The present invention relates to a bunded tank system for transport and storage of bulk chemicals or liquids. In particular, the invention relates to a containerised bunded tank for transport and/or storage of bulk industrial liquids.
The bulk storage of industrial chemicals and in particular liquids, is known and has developed an increasing importance over time due to environmental concerns that arise due to the risk of escape.
In the past it was common to store bulk chemicals in large underground tanks that were filled for storage and then pumped out when needed. Underground storage tanks are less common today due to related leaks and difficulty detecting leaks and the associated environmental risks.
Thus it is becoming increasingly important to have liquids that are used in commercial, industrial and institutional areas bunded to prevent slips, accidents, spills and pollution.
In addition, during the transport of bulk industrial liquids or chemicals is also desirable to have improved safety measures to protect against slips, accidents, spills and pollution.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.
It is an object of the present invention to provide an improved bunded tank system and/or method of storing or transporting same or to at least provide a useful choice.
In one aspect, the present invention broadly consists in a tank system comprising:
a first outer tank having a bottom wall, end walls, enclosing side walls, and an open top,
a second inner tank having a bottom wall, end walls, enclosing side walls and a closed top, and including an aperture for filling and/or emptying said inner tank,
said second inner tank being arranged within said first outer tank,
said first outer tank has a volume of at least 110% the volume of said second inner tank, and
said first outer tank being sized to fit inside the confines of an ISO standard 20 foot half height container.
According to a further aspect at least said enclosing side walls of said first outer tank are corrugated.
According to a further aspect at least said end walls of said first outer tank are corrugated.
According to a further aspect said bottom wall of said first outer tank is ribbed.
According to a further aspect said bottom wall of said second inner tank is ribbed, and
said ribs of said bottom wall of said second inner tank interlock with said ribs of said bottom wall of said first outer tank.
According to a further aspect wherein the corrugated spaces between the first outer tank and the second inner tank, together comprise at least approximately 10% of the volume of said second inner tank.
According to a further aspect said first outer tank is constructed in a single piece.
According to a further aspect said second inner tank is constructed in a single piece.
According to a further aspect said first outer tank has forklift pockets adapted to receive the prongs of a forklift.
According to a further aspect said second inner tank includes a collection point at a lowest region of said bottom wall and the remaining portions of said bottom wall slope towards said collection point.
According to a further aspect said collection point is located at approximately the centre of said bottom wall of said second inner tank.
According to a further aspect said aperture in said second inner tank is located at approximately the centre of said closed top.
According to a further aspect said end walls of said second inner tank are substantially planar.
According to a further aspect said side walls of said second inner tank are substantially planar.
According to a further aspect said corrugated walls of said first outer tank define inner wall portions and outer wall portions, and
wherein neighboring walls of said second inner tank are adjacent and abut said inner wall portions of said first outer tank.
According to a further aspect said tank assembly further comprises a lid for covering said aperture in the closed top of said second inner tank.
According to a further aspect said tank system further comprising a tube extending from the vicinity of said collection point to a location proximate said aperture in the closed top of said second inner tank.
According to a further aspect said tube is associated with a lid for covering said aperture in the closed top of said second inner tank.
According to a further aspect said tanks are positioned adjacent and aligned with each other such that correspondingly adjacent corrugated walls of at least two said first outer tanks contact and interlock with each other.
According to a further aspect said tank assembly comprising a plurality of said tanks positioned adjacent and aligned with each other and fitted inside the confines of an ISO standard 20 foot half height container and wherein said plurality is:
a) two tanks,
b) three tanks,
c) four tanks,
d) five tanks,
e) six tanks,
f) seven tanks, or
g) eight tanks.
According to a further aspect said container is a half height high cube container.
According to a further aspect the total volume of said second inner tanks combined does not exceed approximately 10,000 L.
According to a further aspect the volume of each inner tank does not exceed 3,000 L.
According to a further aspect the volume of each inner tank is approximately 2,500 L.
According to a further aspect said lid includes a valve according to any one of the clauses directed to a valve.
In a second aspect the invention consists in a valve comprising:
a valve body defining a cavity and having a float translatable therein,
a first aperture in said valve body and in fluid communication with said cavity,
a second aperture in said valve body and in fluid communication with said cavity,
a passageway around said float and in fluid communication with said first and second apertures,
said valve having two operating conditions wherein in a first operating condition said float does not block fluid communication between said first aperture and said second aperture, and
wherein when in said second operating condition said float blocks fluid communication between said first aperture and said second aperture.
According to a further aspect said float includes a sealing surface and when in said second operating condition said sealing surface engages with a portion of said valve body to block fluid communication from said passageway to said first aperture.
According to a further aspect said sealing surface includes a resilient element.
According to a further aspect said passageway extends between said first aperture and said second aperture.
In a third aspect the invention consists in a container lock comprising:
a shaft having a locking lug at a first end, said shaft being rotatable about a longitudinal axis and translatable along said axis,
a lifting arm pivotally mounted about a point intermediate a first end and a second end, and
a link between said second end of said lifting arm and said shaft such that rotating said lifting arm about its pivot point causes said link to translate said shaft.
According to a further aspect a second end of said shaft includes a locking handle.
According to a further aspect said lifting arm includes a lifting handle at said first end.
According to a further aspect said shaft is rotatable by at least 90 degrees and rotation of said locking handle rotates said shaft.
According to a further aspect said shaft is indexed to prevent rotation when said index is engaged.
According to a further aspect said shaft is indexed at 90 degree intervals.
According to a further aspect said locking lugs are adapted to engage with a corner block of an ISO container.
According to a further aspect said container locks are positioned on said container to align and engage with a standard ISO container lock configuration.
According to a further aspect said container comprising two container locks.
According to a further aspect said container comprising four container locks.
According to a further aspect said container locks are located at each corner of the top of said container.
According to a further aspect said container comprising six container locks.
In a fourth aspect the invention consists in a method of securing a container including a container lock according to any one of the previous clauses, comprising:
placing said container on a support surface having the standard ISO container lock pattern apertures, such that said container locks are aligned with said apertures,
rotating said lifting arm to translate said shaft such that said locking lug enters said aperture,
rotating said shaft through 90 degrees such that said locking lug engages said support surface.
According to a further aspect said step of rotating said lifting arm is carried out by moving said lifting handle through 90 degrees.
According to a further aspect said step of rotating said shaft is carried out by moving said locking handle through 90 degrees.
In a fifth aspect the invention consists in a tank system substantially as herein described and with reference to any one or more of
In a sixth aspect the invention consists in a tank assembly substantially as herein described and with reference to any one or more of
In a seventh aspect the invention consists in a valve substantially as herein described and with reference to any one or more of
In an eighth aspect the invention consists in a container lock substantially as herein described and with reference to any one or more of
In a ninth aspect the invention consists in a container substantially as herein described and with reference to any one or more of
In a tenth aspect the invention consists in a method of securing a container substantially as herein described and with reference to any one or more of
The term “comprising” as used in this specification and claims means “consisting at least in part of”. When interpreting each statement in this specification and claims that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner.
Preferred embodiments of the invention will be described by way of example only and with reference to the drawings, in which:
a is a front view of a container lock shown with the lock retracted.
b is a front view of the container lock of
a is a side view of a container lock shown with the lock retracted.
b is a side view of the container lock of
With reference to
Inner tank 1 includes a bottom wall 2, end walls 3, enclosing side walls 4, and a closed top 5. The tank is preferably shaped with generally planar walls to form a substantially rectangular volume.
Closed top 5 includes an aperture 6 for filling and/or emptying tank 1. Preferably aperture 6 is located approximately at a mid-point of closed top 5. In alternative embodiments, a filling and/or emptying aperture maybe located in one of the other walls of tank 1, or another position in top 5.
The inner tank 1 is preferably formed from a single piece and defines a substantially rectangular volume. For example, it is preferred that the tank is constructed from a suitable polymer material capable of resisting chemical attack from the industrial liquids or chemicals intended to be contained within. For example: Polyethylene (High, Med or Low density), Polypropylene (High or low density), Nylon, Teflon, PTFE, PVDF or blends or combinations thereof. In one preferred embodiment the material is Alkatuff®.
In preferred polymer embodiments of tank 1, the wall thickness of inner tank 1 is approximately 10-12 mm. In alternative embodiments the tanks may be of a metallic material. For example, Stainless steel, Hastelloy, Aluminium, Titanium or any ferrous metal. In these embodiments the wall thickness may be reduced, for example to approximately 5-7 mm.
One suitable method of constructing inner tank 1 in a single piece is via the method of rotational moulding. This method is particularly preferred where the tanks are large in size. Alternatively, inner tank 1 may be manufactured in a single piece according to other moulding techniques, such as blow moulding or any other suitable techniques.
Alternatively still, inner tank 1 may be constructed from multiple pieces and joined together via a suitable method such as welding or other forms of fastening that may require the joins to be further sealed such as bolts or rivets etc. In these forms the tank may be constructed from a polymer material or alternatively from a metallic material, or alternatively still from both polymer and metallic parts.
With particular reference to
Preferably, bottom wall 2 also includes one or more collection points 8. It is preferable that a single collection point 8 is located approximately centrally to bottom wall 2 and/or located at a low region of said bottom wall 2. In most preferred embodiments the collection point 8 is located at the lowest region of bottom wall 2 so that any liquid in inner tank 1 will drain towards the collection point 8. It is also preferred that ribs 7 form drain ways that slope towards collection point 8.
Inner tank 1 preferably also includes a plurality of lift points (not shown) to aid with gripping and manipulating inner tank 1.
With reference to
Preferably, the pumping tube 10 couples with lid 12. In use, inner tank 1 can be filled and/or pumped out via tube 10. It will be appreciated that because tube 10 has its bottom end located in the vicinity of drain point 8 (and the bottom wall 2 of inner tank 1 drain towards the collection point), the inner tank 1 can be pumped almost completely dry from a single location. In addition, tube 10 allows the tank to be filled from the bottom up thereby reducing foam generation which can be a problem when pumping some chemicals into storage tanks.
Lid 12 includes a filling/emptying aperture 17 and is adapted to engage with aperture 6 of inner tank 1 via screw threads 15 around its peripheral edge. Filling/emptying aperture 17 is in fluid communication with tube 10 so that liquid can be pumped in or out via filling tube through lid 12. An O-ring 16 is provided to complete a hermetic seal when lid 12 is engaged with tank 1. Preferably, filling/emptying aperture 14 is adapted to receive an industry standard cam lock fitting for attachment to a flexible hose for the purpose of pumping in or pumping out fluid. Alternatively, any suitable attachment may be accommodated.
In the most preferred embodiments, lid 12 also includes a valve 11 to allow venting and/or intake of air during the filling and/or emptying process respectively. In addition, the valve 11 may also be effective at reducing or elimination spillage (through the vent valve) if the tank is tipped or dropped. A most preferred structure of valve 11 will be described in more detail later. In alternative embodiments, the vent valve may not be part of lid 12.
It is preferred that inner tank 1 also includes one or more drain channels 13 in closed top 5. The drain channels 13 function to direct any liquids spilled on the surface of the closed top 5 around the sides of inner tank 1, and into the bund (described later). It will be appreciated that channels 13, also function to reinforce and stiffen the tank.
At each corner of inner tank 1, there are preferably recesses 14 extending the height of inner tank 1. The function of these corner recesses 14 is to accommodate containerisation and/or an improved locking mechanism to be described later.
Outer tank 20 includes a bottom wall 21, end walls 22 and enclosing side walls 23. Preferably the outer tank 20 has an open top. The outer tank 20 is preferably shaped with generally planar walls to form a substantially rectangular volume.
Bottom wall 21 of outer tank 20 also preferably includes one or more ribs 24. The bottom wall 21 is preferably generally planar but with ribs that provide a contour extending out of plane with respect to the generally planar bottom wall 21 as illustrated.
The inner outer tank 20 is also preferably formed from a single piece. For example, it is preferred that the tank is constructed from a suitable polymer material capable of resisting chemical attack from the industrial liquids within as described above in respect of the inner tank 1. In preferred polymer embodiments of outer tank 20, the wall thickness is approximately 10-15 mm. Alternatively the outer tank 20 may be constructed of a metallic material or a polymer lined metallic material as described with reference to the inner tank.
Preferably the bottom wall 21 of outer tank 20 also includes fork lift pockets 25 to aid with lifting outer tank 20 via a fork lift. Preferably ribs 24 provide a number of support surfaces 26 distributed across the bottom wall 21 and these support surfaces 26 are at a height above fork lift pockets 25. This reduces the risk of a fork lift prong that misses pockets 25 and pierces outer tank 20 from also piercing the inner tank 1 arranged within outer tank 21 and supported on support surfaces 26.
According to one aspect, side walls 23 of outer tank 20 are corrugated. According to another aspect, end walls 22 of outer tank 20 are corrugated. According to a further aspect, end walls 22 and side walls 23 are corrugated.
The corrugations of side walls 23 and/or end walls 22 provide significant additional stiffness to the outer tank structure. In this context, the corrugated walls of outer tank 20 are intended to mean walls that are generally planar but include corrugations that extend out of plane as illustrated.
It is preferable that the corrugations are substantially linear such that the surface is corrugated in one direction only. However, the term corrugated may also encompass more complicated profiles. The importance of the corrugations is that they provide improved stiffness to outer tank 20 and/or that they interact with corresponding corrugations of an adjacent outer tank as described in more detail later.
Preferably outer tank 20 includes a plurality of lift points (not shown) on side walls 23 or end walls 22 or both. The lift points aid with gripping and manipulating the tank.
Preferably the outer tank 20 includes a low point 28 located to correspond with collection point(s) 8 of inner tank 1 when assembled together. Most preferably, the location of collection point 8, is aligned with the location of aperture 6, so that the tube 10 can extend directly from one to the other.
The tank assembly comprising inner tank 1 located within outer tank 20, will now be described in more detail by way of example with particular reference to
In order to form a bunded tank system, inner tank 1 is placed inside outer tank 20 as shown in
It is preferred that the side walls 4 of inner tank 1 are adjacent and substantially abut the side walls 23 of outer tank 20 as illustrated. That is, the additional 10% volume of outer tank 20 is predominantly provided by the spaces formed by corrugated walls 23.
In alternative embodiments (not shown), where end walls 22 are corrugated, the additional 10% volume of outer tank 20 is provided in those corrugation spaces as well.
Similarly, there may be spaces formed between the bottom wall 2 of inner tank 1 and the bottom wall 21 of outer tank 20, that provide some of the additional 10% volume.
For these above described embodiments the additional 10% (or 10-12%) volume is provided by the cumulative corrugation and/or ribbed spaces between the inner and outer tanks.
The ribs 7 and 24 of the inner and outer tank respectively also function to give improved rigidity to the tanks and corresponding tank assembly. In addition, the ribs 7, 24 also provide crush zones that can absorb shock without the tanks rupturing if for example the tank and/or tank assembly is dropped. This feature is an important safety aspect of the tank system.
Improved rigidity of the tank and bund system is particularly important because the inner and outer tanks 1 and 20 respectively are not cylindrical but rather generally rectangular. Cylindrical tanks are often chosen because of the additional hoop strength achievable. However, a cylindrical tank is less efficient in terms of use of space.
With reference to
This interlocking feature is important as it significantly improves the structural rigidity and strength of the tank system. That is, the corrugated walls are further constrained from bulging or bowing outwards due to pressure from the liquid therein by the adjacent tank and bund structure. It will appreciated that the interlocking nature achieves improved rigidity and strength while having minimal impact on the efficient use of space. That is, the interlocking shapes allow the storage volume to be maximised (while maintaining at least an additional 10% bund volume (or 10-12%) buffer)).
The use of a cylindrical tank, would result in an unnecessarily large bund ratio, and therefore a significantly reduced efficiency in storage volume.
The additional rigidity and strength achieved adds to the overall safety factor of the present tank and bund system. It is preferred that the tank and bund system is manufactured so that the system can be picked up (while full) and maintain its structure without breaking. In particular, the fork lift pockets 25 can be used to lift and manoeuvre the tank and bund system safely.
However, when interlocked with another adjacent and aligned tank and bund system, the combination achieves additional strength and rigidity leading to a better performing and safer system.
In some preferred embodiments the tank and bund system may be contained within an outer shell for protection. For example a wire mesh cage (not shown) may be used to surround one or more tank and bund assemblies. Alternatively, an open metallic cage as shown in
In another preferred embodiment, the tank and bund system is particularly adapted to fit within a standard ISO container envelope. In particular,
In one embodiment the ISO container includes two tank assemblies.
In another embodiment the ISO container includes three tank assemblies.
In another most preferred embodiment the ISO container includes four tank assemblies.
In another embodiment the ISO container includes five tank assemblies.
In another embodiment the ISO container includes six tank assemblies.
In another embodiment the ISO container includes seven tank assemblies.
In another embodiment the ISO container includes eight tank assemblies.
The containerised bunded tank system may be used as a plurality of separate tanks or may be ganged together and used essentially as a single tank. To achieve this, a manifold may be formed by connecting a series of tanks (via lids 12) and pumping through a single point. Alternatively, each individual tank in the containerised assembly may be filled and/or pumped out individually by attaching an appropriate can lock fitting to the respective lid 12 of individual tank. Vent Valve It is preferred that each inner tank 1 includes a valve system to allow venting of gases when the system is being filled or emptied and/or standing. It is preferred that the valve is incorporated into Lid 12. Alternatively, vent valve 11 may be accommodated elsewhere.
As liquid is pumped into tank 1 through lid 12 including valve 11, displaced air is evacuated through the valve.
With reference to
Valve 11 comprises a float 36 located within chamber 37 incorporated in lid 12. At the top of chamber 37 are one or more entry/exit vents 38. Similarly, at the bottom of chamber 37 are one or more entry/exit apertures 39. One or more passageways 40 are formed to allow air to pass around the float into or out of the tank. In one embodiment the passages may be formed by ribs 41 on the exterior surface of the float 36. Alternatively, ribs or protrusions may be formed on the wall of chamber 37.
At the top of float 36 is a sealing portion 42. The sealing portion 42 may also include a compliant seal such as O-ring 43. Valve body 44 includes a correspondingly located and shaped sealing portion 45 for sealing with the float sealing portion 42.
In one preferred form, valve 11 is adapted to be screwed into and sealed with lid 12 via threaded portions 46 which engage with threaded portions on an aperture in lid 12.
In use, float 36 sits in a lower position (as illustrated in
At the same time, if the tank is moved, tipped or dropped etc any liquid in tank 1 that enters aperture 39 in the bottom of the valve body will immediately lift the float upwards until float sealing portions 42 seals with corresponding valve sealing portions 45. This effectively blocks the passageways through the valve body 44 and prevents any liquid from escaping. As soon as the liquid pressure forcing the float upwards subsides, the float 36 can fall back to its lower position re-opening the two way vent valve 11.
Pipe 10 works in conjunction with valve 11 to allow filling and emptying as well as providing surge protection. That is, spills are prevented if the unit is lifted into place, dragged at an angle or unexpectedly dropped while loading or unloading. The valve 11 allows lid 12 to remain securely in place throughout.
An advantage of the containerised bunded tank system is that the same system can function as both an efficient storage system and a transportation system. The containerisation of the tank system according to ISO specifications allows seamless integration into existing transport logistics operations. At the same time, the transport of dangerous industrial liquids achieves additional safety by being bunded throughout. The addition of an ISO container around the outside of the individually bunded tank modules also provides an extra layer of safety containment.
The containerised tank system as described can also perform the function of storage for dangerous industrial liquids. For example, short or long term storage can be efficiently achieved by stacking containers as shown in
In a further aspect an improved locking mechanism will be described with reference to
The container locking mechanisms are adapted to work with other existing ISO container locking systems to allow normal locking methods for both land and sea. However, when desirable, the improved locking mechanism can be used to lock a container onto another object including ISO corner blocks arranged according to the ISO layouts (such as another container etc).
Locking mechanism 50 comprises a shaft 51 having a locking lug 52 at one end. Shaft 51 is rotatable about its longitudinal axis and translatable along its longitudinal axis. Lifting arm 53 is pivotally mounted about a point 54 intermediate its ends. Link 55 is provided between one end of lifting arm 53 and shaft 51, and is preferably pin jointed to each. As shown in
As illustrated in
Channel 58 is located adjacent and aligned with corner block 57. Corner block 57 is preferably an ISO standard corner block for an ISO container. It will be appreciated that channel 58 and corner block 57 are to be located on a container according to the standard ISO pattern. For example,
It is preferred that the lower corners of the container do not contain locking mechanism 50 in order that a traditional locking mechanism may engage with the lower corner blocks.
a and 14a illustrate locking mechanism 50 in an unlocked position. In this position, lifting handle 60 is in its upper position while locking lug 52 is in its lower unlocked position. In order to initiate the first stage of the locking process, lifting handle 60 is pulled downwards in direction of arrow 61 as shown in
It will be appreciated that the locking mechanism 50 can be unlocked by reversing the above described process.
Use of locking mechanism 50 can be achieved without the need for any special handling of the container system. When not in use, locking mechanism 50 is located sufficiently away from the corner blocks to allow use of all normal lifting and locking equipment currently in use around the world. The only difference in configuration of the upper corner blocks of the locking mechanism compared to standard ISO corner blocks is an additional aperture to allow the locking lug to recede into channel 58.
The locking mechanism 50 provides a useful alternative to allow any container including them to have a self contained locking mechanism to adjacent containers etc.
With reference to
For example, indexing may be achieved by including an indexing member 65 rigidly supported on shaft 51 and including at least one indexing lug 63. A corresponding stationary member including indexing slot 64 is provided and located such that indexing lugs 63 can engage with indexing slots 64 at 90 degree intervals. It is preferred that the indexing mechanism is biased into a locking position to prevent inadvertent unlocking of lug 52 once the locking mechanism is set.
Alternatively, it would be appreciated that other indexing methods may be utilised.
The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention as defined by the accompanying claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2012/054786 | 9/14/2012 | WO | 00 | 10/20/2014 |
Number | Date | Country | |
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61535615 | Sep 2011 | US |