EP1805465A1

EP1805465A1 - Sequential cooling methods and apparatus

Info

Publication number: EP1805465A1
Application number: EP05758949A
Authority: EP
Inventors: Michael John Panuccio
Original assignee: Pandura Farms Pty Ltd
Current assignee: Pandura Farms Pty Ltd
Priority date: 2004-07-09
Filing date: 2005-07-08
Publication date: 2007-07-11
Also published as: WO2006005120A1; TW200605824A; US20080092561A1; JP2008504824A

Abstract

A method of cooling and a cooling installation in which the method can be carried out includes two or more separate compartments (34) for receiving product so as to cool the product by sequential movement through each compartment in turn wherein the temperature drop in any one compartment reduces the temperature of exit of the product to a temperature about half of the temperature of introduction of the product to the compartments (34). Advantages of the present invention include that the time taken to cool the product to the required temperature is considerably reduced as the cooling is more effective. The present invention finds particular application to treating fresh produce such as fresh fruit and vegetables, particularly table grapes so as to reduce the incidence of spoilage or deterioration and to increase the usable shelf life.

Description

SEQUENTIAL COOLING METHODS AND APPARATUS

The present invention relates to sequential cooling of products, including methods and processes of cooling as well as equipment and installations used to conduct the cooling.

In one embodiment, the present invention relates to cooling manufactured products, including processed food products or other products. The present invention is not necessarily limited to food or edible products, but can include a wide variety of food and non food products.

In other embodiments, the present invention relates generally to harvesting of products that can be used as a food, particularly harvesting produce such as fresh fruit, vegetables or the like. More particularly, the present invention relates to the post harvest treatment and processing of produce and to the storing and handling of fresh produce. Even more particularly, the present invention relates to immediate post harvest cooling and handling of fresh produce, such as fruit, vegetables and the like.

In still further embodiments, the present invention relates to the use of a cooling installation, such as for example a cooling tunnel for cooling fruit and vegetables after harvesting so as to minimise or reduce the chances of spoilage or deterioration of the fruit or vegetables during storage.

In other embodiments, the cooling tunnel is compartmentalized, segregated or sectioned into cells, preferably with adjustable movable barriers between adjacent cells, to provide different areas for cooling the produce to different predetermined temperatures, preferably in sequence or in a prearranged order, in order to prolong the storage of the produce before the onset of spoilage or deterioration of the produce.

The present invention finds particular application as a method of cooling fresh produce in such a manner that the cooling is quicker and more effective, obviating the need to store the fruit after packing for relatively long periods in order to cool the packed produce to a suitable temperature for transporting the produce.

Although the present invention will be described with particular reference to one form of a handling centre or installation having one form of cooling tunnel allowing fresh fruit, such as grapes, to be processed and packed in a cooled environment in a manner which significantly reduces cooling time prior to transit of the fruit, it is to be noted that the scope of the present invention is not limited to the described arrangement, but rather the scope of the present invention is more extensive, so as to include other methods and other apparatus for cooling food materials, to the use of the various methods and apparatus for treating materials other than fruit and vegetables including non edible manufactured goods, and to other aspects of handling materials in an induced environment, such as a cooled environment, in order to reduce or minimise adverse conditions developing in the produce, particularly in or during storage.

Fresh fruit and vegetables, commonly referred to as fresh produce, need to be harvested as a first step in providing the fresh produce to the ultimate consumers. However, as soon as fresh produce is harvested, ie. , picked, it commences to deteriorate or degrade , primarily through loss of moisture, which often results in the produce being unacceptable for sale to the ultimate customers at some later date, particularly after short or long term storage. The rate of spoilage of the fresh produce is temperature dependent; the warmer the temperature, the faster the spoilage rate.

Fresh fruit and vegetables are usually harvested during the height of the growing season, which is generally the warmest part of the year. Accordingly, the fresh fruit and vegetables are usually harvested in a hot or at least warm environment. In these conditions, as soon as the fruit is picked, it commences to deteriorate through loss of moisture owing to being exposed to high ambient temperatures. The longer the fresh produce is exposed to high temperature, the greater the extent of deterioration. However, the extent of the deterioration is often not manifest until the produce is in storage or is bought by consumers, much to their disappointment and annoyance.

Although there have been previous attempts to cool the fresh produce as soon as possible or to handle the fresh produce in cool conditions as soon as practical after harvesting, such previously available methods have not been entirely successful for one or more reasons.

One of the disadvantages of currently employed cooling methods is the time it takes to cool the fresh produce and the space needed to store the cooling fruit. Even using forced air for cooling the environment or atmosphere, it can take up to in excess of about 24 hours to cool fruit and vegetables from high ambient temperature to temperatures that allow transportation of the produce to markets. Therefore, the area required within which to locate the produce whilst it is being cooled to a low temperature over the up to 24 hour period is extremely high, particularly during intensive harvest seasons in which there is a high yield of produce, most of which requires cooling simultaneously. Any harvested material which cannot be cooled quickly because of the unavailability of cooled storage space usually cannot be sold, and certainly cannot be sold at a premium price to consumers which results in loss of income to growers, distributors and sells of the produce.

Traditionally, boxes of packed fruit typically at temperatures of between about 25°C to about 35°C required about 24 hours of being stored in racks or similar storage assemblies in order for the produce to be chilled to between about 0°C and 1°C before the produce could be transported to market since produce is typically transported at this temperature by refrigerated trucks . The cost of providing racking or shelving of the type required is expensive, not only for the capital cost of the shelving, but also the cost of cooling the air required for circulation among the racks and other fittings.

Not only is the physical size of the installation of the equipment necessary to cool a full harvest for up to 24 hours great, but also the capital cost and cost of operating the equipment is extremely high, which detracts further from the profits available to the growers. Thus, there is a need for a relatively cost effective and efficient cooling system which requires less space and/or takes less time than available methods to cool produce to a temperature where it can be further processed, such as for example, transported to market.

Another problem of currently used cooling methods is that forced air is blown over and around the containers of produce so that the cooling air contacts the top and sides of the container only, resulting in uneven cooling of the produce contained within the container. In many instances, the top layer or layers of produce located in the open top containers is cooled excessively, whilst fruit contained within the interior or in the bulk of the container is cooled inadequately. Furthermore, in storage the heat from the relatively warmer produce located internally within the container is radiated to the relatively cooler produce around the edges which results in the produce being on average at a warmer temperature for a longer time than is desirable thereby further promoting spoilage and a short storage life. The unevenness of cooling and the unmeasured subsequent radiation of heat leads to high variability of the produce in terms of quality and shelf life, not only between batches of produce but also leading to high variability within the one container. The variability of produce within the one container detracts significantly from the reputation of the grower, so that it is difficult for the grower to command premium prices unless further processing of the produce occurs, such as for example, by reclassifying the contents of a container into different groups, such as one group having longer shelf life and others having short shelf life. All of this further processing adds to the cost to the grower.

Therefore, there is a need to provide an improved method, system, arrangement and/or apparatus for cooling products, including the post harvest cooling and handling of fresh produce which results in more consistent and reproducible cooling of the products and produce, so that the produce has more uniform storage qualities .

Further, there is a need for a more efficient cooling system which obviates the need to have expensive and extensive racking or shelving to store produce whilst it cools sufficiently for transportation to market.

Accordingly, it is an aim of the present invention to provide a method and apparatus of cooling individual product or produce items so as to provide more consistent storage quality, and also to cool the produce in a shorter time than hithereto was possible. According to one aspect of the present invention, there is provided a method of cooling a product, particularly a food product or material comprising the steps of:

providing the product in a container;

subjecting the product to a cooling environment in order to cool the product located in the container,

wherein each individual item of product within the container is subjected to a cooling environment so as to more or less substantially uniformly cool the product to reduce or minimise the variability of storage properties or characteristics of the product.

According to another aspect of the present invention, there is provided a method of minimising and/or reducing the extent or deterioration or degradation of a product, particularly a food material comprising:

forming or harvesting the product;

packing the product into a container;

exposing the product in the container to a cooling environment at a temperature lower than the temperature at which the product was packed,

wherein the container is provided with a means for ventilation, allowing the cooling environment to pass through the container, thereby subjecting substantially all of the product in the container to the same cooling environment, thereby minimising or reducing the variability of storage properties or characteristics of the product in the container. According to another aspect of the present invention, there is provided a method of cooling a product using a cooling structure having at least two adjacent sections for providing a cooling environment comprising:

packing the product into a container at an initial temperature;

locating the container in the first of the two adjacent sections at or towards one end of a conveyor means located at least partially within the cooling structure and capable of moving within the cooling structure;

periodically moving the conveyor in order to advance intermittently the container on the conveyor through the sections of the cooling structure in turn,

wherein the container remains in at least each section of the cooling structure for a time sufficient to cool the product to a temperature less than the initial temperature and/or to less than the temperature at which the container exits from the section located immediately preceding the section to which the container is moved, and

wherein the product within the container is subjected to the cooling environment so as to more or less substantially uniformly cool the product by the cooling environment passing through the container so as to enhance storage properties of the product and/or to reduce the time taken to cool the product to a temperature acceptable for storage.

Typically, the method includes the additional step of precooling the product to a moderate temperature by exposing the product in a transport container to a cooling environment at a temperature lower than ambient temperature at which the product is harvested. More typically, the container and the transport container are different containers. Even more typically, the temperature of the cooling environment is lower than a reduced ambient temperature at which the product is precooled.

Typically, the product is an edible or non edible manufactured or processed product or is a fresh product. More typically, the product is a food product such as a fresh fruit or vegetable, a bakery product or other fresh or manufactured food product, such as a food product that is warm or hot manufactured and requires cooling before further treatment, processing, storage, transporting, distribution or the like.

Typically, the cooling environment is an environment at a temperature lower than ambient temperature. More typically, the cooling environment has different parts, sections, regions areas or the like containing the produce at different temperatures. More typically, the cooling environment is at a temperature of less than about 15°C, preferably less than about 12°C, more preferably at a temperature of less than about 8°C. More typically, the cooling environment is at a temperature of lower than about 4°C. Most preferably, the temperature is at about 0°C to 1°C. However, it is to be noted that preferably the produce not be allowed to freeze, particularly that the parts of the product, such as for example, the stalks of the grapes not be allowed to freeze, although temperatures slightly below about O⁰C can be tolerated in some circumstances, provided the stalks of the grapes are not damaged, depending upon other environmental factors, such as humidity, pressure or the like.

Typically, the cooling environment is an air cooled environment. More typically, the air cooled environment is a forced air flow, preferably a fan forced air flow. Typically, the fans are tube axial fans. Typically, the fans can be of a range of sizes, types, power or the like, preferably from about 50 watts in power to about several kilowatts in power. More typically, the pressure of the air is sufficient to force the air through the produce so that each item or member of the produce is independently cooled, preferably each product is subjected to substantially the same environment. Even more typically, the environment is a moist environment or a moisture free environment or a combination of both environments in different parts of the overall installation. Typically, the relative humidity of the cooling environment is determined by the temperature differential across the air cooling coils, the rate of cooling and the amount of moisture condensed onto the cooling coils. The relative humidity and the duration of cooling typically will determine the quantity of moisture evaporated from the fresh produce. Typically, the cooling takes up to about 2 hours, preferably up to about 1 hour.

Typically, the food material is produce. More typically, the produce is fresh produce. Even more typically, the fresh produce is fruit or vegetables. Even more typically, the fresh fruit are grapes, preferably table grapes, more preferably, premium quality table grapes.

According to another aspect of the present invention, there is provided a cooling installation for cooling a food material in which the installation is provided with two or more discrete, separate or separable compartments or areas. Typically, there is at least one cooling tunnel, typically one, two, three, four or more cooling tunnels. Even more typically, each cooling tunnel has at least one compartment. More typically, there are a multiplicity or plurality of discrete compartments or cells. Even more typically, there are from 4 to 8 compartments - preferably 6 compartments - per cooling tunnel. Even more typically, each compartment is provided with one or more barriers, typically movable barriers. Even more typically, each compartment forms a cell for receiving relatively warmer produce and discharging relatively cooler produce.

Typically, the cooling installation of the present invention is a single layer installation having a single layer of product to be cooled or is a multi-layer installation having two or more layers located one on top of the other or in superposed or stacked relationship to each other. More typically, cooled air is forced between the superposed layers from the side as well as from above or below or both. More typically, cooled air is circulated through and around the different layers.

Typically, the container is provided with one or more a ventilation means. More typically, the ventilation means provides or allows passage of air through the container.

Even more typically, the container includes exhaust means. Typically, the ventilation means and/or exhaust means includes one or more slots, apertures, perforations or openings allowing air to pass therethrough for circulation and/or recirculation through the containers. Even more typically, the openings are provided in the side surface of the container, or in the base surface, or in both. Preferably, the openings are provided in the base surface only. More typically, the ventilation means occupies about up to about 20% to 25% of the base surface, preferably up to about 15%, more preferably up to about from 3-13%, and even more preferably about 10%, most preferably about 5% of the base area.

Typically, the openings may adopt any suitable size, shape, orientation or style. More typically, the openings are slots, preferably from about 6 to 12mm in width and from about 50 to 200mm in length, more preferably from about 80 to 120mm in length. More typically, the openings can be arranged in any arrangement, layout or pattern, such as for example in rows, typically staggered rows, spaced apart from each other so as not to unnecessarily weaken the box. The openings may extend in any direction, such as transversely, longitudinally or be angularly inclined to the sides of the box and to each other. The openings may be continuous or discontinuous, being made up of two or more parts or sections with a divider, spacer or similar therebetween. In one embodiment, the edges of the slots are rounded so as to minimise the chances of the box being snagged or similar by the conveyor. Even more typically, the openings allow cooled air to pass through the container. Even more typically, the slots allow cooling air to pass each individual product or produce member or item in the container so that each individual item or member is subjected to substantially the same cooling environment. Typically, there are two, three, four or more openings and/or guides associated with each container. Even more typically, the container is a box, preferably a box made from plastics material, such as polystyrene, styrofoam or the like, or from cardboard or a recycled material, including synthetic and natural materials.

Typically, the sides of the box are associated with and/or provided with baffles, deflectors, seals or guides to direct air to flow through the containers. More typically, the guide is a flap, plate, wing, vane or similar for directing the air flow or for sealing the container to force the air flow through the container. Typically, the flap, etc is mounted for hinged or pivotal movement. More typically, the flap, etc is hingedly mounted to the wall of the tunnel for pivotal movement to and from contact with the boxes as they move along the conveyor, such that when the boxes are being moved, the sealing flap is moved clear of the boxes, whereas when -the boxes are being cooled, the sealing flap is in contact with the side of the box. Even more typically, there is a single sealing flap extending through all of the compartments or cells, which when the flap moves, contacts the boxes simultaneously.

Typically, the conveyor is an open conveyor allowing movement of air through and around the conveyor and the boxes located on the conveyor. More typically, the conveyor is a link chain conveyor or similar. Typically, the conveyor is made from metal or resilient material or is a composite of two or more different materials. More typically, the conveyor is a chain, preferably a bicycle chain or similar. Even more typically, there are two or more separate chains located in spaced apart side by side relationship for supporting the boxes thereon. Typically, the weight of the produce in the container is sufficient to keep the container in contact with the conveyor or to transport the containers when the conveyor moves.

Typically, the chain is provided with wear pads, more typically, resilient or flexible wear pads.

Typically, the conveyor includes an array of rollers, typically the individual rollers are spaced apart, more typically, the rollers are arranged in spaced apart side by side relationship. More typically, the rollers are powered rollers being driven rollers or the like.

Typically, the conveyor moves intermittently and/or continuously. Typically, the conveyor moves periodically, sequentially, or the like. Typically, the time interval between movements is from 0.1 to about 10 minutes, preferably from about 0.1 to about 5 minutes, more preferably from about 0.5 to about 3 minutes, and most preferably from about 1.0 to about 2.5 minutes. Typically, the conveyor moves about the length of the container or the length of a cell each time it moves. Typically, there are the same number of movements to each cell as there are boxes in line within each cell. More typically, the conveyor moves about the length of a single box each time the conveyor moves.

The present invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a top plan schematic view of one arrangement on which the handling centre of the present invention is located in the form of a growing property or farm;

Figure 2 is a top plan schematic view of the layout of one form of the arrangement of the handling centre apparatus having the installation of the present invention, in which the cooling method is conducted;

Figure 3 is a view of one form of the flap seal at the side wall of the cooling tunnel; and

Figure 4 is one example of the base of one form of the container that can be used to hold the produce during the cooling process conducted in accordance with the present invention.

Although the present invention will be illustrated with reference to one example, which is the harvesting and handling of table grapes, it is to be noted that the scope of the present invention is not restricted to table grapes, or even to fresh produce, but rather the scope of the invention includes subjecting any product or material to an artificial environment, particularly a cooling environment and handling or processing the material in this environment. In Figure 1, there is shown schematically one typical layout of a farm property or vineyard for growing table grapes having a handling facility in which the apparatus and method of the present invention are carried out.

A property, generally denoted as 6, is provided with a vineyard or similar 10, having rows of vines 12 for producing table grapes and a handling centre 16 in the form of a packing shed, cool store or similar. At the appropriate time, usually in the hot season when the grapes are ripe, the table grapes are harvested. At this stage, all of the grapes which are ripe are picked as bunches regardless of their size and condition. Of necessity, there is variation in the size, quality and condition of the grapes within a bunch and between bunches. It is to be noted that for table grapes to be sold as premium grade grapes, it is desirable that the bloom contained on the outside of the grapes be maintained, as ultimate purchasers of premium quality table grapes believe the presence of the bloom is an indication of the quality of the grapes, as well as providing an attractive appearance for the grapes. Therefore, subsequent handling of the grapes should be such so as to minimise the removal of the bloom from the grapes. This requirement usually demands that there be minimal mechanical handling and transportation of the grapes. Thus, handling of the grapes is principally by hand.

After picking, the grapes are placed in suitable receptacles (not shown) for transport to a fruit handling centre 16. Such receptacles are termed "picking containers". Any convenient, desirable or suitable means of transporting the grapes to the handling centre can be used, such as for example, motorised vehicles and/or crates, bins or the like, including cooled, chilled or refrigerated vehicles containing the bunches of grapes placed in the crates by the people picking the grapes in the field. If necessary, motor vehicles travel along access road 14 to get to the handling centre.

The handling centre 16 includes a number of discrete sections, such as a first section which can be termed a temporary storage section 18 or a precooling section. Optionally, other pretreatment sections are also provided if required for specific functions, a gassing chamber or room or the like. Grapes are first deposited after being transported from the field at or near to the precooling section 18 on arrival at the handling centre 16, where the picking containers are subjected to forced air cooling. From there the picking containers are moved to a second section which is known as a packing section 22 where individual bunches of grapes are removed from the picking container and are sorted and graded in accordance with their type, size, quality, condition or other properties or characteristics into containers of grapes having generally the same or similar properties, characteristics or qualities. The handling centre 16 is provided with an overall environment which is below ambient temperature, typically a temperature of from about 25°C to about 35°C, so that as soon as the grapes arrive and are deposited in the handling centre, the cooling process commences so as to cool the grapes initially, particularly when the grapes are temporarily stored in the precooling section 18. Preferably, the pre-cooling section is provided with a cooler, such as for example of the type made by

Thermfresh® or the like, for cooling the grapes as soon as the grapes enter the handling centre and whilst awaiting sorting and packing in the packing station. It is desirable that the grapes, after picking, arrive at the handling centre in as short a time as possible and that cooling of the grapes commences as soon as possible after picking to minimise or reduce the onset of deterioration or spoilage, particularly in hot or warm weather. Typically, the pre-cooling of the grapes reduces their temperature from ambient temperature of between about 25°C to 35°C to about 8°C to 16°C, typically between about 12°C to 16°C, whilst in the pre-cooling and/or packing section.

Typically, the produce is located in the packing section 22 and/or pre-cooling section 18 for a dwell time of up to about 8 hours, typically up to about 4 hours, and more typically from about 2 to 3 hours.

After the bunches of grapes are sorted and graded into suitable containers, the containers are passed to a second section of the handling centre 16 which is a cooling section 30 by means of a generally longitudinally oriented conveyor system 26 or similar, and a generally transversely oriented conveyor system, endless belt or similar 28. It is to be noted that the individual conveyor systems can take any number of different forms which are suitable for use with the particular product being cooled.

In one embodiment, the cooling section 30 is provided with a cooling tunnel arrangement 32 having a conveyor system for conveying containers of bunches of grapes from the packing section 22 through to a further section of the handling centre 16 which is the storage section 40. It is to be noted that any suitable conveying system can be used. One particularly advantageous conveying system includes an open system, such as for example, a link chain arrangement, typically a bicycle chain, allowing cooled air to circulate around and through the conveyor and the boxes of grapes located on the conveyor. A particularly preferred form of the conveyor includes at least two spaced apart bicycle chains operating in tandem or unison for supporting the boxes of grapes thereon. It is to be noted that any number of substantially parallel spaced apart conveyor chains can be provided depending upon the number of boxes being transported. The chains are provided with strategically placed wear pads, preferably made from a resilient or shock-absorbing material. Further, it is to be noted that the weight of the full boxes is sufficient to maintain contact between the boxes and the chain, particularly as the boxes are made from relatively soft and/or deformable plastics material, such as styrene or similar, allowing individual links of the chain to bite into and grip the undersurface of the boxes. In other embodiments, the conveyor system includes one or more arrays of rollers arranged in side by side spaced apart relationship to one another. A particularly preferred form of the roller is a powered roller.

The cooling tunnel 32 further includes one or more tube axial fans for blowing cooled air over the grapes to provide the majority of cooling to the grapes.

In one embodiment, the cooling tunnel is divided into six separable compartments 34 or cells located sequentially in line to allow boxes of grapes to pass through each compartment in turn as they are transported from the packing station 22 to the storage station 40. Barriers 36 are located at spaced apart locations to divide the tunnel into the 6 cells. The barriers can be fixed barriers, adjustable barriers or movable barriers, as will be described in more detail later in this specification.

Above each compartment of the cooling tunnel is provided a refrigeration, air conditioning or cooling installation for providing cool air at a predetermined temperature and at a predetermined rate to the compartment, as well as at other predetermined conditions, such as relative humidity, pressure, velocity and the like. Any suitable refrigeration or cooling installation may be used. A particularly preferred installation provides air from above blowing down and through the boxes of grapes and the conveyor system for recirculation back to the refrigeration installation or cooling installation by suitable return systems. In this manner, cooled air is blown onto and through the boxes on the conveyor system to cool the produce individually.

Each cell is provided with one or more fans and each fan can be from a few watts up to several kilowatts. Typically, each fan is from about 50 watts to 10 kilowatts, more typically, from about 50 to 100 watts.

A typical air flow rate is up to 10 litres of air per kilogram of grapes per second. A preferred air flow rate is from about 0.5 to about 10 1/kg/sec, more preferably from 1 to 5 1/kg/sec, a more preferred rate is from 1 to 3 1/kg/sec whilst a most preferred rate is about 2 1/kg/sec. The temperature of the air can be selected in accordance with requirements which will be discussed later in this specification. Further, it is to be noted that in some embodiments, no added moisture is required in the cooling tunnel. However, if required, moisture can be added if necessary or desirable.

In one embodiment, the humidity is controlled or increased by having a spray system for spraying water either continuously or intermittently through nozzles or similar located at spaced apart locations throughout one or more sections of the cooling installation.

In a particularly preferred embodiment of the cooling station, there are 20 boxes of grapes arranged in an array, including four rows of boxes, in which each row has 5 boxes so as to form a cell of 20 boxes. A cell of 20 boxes is located in each compartment and all move simultaneously from one compartment to the next. Therefore, each cell equates to 20 boxes being held in each compartment. Further, it is to be noted that within each cell, all of the 20 boxes are in abutting relationship with adjacent boxes so that there is substantially no gaps between adjacent boxes, such as between adjacent respective side walls and adjacent respective end walls. This has the effect of directing the flow of cool air through the boxes to cool the contents.

It is to be noted that there can be a single conveyor system conveying 20 boxes per cell or two or more conveyor systems located in side by side relationship in which each conveyor conveys 20 boxes per cell depending upon the size of the harvest and/or the handling centre. Thus, each compartment can have 20, 40, 60, 80 boxes or more depending upon whether there are 1, 2, 3, 4 or more conveyors. In Figure 2, there is shown 4 conveyors 38 located in side-by-side relationship in which there are 6 cells for each conveyor.

In operation of one embodiment of the cooling tunnel 32, the first 20 boxes are placed in the first cell in an abutting side by side array where they are retained for a predetermined period of time to allow the temperature of the grapes to reduce to about half the initial temperature. As an example, grapes arriving from the packing station 20 at a temperature of about 16°C or so are cooled to about 8°C in the first compartment. The temperature and flow rate of the air is adjusted accordingly to achieve this temperature drop. It is to be noted that in this first compartment not all of the produce may be reduced to the same temperature, but there may be a slight temperature difference between bunches of grapes where there is increased back pressure to air flow as compared to being located where there is less restriction to air flow in the compartment. However, any variation will be equalised by further movement through the cooling tunnel. When the temperature of the grapes within the first compartment reaches on average the predetermined half initial temperature, the conveyor operates automatically to transfer all of the boxes of grapes to the second compartment, whereupon cooling is applied to reduce the temperature further. It is to be noted that the cooling conditions in the second compartment may be the same as or different to the cooling conditions in the first compartment, depending upon the temperature drop required. Simultaneously with the first group of boxes moving from the first cell to the second cell, a further group of 20 boxes is loaded onto the conveyor in the first cell and subjected to cooling air flow in that compartment so that cooling of the grapes in the first compartment can take place, again from the initial temperature of about 16°C to about 8°C.

A typical time for the boxes to be located in an individual cell is from about 0.1 to about 30 minutes, preferably from about 0.5 to 20 minutes, more preferably from about 3 to 15 minutes, even more preferably from about 5 to 12 minutes, and most preferably from about 8 to 10 minutes.

After the predetermined amount of time for the box to be cooled in the cell has elapsed, the conveyor is operated to transport the boxes of grapes in compartment 2 into compartment 3 and simultaneously transport the boxes in compartment 1 to compartment 2, leaving compartment 1 free to receive a further cell of 20 boxes. After the predetermined time has elapsed, the conveyor again moves the boxes in one cell onto the next cell and so on until each box moves through all of the cells. Thus, the conveyor is operated intermittently every 10 minutes or so to move all boxes simultaneously through each of the 6 compartments in turn. In this embodiment, each movement of the conveyor is about the length of 4 boxes aligned end to end, which is about 1.5 to 2.0m. However, the movement is in accordance with the size of the boxes.

Thus, all of the boxes are subjected to the same cooling as they move progressively through each of the compartments in turn. The conveyor of the cooling tunnel is operated intermittently until all of the production for a particular day is cooled to the required temperature, as each of the boxes is passed through each of the 6 compartments in turn.

A typical temperature reduction in the cooling tunnel is shown in Table I.

TABLE I,

The boxes of grapes are removed from the last or sixth compartment into the storage area 40 located at or towards the end of the cooling tunnel 32 by means of a generally transversely oriented conveyor line, endless belt or the like 42. In storage area 40, the boxes are palletised and the pallets 44 are wrapped in plastic film or similar to retain moisture and to maintain the boxes at a temperature of between about 0.0 to 0.5°C. The individual boxes are wrapped to prevent moisture from egressing through the slots in the base of the boxes and to assist in insulating the boxes. The wrapped boxes are directly placed on pallets where they are ready for almost immediate transportation through discharge docks 48. In this manner, the boxes do not need to be stored in racks or shelves, and certainly not for periods of time of up to 24 hours to cool down sufficiently for transporting to market, since they are already cooled to as low as 0°C - 0.5⁰C. Additional refrigerated storage is provided in refrigerated storage area 50 for storing wrapped pellets or other product.

In this embodiment, the movement of produce through the handling centre is in the direction of the arrows shown in Figure 1, starting with arrow A denoting the introduction of picked containers from the vineyard, and ending with arrow B through discharge dock 48.

In one embodiment, the barriers forming the cells are movable, such as for example, vertically movable curtains, barriers or partitions which are provided to divide the cooling tunnel into the 6 compartments. In this embodiment, there are 7 such movable barriers; 2 at the ends of the tunnel and 5 dividing the tunnel into the 6 compartments. The movable barriers can be lowered until the bottom surface or similar of the barrier is resting upon the top surface of the boxes, particularly the edges of the boxes, or between selected rows of boxes. Typically, the barriers move up and down only a few centimeters if required. A seal of resilient material is provided along the lower edge of the movable barrier to seal the compartment so that cooled air flowing through the compartment is forced to travel through the boxes around the individual berries or grapes to exit through the slots in the boxes.

One embodiment of the seal is a generally D-shaped compressible or resiliently or elastically deformable strip or roll, typically made from a plastics material, rubber material or the like, provided along or attached to the lower edge in use of the movable barriers. The barriers can be raised to allow boxes to pass underneath the barrier when on the conveyor and accordingly, there is a clearance gap between the barrier and the box and then lowered to contact the box when the barrier is in the raised position. The barrier is then lowered to contact the box to seal the cell. In one embodiment, as shown in Figure 3, there is provided a lengthwise extending flap 60 which is hingedly mounted onto the wall 62 for pivotal or hinged movement through about 50-80° of rotation, as shown by arrow Y of Figure 3, to move the flap 60 into engagement with and away from contact with the boxes 64 so that when the boxes 64 are stationary, the flap 60 is in contact with the aligned boxes to direct cooling air through the boxes, and when the boxes are moving, the flap is rotated clear of the boxes to allow the boxes to be transported along the direction of the conveyor.

In another embodiment, the barriers are adjustable in width to allow for different size boxes to be conveyed through the cooling installation. In still further embodiments, the gap or space remaining after the barrier has moved is adjustable in size, particularly width to minimize the amount of heat transferred by operation of the barrier.

Another embodiment of the cooling tunnel includes the following arrangement. The cooling tunnel is divided into individual conveyors, such as 4 conveyors 38, as shown in Figure 2, with each conveyor divided into 6 cells. In this embodiment, the conveyor moves about the length of a single box length, ie., about 450mm every 2.5 minutes or so. In this embodiment, instead of all boxes in a cell moving simultaneously from one cell to the next, the boxes all move in unison from one position to an adjacent position down the line. Thus, the conveyor has five short moves rather than a single long move, so that the boxes remain in the cell for the same length of time and are subject to the same cooling environment as in the previously described embodiment. In this embodiment, a first transverse line or row of boxes of grapes are loaded onto the conveyor in cell 1 along the first position in the cell. After a predetermined interval, the conveyor moves about 1 box length to move the line of boxes to a second position. A further line of boxes is added to the now vacant first line. After the set time interval has elapsed, the conveyor moves the boxes to the next position and so on until all the boxes are transferred through the tunnel from one end to the other end to cool the produce to the required temperature.

In this embodiment, there is provided 15 blank, empty- boxes in front of the first row of boxes filled with produce. In this manner, each box is moved through each cell in turn and resides in each cell sufficiently long enough to be cooled to the required temperature in each cell and overall as it periodically moves from the beginning of cell 1 to the end of cell 6. At the end of a cooling run 15 blank empty boxes are added after the last row of five boxes of produce.

With particular reference to Figure 4, one form of the container having the ventilation means of the present invention will be described. In this embodiment, the container is provided with one form of the vent pattern in the base of the container. Container 70 is in the form of a box provided with an open top, a planar base 72, and four side walls 74 extending substantially perpendicularly from the planar base 72. Base 72 is provided with an array of openings in the form of slots 76 allowing cooling air to pass through container 70. In one embodiment, slots 76 are all arranged to extend in a substantially lengthwise direction substantially spaced apart from each other in substantially parallel relationship so that an alternate array of slots 76 is formed. Although slots 76 are shown as being substantially rectilinear, it is to be noted that the openings may take any suitable size and/or shape and be of any suitable arrangement or pattern in accordance with the purpose of the openings, which is to allow air to circulate and travel through the container whilst the integrity, strength, rigidity or the like of the container is maintained, enabling storage and transport of the containers.

An optional feature of the cooling installation is the presence of a pretreatment area or enclosure such as for example a gas treatment room, gas chamber, sealed atmosphere room or the like for subjecting the product to a gaseous atmosphere in accordance with requirements. One example of a gas treatment is to assist ripening of fruit or vegetables. Another example of a gas treatment is a fumigation treatment required if the produce is to be exported or the like.

Advantages of the present invention include that the time taken to cool the fruit or other fresh produce to the required temperatures is considerably reduced, as the cooling is more effective by allowing the cooled air to flow through the boxes and not around the boxes. This in turn allows the fruit to be subjected to more constant conditions so that there are constant storage characteristics for the fruit. The cooling method of the present invention is faster. There is no need to provide large capacity storage shelves or racking.

The described arrangement has been advanced by explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features herein disclosed.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method of cooling a product, particularly a food product or material comprising the steps of providing the product in a container and subjecting the product to a cooling environment in order to cool the product located in the container characterised in that each individual item of product in the container is subjected to a cooling environment so as to more or less substantially uniformly cool the product to reduce or minimise the variability of storage properties or characteristics of the product.

2. A method of minimising and/or reducing the extent of deterioration or degradation of a product, particularly a food material comprising the steps of forming or harvesting the product, packing the product into a container, exposing the product in the container to a cooling environment at a temperature lower than the temperature at which the product was packed characterised in that the container is provided with a means for ventilation, allowing the cooling environment to pass through the container, thereby subjecting substantially all of the product in the container to substantially the same cooling environment thereby minimising the variability of storage properties or characteristics of the product in the container.

3. A method of cooling a product using a cooling structure having a least two adjacent sections for providing a cooling environment characterised in that the method includes packing a product into a container at an initial temperature, locating the container in the first of the two adjacent sections at or towards one end of the conveyor means located at least partially within the cooling structure and capable of moving within the cooling structure, periodically moving the conveyor in order to advance intermittently the container on the conveyor through the sections of the cooling structure in turn, such that the container remains in at least each section of the cooling structure for a time sufficient to cool the product to a temperature less than the initial temperature and/or to less than the temperature at which the container exits from the section located immediately preceding the section to which the container is moved and wherein the product within the container is subjected to the cooling environment so as to more or less substantially uniformly cool the product by the cooling environment passing through the container so as to enhance storage properties of the product and/or to reduce the time taken to cool the product to a temperature acceptable for storage.

4. A cooling installation for cooling a product in which the installation is provided with two or more discreet separate or separable compartments or areas arranged such that the product is moved sequentially through the installation from one of the compartments to the other compartment such that the product is subjected to a cooling environment by periodically moving the product through the compartments.

5. A cooling installation or method according to any preceding claim characterised in that it includes an additional pre-treatment section or additional step of pre-cooling the product to a moderate temperature by exposing the product to a cooling environment at a temperature lower than ambient temperature.

6. A method or cooling installation according to any preceding claim characterised in that the product is an edible or non-edible product including a manufactured or processed product or a fresh product.

7. A cooling installation or method according to any preceding claim characterised in that the cooling environment has different parts, sections, regions, areas or similar for subjecting the product to different temperatures such as a temperature of less than about 15°C, preferably less than about

12°C, preferably less than 8°C, more preferably lower than 4°C and most preferably between about 0° - 1°C.

8. A method or cooling installation according to any preceding claim characterised in that the cooling environment is provided by a forced air flow, preferably a fan forced air flow and more preferably a tube axial fan.

9. A method or cooling installation according to any preceding claim characterised in that the cooling environment is a moist environment or a moisture free environment.

10. A method or cooling installation according to any preceding claim characterised in that the relative humidity of the cooling environment is determined by the temperature differential across the air cooling coils, the rate of cooling and the amount of moisture condensed onto the cooling coils provided for each cooling section of the installation.

11. A method or cooling installation according to any preceding claim characterised in that there is at least one cooling tunnel comprising one, two, three, four or more cooling compartments.

12. A method or cooling installation according to any preceding claim characterised in that there is a single cooling layer or multiple cooling layers such as two superposable layers located one on top of the other.

13. A method or cooling installation according to any preceding claim characterised in that the product is located in a container when in the cooling compartment wherein the container is provided with one or more ventilation means allowing passage of air through the container to substantially cool each individual item in the container.

14. A method or cooling installation according to any preceding claim characterised in that the ventilation means includes one or more slots, apertures, perforations, openings or passages provided in the base and/or walls of the container allowing air to pass therethrough for circulation and/or recirculation through the container.

15. A method or cooling installation according to any preceding claim characterised in that the sides of the container are provided with baffles, deflectors, seals or guides to direct air flow through the containers wherein the guide is a flap, plate, wing, vane or similar for directing the air flow through the container or for sealing the container to force air flow through the container.

16. A method or cooling installation according to any preceding claim characterised in that the guide is mounted or hinged for pivotable movement with respect to the container.

17. A method or cooling installation according to any preceding claim characterised in that the compartment is provided with a conveyor system for transporting the product through the compartment wherein the conveyor allows movement therethrough and around the conveyor.

18. A method or cooling installation according to any preceding claim characterised in that the conveyor is an open conveyor in the form of a link chain conveyor or roller conveyor having spaced apart elements.

19. A method or cooling installation according to any preceding claim characterised in that the conveyor moves intermittently or continuously.

20. A method or cooling installation according to any preceding claim characterised in that the conveyor moves periodically with the time interval between movements from about 0.1 to about 10 minutes, preferably from about 0.1 to 5 minutes, more preferably from about 0.5 to 3 minutes, most preferably from about 1 to about 2.5 minutes.

21. A method or cooling installation according to any preceding claim characterised in that the produce is table grapes.

22. A method or cooling installation according to any preceding claim characterised in that the cooling tunnel is divided into six separable compartments or cells located sequentially in line allowing containers of product to pass through each compartment in turn as they are transported through the tunnel.

23. A method or cooling installation according to any preceding claim characterised in that there is a multiplicity barriers located at spaced apart locations to divide the tunnel into the compartments wherein the barriers are fixed barriers, adjustable barriers or movable barriers arranged to prevent or minimise the loss of heat from the compartments.

24. A method or cooling installation according to any preceding claim characterised in that each compartment is provided with an air flow rate of cool air wherein the air flow rate is up to 10 litres of air per kilogram of product per second being treated in the tunnel, preferably a rate of from 0.5 to about 10 1/kg/s, more preferably from 1 to 5 1/kg/s, more preferably 1 to 3 1/kg/s and most preferably about 2 1/kg/s.

25. A method or cooling installation according to any preceding claim characterised in that the temperature is reduced from about 16°C to about 20°C in the first compartment.

26. A method or cooling installation according to any preceding claim characterised in that the container resides in a compartment from about 0.1 to about 30 minutes, preferably from about 0.5 to 20 minutes, more preferably from about 3 to 15 minutes, even more preferably from about 5 to 12 minutes and most preferably from about 8 to 10 minutes.

27. A method or cooling installation according to any preceding claim characterised in that the temperature in the first compartment is reduced from about 16° to about 8°C, in the second compartment from about 8°C to about 4°C, in the third compartment from about 4°C to about 2°, in the fourth compartment from about 2°C to about 1°C, in the fifth compartment from about 1°C to .5⁰C and in the sixth compartment from about .5°C to about

0°C.

28. A method or cooling installation according to any preceding claim characterised in that each compartment is provided with at least one sealed barrier for preventing heat loss wherein the barrier is provided with a seal.

29. A method or cooling installation substantially as hereinbefore described with reference to the accompanying drawings.