AU2010100553A4

AU2010100553A4 - A tank system for the storage and maturation of wine

Info

Publication number: AU2010100553A4
Application number: AU2010100553A
Authority: AU
Inventors: Neal Palmer
Original assignee: REDOAKER Pty Ltd
Current assignee: Individual
Priority date: 2008-12-24
Filing date: 2010-06-02
Publication date: 2010-09-09
Anticipated expiration: 2029-12-18
Also published as: AU2009251011A1; AU2010100553B4

Description

2 A tank for the storage of fluids FIELD OF THE INVENTION The present invention relates to a tank for the storage of fluids and, in particular, to a tank system for the storage and/or maturation of an alcoholic beverage 5 in particular to the maturation of wine. BACKGROUND OF THE INVENTION Traditionally wooden barrels have been used to store and mature alcoholic beverages such as wine. Wood barrels are used because they allow the wine to breath during the maturation process and they impart favourable characteristics to the wine. 10 The difficulty with wooden barrels is that they are expensive and only have a limited 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 15 intervals during the maturation process. Typically the barrel is topped up from 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 oak planks or chips. Furthermore, pitting 20 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 25 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 3 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. In recent times thin walled polyethylene vessels have been used to mature wine. Polyethylene is easy to sanitise and can be cleaned with mild caustic 5 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 is therefore good at retaining its gas permeability. A problem with thin walled polyethylene vessels is that because they are 10 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. The containers are also, because of thickness limitations to obtain the desired oxygen permeability, relatively fragile and need to be supported from collapsing under hydro static loads, 15 Further still, wineries often require vessels which they can use not only for maturation purposes, but also for long term storage. Vessels constructed completely of gas permeable material are suitable only for maturation of liquid because of the thin walled polyethylene properties. They also fail to promote the controlled ingress of oxygen into the vessels during maturation, fermentation and oxygen exlusion. They 20 are not suitable for holding liquid in a sealed inert environment, which means that additional gas impermeable vessels typically need to be purchased. A yet further problem encountered with prior art vessels of this type is that they typically include internal threads or fasteners for attaching a valve to the vessel. This often presents leaking, cleaning and sterilisation issues in that the internal fittings 25 may promote, allow or permit the propagation of bacteria, such as acetobactors, which may spoil the wine. 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.

4 SUMMARY OF THE INVENTION Therefore in one form of the invention there is proposed a tank for the storage and/or maturation of a liquid, said vessel including: a body adapted to hold a quantity of said liquid therein, said body having associated 5 therewith a first material having a first oxygen transfer rate, and a second material having a second oxygen transfer rate which differs from said first oxygen transfer rate. Preferably said body includes a main body portion and an opening in said main body portion, said opening adapted to be sealed by a removable body portion, 10 whereby said main body portion is constructed of said first material and said removable body portion is constructed of said second material. In preference said second material has a greater oxygen transfer rate than said first material. Preferably said first material is gas impermeable. 15 In preference said main body portion includes a base, a side wall, and a ceiling defining a headspace in said tank, said opening being disposed in said headspace, and said removable body portion being in the form of a removable membrane adapted to seal said opening. In preference said opening includes an upstanding external threaded portion 20 adapted to be engaged by a correspondingly shaped nut, said removable membrane being disposed between said threaded portion and said nut such that tightening thereof causes said membrane to seal the opening. Preferably said liquid is wine. In preference the tank further includes an internal frame adapted to suspend at 25 least one wooden member for the purpose of oaking of the liquid contained therein. In a further form of the invention there is proposed an apparatus for the storage and/or maturation of a liquid, said apparatus including: 5 a vessel adapted to hold a quantity of the liquid therein, said vessel being gas impermeable or at least having a low oxygen transfer rate to facilitate storage of said liquid; and a means of accommodating a gas permeable membrane in a headspace of said vessel, 5 said gas permeable membrane having a higher oxygen transfer rate relative to the vessel to facilitate the controlled ingress of oxygen into said vessel. In preference said vessel is constructed of polyethylene. Preferably said membrane is constructed of polyethylene. Alternatively said membrane is constructed of silicon rubber. 10 In a still further form of the invention there is proposed an apparatus for storage and/or maturation of a liquid, said apparatus including: a vessel adapted to hold a quantity of the liquid therein; a substantially rigid frame including a base adapted to support said vessel and prevent undesirable expansion of the vessel, said base being angled to facilitate draining of 15 liquid out from the vessel. Preferably the frame is adapted to accommodate the prongs of a forklift. In a yet further form of the invention there is proposed an apparatus for storage and/or maturation of a liquid, said apparatus including: a vessel adapted to hold a quantity of the liquid therein; and 20 an integrally formed fitting extending a predetermined distance outwardly from a wall of said vessel, said fitting configured to receive an attachment using an external fastening means, said fitting used to allow the passage of liquid there through. Preferably said apparatus further includes a seal disposed between said fitting and said attachment. 25 In preference said attachment is configured for connection to a hose. Preferably said fitting and said attachment include circular cross sections, and said external fastening means is in the form of a hinged annular clamp.

6 In a yet further form of the invention there is proposed an apparatus for storage and/or maturation of a liquid, said apparatus including: a vessel adapted to hold a quantity of the liquid therein, said vessel having a low oxygen transfer rate to facilitate long term storage of said liquid; 5 a means of accommodating a gas permeable membrane in a headspace of said vessel, said gas permeable membrane having a high oxygen transfer rate relative to the vessel to facilitate controlled ingress of oxygen into said vessel; an integrally formed fitting extending a predetermined distance outwardly from said vessel, said fitting configured to receive an attachment using an external fastening 10 means, said fitting adapted to allow the passage of liquid there through; and a substantially rigid frame including a base adapted to support said vessel and prevent undesirable expansion of the vessel, said base being angled to facilitate draining of liquid out from said fitting. Preferably the liquid is wine. 15 In preference said vessel is constructed from polyethylene. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. 20 In the drawings, Figure 1 illustrates a perspective view of a tank system of the present invention in a stacked arrangement; Figure 2 illustrates a perspective view of stacked tank frames forming part of the system of Figure 1, in accordance with a first aspect of the present 25 invention; Figure 3 illustrates an enlarged perspective view of a tank lid forming part of the tank system of Figure 1, in accordance with a second aspect of the invention; 7 Figure 4 illustrates an exploded, perspective view of the tank lid of Figure 3, separated from the tank; and Figure 5 illustrates an enlarged perspective view of a tank base forming part of the tank system of Figure 1, including an enlarged, exploded view of 5 the tank valve in accordance with a third aspect of the invention. 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 10 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 15 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 two individual units placed one on top of the other. As would be appreciated the ability to stack the units has significant space saving advantages. Each tank 12 includes a headspace defined 20 by a lid 16, and a valve assembly 20. The frame 14 includes a substantially square base plate 22 supported in an elevated configuration by four upright legs 24 located at each comer. It is envisaged that the legs 24 will be constructed from steel square hollow sections (shs) or rectangular hollow sections (rhs) to provide the greatest strength whilst minimising 25 the overall weight of the apparatus. The frame 12 further includes at least one brace member 25 joining two of the legs 24. The base plate 22 is of a strength which allows a forklift to be used to transport the frame 14 by inserting forklift prongs beneath the plate 22. In this way 8 each unit 10 can be moved independently for the purposes of storage, cleaning or accessing the wine contained therein. Although not shown specifically in the drawings, the frame 14 also includes a forklift intrusion guard protecting the base of the tank from accidental intrusion by forklift prongs. 5 Each leg 24 terminates at the bottom end in a locating lug 26, which may for example be welded to the leg 24. The upper end of each leg 24 is adapted to be received in a corresponding locating lug 26 of a frame 14 stacked there above, as illustrated in Figures 1-2. The tank 12 is preferably constructed from a food grade polyethylene polymer 10 that is inert to wine. The material is inherently gas permeable, however, the tanks have a wall thickness, material density, and surface area to volume ratio which is specifically formulated to allow for inert longer term storage. The tank wall could be coloured or translucent for clear view of contents and fill levels, and is of a heavy wall cylindrical design. This eliminates side wall bulging and the requirement for the frame 15 to support the wall preventing it from bulging, and also assists cleaning. The tank is preferable rotationally moulded. In being configured this way, the tank 12 is also prevented from expanding undesirably. This also 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 20 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. As mentioned, it is preferred that the tank 12 will be constructed out of polyethylene of a thickness which limits oxygen permeating through the tank walls. This ensures that the tank 12 can be used as a long term storage tank for many oxygen 25 sensitive foodstuffs. 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.

9 As is further illustrated in Figures 1 and 2, the base plate 22 of the frame 14 is slightly angled towards one side. For example, in the embodiment shown, the plate 22 is higher on the brace side than on the opposed side of the frame 14. The tank 12 is adapted to be lowered onto the plate 22 between the legs 24 so that the valve 5 assembly 20 is located at the lowest position of the angled plate 22 to facilitate flow out of the tank 12. The valve assembly 20, which shall be described in more detail below, can be used as both an inlet and an outlet for wine. The valve assembly 20 is also used during the cleaning process to remove the used mild caustic solution. As illustrated in Figure 3 the upper surface 28 of the tank 12 slopes upwardly 10 and inwardly towards the headspace. This prevents air pockets from forming as the tank 14 is filled with wine. The apparatus 10 may further include an internal frame adapted to suspend portions of oak (not shown) within the wine. It is envisaged that the frame 14 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 15 desired time during maturation of the wine. As mentioned, the headspace is defined by the round lid 16 of the tank 12, shown in detail in Figure 4. The lid 16 includes a body 32 having upper strengthening ribs 34 and a central aperture 36 defined by a male threaded shaft 38 which upstands from the body 32. In a preferred embodiment, the male threaded shaft 38 is integrally 20 moulded with the body 32. The male threaded shaft 38 is adapted to be engaged by a female threaded open nut 40. Wedged between the threaded components to thereby seal aperture 35 is a liquid tight closure plate or membrane 44. The closure membrane 44 can be made of a range of materials depending on the desired effect inside the tank 12. For example, where oxygen transfer is required 25 for the purpose of driven maturation, the closure membrane 44 could be in the form of a gas permeable silicon rubber membrane. Such membranes are significantly more permeable than polyethylene, and therefore require only a fraction of the surface area to permit equivalent oxygen transfers, hence the small membrane in the lid of the tank. Should the tank be required for reductive oxygen storage only, then the 10 membrane 44 would be of a gas impermeable material. Alternatively, for storage purposes, the nut 40 could simply be replaced with a closed cap nut (not shown). It is further envisaged that the apparatus 10 will include multiple membrane types to suit specific jobs. For example, some wine may require greater oxygen 5 transfer rates than others, and so a more gas permeable membrane 44 will be required, in comparison to a membrane used for wine that requires little oxygen rationing. It is to be further understood that the position of the membrane 44 need not be limited to the tank lid 16. Figure 5 illustrates the valve assembly 20 in more detail. The valve assembly 10 20 is located in a low profile side wall recess 55 in the tank body at its base, and includes a fitting 56 which is integrally moulded with the tank wall. The fitting 56 is in the form of a circular cross section pipe 57 which extends forwardly from the tank 12 a short distance, and terminates in an annular shoulder 58. A valve 60 includes an annular rearward portion 62 adapted to compress a gasket seal 64 against shoulder 58, 15 and a forwardly extending male threaded portion 66. A hinged clamp 68 is used to couple the valve 60 and the fitting 56 by enclosing and gripping against both the fitting shoulder 58 and the rearward portion of the valve 60. The male threaded portion 66 is then available for engagement with a female thread on the end of a hose fitting (not shown) for the purpose of transferring the 20 vessel's liquid contents through the hose, or alternatively liquid from outside into the vessel. This feature of the apparatus 10 is important because it does away with the need for internal fasteners, which are a common cause of bacteria propagation, leakage, and wine spoilage. In this case, the fitting 56 forms an integral part of the 25 tank 12, and the clamp 68 which is used to attach the valve 60 is an external fastener. The fitting is then able to communicate with known and standard hygienic fittings typically used by wineries, and the chance of bacteria propagation is greatly minimised. Although not shown, the tank 12 should also include a means of purging.

11 The skilled addressee will now appreciate the many advantages of the present invention. The tank 12 provides unparalleled versatility in that it can be used as both a maturation vessel and a long term safe storage vessel, simply by changing between different membranes in the lid of the tank. For example, a wine maker would be able 5 to successfully switch between barrel rates of oxygen driven maturation (up to 50m1/l/yr), and inert longer term storage (<5m1/l/yr). The unit 10 creates opportunities for the controlled ingress of oxygen during maturation, fermentation and oxygen exclusion, whilst safely storing wine in a vessel capable of doubling cellar storage space by comparison with traditional oak barrel storage. Furthermore, the units 10 are 10 particularly easy to clean, use a fraction of barrel cleaning resources, provide for complete control of oak integration and variation, do not require topping up, and are easily stacked and transported. It is envisaged that when say 4x4x4 units are stacked up, they will store up to 64,000lts of wine. The same floor storage space and stack height using oak barrels 15 stacked using typical barrel racks will store around 34,000lts of wine only. 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 20 and spirit of the invention. Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in this field. In any claims that follow and in the summary of the invention, except where 25 the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.

Claims

1. A gas permeable tank system for controlling the transfer of atmospheric oxygen into a vessel for the storage and/or the maturation of 5 wine comprising; a vessel adapted to hold a quantity of said liquid therein, said vessel walls having a fixed rate of oxygen transfer from the atmosphere into the vessel and; a means of accommodating a liquid tight gas permeable membrane 10 wherein said membrane increases the rate of oxygen transfer from the atmosphere into the vessel; a vessel having an outlet and a lower body, said lower body being shaped so as to enable the draining of substantially all liquid from said vessel when the outlet is opened; 15 a substantially rigid supporting frame, said supporting frame adapted so as to enable one vessel to be stacked upon another.

2. A tank system as in claim 1 wherein said vessel and membranes are constructed of materials that are inert to wine. 20

3. A tank system as in claims 1 and 2 wherein said supporting frame is adapted to accommodate the tynes of a forklift truck

4. A tanks system as in claims 1 to 3 wherein said vessel has an 25 upper body and opening, said upper body being shaped so as to allow substantially all gases to escape through the upper opening when the vessel is filled with wine.

5. A tank system as in any one of the above claims wherein the 30 permeation of oxygen into said vessel is metered without the manual addition of oxygen.