AU2007231867A1 - Tank system for storage and/or maturation of an alcoholic beverage - Google Patents

Description

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Tank system for storage and/or maturation of an alcoholic beverage 0 z FIELD OF THE INVENTION The present invention relates to the storage and/or maturation of an alcoholic beverage in particular to the maturation of wine.

00 BACKGROUND OF THE INVENTION Traditionally wooden barrels have been used to store and mature alcoholic Obeverages such as wine. Wood barrels are used because they allow the wine to breathe during the maturation process and they impart favourable characteristics to the wine. The issue with wooden barrels is that they are expensive and only have a limited useful life. After roughly three years, most of a barrel's flavour compounds have been leached out and the pores in the wood have become clogged with detritus and are not able to function effectively. The wood barrels also allow for the evaporation and potentially the leakage of wine which means that they need to be topped up at intervals during the maturation process. Typically the barrel is topped up from wine stored in another barrel.

More recently stainless steel vessels have become popular. These vessels allow for bulk storage and maturation of wine. However they require the manual addition of oxygen (micro-oxygenation) and the use of oak planks or oak chips.

Furthermore, pitting of the stainless steel interior can destroy the integrity of the tank thereby rendering the tank useless. Pitting can occur when stainless steel is subjected to high concentration of chloride ions such as during cleaning of the vessel with a mild caustic solution.

During the maturation process oxygen must be rationed to the wine. If too much oxygen comes into contact with the wine the oxidation of ethanol will produce vinegar. Accordingly it is important to minimise the atmospheric air coming into direct contact with the wine during maturation. This is particularly important in the headspace or ullage of the maturation vessel. If oxygen is not minimised in the headspace it can lead to aerobic bacterial spoilage of the wine. As can be appreciated the resultant formation of scum and mound is detrimental to the wine.

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In recent times thin walled polyethylene vessels have been used to mature z wine. Polyethylene is easy to sanitise and can be cleaned with mild caustic preparation without the risks associated with stainless steel vessels. Furthermore, the material is gas permeable which allows for the rationing of oxygen. Unlike traditional wooden barrels however the material does not have pores that clog over time. The material therefore is therefore good at retaining its gas permeability.

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The problem with these thin walled polyethylene vessels is that because they are flexible they are difficult to transport. Furthermore, the vessels tend to expand and distort out of shape which can pose problems if they are being stored in close proximity to other vessels. There are also difficulties associated with purging the headspace.

It is therefore an object of the present invention to overcome at least some of the aforementioned problems or provide the public with a useful alternative.

It is yet a further object of the present invention to provide for a tank system for use in the maturation of wine.

SUMMARY OF THE INVENTION Therefore in one form of the invention there is proposed an apparatus for the storage and/or maturation of a liquid, including: a gas permeable flexible vessel adapted to hold a quantity of the liquid therein; and a substantially rigid frame adapted to prevent undesirable expansion of the vessel.

Preferably the liquid is wine.

In preference the wine is housed within the flexible vessel for the purposes of maturation.

Preferably the flexible vessel is gas permeable.

Most preferably the vessel is constructed from polyethylene.

Preferably the frame includes transversely extending members adapted to accommodate the prongs of a forklift. These members may be located towards the 4 bottom of the frame or indeed may be located closer to the top the latter configuration z ensuring that the vessel is not punctured by forklift tynes.

In preference the sump is supported on and partially extends below the transversely extending members to thereby lower the centre of gravity of the 5 apparatus and to assist in the removal of the liquid therefrom.

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00 Preferably the flexible vessel further includes a headspace, a bung tap and a fluid passage.

In preference the bung tap is located in close proximity the headspace.

Most preferably the bung tap is adapted to be used as an outlet for the liquid contained within the flexible vessel and an inlet for a gas.

Preferably the gas is an inert gas which is interjected into the flexible vessel to replace the oxygen containing air in the headspace.

In preference the bung tap includes a connection member adapted to be connected to a hose which is in communication with a source of compressed inert gas.

Preferably, the fluid passage is located at the lowest point of the sump.

In preference the fluid passage includes a valve adapted to control the passage of liquid therethrough.

Most preferably the fluid passage is configured to be used as an inlet or as an outlet.

Preferably a cleaning member can be inserted into the flexible vessel to thereby undertake cleaning.

In preference the apparatus includes an internal frame which is adapted to suspend at least one wooden member for the purpose of oaking of the liquid contained therein.

BRIEF DESCRIPTION OF THE DRAWINGS

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The accompanying drawings, which are incorporated in and constitute a part 0 of this specification, illustrate several implementations of the invention and, together z with the description, serve to explain the advantages and principles of the invention.

In the drawings, 5 Figure 1 is a perspective view of a tank system of the present invention in a

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0 stacked arrangement; Figure 2 is a perspective view of the tank system of Figure 1; Figure 3 is an underside perspective view of the tank system of Figure 1; Figure 4 is a front cross-sectional view of the tank system of Figure 1 illustrating an optional internal frame for suspending planks of oak; Figure 5 is a side cross-sectional view of the tank system of Figure 1, illustrating the injection of inert gas through the bung tap; Figure 6 is a perspective view of the tank system of Figure 1, illustrating the insertion of oak planks into the tank; and Figure 7 is a perspective view of the tank system of Figure 1, illustrating the attachment of a cleaning apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.

Referring to the drawings for a more detailed description, an apparatus or unit 10 is illustrated, demonstrating by way of example one arrangement in which the principles of the present invention may be employed. The apparatus 10, as illustrated in Figure 1, includes a flexible vessel or tank 12 and a substantially rigid frame 14. Figure 1 illustrates apparatus 10 in a stacked arrangement with three 6 individual units placed one on top of another. As would be appreciated the ability to z stack the units has significant space saving advantages. Each tank 12 includes a headspace 16 with removable lid 18, a valve assembly 20 and a bung tap 22.

The frame 14 includes two transversely extending members 24 adapted to 5 accommodate the prongs 26 of a forklift 28. In this way each unit 10 can be moved oO independently for the purposes of storage, cleaning or accessing the wine contained t' therein. Although shown located towards the bottom of the frame the members may equally be located towards the top of the frame. This would also generally need the leg supports to be longer at the top to ensure that the top of the members are still C 10 within the space defined by the frame and do not extend beyond it.

Although the tank 12 is constructed from a material that is gas permeable and is relatively thin walled, the tank 12 is prevented from expanding undesirably by the use of the substantially rigid frame 14. This allows for unit 10 to be placed in close proximity to another without the risk of the tank 12 expanding in such a way as to encroach upon another unit 10. As the reader would appreciate, if this was to occur between adjacent stacks it may result in a domino effect with disastrous consequences.

It is envisaged that the tank 12 will be constructed out of 3mm-2.5cm thick polyethylene. Typically such vessels have oxygen permeability in the range between 10mg and 70mg of atmospheric 0 2 /m 2 of tank surface per 24hr for each 1mm of tank wall thickness at typical storage temperatures of 20-25 0 C. Polyethylene is easy to sanitise and can be cleaned with mild caustic preparation without the risks associated with cleaning of stainless steel vessels with this type of solution.

Furthermore the material does not have pores that clog over time as occurs in traditional wooden barrels. The material therefore retains its gas permeability. It should however be appreciated that the invention is not limited to the thickness or the material and any material could be used provided it is permeable to gas.

As illustrated in Figure 2 the frame includes vertical extending legs 30 located at each corner, with horizontal beams 32 extending therein between. It is envisaged that the legs 30 and beams 32 will be constructed from steel square hollow sections (shs) or rectangular hollow sections (rhs) to provide the greatest strength whilst minimising the overall weight of the apparatus. The frame 12 further includes brace 7 members 34 and rails 36. The brace members 34 are positioned to prevent O undesirable expansion in the side walls 38 of the tank 14. The rails 36 which are constructed from 90' steel extrusion are welded onto legs 30. The rails 36 serve a dual purpose; firstly they prevent movement of the legs 30 due to the forces applied to them by the tank 12 when filled and, secondly they serve as a locating means for the legs of a second unit during stacking as illustrated in Figure 1.

00 t' As illustrated in Figure 3 the transversely extending members 24 include two rectangular hollow sections (rhs) 40 interconnected by a length of C-section 42. It is Senvisaged that sections 40 and 42 will be constructed from steel and be welded to the underside of beams 32. The C-section 42 acts as a guide for the forklift prongs and as a support for the underside 44 of the tank 14 in conjunction with the beams 32 as illustrated in Figure 4.

As is further illustrated in Figures 3 and 4 the tank 14 includes a sump 46 that extends in a downward direction between the adjacent transversely extending members 24. This means that the centre of gravity of the apparatus 10 is lowered which increases its stability during transportation. The valve assembly 20 is located at the lowest point of the sump 46 and is used for both an inlet and outlet for wine.

The valve assembly 20 is also used during the cleaning process to remove the used mild caustic solution. However the reader must appreciate that indeed the tank may not have a sump and that the floor of the tank is relatively flat with the valve assembly located in the middle of the floor.

As illustrated in Figure 4 the upper surface 48 of the tank 14 slopes upwardly and inwardly towards the headspace 16. This prevents air pockets from forming as the tank 14 is filled with wine 50. The apparatus 10 may further include an internal frame 52 adapted to suspend portions of oak 54 within the wine. It is envisaged that the frame will include at least one removable portion which is adapted to engage the oak portions. In this way the oak can be easily removed from the tank at any desired time during maturation of the wine.

If the headspace contains high oxygen levels during maturation and storage the wine in the upper layers becomes oxygen rich. This increases the levels of aerobic bacteria which produce volatile acidity and acetaldehyde. For this reason head spaces are often purged with an inert gas such as nitrogen so that the wine can 8

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be safely kept in storage for a longer period of time. It is standard practice to limit the 0 oxygen content within the headspace to around The difficulty arises in trying to z purge the headspace whilst preventing or at least minimise the oxygen from entering.

In the present invention, as illustrated in Figure 5 the bung tap 22 is adapted to connect to a conventional high pressure hose 56 which is in communication with a N source of compressed gas (not shown). Traditionally bung taps are solely used for the purposes of obtaining a sample of wine during maturation and storage. In the present invention the bung tap 22 can also be used for injecting the inert gas into the Stank 12 to replace the oxygen rich air in the headspace 16. This is accomplished by N 10 passing an inert gas through the hose 56 which is in communication with a source of compressed inert gas in the direction of arrow 58. The inert gas enters the body of wine 50 and bubbles to the highest point of the tank 12 in the direction of arrows A gas analyser 62 can be connected to an access point 64 in the lid 18 by way of pipe 66. In this way the level of oxygen in the headspace 16 can be measured as the air is forced out in the direction of arrows 68. The vintner can then accurately measure the oxygen concentration within the headspace. As the reader would now appreciate the invention provides an accurate way of purging the headspace irrespective of its size.

As further illustrated in Figure 6 the internal frame 52 includes a removable hanger 70 to which oak planks 54 can be attached. This hanger 70 can be inserted into or removed from the tank 12 at any stage of maturation of wine as illustrated by arrow 72. Furthermore, as the skilled addressee would appreciate the hanger 70 and attached oak planks 54 can be removed during the maturation process without having to remove the wine. This can be done to remove, reduce or even replace the oak planks thereby enabling the vintner to control the degree of oak extraction.

As the skilled addressee would appreciate, polyethylene tanks are easy to sanitise with mild caustic preparation. Figure 7 illustrates a cleaning apparatus 74 which includes a shaft 76 and rotatable spray head 78 that is adapted to be inserted through the access point 64 in the lid 18. The cleaning apparatus 74 can be connected by way of pipe 80 to a source of cleaning solution 82. The source 82 is further connected to the valve assembly 20 by way of pipe 84 to complete a closed system. This means that the cleaning solution can be recycled and it is envisaged 9 that the source 82 will further include various filters and pumps which are not shown o to assist in the recycling of the solution.

z The skilled addressee will now appreciate the many advantages of the present invention. The invention provides a useful tank system that can be used for 5 the maturation and storage of wine and other alcoholic beverages which overcomes 00 many of the problems with the prior art. The tank system is easy to transport and t' minimises the space usage by being able to be stacked. The tanks system utilises the benefits of gas permeable polyethylene whilst overcoming the issues relating to Sundesirable expansion of tank. The tank system also provides an accurate way of C 10 purging the headspace irrespective of its size.

There are a number of separate advantages of the present invention that may e present individually or in combination. These include: The rectangular shape of the tank and the support provided by a frame extending around the whole of the tank thereby minimising or completely avoiding bulging of the tank.

The configuration of the frame that lends itself to vertical stacking of a number of tanks without requiring sideways support, that is, the tank does not need to be secured to another frame before a second tank can be stored on top.

The use of a secondary sampling or bung hole that enables the contents of the tank to be sampled.

The use of members that accommodate the tynes of a forklift located either at the bottom or the top of the tank The draining of the wine through a sump located at the bottom of the tank to ensure that all of the wine can be drained.

Yet further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention.

Any discussion of the prior art throughout the specification should in no way O be considered as an admission that such prior art is widely known or forms part of Z the common general knowledge in this field.

In the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in 0 the sense of "including", i.e. the features specified may be associated with further 00 Ifeatures in various embodiments of the invention.

Claims (13)

1. An apparatus for the storage and/or maturation of wine including: a gas permeable flexible vessel adapted to hold a quantity of the liquid therein; and a substantially rigid frame adapted to prevent undesirable expansion of the vessel. \D o00 5

2. An apparatus as in claim 1 wherein the flexible vessel is gas permeable.

S3. An apparatus as in claim 1 or 2 wherein the vessel is constructed form polyethylene.

4. An apparatus as in any of the above claims wherein the frame includes transversely extending members adapted to accommodate the prongs of a forklift.

5. An apparatus as in claim 4 wherein the members are located adjacent the bottom of the frame.

6. An apparatus as in claim 4 wherein the member are located adjacent but do not extend beyond the top of the frame.

7. An apparatus as in any one of the above claims further including a sump supported on and partially extending below the transversely extending members to thereby lower the centre of gravity of the apparatus and to assist in the removal of the liquid therefrom.

8. An apparatus as in any one of the above claims further including a headspace, a bung tap and a fluid passage.

9. An apparatus as in any one of the above claims wherein the bung tap is located in close proximity the headspace.

An apparatus as in any one of the above claims including an internal frame which is adapted to suspend at least one wooden member for the purpose of oaking of the liquid contained therein.

11. A tank assembly for the storage and/or maturation of wine including: a gas permeable flexible tank adapted to hold a quantity of wine therein and having an underside, an upper surface and side walls, each said side wall being 12 generally flat; z a frame for supporting the tank and including bracing elements extending horizontally around the whole tank to brace the flat side walls of the tank against Sbulging; a headspace extending from the upper surface; Sa valve for draining wine from the tank; and 00 prong access means for allowing entry of the prongs of a forklift.

12. A tank assembly as in claim 11 further including a sampling outlet located on one Sof said side walls.

13. A tank assembly as in claim 11 where a first frame is configured to hold a second frame on top of the first frame.