WO2016097729A1

WO2016097729A1 - Compressible fluid storage apparatus

Info

Publication number: WO2016097729A1
Application number: PCT/GB2015/054039
Authority: WO
Inventors: John Walsh; Rhys WATKINS
Original assignee: Exagenica Research Limited
Priority date: 2014-12-16
Filing date: 2015-12-16
Publication date: 2016-06-23
Also published as: GB201711064D0; GB2548530A

Abstract

Provided is a compressible fluid storage apparatus suitable for a ship's Hold. The apparatus comprises a plurality of compressible and fluid-impermeable compartments. The apparatus also comprises a compression mechanism to compress each compartment. Methods of use are also provided.

Description

COMPRESSIBLE FLUID STORAGE APPARATUS

The present invention relates to a compressible fluid storage apparatus suitable for a ship's hold and methods of use.

Sea-borne transport of oil and other bulk cargoes such as iron ore is an important part of the world economy. Currently oil tankers typically make their return journeys empty, which is commercially wasteful due to the additional fuel costs and the resulting emissions which are linked with global warming.

Various attempts have been made to "dual purpose" a ship (or one or more of the ship's holds). This involves transporting a secondary cargo of fluid in an empty hold of the ship. The ship's primary cargo may be, for instance, oil, but as mentioned above the hold can often be empty on the return leg of a delivery journey. One approach is to simply wash out the hold and then transport the fluid directly in the empty space. However, this has an environmental impact as not only does the oil or other previously-transported material end up being washed into the sea, but flushing the ballast tank can also make bio-contamination occur, as foreign species may be washed out as well. Cargo cleaning can also cause explosions and has a potential to leak into the double skin causing corrosion.

Some approaches use a bag or other container to line, or be placed inside, the emptied hold of the ship. These include DE102007054687, JP2005014698, US3005317A, DE4227264, KR20030019063, WO2013016417, WO20081 10762, US20040144294, WO2013016440, CN201309570, CN2201336, and CN201362880, but none of these have been commercially successfully. One reason for this is that these approaches do nothing to mitigate sloshing of fluid. Sloshing (slosh resonance) occurs when fluid is contained within, but does not completely fill, a confined space. This is principally an issue with liquids rather than gases, but has serious safety implication in ships as it can lead to poor weight distribution which thus unbalances the ship, leading, potentially, to the ship capsizing.

Another issue is what to do with the apparatus that carries this secondary cargo when the hold of the ship is full with its primary cargo. An apparatus that takes up a lot of room, or makes it harder to load or unload the primary cargo, is uneconomic.

Surprisingly, we have found that it is possible to "dual purpose" nautical vessels to enable multiple types of liquid cargoes to be carried without the need for traditional hold area cleaning. Fundamentally, the art fails to provide a practical apparatus that can be used in a safe and effective manner in the hold of a ship, and then stowed away when not required. The present invention addresses this by providing numerous compartments which can be collapsed when not required to carry cargo, thereby providing additional space for a different cargo in the same hold. Multiple compartments also prevent or reduce sloshing. Furthermore, by providing these compartments in a honeycomb formation, we have found that the apparatus can be larger than would otherwise be possible with a single bag arrangement, and the compartments (and hence the apparatus) can be self-supporting (i.e. free-standing without the need to contact the sides of the hold for support) when loaded. This makes installation more straightforward and avoids interference with structural components such as bulkheads. The invention also provides a mechanical or magnetic compression mechanism for collapsing the compartments, thus stowing the apparatus away when it is not required which aids with loading and unloading of the primary cargo material in the rest of the hold. Again, the freestanding nature of the compartments makes collapsing the apparatus easier.

SUMMARY OF THE INVENTION

Thus, in a first aspect, the present invention provides a compressible fluid storage apparatus suitable for a ship's hold comprising:

• a plurality of compressible and fluid-impermeable compartments; and

• a compression mechanism to compress each compartment,

wherein the compartments are arranged in a honeycomb pattern.

In some embodiments, each compartment preferably comprises a fluid-impermeable membrane (9) sealed to retain fluid therein. In some embodiments, the compression is horizontal. In other embodiments, the compression is vertical. In some embodiments, the apparatus may comprise a pump to insert or remove fluid from the or each compartment. In some embodiments, the apparatus may comprise a heating or cooling system to heat or cool the fluid within the or each compartment. In some embodiments, the compression mechanism may comprise a compression plate to compress the compartments or each compartment. The compression plate may comprise the heating or cooling system to heat or cool the fluid within the or each compartment.

In some embodiments, the apparatus may comprise a base and support plates to support the base of each compartment (6) and, optionally, said support plates comprise heating or cooling system to heat or cool the fluid within the or each compartment. In some embodiments, the apparatus may comprise extraction means, such as a system of pipes and at least one pump, to extract cargo from the top of each, or at least one of the, compartments. In some embodiments, the apparatus may comprise an inlet comprising a valve through which the fluid is distributed to each, or at least one of the, compartments. In some embodiments, the extraction means may comprise a pump, pipework and an inlet/outlet at the top of the compartment. The Inlet and or outlet may also be at the bottom of the compartment. The inlet may be separate from the outlet or one can perform both filling and extracting roles.

In some embodiments, the compression is horizontal and the apparatus comprises a frame, the frame comprising runner beams running in parallel to the direction of the horizontal compression, with a series of mobile tracks attached to said runner beams and the compression plates and the top of the membrane compartments each attached to one or more runner wheels which run along the mobile tracks allowing the compression plates to move freely towards the centre or side of the hold during compression of the apparatus. In some embodiments, the compression mechanism may comprise a pulley system comprised of two mutually exclusive pulleys; and/or a vice mechanism such as a screw thread or hydraulic clamp mechanism. In some embodiments, the base of the compartments abut a base and the base in turn abuts the floor of the hold. In some embodiments, the base may comprise a conveyer belt roller mechanism. In some embodiments, the apparatus may further comprise a rain water collecting device.

The following applies to all aspects, unless otherwise apparent. The compartments are preferably hexagonal with six sides of equal length. The honeycomb arrangement refers to the positioning of multiple compartments next to, and abutting, each other. The honeycomb arrangement is preferably as viewed from above, along the gravitational axis of the Earth (i.e. towards the centre of the Earth) considering that the apparatus is suitable for placement in, or is to be placed in, the hold of a ship.

In some embodiments, the compression mechanism compresses one or more of the compartments rather than each compartment.

The compartments are ideally discreet, i.e. separate, but formed of a fluid-impermeable membrane. The membrane itself may be formed of one or more sections or strips, so as to provide walls and/or a base for each of the plurality of compartments. The fluid-impermeable nature of the compartments means that the fluid cannot pass through the compartment walls and/or base. There may be apertures between the compartments, in some embodiments, to enable some fluid to pass them between, where required but this is ideally in a controlled manner. The provision of a plurality of compartments serves to reduce or substantially eliminate sloshing especially for large volumes that can destabilize a vessel as the sloshing around of the fluid occurs. The compartments are compressible so as to free up room when one or more compartments are not required, and thus enable dual-use (dual-purposing) of the hold space in which the apparatus may be installed or positioned. The compartments may comprise a closed aperture, roof or lid at the top, especially where the fluid is a gas.

In some embodiments it is preferred that the membrane extends between compartments. As such, the membrane may be considered to be unitary or formed of one piece. Alternatively, it may be stitched or bonded together in parts.

In some embodiments, each compartment comprises a fluid-impermeable membrane sealed to retain fluid therein. The membrane may form the walls and, optionally, the base of the compartment. The membrane may be made of Kevlar ®, Cuben Fibre®, Spectra®, Tensylon™ or other polymer or a laminate including rubberised or rubber coated material such as rubberised/coated tarpaulin. The membrane ideally has the same or greater tensile strength than and the same or greater flexibility than Kevlar ®, Cuben Fibre®, Tensylon™, or Spectra®. Cuben Fibre® or Spectra® are particularly preferred.

The compartments preferably have a base portion and their walls are preferably substantially vertical.

The compression can be in any direction and does not have to be in a single plane. In some embodiments, compression is horizontal. In other embodiments, the compression is vertical. In some embodiments, the compression may be both horizontal and vertical. Horizontal and vertical may be defined relative to the axes of the ship or the sea (or fresh water upon which the ship floats), such that horizontal can be in a plane parallel to the sea or in the plane formed ship's deck. It may be along or perpendicular to the plane formed by the longitudinal axis of the ship (bow to stern) or port to starboard, but any direction in that plane is envisaged. The vertical axis is preferably along the gravitational axis of the Earth, which as stated elsewhere is along the axis or line that runs from the apparatus towards the centre of the Earth.

In some embodiments, the compression mechanism comprises a compression plate to compress the compartments or each compartment. In some embodiments, multiple compression plates are provided. For instance, two compression plates side by side may be used and other multiples are envisaged.

The base of the apparatus may be provided with one or more support plates. The base of the or each compartment may abut against this. In this way, the base may help support the weight of the compartment, especially when the compartment is loaded. Rollers to engage the underside of the apparatus' or each compartment's base may also be provided in the apparatus to assist with the compression, especially in the case of horizontal compression. In some embodiments, the apparatus comprises a heating system to heat the fluid within the or each compartment. Alternatively or in addition, a cooling mechanism may be provided. The heating and/or cooling mechanisms may be provided in the compression plate and/or in the base of the or each compartment. In some embodiments, a pump may be provided to insert or remove fluid from the or each compartment.

The cargo, which may be referred to as "secondary cargo", to be placed and/or transported in the apparatus is a fluid. This fluid may be a gas or may be a liquid. Preferred liquids include wine, speciality liquid chemicals, liquid fuel (including diesel and other marine/nautical fuels), oil (including crude) and water. Water and oil are particularly preferred as the primary and secondary cargoes. In some embodiments, the primary cargo is water, and the secondary cargo is oil. In some embodiments, the primary cargo is oil, and the secondary cargo is water. In some embodiments, water is placed and/or transported in the apparatus. In some embodiments, oil is placed and/or transported in the apparatus. In some embodiments, water is placed and/or transported in the apparatus and oil is placed and/or transported in the hold of the ship, and vice versa.

If the apparatus was placed in a bulk carrier then the fluid, e.g. water, would be placed and/or transported in the apparatus with the bulk iron ore etc. in the hold. The bulk may be added around the apparatus. The apparatus could also be a temporary solution that is loaded into the bulk carrier hold when transporting water but then removed and stored on the deck, for example, when not in operation. This allows, for example, other cargoes to occupy the hold without inhibiting the loading and unloading operation.

An advantage of the present apparatus is that it is free-standing. In other words, although it may rests on the floor of a hold, it does not need to be supported by the sides of the hold. As such, the apparatus is free-standing.

In some embodiments, a mixture of fluids, one in each compartment, is envisaged. For example, one compartment may contain water, another within the same apparatus may contain oil. In general, however, it is preferred to have only one type of fluid in a single apparatus.

The hold of the ship may be a cargo hold. However, it may also be a fuel tank of the ship or even a ballast tank. In some embodiments, the apparatus is placed in the fuel tank of the ship and in this example, fuel itself may be placed and/or transported in the apparatus. It is likely that there will be at least two apparatuses per fuel tank. Each apparatus has the capability to extend to 50%, 70% or 90% of the capacity of the tank. This will allow different grades of fuel to be loaded in different proportions. This addresses regulations that require low sulphur fuels to be used in certain international waters. This low sulphur fuel is more expensive than the current grade and therefore the present apparatus facilitates a mixture of fuel grades to exist within the same tank space. It also facilitates the proportions of different cargoes to be adjusted for a particular voyage and then further adjusted for a subsequent voyage, as required. This flexibility is useful given the costs involved.

Also provided is a ship comprising the apparatus positioned or installed within one or more of its holds. In some embodiments, the compressible fluid storage apparatus is positioned within a cargo hold, a ships own fuel tanks or ballast tanks.

The invention also provides a method of installing the apparatus in the hold of a ship and a method of repairing the apparatus. In particular a method of use is provided. This method of using the apparatus typically comprises:

• optionally, expanding one or more collapsed compartments;

• at least partially filling one or more compartments with a fluid at a first port;

• optionally, partially emptying said compartment(s) at a second port;

• optionally, topping up or adding to a partially full compartment at a second or further port; and

• optionally, unloading the fluid by emptying the compartment(s) at a third port.

Thus, in one aspect, the invention provides a method of filling or loading the hold of a ship with a fluid, comprising at least partially filling (loading) one or more compartments of the present apparatus with a fluid at a first port. Optionally, expanding one or more collapsed compartments precedes this loading step. Preferably, the fluid in unloaded by emptying the compartment(s) at a further/third port. In between the loading and unloading steps, the following are preferred:

• optionally, partially emptying said compartment(s) at a second port; and/or

• optionally, topping up or adding to a partially full compartment at a second or further port.

At least partially filling or at least partially emptying or unloading may comprise fully filling/loading or emptying or unloading the fluid from the or each compartment. Optionally, the method may also comprise collapsing one or more empty compartments.

Given the potential weight of a fully laden compartment (membrane), it's envisaged that a horizontal compression mechanism which compresses the membrane from 2, preferably opposite, sides (i.e. towards the centre or central axis of the hold) will be most effective. The compartments may be arranged in a number of rows or in a grid, for example of 3 x 5 or 10 x 20 compartments. The numbers may vary according to hold size or the preferred volume for each compartment, for example.

Each hold within a ship may contain a single apparatus or multiple apparatus depending on the capacity of the hold.

In a further aspect, provided is a compressible fluid storage apparatus suitable for a ship's hold comprising; a plurality of compressible and fluid-impermeable compartments; and a compression mechanism to compress each compartment, wherein the compartments are square or rectangular in cross-section. Other non-hexagonal cross-sections are also envisaged, such as pentagons, heptagons or octagons. The apparatus may be further defined as described herein unless otherwise apparent. Also provided is a ship comprising said apparatus.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be described with reference to the accompanying figures, wherein:

Figure 1 : an embodiment of a series of apparatuses (3) within an oil tanker

Figure 2: side view of the apparatuses (3) fitted within the fuel tanks (4) of a vessel (1)

Figure 3: horizontal cross-section view of the compartments (6) of the apparatus (3) in various stages of compression

Figure 4: vertical cross-section view of the apparatus' (3) membrane (7) Figure 5: turned view of a corner of the apparatus (3)

Figure 6: vertical cross-section view of the preferred embodiment of the apparatus (3) for oil tankers

Figure 7: vertical cross-section view of an embodiment of the apparatus (3) incorporating a vertical compression mechanism using magnetic bands (17)

Figure 8: vertical cross-section view of the base construction (18) incorporating conveyor belts (19) formed of rollers (23) and base plates (20), and a central stand (22)

Figure 9: top view of the conveyor belts' (19) base plates (20) incorporating hot water / steam pipes (24) Figure 10: vertical cross-section view of an embodiment of the apparatus (3) with horizontal compression and hinged (22) base construction (18)

DETAILED DESCRIPTION

The honeycomb arrangement of the compartments in combination with a compression mechanism is useful, as illustrated in Figure 3. One reason for this is that significant support is provided by this type of structure. In fact, the use of a honeycomb arrangement, preferably of hexagonal compartments when viewed from above (Figure 3), is self-supporting. This arrangement reduces sloshing, and having compartments with an even number of sides also helps with collapsing/folding (even when the compartments are made with soft materials). As such, a heterogeneous mixture of compartments, for example a mixture of hexagonal and pentagonal compartments, may be used but is generally not preferred.

Furthermore, without being bound by theory, we have found through FEA modelling of the honeycomb subdivides that this shape proved to be approximately 30% stronger than a square or rectangular configuration. The strongest subdivide shape was proven to be a cylindrical shape however the space between subdivides and the ability to compress the membrane efficiently discarded the cylindrical subdivide design. The benefits of the honeycomb subdivide arrangement is that the additional strength means that the material thickness of the membrane can be reduced thereby reducing costs and increasing the flexibility of the apparatus. This improved flexibility and a reduction in the quantity of material for the membrane will also facilitate in the reducing the capacity and structure of the compression mechanism and the apparatus as a whole, when compressed, thus freeing up hold space when the apparatus is not required.

The FEA modelling also proved the subdivides within the membrane (i.e. the formation of a plurality compartments) increased the strength of the apparatus and thereby reduced the pressure on the outer wall of the membrane. This in turn reduces the thickness of the material to be used in the membrane construction. As such, the provision of a sub-divided membrane formed of a plurality of compartments which together make up the membrane for holding the cargo, is advantageous.

Advantageously, the internal subdivision to form the compartments takes pressure off the outside walls, improving the structural stability when the compartments are filled. In this respect, the membrane is said to be subdivided into compartments and in this case those compartments are in a honeycomb arrangement, so are preferably each hexagonal. DE102007054687 uses bags of oil in tanks filled with fresh water or vice versa (bags of fresh water in tanks of oil), but no mechanical compression of bags is described and certainly no moveable compression plate or honeycomb structure is disclosed. JP2005014698 discloses how an empty water container sits on the deck above or next to an oil tank. It is then lowered, via a hoist and/or a pantograph ("lazy tongs") arrangement beneath the container into an empty oil tank, and is then filled with fresh water. This would require the deck to be retractable, which would be disadvantageous as it would require large amount of alterations such as moving the pipes, etc. In addition, the water container does not seem to be compressed and there is no honeycomb arrangement within the fresh water container.

US3005317A relates to a storage mechanism for multi purposing a vessel to transport both dry and liquid cargoes. Fluids, such as liquefied gases may be transported, but only a single impervious bag is provided to contain the fluids. In contrast, the present invention provides a plurality of compartments arranged in a honeycomb pattern. These sub-divisions add strength and structure to the membrane. Without these subdivisions the structure would fail under the immense pressure that the liquid would enforce on the outer walls. To reduce this pressure, the liquid storage area would have to be a much smaller unit than can be achieved with the present invention, or there would have to be significant reinforcement of the apparatus which would hamper the collapsing of the apparatus.

Furthermore, the hold of many vessels have a number of obstacles, such as bulkheads, which cannot be simply removed. This means that any solution needs to be strong enough to withstand the pressure of the fluid (especially a liquid) when freestanding, or is otherwise constrained by the distance between bulkheads, as in US3005317A. Accordingly, it is an advantage of the present invention that the compartments or membrane do/does not need to come into contact with the sides of the hold for support.

The present apparatus is a freestanding solution which does not rely on touching., or requiring support from, the hold walls to reduce the pressure on the outer surface. In this regard, materials such as those described herein and including Kevlar®, Cuben Fibre®, Tensylon™ or Spectra® are preferred.

DE4121508 focusses on water for use as ballast and uses separate containers which are collapsible, e.g. a bag, and corrosion resistant. DE4227264 also focuses on ballast and the reduction in rust by using a cover or diaphragm.

KR20030019063 appears to focus on switching ballast tanks from fresh to sea water (and perhaps vice versa), particularly in relation to peripheral ballast tanks on dual-hulled tankers. WO2013016417 A1 and WO2013016440 A1 mention oil/water transport in tankers and using fresh water instead of sea water for ballast. It focuses on drop-in or flexible liners to contain the fresh water. WO2008110762 A1 relates to a method of processing sea water (e.g. desalination) en route but mentions nothing on how the fluid is stored.

US20040144294 A1 relates to a flexible vessel that, it seems, is towed behind a ship and is used to store and transport fresh water in a marine environment. US 2004/0154515A1 is a CIP of US20040144294 A1.

CN201309570 is a utility model and discloses a tanker with a fresh water container on top of an oil container, but the purpose is to prevent poor load distribution. CN2201336 is another utility model and discloses a tanker with water. A flexible structure is disclosed, but the purpose is for increased security.

CN2877274, a Chinese utility model, relates to a bag for water storage in deserts. The bag includes a honeycomb structure. No mention of compression or dual-purposing for ship holds is made. CN201362880 is another Chinese utility model that discloses a honeycomb structure, but this time for use in the wall of a cistern for a toilet, so it does not even hold any fluid, but is merely to use up less material in the cistern wall construction.

Advantages of the present dual-purposing invention include:

• reduced wastage of fuel, leading to cost savings and environmental benefits;

• reduced or no washing out of dirty holds, reducing environmental impact;

• ability to part unload / re-load at an intermediate port along a route;

• partitioning, leading to reduced sloshing effect;

• partitioning, leading to greater protection and hence reduced chance of breach and spillage in the event of breach;

• provision of support to the fluid through partitioning (subdivision) and hence reducing pressure on parts of the hold or hull - i.e. the membrane is subdivided into compartments. The apparatus is free-standing or self-supporting;

• potentially removing dedicated ballasts and increasing cargo carrying capacities.

The apparatus may be retrofitted or is retrofittable to an existing ship's hold, or may be included in the original construction of the ship.

The apparatus is compressible, as shown in Figure 3. This means that it can be squashed or folded from an expanded state to a compressed state such that one or more compartments decrease in available volume (for the fluid). The apparatus may also be expandable. This means that it can be expanded from a squashed or folded state, where one or more compartments have a reduced volume, to an expanded state where the one or more compartments have a greater available volume for fluid. Various fluids are described above. The fluid may be described as a secondary cargo because the ship was primarily designed to convey or transport a primary cargo, say oil (an oil tanker) or iron ore (a bulk carrier).

Storage in the present sense can be temporary storage during transport from one port to another. The apparatus is suitable for ships' holds. Various types of holds are described herein. For cargo holds, this means that the apparatus may be sized to accommodate 100's, 1000's, 10,000's or even 100,000's litres of fluid. For a preferred example where water is placed in the apparatus and the apparatus is placed in the hold of an oil tanker, suitable ranges may be for oil tanker capacity may be 10,000 to 440,000 DWT (Deadweight Metric Tons). The ship may be an oil tanker (capable of carrying, for example, crude, petrol, diesel etc.), a bulk carrier for ores (e.g. iron or aluminium ores), or a bulk carrier for (speciality) chemicals such as vegetable oil, sulphuric or phosphoric acid. The size of the ship is not particularly important, so whilst it may be a large vessel, it could also be any other nautical vessel with a suitable storage compartment (hold) or fuel or ballast tank. The apparatus can be sized accordingly.

In some embodiments, the compartments are fluid impermeable, meaning that fluid cannot penetrate the walls or base of the compartment, thus avoiding leakage. The compartments are sealed such that the fluid cargo does not escape. This means that the compartments are fully sealed at the bottom and at least a lower portion of the sides. An upper portion of the sides, ideally less than 50% and most preferably less than 25% or 10% of the total height of the compartment, and the top of the compartment may be open or sealed closed as appropriate. The compartments are compressible, so can be collapsed or expanded accordingly and under action from, or urged by, the compression mechanism.

In other embodiments, the compartments are sealed at the base but there is a small aperture at the base of the compartments to allow fluid to flow between adjacent compartments. This design is to facilitate loading and unloading the liquid contents from the base of the apparatus. In this second variation the compartments maybe open or sealed closed at the top as appropriate.

The compression mechanism may comprise an aperture and an inlet (with optional separate outlet) for the fluid, as shown in Figure 4. The frame provides a structure for supporting the compartments. The compartments may hang from the frame. The compartments may be supported at their base by the frame or by a further base in the frame. The frame base may comprise one or more base plates. The compartments may also be engaged with rollers or a low-friction surface to assist with sliding as they compress together, for example to one side of the or each hold as envisaged for bulk carriers, or towards the centre of the or each hold for oil tankers. This is due to bulk carriers being typically smaller than oil tankers, so the smaller towards-the-side apparatuses are used for their smaller compressed sizes, whereas oil tankers are typically larger than bulk carriers, and therefore a towards-the-centre compression provides more stability to the heavy vessels.

As shown in Figure 8, the base plates may be comprised within a conveyor belt. Accordingly, an optional conveyor belt is provided to reduce friction within the base of the hold and facilitate membrane collapse, as illustrated in Figure 6.

The horizontal compression design envisaged for oil tankers may be comprised of two conveyor belts, one for each half of the Membrane, as shown in Figure 6. This allows the Membrane to collapse from each side, preferably towards the centre of the hold. The purpose of the belts is to remove the friction between the Membrane and the base of the hold. It also facilitates the way in which the Membrane collapses. Preferably, these belts will move at the same rate as the (overarching) compression process. The plates may be joined by one or more hinges to allow them to fold under each other. At the centre of the hold and fed by both conveyor belts there is preferably a central stand. The membrane preferably comes to rest on this central stand. This is a preferably a static plate and takes the lighter weight of the Membrane when fully collapsed.

The compression mechanism is mechanical. It may comprise a compression plate as shown in Figure 10. There may be one or more compression plates. Where there is more than one compression plate, as shown in Figure 6, each compression plate may act against a separate compartment or against separate parts of the same compartment. Each compression plate may be independently controlled.

A driver preferably urges the compartments to collapse or expand. This may be through driving the compression plate via a cam, bar rod, screw thread or other driving arrangement such as a pulley system or net. A combination may be used. For example, an arrangement that uses both a pulley that may be connected to a counter weight and a cam or a screw thread, as illustrated in Figure 6. This is advantageous, especially when the pulley is used at the earlier stages of compression, as it is energy efficient to use a pulley. Towards the end of the compression, there may be increased resistance to being further folded or squashed together, so the addition of a screw-thread or cam may be used to stow the compartments tightly, neatly and also to lock them securely. The final compression could equally be a hydraulic device that hooks and squeezes the final movement. For resiliency purposes, the pulley system may be comprised of two mutually exclusive pulleys so that in the event of a failure, an individual pulley system is be capable of completing the compression process. In some embodiments, vertical compression is used, i.e. the compression develops vertically so that the compartments collapse from the bottom or from the top, either towards the floor or towards the roof of the hold. The compression may be greater at, or complete first at, the base or roof of a compartment, compared to the top. This is akin to the way that a tube of toothpaste can be squeezed from the bottom towards the top. This helps force out air or any remaining secondary cargo from the compartments. In some embodiments, however, all the compartments are compressed equally (or at least at the same time).

Where reference is made herein to compressing or a part being compressed, it is understood that the same mechanism applies in the opposite direction for the expansion of the or each compartment.

A heating mechanism may be incorporated and can be any such known mechanism, including a filament or other suitable heater for heating the plate or base. The cooling mechanism may be of the type used in a refrigerator, for example. Such temperature control measures can be seen in Figure 9. The use of such heaters or coolers is advantageous as they can be used to change the viscosity of the fluid in the compartments. For example, it may be useful to make crude oil less viscous and therefore easier to pump. It may also be useful to cool the crude quickly and faster than the natural cooling effect of the nearby sea-water to keep the lighter fractions of the crude less volatile or make it more viscous and therefore increase the stability of the ship in heavy seas.

Existing solutions include a grid of pipes at the bottom of the hold that heats the oil to facilitate unloading. The present invention heats the oil at the bottom of the compartment through the support plates. As the present invention preferably extracts the oil from the top of the compartments and heat rises this will further facilitate the unloading. The known methods heat the oil but extract it from the base of the hold where the most viscous (coolest) oil exists.

The compartments may be partitions. In further aspects, they may be any appropriate shape, although a generally tubular or cylindrical structure is preferred along a vertical axis. In cross- section (looking down on them from above, i.e along the gravitational axis of the Earth and towards the centre of the Earth) they may be circular, triangular, or pentagonal but a polygon as defined below is preferred. The polygon may have 2n sides, where n is an integer greater than or equal to 2. Thus, the polygon may be a, or a mixture of: a. Hexagons;

b. Octagons (any even numbered (no. of sides) shape) etc;

c. a mixture of hexagons and other polygons;

d. Squares; and

e. Rectangles In the present invention, a honeycomb arrangement for the compartments is envisaged. As such, hexagons are particularly preferred, as shown in Figure 3, although octagons are also possible. A mixture of hexagons and/or octagons, as well a mixture of these and nd other shapes is possible, so long as they don't interfere with the honeycomb arrangement. Most preferably, the sides of each compartment have equal length.

The number of compartments may be 3 upwards, including 3-20, 10-100, 5-200 and so forth.

The compartments may be considered to be columns. The apparatus may be referred to as a pod.

The inlet may comprise a valve. The fluid is preferably distributed from this valve to each honeycomb compartment. The inlet valve preferably feeds the apparatus from the top. When filling the compartments, the apparatus is preferably in an uncompressed state and fully expanded. The central compartments fill first and then over spill to the adjacent compartments. This continues to occur until the apparatus is completely full. Alternatively, a pipe may extend to the top of each compartment. The top of each compartment will be the end distal to the sea (along the gravitational axis of the Earth).

In a second variation where the apparatus is filled from the bottom and there are (small) aperture openings at the base of each column so that the fluid will flow across each compartment equally until all columns are filled. In this variation the apparatus is in a compressed state and the filling of the liquid from the bottom to the top of each column equally drives the apparatus to expand.

The present apparatus has been designed specifically to enable crude oil tankers of all sizes to carry different liquid cargoes, without the need for costly and dangerous hold cleaning procedures that also negatively impact the environment. The apparatus itself further has the potential to be implemented to dual purpose use in ships carrying crude oil, product (refined petroleum), chemical or bulk ores (such as iron ore) and so forth.

Currently oil tankers make their return journeys empty which is commercially is highly profligate. Dual purposing merchant vessels using the apparatus would take advantage of this commercial waste by enabling fleet owners to ship potable water on return journeys, without having to clean each hold area first.

The apparatus can be used to contain any fluid, but most preferably a liquid, including heavier and more viscous crude fractions. Gases can be carried, with the simple adaption that the fluid-impermeable compartments are fully sealed including at the top (with liquids this may be fully sealed or left open). Given that current global water stresses are expected to increase dramatically over the next decades, an objective of the apparatus is to enable merchant vessels to carry potable water on their return journeys. However other commercially viable liquid cargoes (e.g. wine) could also be transported.

The apparatus solution may be pre-fabricated in one location, for example the UK, so it can then be transported to a vessel's home port anywhere in the world for assembly and implementation, in each of its respective hold areas. The apparatus is comprised of 2 primary components; a membrane and a compression mechanism.

The following example refers specifically to a preferred embodiment of the apparatus in the context of crude oil tankers. Design variants for product, chemical or bulk carriers are not specifically referenced but are envisaged.

Currently oil tanker vessels (1) store crude oil cargoes in their hold (2) areas, as defined by steel bulkheads and the vessel's (1) hull. In vessels (1) converted or comprising the present apparatus, the crude oil cargoes will instead be stored inside the apparatus' (3) membrane (7), and the apparatus (3) will be stored in the or a hold (2) of the vessel (1). Figure 1a illustrates the top view of one embodiment of the apparatus (3) in its uncompressed (expanded) configuration in position in an oil tanker's hold (2), and Figure 1 b illustrates the side view of the same embodiment in its uncompressed configuration in an oil tanker's hold (2). Figure 2 shows the side view of an embodiment where the uncompressed apparatus (3) is placed in the fuel tank (4) of a vessel (1), such that, when compressed, the fluid empties directly into the engines (5). It will be appreciated that tankers have a large number of holds and that, even within this, the number and arrangement of the holds can vary from ship to ship. Figure 1a happens to show a vessel (1) with eight rows of holds (2), whilst Figure 1 b shows a vessel (1) with five rows of holds (2).

When a membrane (7) is filled to capacity with crude oil the apparatus will reside, fully expanded, inside the traditional hold (2) area of a vessel (1). The apparatus' (3) membrane (7) is designed to be fully collapsible when not carrying crude oil cargoes so that it then occupies a smaller area of a vessel's (1) hold (2). By collapsing the membrane (7) when empty, this then leaves the rest of the traditional hold (2) area available to carry other liquid cargoes. In the preferred embodiment, some of the structural elements of the apparatus may not be collapsible, such as the runner beam described below. The smaller the collapsed membrane (7) footprint that can be achieved, the greater the secondary liquid carrying capacity of a vessel. The membrane's (7) walls will typically comprise or consist of a series of strips of material (running vertically or horizontally) bound together, rather than a large singular piece per wall. This construction will enable the membrane (7) to collapse neatly upon itself, minimising the space within the hold (2) it occupies when empty. The strips may be suitably bonded together by thermal bonding, epoxy adhesives, conventional stitching methods or multiples of these methods.

The membrane (7) may be constructed of a material such as Kevlar®, Cuben Fibre®, Tensylon™ or Spectra®. The material whilst having the tensile strength of steel is also flexible enough to allow the membrane (7) to be collapsed. Kevlar' s® ability to withstand high velocity impact is expected to better protect oil cargoes from hull breaches.

Internally the membrane (7) is divided into compartments (6), which further defines an aperture (10) at the top of the membrane (7). These compartments (6) can take any shape, but vertical columns with cross sections of polygons with 2n sides, where n is an integer greater than or equal to 2, such as rectangles, are preferred. Those with hexagonal cross sections, as illustrated in Figure 3, are particularly preferred, as it is believed that a honeycomb structure will be self-supporting. These compartments (6) will be used for the storage of liquid hydrocarbons. The subdivision is sealed to the bottom wall of the membrane (7) but left open at the top to enable cargos to be loaded and unloaded. The objective of this subdivision is to improve the structural integrity of the membrane (7) while also compartmentalising storage - meaning breaches would result in a more localised loss of oil. This in theory would minimise the environmental damage caused by hull breaches. Subdivision may also reduce the impact of slosh resonance, enabling ships to travel at faster speeds.

The aperture (10) stretching horizontally under the top wall of the membrane (7) is designed to aid the offloading process. At the top of the membrane (7) there is an inlet / outlet valve (9) to allow for the loading and unloading of liquid hydrocarbon within the membrane (7). Crude oil will be able to move freely within the aperture (10). When a membrane (7) is compressed, the oil will be pushed from the honeycomb storage compartments (6) into the aperture (10) where it can then be easily removed via inlet / outlet valve (9) - likely using a vacuum pumping mechanism native to the vessel (1). As elsewhere herein, the top side or end is distal to the sea, whilst the bottom side or end is proximal to the sea, when the apparatus is installed and the ship is sitting in the sea. Reference to the sea may include any body of water. Figure 3 also illustrates the top view of one embodiment of how such a honeycomb structure can be collapsed when the compartments (6) are compressed horizontally, where Figure 3A shows the compartments (6) in their fully-expanded state, Figure 3B shows the compartments (6) in their semi-compressed state, and Figure 3C shows the compartments (6) in their fully- compressed state.

Optionally, in any embodiment, Elastic cables (8) may be incorporated into the construction of the membrane (7) to help keep its shape during compression, one embodiment of which is shown in Figure 4.

In any embodiment, a valve (9) may be placed at the top of the apparatus (3), connected to a top aperture (10), as shown in Figure 4. Figure 5 shows the turned view of a corner of one embodiment of the apparatus (3), showing the top aperture (10) and compartments (6) with hexagonal cross sections.

Optionally, in any embodiment, an inlet / outlet valve (9) may be positioned at the bottom of the apparatus (3), for example when the apparatus (3) is placed in the fuel tank, such as in Figure 2.

Optionally, in any embodiment, the apparatus (3) may have a number of valves (9) and / or apertures (10).

The apparatus' (3) second primary component group is its compression mechanism. The mechanism will have two primary functions: aiding the process of unloading crude oil from inside the membrane (7) and compressing the membrane (7) from an expanded, crude oil filled state to a fully collapsed, empty one.

A mechanical mechanism may be used to aid the expansion of the apparatus (3) when loading fluids, or the compression when unloading fluids, or both. The compression may be in a horizontal or vertical direction, or a combination of both.

Vertical (top and bottom) or horizontal (sideward) compression mechanisms are envisaged to aid the unloading process. Both are designed to compress a membrane (7) and force its liquid hydrocarbon cargo from each of honeycomb compartments up into the aperture (10) at the top of the membrane (7). Given the aperture's (10) relatively small depth, once oil enters the aperture (10) it can then be removed easily with minimal suction force required to do so.

The unloading process will effectively consist of a synchronised, gradual compression of the membrane (7) and suction of oil from within the aperture (10) via the inlet / outlet valve (9). Suction may be provided by a pump (not shown). Given the potential weight of a fully laden membrane (7), it is envisaged that a horizontal compression mechanism which compresses the membrane from 2 (ideally opposite) sides of the apparatus (towards the centre of the Hold (2)) will be most effective. This is the primary design described here, which is the preferred embodiment for use in oil tankers, but compressing to either side using optionally only one compression plates (1 1) is also envisaged.

In a horizontal compression mechanism design, compression plates (1 1) are located at either side of the membrane (7) and are used to compress the membrane (7) using an action similar to a vice. The plates (1 1) are constructed by bolting a number of smaller plates together to form a completed plate. Plates (11) are manufactured of either solid steel plating or a laminated plate using a "sandwich-structure" made of stainless steel. There are a number of laminate methods which could be employed.

For horizontal compression, each compression plate (1 1) is suspended from the roof of a tanker's hold (2) area. This is achieved by placing runner beams (12), optionally composing of steel "H" beams (multiple RSJs), across the roof of each hold (2) to provide a frame, in the direction of the compression mechanism. Attached to the runner beams (12) will be a series of mobile tracks. These mobile tracks include multiple runner wheels (13) distributed evenly on each side of the runner beam (12). Attached to the mobile tracks are both the compression plates (11) and the top of the membrane (7). This allows the compression plates (1 1) to move freely towards the centre of the hold (2). Equally, they support the membrane (7) to maintain its vertical structure both during compression and when in a fully compressed (empty) state.

The mobile compression plates (11) are aided by additional drive mechanisms, such as a motor-driven pulley system (14) or vice mechanism (15) connected to a power winch (16), or electromagnetically using magnetic bands (17) or a counter weight, which could also be used. The additional vice mechanism (15) may be a screw thread mechanism or a hydraulics system. Figure 7 shows one embodiment of a vertical compression mechanism using a set of magnetic bands (17). Optionally, any combination of some or all of the additional mechanisms may be used in conjunction with any embodiment of the apparatus (3).

In the preferred embodiment, the compression plates (11) will be pulled together to the centre, or towards the central axis, of an oil tanker's hold (2) area by means of a pulley system (14). For improved reliability, the pulley system (14) may be comprised of 2 mutually exclusive pulleys so that in the event of a failure, an individual pulley system (14) is capable of completing the compression process. To ensure the compression process completes at the centre of the hold (2), the membrane (7) will be fixed at the centre points, preventing an uneven distribution of the pulling force. The final compression of the membrane (7) will be achieved using a vice mechanism (15) such as screw thread or hydraulic clamp mechanism that will be engaged in the in the final third or quarter of the compression process. This final engagement will provide more force and completely collapse the membrane (7) and therefore ensure there is very little residue left in the membrane (7).

The final component of the compression mechanism is its base construction (18). The base construction (18) supports the superficial weight of the membrane (7) and its contents while transferring the ultimate force onto the floor of the hold (2). The hold (2) area is designed to take the weight of substantial liquid hydrocarbon volumes. As such, the present apparatus is arranged such that the membrane abuts the base and the base in turn abuts the hold floor, so that the force from the weight of the membrane (especially when full) is transferred to, and supported by, the hold floor. Optionally, in any embodiment, a base construction (18) incorporating a conveyer belt (19) roller mechanism, as shown in Figures 7 and 9, may be incorporated into the apparatus (3) at the floor of the hold (2). This functions to reduce friction and thereby aid the compression and expansion processes. Optionally, the base construction (18) roller mechanism may consist of base plates (20) (also referred to herein as support plates) connected with hinges (21) to allow them to fold under each other. It may be driven by rollers (23), one embodiment of which is illustrated in Figure 8. This conveyor belt (19) moves as the compartment compresses to the centre of the hold (2).

The horizontal compression design is comprised of two conveyor belts, one for each half of the membrane (7) allowing the membrane (7) to collapse from each side, towards the centre of the hold (2). The purpose of the belts is to remove the friction between the membrane (7) and the base of the hold (2). It also facilitates the way in which the membrane (7) collapses - we expect the membrane (7) honeycomb subdivided structure will collapse first. These belts will move at the same rate as the overarching compression process. At the centre of the hold (2) and fed by both conveyor belts (19) is a central base stand or bulkhead (22) that the membrane (7) will come to rest on. This is a static plate and takes the lighter weight of the membrane (7) when fully collapsed.

To facilitate the conveyor belts (19) moving fluently they will sit on top of a roller system. This is constructed of a series of parallel rollers (23) instead of a single roller to allow for easy maintenance and replacement. The rollers (23) will be similar to those used on pallet trucks at the rear. The roller (23) is made from a plastic type material.

Optionally, in any embodiment, hot water or steam may be used to adjust the viscosity of the fluid during transport, loading or unloading. Optionally, pipes (24) for hot water or steam may be incorporated into the base construction (18), as shown in Figure 9. This is advantageous, especially when unloading oil as, upon heating, the oil becomes less viscous and, therefore, easier to unload. Accordingly, each conveyor belt's (19) base plate (20) is constructed of two plates sandwiched together and separated by a gasket. This allows hot water to pass from one end of the base plate (20) to the alternative end through a channel. The hot water is then fed to the next base plate (20) via a hydraulic hose. As such, water may can pass from one plate to the next until finally returning to be reheated in a sealed circuit. Heating the base plates (20) will heat the base of the membrane (7) and, in turn, the crude oil cargo within the membrane (7). Heated crude oil is easier to pump through the top of the membrane (7). As the heated material rises the hottest content will also be at the top of the membrane (7).

Optionally, in any embodiment, the base construction (18) may incorporate a hinge (21) or hinges (21) to compact the apparatus (3) further after unloading the fluid. One embodiment of this as envisaged for bulk carriers is shown in Figure 10, although this feature can be adapted into any embodiment with base constructions (18), such as the towards-the-centre compression embodiment for oil tankers.

A material like latex can be used to coat the apparatus which protects the liquid cargo, for example, rust and corrosion or contamination.

The variant as seen in Figure 2 was designed to extract the oil from the bottom of the bag. A central aperture runs across the diameter of the apparatus instead of being separated in honeycomb compartments. This allows the oil that was in adjacent compartments (6) to flow to the central aperture (10) and then be extracted from the bottom of the apparatus (3). This will be connected to existing sump which extract oil in current oil tankers. This approach allows gravity to help in the extraction process. However, extracting from the top of the apparatus (3) is still preferred as it could also be attached to the sump at the bottom of the hold. This still allows gravity to assist without having to have a large cross section aperture.

Vertical compression

Vertical compression may take the form of top-down or bottom-up compression, being substantially along the gravitational axis of the earth.

Top-down compression

Given the weight of a fully laden membrane, an alternative arrangement for the compression mechanism may take advantage of working with gravity (rather than against it). This may require the compression mechanism to provide less force. A design comprises a compression elevator which simply resides above the roof of the membrane and applies downward force. To enable top down compression, said variant comprises a fixed frame for (i.e. around) the aperture. This serves to support the aperture in an open configuration. This is advantageous as it prevents the apparatus and particularly the membrane from collapsing under its own weight. An extendable/retractable pipe may also be required to attach to the inlet/outlet valve and may extend and collapse as the membrane does. This - allows cargo to be loaded and unloaded.

Magnetic (top-down) compression using bands

Magnetic bands may run horizontally (perpendicular to the gravitational axis of the earth) around the membrane. They may serve one or more important purposes; providing an electromagnetic means of compression and/or maintaining the shape of the membrane so that it collapses neatly. Compression may be achieved by each subordinate band pulling down the peer located above it.

Rain water catchment

One of the potential extensions of vessels converted using the present apparatus is that they can be used to catch rain water in open seas. Tankers are prone to periods of gluts meaning they can sit around unused for long periods. During such times, tankers could park up for a period in high precipitation areas and store the rain water that falls - effectively diverting it to the hold areas. Simple pipe work leading into the apparatus should be sufficient to enable rain water catchment.

Thus, provided is an apparatus according to the present invention comprising a rain-water collecting device. The rain water collecting device may comprise a system of pipes or gutters to collect rain water falling onto or running off the deck or upper surface of the ship and divert or channel it in the compartments. The rain water collecting device may comprise one or more funnels to be placed on or above the deck or upper surfaces of the ship so as to collect the rain water as it falls.

The approximate size of one preferred but exemplary embodiment of the apparatus is so that it can hold approximately 1500-1600 cubic meters of fluid. In this particular embodiment, there may be 6, 7, 8, 9, 10, 12 or 15 compartments, each compartment being preferably capable of holding between 150 and 270 cubic meters of fluid, preferably 180-220 and most preferably 200 cubic meters of fluid. Ideally, each compartment should be capable of holding, i.e. have a capacity, a similar volume of fluid to its adjacent compartments and preferably all compartments in the apparatus should be capable of holding, i.e. have a capacity, a similar volume of fluid. By similar, here is meant within 5 or 10% and preferably 1-2%, most preferably the same, i.e. zero per cent. Approximate sizes and dimensions for each compartment, in some preferred embodiments, are 4, 5, 6, 7, 8, 9, 10, 12 or 15 meters in diameter. In some preferred embodiments, heights for each compartment may be in the range of 20-30 meters high, with 20, 25, 30 or 35 meters preferred. Any of the following capacities may be used and all ranges between each integer are preferred.

In some embodiments, six compartments are preferred. These may be arranged in 2 rows of 3. In some embodiments, nine compartments are preferred. These may be arranged in 3 rows of 3. In some embodiments, 8 compartments are preferred. These may be arranged in 2 rows of 4. In some embodiments, 10 compartments are preferred. These may be arranged in 3 rows of 3, plus one; or in 2 rows of 5. In some embodiments, 12 compartments are preferred. These may be arranged in 4 rows of 3; or 2 rows of 6. In some embodiments, 15 compartments are preferred. These may be arranged in 5 rows of 3.

Claims

A compressible fluid storage apparatus, suitable for a ship's hold (2), comprising:

• a plurality of compressible and fluid-impermeable compartments (6); and

• a compression mechanism to compress each compartment (6), wherein the compartments (6) are arranged in a honeycomb pattern.

An apparatus according to claim 1 , wherein each compartment comprises a fluid- impermeable membrane (9) sealed to retain fluid therein.

An apparatus according to any one of claims 1 or 2, wherein the compression is horizontal.

An apparatus according to any one of claims 1 to 2, wherein the compression is vertical.

An apparatus according to any preceding claim, comprising a pump to insert or remove fluid from the or each compartment (6).

An apparatus according to any one of the preceding claim, comprising a heating or cooling system to heat or cool the fluid within the or each compartment (6).

An apparatus according to any one of the preceding claims, wherein the compression mechanism comprises a compression plate (1 1) to compress the compartments (6) or each compartment (6).

An apparatus according to preceding claim 7, wherein the compression plate (11) comprises the heating or cooling system to heat or cool the fluid within the or each compartment (6). An apparatus according to claim 5, wherein the apparatus comprises a base (18) and support plates (20) to support the base of each compartment (6) and, optionally, said support plates comprise heating or cooling system to heat or cool the fluid within the or each compartment (6).

An apparatus according to any one of the preceding claims, comprising extraction means to extract cargo from the top of each, or at least one of the, compartments (6); and optionally an inlet comprising a valve through which the fluid is distributed to each, or at least one of the, compartments (6).

An apparatus according to any of claims 7-10, wherein the compression is horizontal and the apparatus comprises a frame, the frame comprising runner beams (12) running in parallel to the direction of the horizontal compression, with a series of mobile tracks attached to said runner beams (12) and the compression plates (11) and the top of the membrane (7) or compartments (6) each attached to one or more runner wheels (13) which run along the mobile tracks allowing the compression plates (11) to move freely towards the centre or side of the hold (2) during compression of the apparatus.

An apparatus according to any one of the preceding claims, wherein the compression mechanism comprises:

a pulley system (14) comprised of 2 mutually exclusive pulleys; and/or a vice mechanism (15) such as a screw thread or hydraulic clamp

mechanism.

An apparatus according to any one of the preceding claims, wherein the base of the compartments (6) abut a base (18) and the base (18) in turn abuts the floor of the hold (2).

An apparatus according to claim 13, wherein the base (18) comprises a conveyer belt (19) roller mechanism.

15. An apparatus according to any one of the preceding claims, wherein the apparatus further comprises a rain water collecting device.

16. A ship comprising an apparatus according to any preceding claim positioned within one or more of its holds (2).

17. A ship according to claim 8, wherein the apparatus is positioned within a cargo hold (2) or a fuel tank.

18. A method of filling or loading a hold of a ship with a fluid, comprising at least partially filling (loading) one or more compartments of the apparatus according to any of claims 1-15 with a fluid at a first port.