposed.

[0053] Referring to Fig. 1, an embodiment of a material freezing system 10 for forming frozen blocks of material in accordance with the present invention is depicted. The system 10 will be described below in relation to an apparatus for freezing material; however, it will be appreciated that the apparatus may be employed for partial freezing or chilling material, as may be required.

[0054] The system 10 comprises an inlet 12 for receiving the material to be processed which is supplied under pressure by a pump (not shown). The system 10 also comprises a collection region 16 for receiving the frozen blocks of processed material.

[0055] A plurality of heat exchange modules 14 are arranged in fluid communication with the inlet 12 to receive the material to be processed. The material is delivered under pressure into an inlet manifold 15 of the heat exchange modules 14. In the embodiment as shown, the heat exchange modules may be arranged in an array comprising ten vertically spaced banks of parallel heat exchange modules 14, with each bank having eight horizontally spaced modules 14. However, it will be appreciated that the maimer in which the modules 14 are arranged can vary depending on space requirements, other array configurations are also envisaged.

[0056] The inlet manifold 15 of each heat exchange module 14 may be connected to the inlet 12 by way of a pinch valve 13 that is controlled to release material into the heat exchange module 14, as required. Upon delivery of the material into the heat exchange modules 14, a heat exchange medium, such as a refrigerant, is supplied to the module 14 and the material is exposed to the freezing temperatures of the heat exchange medium through the walls of the module 14. This will cause the material present in the modules to freeze.

[0057] When the material delivered into the modules 14 is exposed to the freezing temperatures present therein for a predetermined period of time, the refrigerant is then replaced with a defrost fluid. The defrost fluid may be the same refrigerant at a higher temperature than the refrigerant, but still at or below freezing temperature, or may be a warm gas or liquid that flows along the length of the modules 14. The introduction of the defrost fluid initiates a defrost cycle that causes the frozen material in contact with the inner wall of the module to have an elevated temperature than the remainder of the material in the module, to facilitate release of the frozen material from the module 14.

[0058] To eject the frozen material from each module 14, pressure is applied at an end of the module, which may be by way of pressurised air or replacement fresh material being pumped behind the frozen block of material to displace the frozen block of material within the module 14. This acts to push the frozen block out of the module 14 following the de-frost step. Other means for pressurised ejection of the frozen block of material from the module 14 are also envisaged, including in combination with gravity.

[0059] The collection region 16 of the freezing system 10 will receive the frozen material expelled from the modules 16 in elongate blocks of frozen material. The collection region may include cutters, guillotines, and robotic handling systems to receive and process the frozen blocks of material into predetermined sized slabs, which can be then delivered to a processing station for further palletizing and stacking for storage.

[0060] To provide for improved handling of the formed blocks of frozen material and to minimise the likelihood of the blocks freezing and sticking together as a combined mass, the modules 14 are configured to form a block with upper and lower surfaces that are not substantially flat or planar along their lengths.

[0061] Typically, the modules 14 are formed a metal, such as aluminium, by way of an extrusion process and as such, the shape of the extruded module can be controlled to achieve a desired configuration for the internal surfaces that form the shape of the block to be created.

[0062] An embodiment of one form of a module 14 is depicted in Fig. 2 and Fig. 3. In this embodiment the module 14 is shown as being an open conduit having a hollow centre 20 through which the material flows as it passes through the module 14. The module 14 has an inner wall 21 and an outer wall 22 that defines a space therebetween for receiving the refrigerant for freezing the material present within the hollow centre 20 of the module 14 as well as receiving the defrost fluid for defrosting the perimeter of the frozen material, prior to ejection from the module 15.

[0063] As can be more clearly seen in Fig. 3, the upper inner wall 21a and the lower inner wall 21b have a slightly convex configuration at the central portion thereof such that the distance between the inner walls of the hollow centre 20 of the module 14 is slightly narrower at the centre point than it is at its ends. In the embodiment as shown, both the upper inner wall 21a and the lower inner wall 21b have the convex configuration, however it will be appreciated that only one of the upper or lower inner wall needs to be configured in this manner. It is also noted that each of the comers of the hollow centre 20 are also curved such that the resultant block will not have straight comers but curved comers, as will be discussed in more detail below.

[0064] Such an arrangement of the hollow centre 20 of the module 14 ensures that the frozen block of material formed by the module 14 will assume the same or similar shape as the hollow centre 20. Thus, the resultant frozen block of material 30 will have both an upper surface 31 and lower surface 32 having a concave configuration with curved edges, as is shown in Fig. 4.

[0065] In the embodiment of the blocks 30 depicted in Fig. 4, when the blocks 30 are arranged in a vertical stack, the concave shape of the upper surface 31 and lower surface 32 form a gap 35 between vertically adjacent blocks 30. In this embodiment, the gap 35 is larger at the central axis of the blocks with the blocks 30 only being in contact at a specific point adjacent the ends thereof. The comers 33 of the blocks 30 are also rounded rather than square due to the internal shape of the hollow centre 20 of the module 14, which further minimises flat-to-flat surface contact between vertically adjacent blocks 30. With such a configuration of blocks 30, the blocks 30 can be arranged in large vertical stacks as depicted in Fig. 5 for storage, as required.

[0066] In such a stack of blocks 30 as depicted in Fig. 5, each of the vertically stacked blocks 30 will experience a degree of adhesion at their contact points which will provide stability to the stack of blocks 30 to avoid the stack of blocks 30 falling or becoming unstable. However, this adhesion between vertically adjacent blocks 30 can be simply broken by applying a leverage force between the blocks via the gap 35, or at the rounded comers extending along the sides of the stack, to break the bond between the blocks and access each individual block.

[0067] The provision of the gap 35 between vertically adjacent blocks 30 in a stack also provides a passage for air to flow through the stack of blocks so as to pass between the blocks which can be used to aid in hardening of the blocks 30 at the centre of the stack and transferring the adjacent air uniformly along the stack, which may be for refrigeration or tempering purposes.

[0068] It will be appreciated that the manner in which the modules 14 are configured and the resultant blocks 30 are shaped may vary and achieve the same purpose. As discussed above, by metal extrusion of the modules 14 the shape of modules and the internal cavity of the modules can be controlled to form any desired shape and configuration.

[0069] As shown in Fig. 6, in one embodiment, the modules 14 may be shaped to form a block 30 having a substantially flat or planar upper surface 31 and a lower surface 32 having a pair of feet 36 formed along opposing ends thereof. The comers of the block are also rounded. The feet 36 may be formed by providing a ridge extending longitudinally along opposing sides of the lower surface of the internal wall of the module 14. Such blocks 30 formed in this maimer are shown in a stacked formation in Fig. 8, whereby a gap 35 is formed between vertically adjacent blocks in the same manner as shown in Fig. 5.

[0070] Fig. 7 shows yet another embodiment of a block 30 formed in accordance with the system and method of the present invention, whereby both the upper surface 31 and the lower surface 32 of the block has feet 37 formed along opposing sides thereof. The feet 37 may be formed by providing a ridge extending longitudinally along opposing sides of the upper surface and lower surface of the internal wall of the module 14. It will be appreciated that in such an arrangement, stacked blocks will be in contact at the feet 37 and a gap will be formed between vertically adjacent blocks in the manner as described above.

[0071] Referring to Fig. 9 and Fig. 10, another embodiment of a block 30 is depicted that enables the blocks 30 to be stacked in a “nested” configuration as shown. In this embodiment, the lower surface of each block has a recessed or stepped region 38 formed along the opposing edges that creates a space above the central lower surface. The upper surface of each block 30 has a raised edge 39 formed along opposing edges thereof that is raised above the central region of the upper surface as shown, and the edges of the block are rounded.

[0072] In this embodiment, when the blocks 30 are stacked in the manner as shown, the upper block is nested into position on the lower block to provide contact at the interface between the raised edge 39 of the lower block with the stepped region 38 of the upper block. A gap 40 is then formed between the upper and lower block that extends the length of the block to provide a path for air to flow along the centre of the blocks. Such an arrangement ensures that the blocks are stable when stacked and the adhesion between vertically adjacent blocks only occurs at the interface between the raised edge 39 of the lower block and the stepped region 38 of the upper block. Such a stack of blocks provides improved stability for transport and movement from a pallet, and to break the adhesion forces between blocks a crowbar or similar tool can be simply inserted into the gap 40 or along the gap formed due to the rounded edges of the blocks, to separate the vertically adjacent blocks. Yet another embodiment of a block 50 is depicted in Fig. 11 - 13. In this embodiment the block 50 is configured to have a channel 52 formed in both the upper surface and the lower surface thereof with the channels 52 being offset on either side of a central axis of the block 50. Each of the channels 52 extend partially over the upper and lower surface of the block 50 and terminate before the edge of the block to define an edge of the block 50 that is raised with respect to the channel 52, the edges of which are rounded. The depth of the channel 52 may vary between blocks.

[0073] When the blocks 50 are stacked in the maimer as depicted in Fig. 12, two gaps 55 are formed between the vertically displaced blocks 50 to minimise adhesion forces due to reduced contact surface area between the blocks 50 and to maximise airflow therebetween. The gaps 55 are formed by the channels 52 being spaced from the planar surface of the vertically adjacent block.

[0074] When the blocks are stacked in the manner as depicted in Fig. 13, a single gap 57 is formed between the vertically displaced blocks 50. The gap 57 has a wider opening than the gap 55 depicted in the arrangement of Fig. 12, but the adhesion forces present in the stack of blocks is greater due to a greater contact surface area between the blocks 50 than is provided in the arrangement of Fig. 12. It will be appreciated that with the block configuration 50 of Figs 11 - 13, the blocks 50 can also be arranged in a cross-hatched manner to provide multiple air gaps between the blocks as desired.

[0075] Fig. 14 and Fig. 15 shows yet another embodiment of a block 60 in accordance with an embodiment of the present invention. In this embodiment the block 60 is configured to have a substantially rectangular cross-sectional configuration, but has the comers 62 formed in an arcuate or curved manner. In this regard the upper surface 63 and the lower surface 64 of the block 60 have a substantially planar surface for a majority of the width of the block, but which curves away at the edges thereof to form a convex shape at the corners 62. Thus, the upper and lower surfaces 63, 64 of the block 60 is non-planar due to this curvature along the edges thereof. The blocks 60 are formed by an extruded module having an internal cavity formed to have a substantially rectangular configuration with rounded comers to produce the block 60 as shown.

[0076] As is shown in Figure 14, when such a block 60 is arranged in a stack on a pallet 5 as shown, a gap 66 is formed at the upper comers and lower comers of the block as shown. Such a gap 66 facilitates air flow between blocks 60 and provides an opening to apply a force to break any adhesion forces between the blocks 60. It will be appreciated that using the system and method of forming frozen blocks of material in accordance with the present invention, each formed block has at least one irregular or non-planar side or surface to reduce the surface contact points between vertically adjacent stacked blocks. The creation of specific contact points between vertically adjacent blocks ensures that any adhesion between blocks at these contact points is utilised to provide stackable block strength. However, as the adhesion is only present at the dedicated contact points, such adhesion can be readily broken to release the blocks, as required. The provision of a gap between vertically adjacent blocks can be utilised to apply a leverage action by way of a vertical force between the blocks to break the blocks apart for removal and further processing, as well as to maximise air flow between blocks to ensure blocks remain hardened and to minimise melting.

[0077] It will also be appreciated that the system and method of the present invention also avoids the vacuum effect that can occur when individual blocks are separated and stored on a flat surface. As the undersurface of the block has a non-uniform or non- planar surface, the block can easily be lifted and handled from a flat surface, as required.

[0078] Whilst the present invention has been explained in relation to a modular or tubular freezer system, the blocks of the present system could also be formed using a conventional plate-freezer system whereby the shaped surfaces are formed by forming the appropriate shapes onto the inner surfaces of the plates that form the blocks.

[0079] Throughout the specification and claims the word “comprise” and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word “comprise” and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.

[0080] Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the block uppermost.

[0081] It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.

Claims

The claims defining the invention are as follows:

1. A system for forming blocks of frozen material comprising: a heat exchange module comprising a conduit for receiving material to be frozen, the conduit having an internal wall defining an internal recess and an external wall spaced from the internal wall to define a space for receiving a heat exchange fluid; a material supply unit for supplying a flow of material to be frozen into the internal recess of the conduit; a controller for controlling the delivery of the heat exchange fluid to the heat exchange module to cause the material present in the internal recess to freeze to form a block of frozen material; and an extractor for extracting the block of frozen material from the conduit; wherein, the internal recess of the conduit is configured such that at least a portion of an upper or lower surface of the block of frozen material is formed to have a non-planar surface along its length.

2. A system according to claim 1, wherein either an upper surface or a lower surface of the internal wall of the conduit has a non-planar surface to form the block of frozen material having the non-planar surface along its length.

3. A system according to claim 1, wherein both the upper surface and the lower surface of the internal wall of the conduit has a non-planar surface to form the block of frozen material having the non-planar surface along its length.

4. A system according to claim 2 or claim 3, wherein the non-planar surface of the upper surface and / or lower surface of the internal wall of the conduit is at least partially convex in a direction orthogonal to a longitudinal axis of the conduit.

5. A system according to claim 2 or claim 3, wherein the non-planar surface of the upper surface and / or lower surface of the internal wall of the conduit is at least partially concave in a direction orthogonal to a longitudinal axis of the conduit.

6. A system according to claim 2 or claim 3, wherein the non-planar surface of the upper surface and / or lower surface of the internal wall of the conduit has a ridge extending longitudinally along opposing sides of the conduit.

7. A system according to claim 1, wherein the internal recess of the conduit is configured such that ends of the internal recess has a substantially rectangular cross-sectional configuration with at least one comer of the substantially rectangular cross-sectional configuration being curved such that upper or lower surface of the block of frozen material is formed to have a at least one curved comer extending along its length.

8. A block of frozen material comprising: an elongate body of frozen material formed by passing the material into a conduit and freezing the material within the conduit to form a block, said block having an upper surface, a lower surface extending between opposing ends; wherein at least a portion of the upper or lower surface of the block is formed to have a non-planar surface along its length such that a plurality of said blocks can be stacked in a vertical arrangement and surfaces of adjacent blocks in said stack contact at distinct points along their adjacent surfaces.

9. A block of frozen material according to claim 8, wherein both the upper surface and the lower surface of the block have a non-planar surface formed along its length.

10. A block of frozen material according to claim 8, wherein the upper surface and / or lower surface of the block is at least partially convex in a direction orthogonal to a longitudinal axis of the block.

11. A block of frozen material according to claim 8, wherein the upper surface and / or lower surface of the block is at least partially concave in a direction orthogonal to a longitudinal axis of the block.

12. A block of frozen material according to claim 8, wherein the upper surface and / or lower surface of the block has a ridge extending longitudinally along opposing sides of the block.

13. A block of frozen material according to claim 8, wherein the upper surface and / or lower surface of the block has at least one curved comer extending longitudinally along at least one side of the block.

14. A stack of frozen blocks according to any one of claims 8 - 13, wherein when the frozen blocks are stacked in rows of vertically stacked blocks, a gap is formed between adjacent blocks.

15. A stack of frozen blocks according to claim 14, wherein the gap provides a path for air to flow between blocks in the stack of blocks.

16. A stack of frozen blocks according to claim 14, wherein the gap provides a leverage point to separate blocks in the stack of blocks.

Images