WO2017020913A1

WO2017020913A1 - Inlet stratification device

Info

Publication number: WO2017020913A1
Application number: PCT/DK2016/050259
Authority: WO
Inventors: Martin Spanggaard
Original assignee: Eyecular Technologies Aps
Priority date: 2015-08-06
Filing date: 2016-08-03
Publication date: 2017-02-09

Abstract

The present invention relates to an inlet stratification device (1) comprising an inlet stratification pipe (2), and a method of installing said inlet stratification pipe (2) in a storage tank (3), and wherein said device (1) comprises at least one positioning means (7,9,9',9'',9''', 43,50) arranged for ensuring that the inlet stratification pipe (2) is maintained in a predetermined stretched vertical position. In this way undesirable creases and creeps due to an incorrect tension in the inlet stratification pipe (2), are effectively prevented.

Description

Inlet stratification device

The present invention relates to an inlet stratification device comprising an inlet stratification pipe, and a method of installing said inlet stratification pipe in a storage tank.

Thermal energy storage have increasingly become important with regard to efficient energy heating, since it allows excess thermal energy to be collected for later use, a requirement which is especially relevant for renewable energy.

A key parameter in thermal energy heating systems is the stratification efficiency of the thermal energy storage unit.

Stratification in thermal energy storage is a natural phenomenon encountered in liquid storage systems such as water tanks above a temperature of 4°C. Due to buoyancy forces, hot water tends to accumulate at the top of a thermal energy storage, whereas colder water will always be forced to move downwards. Therefore, a thermal energy storage based on water will always show a certain amount of thermal stratification.

Experimental and theoretical investigations have however showed that the overall system performance of a thermal energy storage, e.g. a solar heating system for domestic hot water preparation and/or space heating, can be increased with an optimal thermal stratification in the solar storage compared to systems without stratified conditions in the storage.

Different factors tend to destroy the stratification. One example is mixing of water due to natural convection caused by buoyancy of hotter fluid that is surrounded by colder fluid, e.g. if the fluid inlet is hotter than the temperature at the position of the inlet or if a thermal energy storage is charged with an immersed heat exchanger. A different problem is by jet mixing (or plume entrainment) caused by the kinetic energy of the water entering the thermal energy storage unit or with thermal conduction and diffusion within the fluid itself, the thermal energy storage tank and components immersed in the fluid .

Accordingly, the ability to promote stratification during charging and discharging of the fluid in a storage unit, is not only dependent on the construction of a storage unit but also on any stratification enhancing devices present in the unit. Therefore, the boundary conditions of the charging and discharging processes play a crucial role for the maintenance of any stratification efficiency.

Several different kinds of stratification devices are known in the art, wherein the stratification device enables an inflow at variable heights of the storage tank. Among these, are both rigid inlet stratifiers equipped with openings and 'non-return' valves, and flexible inlet stratification pipes placed vertically in the storage tanks.

When the inlet stratification pipes are flexible, as is the case in e.g. in WO2006084460, it is essential to ensure that the inlet stratifications pipe is held in a vertical position, and that the correct tension is applied to said pipe.

If the tension is either too low or to high, the openings through which the fluid will flow from the flexible inlet stratification pipe to the storage tank, will be negatively affected. For instance if the flexible inlet stratification pipe is too relaxed, the material will crease and if the inlet stratification pipe is too tense it will creep, in both cases there will be provided folds in the inlet stratification pipe unintentional either blocking or opening the openings in said inlet stratification pipe, reducing the stratification efficiency of the pipe. In order to prevent this, WO2006/084460 describes a construction in which the flexible inlet stratification pipe is held in the vertical position by means of a framed structure. However, if said frame structure in any way is damaged when handling the structure, e.g. during production, transportation or installation, the tension of the flexible inlet stratification pipe will be affected and cause a decrease in the thermal stratification performance due to either too high or too low tension in the pipe.

A further disadvantage of the rigid frame structure is that the mounting of the system in conventional tanks is virtually impossible, and will be both expensive and time consuming. Conventional storage tanks have a height depending on the intended use, but heights up to, or higher than ten meters are not uncommon, and since the inlet stratification device, and hence the rigid frame structure, will have to extend in the full length of the tank in order to ensure optimal stratification efficiency, it can be very challenging to ensure that the rigid frame structure is correctly positioned inside the storage tank, especially since visual inspection of the stratification pipe and frame is impossible. In order to solve this problem, W02014 / 106643 provides a system in which one end of the inlet stratification pipe is secured to the bottom of the tank and the opposite end is provided with a floating device ensuring that the stratification device is held in a vertical position. In order to counteract the buoyancy of the floating device a wire is attached to the floating device and to the bottom of the tank, in order to prevent that the tension in the inlet stratification pipe becomes too high.

However, said wire can only prevent the tension in the inlet stratification pipe becoming to high, and if the inlet stratification pipe creeps over the lifetime of the device, then the system cannot absorb this in the system, due to the presence of the fixed length of the wire, whereby the tension in the inlet stratification pipe will be reduced, and creases, folds and the like, will be provided in the material of the inlet stratification pipe, significantly reducing the performance of the inlet stratification pipe.

Thus, there is a requirement for providing a simple and inexpensive inlet stratification device in which the inlet stratification pipe is held in the vertical position during use and in which the correct and predetermined tension is applied to the inlet stratification pipe during operation, and which ensures that the fluid can be delivered to the correct thermal layer in the storage tank without causing any unnecessary turbulence and/or heat exchange between the layers.

It is accordingly a first aspect of the present invention to provide a inlet stratification device arranged for thermally stratifying the fluid in a thermal storage tank and which increases the thermal performance of the storage tank and/or the heating system, and where the inlet stratification pipe is held and maintained in the vertical position during use without causing the material of said inlet stratification pipe to crease and/or creep.

It is a second aspect of the present invention to provide a system arranged for ensuring that the inlet stratification pipe can be maintained in an optimal vertical position during use independently of the forces acting upon the inlet stratification pipe, and in which it is ensured that the optimal tension is applied to the inlet stratification pipe.

It is a third aspect of the present invention to provide an inlet stratification device, which can be used with existing thermal storage tanks. It is a fourth aspect of the present invention to provide a simple inlet stratification device, which is simple to install, use and maintain. It is a fifth aspect of the present invention to provide a method for installing the inlet stratification pipe in a vertical position during use, in a simple and inexpensive way.

The novel and unique features whereby these and further aspects are achieved according to the invention is the fact that the inlet stratification device comprises at least one flexible inlet stratification pipe, said pipe comprises a number of openings, and is being configured to contract and expand such that exchange of fluid through the openings of the pipe is substantially prevented in regions of the pipe, where the temperature of the fluid inside the pipe is higher than the temperature of the fluid outside the pipe and wherein said device further comprises at least one positioning means arranged for ensuring that the inlet stratification pipe is maintained in a predetermined stretched vertical position.

The inlet stratification device is preferably arranged for circulating a fluid having a vertical temperature gradient through a storage tank, and it is therefore essential that said inlet stratification pipe is arranged vertically in the storage tank. The flow of fluid from the pipe is constrained from mixing with the fluid in the storage tank until, by virtue of the forces on the inlet stratification pipe created by the density difference between the fluid in the tank and the fluid in the inlet stratification pipe, the fluid moves to the layer within the tank at or close to the temperature of the fluid emerging from the inlet stratification pipe.

Using a flexible inlet stratification pipe arranged for expanding/unfolding or collapsing will lead to an equalization of the pressure in the pipe and in the tank, ensuring that inflow and outflow through the openings in the pipe are prevented until a level of equal densities and thus temperatures in the pipe and the tank are reached. Thus, the fluid in the pipe will not enter the tank until it either reaches the top of the pipe, where it is forced to leave the pipe, because new fluid is constantly fed into the pipe, or when the temperature of the fluid in the pipe equals the temperature of the fluid in the tank leading to a slightly higher hydrostatic pressure in the pipe than in the tank. The pipe will expand in an attempt to equalize the pressure difference, but the expansion is limited by the expansion properties of the pipe, which leads to a flow of fluid from the pipe into the tank at the right temperature level. However, in order to ensure that fluid is only allowed to flow out of the inlet stratification pipe at the correct thermal layer, it is relevant that the inlet stratification pipe is placed in a predetermined stretched vertically position in the storage tank, such that the pipe does not crease or the material does not creep, as this could affect the functionality of the pipe. The device according to the invention therefore comprises at least one positioning means arranged for ensuring that the inlet stratification pipe is maintained in a predetermined stretched vertically position during use.

In the context of the present invention the term "predetermined stretched vertically position" means that creases, creeps, wrinkles, folds etc. which could have an impact on the opening/closing functioning of the openings in the inlet stratification pipe, substantially will be prevented from arising in the material of the inlet stratification pipe during operation. Thus, said positioning means is preferably arranged for ensuring that the correct tension is applied to the inlet stratification pipe, e.g. by absorbing said creases, creeps etc. if/when they arises in the material of the inlet stratification pipe. This is preferably performed during the lifetime of the system, i.e. around 20 years or even longer.

Said position means will preferably subject the inlet stratification pipe to an excessive force, such that a longitudinal slack or longitudinal elongation in the material of the inlet stratification pipe automatically will be absorbed/taken up by the position means. However, the excessive force must not be so high that the inlet stratification pipe creeps. The inventors have found out that using an inlet stratification pipe made of 0,025 mm thick ethylene tetrafluoroethylene having a height of 2 meters said excessive force i.e. the pull force applied to the inlet stratification pipe from the position means is around 100 g - 300 g. However said excessive force will depend on the inlet stratification pipe used, and the height of said pipe, and can be both higher or lower.

Within the context of the present invention, the term "flexible inlet stratification pipe" means any kind of inlet stratification pipe arranged for expanding/unfolding and collapsing in response to the temperature/density of the fluid in the pipe and tank. Accordingly, said term both encompasses inlet stratification pipes that are completely made of a flexible material and inlet stratification pipes that are partly rigid and partly flexible.

Said inlet stratification pipe could in one embodiment be made of a fabric such as the one disclosed in WO2006084460. The openings of such a fabric inlet stratification pipe will however be very small in the form of pores, which means that the inlet stratification pipe will function as a filter for the liquid. All particles larger than the pores of the fabric, e.g. rust, dirt, various flaking and any other floating material in the fluid system, will be caught by the porous fabric. This will gradually block the pores in the fabric, and eventually disable the stratification capabilities of the stratifier completely .

It is accordingly preferred to use a flexible inlet stratification pipe, made of a flexible non-porous material, and wherein the openings are regular holes, having a size that allows particles and/or sediments present in the fluid to pass through the holes without difficulties, i.e. the holes are so large that they cannot clog. The holes in the pipe are preferably arranged at different vertical heights and with a predetermined vertical distance to allow the exchange of fluid in all relevant and desired vertical thermal layers of the storage tank. The preferred flexible inlet stratification pipe for use with the present invention is disclosed in the applicants own patent application no. PCT/DK2015/050050 (not yet published) , and further details relating to the inlet stratification pipe can be found here. Said inlet stratification pipe could in a preferred embodiment comprise more than one layer of material. Said layers could e.g. be placed at a distance from each other, ensuring that the distance between the layers will function as a thermal insulation layer. Each layer has a number of vertical holes, and it is preferred that the holes in one layer of material is vertically displaced in relation to the holes in one or more adjacent layer (s), as this has proven to provide a significantly improved fluid exchanged in the correct thermal layers of the storage tank.

The use of the flexible inlet stratification pipe in PCT/DK2015/050050 (not yet published) further has the advantage that said pipe is not elastic, i.e. the excessive force applied to said pipe by the positioning means, can be taken up by the pipe without causing any kind of deformation of the pipe. Accordingly, using said pipe in the device according to the present invention, provide an especially advantageously embodiment . A person skilled in the art will furthermore understand that depending on the material of the flexible pipe, it can in some situations be difficult to completely prevent that the material creeps, and even though the use of a positioning means arranged for maintaining the inlet stratification pipe in a predetermined stretched vertical position, automatically will absorb and/or take up such a creep, it is preferred to use a material that cannot creep more than about 5%, preferably less than 1% or even better less than 0.5%. Preferred flexible non- porous materials meeting the above definitions are for example polymer films e.g. made of ethylene tetrafluoroethylene (ETFE) , polyvinylidene difluoride (PVDF) , polypropylene (PP) , or modified polytetrafluoro-ethylene (mPTFE) .

In a preferred embodiment the at least one positioning means arranged for ensuring that the inlet stratification pipe is maintained in the predetermined stretched vertical position during use comprises a bottom mount and a top mount, and wherein one end of the inlet stratification pipe is attached to the bottom mount and the opposite end of said pipe to the top mount .

In order to ensure that the inlet stratification pipe is maintained in the predetermined "stretched" condition in the storage tank, it is preferred that the bottom mount is arranged for being attached to a lower part of the storage tank, e.g. the bottom wall or a lower part of the side wall, and the top mount is arranged for being attached to the top wall or an upper part of the side wall. Attaching both ends of the inlet stratification pipe to the storage tank via the top and bottom mount, will not only ensure that the correct tension in the inlet stratification pipe easily can be maintained but also that the inlet stratification pipe can be maintained in the correct position during transport. The latter is especially relevant if the inlet stratification pipe is placed in the position of use, and the tank during transport is tilted e.g. 90 degrees about the vertical axis of use, as this would allow the inlet stratification pipe to collapse along one of the side walls of the storage tank. It would further be very difficult to ensure that the inlet stratification pipe is re-established in the proper vertical stretched position if said inlet stratification pipe were not attached to the top and bottom of the storage tank, e.g. via top and bottom mounts. Accordingly, this arrangement prevents the inlet stratification pipe from moving in an uncontrolled manner during manipulation of the tank, damaging not only the inlet stratification pipe, e.g. by ripping undesirable holes in said pipe, but also the storage tank, by causing cracks in the inside glaze of the tank, or other tank components.

It will be understood that the inlet stratification pipe need not to be distributed in the complete length of the storage tank. In some situations it can be desired to have an inlet stratification pipe only extending over a section of the tank, e.g. if the fluid to be used from the storage tank have to be less warm than the water at the top of the storage tank, or if the fluid returning to the storage tank, is warmer than at the bottom part of the storage tank. In such situations the top and bottom mount will not be attached to the top and bottom of the storage tank, but to the top and bottom of the specific section in which the inlet stratification pipe is placed. Said section can be anywhere in the storage tank, and in the context of the present invention, the use of the term top and bottom of the storage tank, also encompass the top and bottom of only a section of said tank.

It is further understood that a storage tank can comprise more than one inlet stratification pipe, e.g. one or more inlet stratification pipes which spans the entire storage tank, and one or more inlet stratification pipes which spans only a section of said tank, thereby providing an efficient way of optimizing both use of the fluid in the storage tank as well as the conditions in the stratification device according to the invention . In a preferred embodiment the at least one position means comprises at least one tension unit, arranged for ensuring that the inlet stratification pipe maintains the correct tension independently of the conditions in the tank, e.g. the buoyant power, temperature, flow and density differences, preferably by applying a predetermined excessive force to the inlet stratification pipe. In this way the flexible inlet stratification pipe will maintain its original vertical position and at the same time ensure that creases, creeps, wrinkles, folds etc. which could have an impact on the opening/closing functioning of the openings in the inlet stratification pipe, substantially will be prevented from arising in the material of the inlet stratification pipe during operation . In a preferred embodiment the tension unit is part of the top mount, however, said tension unit could also be part of the bottom mount or part of both the top and bottom mount. The latter may be relevant if the storage tank is very large and/or high, since tension units in both mounts will ensure that the tension in the inlet stratification pipe is and remains substantially constant.

In one embodiment the tension unit is a resilient member, such as a suspension spring, arranged for providing a substantially constant predetermined excessive force/tension to the inlet stratification pipe in the storage tank during use. Accordingly the suspension spring will prevent both too excessive and too limited tension in the inlet stratification pipe, whereby an optimal operation of the stratification device according to the invention can be obtained. A person skilled in the art will understand that the resilient means can be any suitable means having an elasticity and resilience capable of both providing a substantially constant tension to the inlet stratification pipe, and which at the same time will ensure that the inlet stratification pipe is maintained in the stretched vertical position during use. Examples of such means are e.g. an unit/part made of a resilient elastic material, e.g. an elastomer. Such materials are well known in the art, and will not be discussed in further details in this application.

In an alternative embodiment, the tension unit comprises a counterbalance arranged for ensuring that the inlet stratification pipe is maintained in the predetermined stretched condition. If said counterbalance is placed in (or attached to) the top section of the flexible inlet stratification pipe, it is preferred that the pipe can be folded/looped about a rod (or the like) placed substantially horizontal in the top part of the storage tank or section, since it has been found that such an arrangement will not impose detrimental stresses on the inlet stratification pipe. In this way the stretch/tension of the inlet stratification pipe will automatically be adjusted, e.g. depending on the forces acting upon the inlet stratification pipe, simply by allowing the inlet stratification pipe to slide about the bar/rod, since the counter balance will ensure that the flexible inlet stratification pipe will always be placed in the desired stretched vertical position. Alternatively, the rod for the counterbalance can be connected to the bottom of the storage tank by means of one or more connection means. Said connection means is preferably a telescopic pole, an articulated pole connected by means of an elastic string, a flexible bar or other similar means. In a preferred embodiment, the rod/bar is simply attached to the top part of the storage tank or the relevant section of said storage tank, preferably using a conventional rigid connection means e.g. a metal rod or the like, as this will provide a simple embodiment eliminating the need for providing e.g. a pole or the like in the complete height of the storage tank .

It is preferred that the counterbalance has a density higher than the fluid in the storage tank, however, the weight /density must not be so high that a too excessive tension is applied to the flexible pipe, causing the material to creep to an undesirable degree. In a still further embodiment the tension unit comprises a floating device, however in order to ensure that the floating device is not displaced during operation, said floating device is connected to the top of the tank or the respective section, e.g. by a securing means. The securing means is preferably made of a non-elastic wire, e.g. a stainless steel wire.

The floating device preferably has a buoyancy which will ensure that the inlet stratification pipe has the correct predetermined tension. The floating device can be made of any relevant material, as long as the correct tension is applied to the inlet stratification pipe. Such materials are well known in the art, and will not be discussed in further details.

The bottom mount is preferably arranged for securely attaching one end of the inlet stratification pipe to an inlet tube of the tank. It is preferred that the inlet opening of the inlet stratification pipe and the inlet tube are in direct fluid communication, such that the fluid can be added to the storage tank via the inlet stratification pipe from the inlet tube. If a conventional storage tank is used, said inlet tube is preferably the inlet tube already provided in the tank. However, the inlet tube can also be custom made in combination with the installation of the inlet stratification pipe in the tank and will accordingly be arranged in the bottom part of the tank, e.g. in the bottom wall of said tank or in the side wall close to the bottom of said tank.

The inlet stratification pipe can be attached to the inlet tube, i.e. to the inlet connection, of the tank, in any convenient way, however in a preferred embodiment the bottom mount comprises an inlet attachment part and at least one fastening means. Said inlet attachment part is preferably arranged for extending through the inlet tube of the tank, such that a first end of the inlet attachment part extends inside the storage tank and the second end, opposite the first end, extends outside the storage tank, such that said inlet attachment part at said second end can be fastened to the storage tank via the fastening means. The inlet stratification pipe is preferably attached to the first end of the inlet attachment part, whereby a simple construction is provided.

It is preferred that said fastening means can also be used for attaching the tubes/pipes used for circulating the fluid through the relevant units, e.g. heating devices, heat exchanges, domestic appliances and the like. As one example can be mentioned a simple union bolt/nut, however other fastening means are also contemplated within the scope of the present invention, including those which requires further adaptors and/or connectors in order to provide a functional system. Such fastening means are well known in the art and will not be discussed in further details in this application. In a preferred embodiment the inlet stratification pipe is attached to the storage tank using a bottom mount arranged for ensuring that said pipe can not be rotated during the mounting in the storage tank. In a preferred embodiment such a bottom mount comprises e.g. a union nut, a flange attached to the inlet pipe, and a treaded connection on the tube on which said pipe is to be mounted, but other similar means known in the art is also contemplated within the scope of the present invention.

The first end of the inlet attachment part will preferably have a substantially circular, oval or round cross-section, which will contribute to provide a desired cross-section of the fluid column flowing into the inlet stratification pipe, and which, when the inlet stratification pipe is made of a flexible non- porous material, will assist in providing a simple and effective opening and closing of the holes in said pipe.

The inlet stratification pipe can be connected to the first end of the inlet attachment part via any conventional means, e.g. by using at manacle rings, cable ties, tie-wraps or 0-rings, or via customized means, e.g. by using snap fits, and depending on the material of the inlet stratification pipe and the inlet attachment part, other attachment methods, such welding, glue, or the like, are also contemplated within the scope of the present invention. The only requirement in this respect is that the inlet stratification pipe is securely attached/connected to the bottom mount, e.g. via the inlet attachment part, in a way that the inlet stratification pipe cannot be detached from the bottom mount during operation, such that fluid unintentionally can exit/enter the inlet stratification pipe at the attachment point .

The inlet stratification pipe may in a preferred embodiment comprise an expanding means, arranged for expanding the flexible inlet stratification pipe, i.e. preventing the flexible inlet stratification pipe from collapsing, and/or for decreasing the velocity of the fluid in said pipe.

Said expansion means can in one embodiment be one or more ringlike structures. Said ring-like structures can be a complete ring, but in some embodiments only a part of a ring is necessary . Said expansion means may in one embodiment have a diameter of at least twice the diameter of the inlet tube, but the expansion means may in principal have any diameter which ensures that the inlet pipe remains in the expanded position and/or decreases the velocity of the fluid to a preferably laminar flow.

The expansion means may either be placed at the top and/or the bottom of the inlet pipe, and/or extend in substantially the whole length of the pipe, e.g. placed at intervals in an area opposing a single row of holes.

The expansion means may be flexible, allowing said means to be inserted though small openings, but the expansion means may also be a rigid construction, if this is more appropriate.

Having expansion means arranged in the inlet stratification pipe will among others ensure that the velocity of the fluid coming from the inlet stratification pipe is reduced, preferably to at least 0.1 m/s . This will ensure that the fluid entering said inlet pipe will be slowed down to such an extend that the fluid can be delivered to the correct thermal layer in the storage tank. If the velocity of the fluid is too high when entering the inlet stratification pipe, the result may be that said fluid will pass the correct thermal layer, and exit said inlet pipe in a too high level. In the storage tank said fluid will then try to move "back down" to the correct layer, causing undesirable turbulence and accordingly mixing of the fluid. Thus, when the inlet stratification pipe comprises an expansion means, the inlet stratification device according to the invention will function even more effectively.

In a similar way the top mount is preferably arranged for securely attaching the opposite end of the inlet stratification pipe to the upper top part of the storage tank, e.g. a top wall of said tank or a top part close to the top wall. This will not only provide a simple and inexpensive embodiment but also ensure that the inlet stratification pipe is kept in a predetermined stretched position. Thus, undesirable creases and creeps due to an incorrect tension in the inlet stratification pipe, are effectively prevented, simply because a constant predetermined tension is applied to the inlet stratification pipe .

The top mount will preferably comprise a top attachment part, arranged for fixing the flexible inlet stratification pipe to the top mount, and a second fastening means, arranged for attaching the top mount to a mounting means in the tank. In a preferred embodiment one or more of said means may be part of the storage tank or retrofitted to said tank.

In a preferred embodiment the inlet stratification pipe is attached to the top attachment part via any conventional means such as manacle rings, cable ties or tie-wraps, i.e. in a similar manner as the inlet stratification pipe is attached to the inlet attachment part. If the inlet stratification pipe comprises an expansion means at the top, said top attachment part can also be connected to the inlet pipe via said expansion means, or be an integrated part of said expansion means. Conventionally the inlet stratification pipes have been inserted through the hand hole cleanouts placed in a bottom part in the tank and attached to only the bottom of the storage tank. The purpose of a hand hole cleanout is however to ensure that lime and sediment can be removed from the tanks on a regular basis, and said holes are accordingly relatively small making the mounting of the inlet stratification pipe inside the tank rather difficult, especially since it is difficult to visually observe whether or not the inlet stratification device are placed at the desired position during installation or during maintenance. This is particularly the case when the framed structure of WO2006/084460 is mounted through the hand hole, and said mount will often lead to the fact that the framed structure either is not installed in the vertical position or that said position cannot be maintained, since the inlet stratification pipe is subjected to excessive forces during both transport and operation. Accordingly the efficiency of said inlet stratification device will not be optimal. It will further be appreciated that the tanks can have a height up to more than 10 m rendering them difficult to handle.

Thus, in order to ensure that the person mounting the inlet stratification pipe according to the invention can handle and attach the inlet stratification pipe to the top part of the tank, it is preferred that a top opening is formed in the tank.

The mounting means for attaching the top mount to the tank is preferably also installed in the tank via said top opening, i.e. said mounting means is placed in the vicinity of the top opening. Depending on the top mount, the mounting means for attaching the flexible inlet stratification pipe to the top part of the storage tank or section can be a simple bar, a hook, a wire or the like e.g. welded to the top wall or side part of the storage tank. In this way the top opening and the mounting means can easily be retrofitted to conventional storage tanks, thus the need for custom made tanks are eliminated .

The present invention also relates to a method of mounting the inlet stratification pipe in the storage tank. method comprises

providing a flexible inlet stratification pipe comprising a number of openings, providing a storage tank with an inlet opening at a bottom part of the storage tank, and a top opening in a top part of the storage tank,

guiding an installation means via the top opening, through the tank and out of the inlet opening,

attaching one end of the flexible inlet stratification pipe to the installation means,

pulling the installation means in the reverse direction through the storage tank, until the flexible inlet stratification pipe is disposed at the predetermined stretched vertical position between the inlet opening and the top opening, and

attaching the inlet stratification pipe to the top and bottom parts of the storage tank.

In this way a very simple and effective way of ensuring that the inlet stratification pipe is correctly positioned both during installation and during operation is provided, thereby completely eliminating the difficult and time consuming installation procedures in which either the hand hole cleanouts are used or the inlet stratification pipe is installed in the storage tank during the manufacturing of said tank. The latter makes the stratification pipe exposed to damages as well as displacement inside the tank during transport.

Furthermore, the use of a top opening will ensure that the person installing the inlet stratification pipe is allowed to visually inspect, e.g. using a camera, whether or not the pipe is correctly installed, a possibility which has not been practicable earlier. Furthermore, said top opening, depending on the size, can also be used to observe whether or not the inlet stratification pipe is maintained in the correct position and has the correct tension e.g. after a period of use, providing an effective means for maintaining the optimal conditions in the stratification device. Said method can be used irrespectively of whether or not the storage tank comprises a hand hole, since both the inlet and top opening can be formed in the tank on demand, and accordingly the method according to the invention can be used with any conventional storage tank. In a preferred embodiment the inlet opening will however be the inlet opening already provided in a storage tank, such that only the top opening needs to be specifically formed in the tank before the installation .

The inlet stratification pipe is preferably attached to a top and bottom mount as described previously, it is however preferred that the top opening after installation of the inlet stratification pipe to the top part of the storage tank, can be closed with a cap or lid member, e.g. using a threaded connection .

In order to ensure that the inlet stratification pipe is not rotated about is longitudinal axis during installation, it is preferred that the inlet stratification pipe is pulled through the storage tank to the desired position in a way which prevents rotation, e.g. by slowly feeding the inlet stratification pipe through the inlet tube and at the same time pulling the pipe through the storage tank. Furthermore, when the pipe is almost in the correct position, the inlet stratification pipe can be secured to the bottom part of the tank, before the inlet stratification pipe is placed in the correct position, whereby a simple and effective way of ensuring that the inlet stratification pipe is placed in the correct position at the lower part of the tank, i.e. not rotated during installation or pulled "t o far" into the tank, is provided.

The installation means is substantially elongated and is arranged in such a way that it can first be guided through the top opening, the storage tank and the inlet tube, and then pulled in the reverse direction for placing the inlet stratification pipe in the desired position, and comprises an attachment means for securing the inlet stratification pipe or the top mount to the installing means during the reverse pulling operation, e.g. a clamp, hook, or the like.

The installation means can be made of any convenient material, such as yarn, a plastic rope, a wire or a chain with links of plastic or other suitable materials such as metal. It is however preferred that the installation means is arranged for ensuring that it cannot rotate about its own axis thereby ensuring that the inlet stratification pipe will not rotate about its own axis either, when the installation means pulls said pipe into the correct and desired position in the storage tank. It is accordingly preferred that said installing means is a flat steel unit that provides the desired flexibility for handling. If said flat steel unit further has different colors on each side (e.g. red/green), the operator can visually ensure that the correct position of the installation means is provided, whereupon rotation about its axis is effectively prevented .

The installation means preferably comprises a handle for easy manipulation both when the installation means is guided through the storage tank and later pulled back again. Said handle preferable has a size which ensures that it cannot fall through the top opening in the storage tank, such that the installing means cannot be lost inside the tank e.g. if the user is losing his/her grip on the handle during manipulation of said installation means. In addition the installation means can advantageously comprise a marking in the first end, i.e. the end to which the flexible inlet stratification pipe is attached, in order to provide a visually marking for the user, that the inlet stratification pipe has reached or is close to reaching the predetermined stretched position in the storage tank . It is preferred that the mounting means is installed in the storage tank after the top opening has been provided and before the inlet stratification pipe is placed in said tank. Depending on the top mount, the mounting means can be a simple bar, a wire or the like. For instance if the top mount comprises a resilient member, e.g. a suspension spring, said means could be a hook e.g. provided with a locking bolt in order to ensure that the top mount cannot be detached after mounting. If the top mount comprises a counterbalance, said mounting means could, as described earlier, be a substantially horizontal rod upon which the inlet stratification pipe can slide. Other suitable means are also contemplated within the scope of the present invention.

Depending on the size of the inlet tube in the storage tank, it can be difficult to guide the installation means out of said tube in order for allowing the flexible inlet stratification pipe to be attached to the installing means, e.g. by means of a hook, clamp or the like. It is therefore preferred that a funnel arranged for collapsing and expanding, is inserted through the inlet tube in the collapsed state, whereupon it is expanded inside the storage tank, such that the installation means easily can be guided along the sides of the funnel and out through the inlet tube, e.g. by pulling it out through the inlet tube together with the collapsed funnel after the installation means has reached the funnel.

When the positioning means comprises a floating device, the inlet stratification pipe can in an alternative installation method be placed in the correct position in the storage tank by attaching the securing means to a rod extending in the complete length of the side wall of the storage tank or the respective section, and allowing said floating device to be vertically displaced along said rod, when fluid is added to the tank. If the inlet stratification pipe in this embodiment further is rolled up and wrapped in a water soluble packaging, which dissolves when water is added to the tank, then the inlet stratification pipe is effectively prevented from rotating about is own axis both during transport of the tank, and during the vertical displacement when water is added. The latter is effectuated since the securing means is displaceable connected to the rod in the storage tank. Accordingly, the inlet stratification pipe with the floating device can be placed in the storage tank during the manufacture of the tank, which provides a simple and effective embodiment according to the invention .

The invention will be explained in greater detail below, describing only exemplary embodiments of the stratification device with reference to the drawing, in which

Fig. 1 shows a schematic view of a first embodiment of an inlet stratification device 1 according to the invention,

Fig. 2. shows the bottom mount of fig. 1 in more details,

Fig. 3 shows the top mount of fig. 1 in more details, Fig. 4a-4e schematically illustrates the installation method of the inlet stratification pipe in a storage tank,

Fig. 5 shows a preferred way of attaching the installation means to the top mount,

Fig. 6 shows a preferred way of guiding the installation means out through an inlet tube in the bottom wall of the storage tank ,

Fig. 7 shows a second embodiment of the top mount according the invention, Fig. 8 shows a third embodiment of the top mount of the invention, Fig 9a and 9b shows a second embodiment of a bottom mount according to the invention,

Fig. 10 shows a schematic view of a second embodiment of an inlet stratification device 1 according to the invention, and

Fig. 11 shows the top mount of fig. 10 in larger details.

The invention will be described below with the assumption that the flexible inlet stratification pipe is made of a non-porous flexible material and wherein the openings are holes. However, this assumption is not to be construed as limiting, and the inlet stratification pipe can just as easily be made of a fabric or similar material. Fig. 1 shows a schematic view of a first embodiment of an inlet stratification device 1 according to the invention. The inlet stratification pipe 2, shown in dotted line, is arranged vertically in a thermal storage tank 3 comprising a thermal storage fluid/liquid 4, e.g. water.

The inlet stratification pipe 2 is made of a non-porous flexible material and comprises an inlet opening 5, and a number of holes 6 arranged in a single row in the longitudinal direction of the pipe 2.

In the first embodiment the first end 2a of the inlet stratification pipe 2 is fixed to a first embodiment of a bottom mount 7 which is secured to the bottom wall 11 of the lower part 8 of the tank 3, and the opposite second end 2b of the pipe 2 is fixed to a top mount 9, secured to the upper wall 21 of the upper part 10 of the tank 3. The use of a top and bottom mount respectively attached to opposite parts of the storage tank, ensures that the inlet stratification pipe 2 is maintained in a predetermined stretched vertical position during use. This will not only provide a simple and inexpensive embodiment but also ensure that the inlet stratification pipe 2 has a substantially constant tension, such that undesirable creases and creeps due to an incorrect tension in the inlet stratification pipe 2 are effectively prevented. The tank 3 is connected to one or more units, e.g. heating devices, domestic appliances and the like (not shown), which may comprise a heat exchanger or absorber for transmitting the thermal energy produced in the heating device to the liquid in the storage tank 3. Such units are well known in the art and are not shown in the drawings, however, in short, circulation of the fluid is provided in the heating system, from an outlet at the bottom part of the storage tank 3, where the liquid is coldest, through an outlet pipe to the desired use unit, e.g. a heat exchanging device, and from there in its heated condition back to the thermal storage tank via an inlet opening in the inlet tube 12, which is in fluid communication with the inlet opening 5 of the inlet stratification pipe 2.

As best seen in fig. 2, the bottom mount 7 is attached to the tank 3 via an inlet tube 12. The bottom mount 7 comprises an inlet attachment part 14 and a first fastening means 15 in the form of a union nut. In the assembled stage, shown in fig. 1, the inlet attachment part 14 extend through the inlet tube 12, such that the first end 17a is placed inside the tank 3. The opposite second end 17b of the inlet attachment part 14 is via a threaded connection 13 on the inlet stratification pipe and union nut 15 secured to the inlet tube 12. Said union nut 15 also comprises a coupling 18 for attaching the tubes/pipes (not shown) that is used for circulating the fluid in the system as described above. It will be understood that the inlet attachment part 14 fits exactly and tightly in the inlet tube 12, in order to provide a safe bottom mount for the inlet stratification pipe.

In the embodiment shown the first end 17a of inlet attachment part 14 comprises two circumferential grooves 16 in which e.g. two manacle rings or two cable ties can be fastened thereby ensuring that the lower end 2a of the inlet stratification pipe 2 can be completely secured to the inlet attachments part 14 of the bottom mount 7. The first end of the inlet attachment part 17a is furthermore chamfered, which enables the inlet stratification pipe to easily slide onto the inlet attachment part .

Fig. 3 shows the top mount 9 of fig. 1 in more details. Said top mount comprises a top attachment part 19, arranged for fixing the second end 2b of the flexible inlet stratification pipe 2 to the top mount 9, and a tension unit in the form of a suspension spring 20. Said suspension spring 20 is arranged for creating the desired tension in the inlet stratification pipe such that said pipe always has the correct tension, e.g. by absorbing any creases, creeps etc. in the material of the inlet stratification pipe.

The top mount 9 is attached to the top wall 21 of the storage tank 3, thereby ensuring that the inlet stratification pipe 2 is kept in a predetermined stretched position. Thus, undesirable creases and creeps due to an incorrect tension in the inlet stratification pipe, are effectively prevented. The top mount comprises a second fastening means in the form of a hook 22, such that the top mount 9 can be attached to a mounting means in the form of a bar 23 in the tank 3.

In order to ensure that the person mounting the inlet stratification pipe 2 can handle and attach said inlet stratification pipe to the top wall 21 of the tank, a top opening 24 is formed in the top wall 21 in the tank 3, substantially above the inlet opening 5 of the inlet stratification pipe 2 in order to ensure that the inlet stratification pipe 2 is placed substantially vertical in the tank 3, as shown in fig. 1. Said top opening 24 is closed e.g. by a lid and/or plug 26 by means of a threaded connection 27.

Fig. 4 schematically illustrates the installation method of the inlet stratification pipe 2 in a storage tank 3, having an inlet tube 12, and a top opening 24.

In the embodiment shown the inlet tube 12 is provided in the side wall 28 of the lower part 8 of the storage tank 3, however the top opening 24 is still formed in the top wall 21 in the tank 3, substantially above the inlet opening 5 of the inlet stratification pipe 2. This is best shown in fig. 4e. It will be understood that said top opening also could have been placed in the upper side wall of the tank instead, the only requirement being that said top opening allows the user to access the top part of the storage tank, e.g. in order to install the mounting means, or to install the inlet stratification pipe.

In a first step, shown in fig. 4a an installation means in the form of a bendable flat steel unit 30 is introduced into the tank 3 via the top opening 24 and is guided through the tank 3, preferably simply by allowing said flat steel unit to hang at rest, whereby it will be placed in a vertical position due to gravity, see fig. 4b. Said flat steel unit 30 will have a form and a dimension which prevents the flat steel unit from rotating about its own axis

The flat steel unit 30 comprises a handle 31 at a first end 32 of the flat steel unit for easy manipulation. Said handle 31 preferable has a size/dimension and/or shape which ensures that it cannot fall through the top opening 24 in the storage tank 3, thereby preventing the flat steel unit from getting lost inside the tank e.g. if the user is losing his/her grip on the handle 31. Since the inlet tube 12 in the embodiment shown is placed in the side wall of the tank 3, it is difficult to guide the flat steel unit out of said tube. Thus a guiding means in the form of a hook 33 is inserted into the tank via the inlet tube, in order to pull the flat steel unit 30 out of the inlet opening 12. This is shown in fig. 4b and 4c.

Fig. 4d shows that after the flat steel unit 30 is drawn out of the inlet tube 12, the top mount 9, which is connected to the flexible inlet stratification pipe 2, is releasable attached to the flat steel unit 30, whereupon the flat steel unit 30 is pulled in the reverse direction through the storage tank 3, until the flexible inlet stratification pipe 2 is disposed at the predetermined stretched vertical position between the inlet tube 12 and the top opening 24. If the inlet stratification pipe 2 comprises one or more flexible expansion means (not shown) , these can due to their flexibility be compressed and also guided through the inlet tube 12.

Finally, the top and bottom mounts 9 and 7 are attached to the inlet tube 12 and top opening 24, respectively e.g. as described in more details earlier under fig. 2 and 3, thereby proving the completed inlet stratification device 1 shown in fig. 4e. It is preferred that the bottom mount 7 is attached first, e.g. before the installation means 30 is pulled back in the reverse direction through the tank.

The method according to the invention provides a simple and inexpensive way of ensuring that the inlet stratification pipe 2 can be correctly positioned inside the storage tank 3 during installation, thereby completely eliminating the difficult and time consuming installation procedures in which only the hand hole cleanouts are used or the inlet stratification pipe has to be installed in the tank when the tank is manufactured.

Furthermore, the use of a top opening 24 in the tank 3 ensures that the inlet stratification pipe 2 e.g. can be visually inspected both during installation and during maintenance, e.g. in order to ensure that said pipe 2 is correctly installed, and remains in said position after a period of use. In order to ensure that the flat steel unit 30 can pull the inlet stratification pipe with it through the storage tank, the end 34 of the flat steel unit extending outside the inlet tube 12, comprises an eye 35 arranged for being connected to the top mount 9. Fig. 5 shows how the top mount 9 shown in fig. 3 is connected to the eye 35, providing a safe and reliable connection when the inlet stratification pipe is installed in the storage tank 3.

The person skilled in the art will understand that the means for securing the top mount or inlet pipe to the installation means (flat steel unit), can be any convenient means, e.g. clamps, hook and eye, or the like and can be adjusted and designed based on the configuration of the top mount. If the inlet tube 12 is provided in the bottom wall 11 as shown in fig. 1, it can be difficult to guide the installation means 30 out of said tube 12 in order for allowing the flexible inlet stratification pipe to be attached to the installing means. Fig. 6 shows a collapsible funnel 36 arranged for assisting with withdrawing the installation means from the inlet tube 12. Said funnel 36 is inserted through the inlet tube 12 in the collapsed state, whereupon it is expanded inside the tank, such that the installation means easily can be guided along the sides of the funnel and out through the inlet opening 12. Fig. 7 shows a second embodiment of the top mount 9' were the force absorbent tension means comprises a counterbalance 37. The counterbalance is attached to the top section 38 of the flexible inlet stratification pipe 2, and said top section 38 is folded/looped about a mounting means in the form of a rod

39, upon which the top section 38 of the inlet stratification pipe 2 can slide. In this way the "stretch" of the inlet stratification pipe 2 can easily be adjusted, e.g. depending on the forces acting upon the inlet stratification pipe, simply by allowing the inlet stratification pipe to slide about the rod, since the counter balance 37 will force the flexible inlet stratification pipe 2 to be placed in the desired stretched vertical position. It will be understood that the rod 39 instead of being connected to the top part of the storage tank, instead could be connected to the bottom of said tank by means of one or more connection means, it is however relevant that said rod 39 is placed in the top part of the tank. Said connection means is preferably a telescopic pole, an articulated pole connected by means of an elastic string, a flexible bar or other similar means .

Fig. 8 shows a third embodiment of the top mount 9'' according to the invention where the tension unit is a floating device

40. Said device 40 is connected to the top part 10 of the tank 3, by a securing means 41 (wire) and a mounting means 42 in the form of a rod, thereby ensuring that e.g. the floating device cannot dance around during use.

In the embodiment shown the inlet stratification pipe were placed in the correct position in the storage tank by attaching the wire 41 to the rod 42 extending in the complete length of the side wall of the storage tank, and allowing said floating device to be vertically displaced along said rod, when fluid is added to the tank. The securing means 41 is preferably made of a non-elastic wire, e.g. a stainless steel wire, having a length which prevents the inlet tube 2 rotating about its own axis during installation and use.

Fig 9a and 9b shows a second embodiment of a bottom mount 43. In fig. 9a the bottom mount 43 is shown in the state of use, when it is secured to the bottom wall 11 of the lower part 8 of the tank 3. As for the first embodiment, the bottom mount 43 is attached to the tank 3 via an inlet tube 12. Fig. 9b is an exploded view of the bottom mount 43.

On the lower part of the inlet stratification pipe 2 is attached an inlet attachment part 44 in the form of a flange 45. A treaded connection 46 is placed at the top 12a of the inlet tube 12, i.e. at the end to which the inlet stratification pipe is to be connected. A union nut 47 can then be used to effectively connect the inlet pipe 2 to the inlet tube 12, via the flange 45 and the treaded connections 46, e.g. when a user extend an arm through the hand hole cleanout 48 placed in a lower part 8 of the tank 3. It will be understood that the threaded connection 46 can be made either directly in the inlet tube 12, or be retrofitted in any conventional way.

Using the second embodiment of the bottom mount 43 has the advantage, that the inlet stratification pipe can be mounted in the tank 3 in a manner that ensures that said pipe is not rotated during said mounting, as the union nut 47 will abut against the flange 45 but without rotating said flange, and accordingly without rotating said inlet stratification pipe 2.

In the embodiment shown the first end 2a of the inlet stratification pipe 2 comprises an expansion means 49 in the form of e.g. a rigid ring placed near the inlet opening 5, thereby ensuring that the velocity of liquid coming from the inlet tube 12 is decreased when it reached the larger diameter of the inlet stratification pipe 2, compared to the diameter of the inlet tube 12. This will ensure that the velocity of the liquid shortly after it has entered the inlet pipe 2 has been reduced to such an extend that the liquid can be delivered to the correct thermal layer.

Fig. 10 shows a schematic view of a second embodiment of an inlet stratification device 1' according to the invention, said embodiment corresponds to the first embodiment of fig. 1 with the modification that the inlet tube 12 is provided in the side wall 28 of the lower part 8 of the storage tank 3, and the top opening 24 in the form of a top tube 24' formed in the upper side wall 50 of the tank 3.

The first end 2a of the inlet stratification pipe 2 is attached to the tank 3, via a third embodiment of a bottom mount 51, and the opposite second end 2b of the pipe 2 is fixed to the tank via a forth embodiment of the top mount 9 ' ' ' .

The bottom mount 51 corresponding in principal to the second embodiment of the bottom mount 43 shown in fig. 9, with the modification that inlet tube has been extended by an elbow pipe 52, allowing said inlet tube 12, to change direction, such that the inlet pipe 2 can be placed vertically in the tank, in the position of use.

The forth embodiment of the top mount 9 ' ' ' in shown in more details in fig. 11. Said top mount comprises a top attachment part 19, arranged for fixing the second end 2b of the flexible inlet stratification pipe 2 to the top mount 9' ' ', and a tension unit in the form of a suspension spring 53.

Said suspension spring 53 comprises a coil 54 arranged for creating the desired tension in the inlet stratification pipe 2 such that said pipe always has the correct tension, e.g. by absorbing any creases, creeps etc. in the material of the inlet stratification pipe.

The suspension spring 53 comprises a retaining means 55 that will ensure that the spring 53 can be secured to the top opening 24. In the embodiment shown said retaining means 55 consist of a coil 56 and a bending 57, and wherein said retaining means 55 has an extension that will ensure that the suspension spring can be held in the top opening 24 by means of friction, by pressing the coil 56 and bending 57 against the inner side 58 of the top tube 24' .

In the embodiment shown the top attachment part 19 is in the form of an expansion means 58 in the form of a ring 59 placed at the upper end 2b of the inlet pipe 2. The ring 59 and the suspension spring 53 may either be an integrated unit or be secured to each other by any known means.

After the inlet stratification device has been correctly installed in the storage tank, said tank can be connected to a tubing system (not shown) that allows the fluid in the storage tank 3 to be circulated from an outlet in the tank, through one or more relevant units, e.g. heating devices, heat exchanges, domestic appliances and the like and back to the storage tank via the inlet tube. Thereby the thermal energy in said heating devices will be stored in the storage tank by thermally stratification. Said storage tank can be used for both domestic and industrially hot water storage and other types of heating. The inlet stratification device according to the invention has a simple and inexpensive design, and can therefore be used equally well for both domestic and industrially hot water storages and other types of heating. The stratification device may be designed to allow more than one source of heat to feed the thermal storage medium, for example, solar thermal, a heat pump or a gas boiler. Also, there may be several "consumers" to draw and return fluid from the thermal storage such as radiators, under-floor heating, heat exchangers for swimming pools and plate heat exchangers for hot water preparation. Modifications and combinations of the above principles and designs are foreseen within the scope of the present invention.

Claims

An inlet stratification device (1) for providing and maintaining stratification of a fluid (4) in a storage tank (3), said device (1) comprises

- at least one flexible inlet stratification pipe (2), said inlet stratification pipe (2) comprises a number of openings (6) and is configured to contract and expand such that exchange of fluid (4) through the openings (6) of the pipe (2) is substantially prevented in regions of the pipe (2), where the temperature of the fluid (4) inside the pipe (2) is higher than the temperature of the fluid (4) outside the pipe ( 2 ) , and

- at least one positioning means ( 7 , 9 , 9 ' , 9 ' ' , 9 ' ' ' , 43 , 50 ) arranged for ensuring that the inlet stratification pipe (2) is maintained in a predetermined stretched vertical position.

An inlet stratification device (1) according to claim 1, wherein the at least one positioning means (7, 9, 9 ' , 9 " , 9 ' ' ' , 43, 50) comprises a bottom mount (7, 43, 50) and a top mount (9, 9', 9'', 9' ' ' ) , and wherein one end (2a) of the inlet stratification pipe (2) is attached to the bottom mount (7, 43, 50) and the opposite end (2b) of the pipe (2) to the top mount (9, 9', 9'', 9''')·

An inlet stratification device (1) according to claim 2, wherein the bottom mount (7) is arranged for being attached to a lower part (8) of the storage tank (3), e.g. the bottom wall (11) or a lower part of the side wall (28) .

An inlet stratification device (1) according to claim 2 or 3, wherein the top mount ( 9 , 9 ' , 9 ' ' , 9 ' ' ' ) is arranged for being attached to an upper lower part (10) of the storage tank (3), e.g. the top wall (21) or an upper part of the side wall (28).

An inlet stratification device (1) according to any of the preceding claims, wherein the at least one positioning means ( 7 , 9 , 9 ' , 9 " , 9 ' ' ' , 43 , 50 ) comprises a tension unit (20,40) .

An inlet stratification device (1) according to claim wherein the tension unit (20, 37, 40) is part of the mount (9, 9 ' , 9 ' ' , 9 ' ' ' ) and/or the bottom mount (7, 43, 50)

An inlet stratification device (1) according to claim 5 or 6, wherein the tension unit is a resilient unit, such as a suspension spring (20,53).

An inlet stratification device (1) according to claim 5 or 6, wherein the tension unit comprises a counterbalance (37) .

An inlet stratification device (1) according to claim 5 or 6, wherein the tension unit comprises a floating device (40) .

An inlet stratification device (1) according to any of the claims 2 - 9, wherein the bottom mount (7,43,50) is arranged for attaching the inlet stratification pipe (2) to an inlet tube (12) of the storage tank (3) .

An inlet stratification device (1) according to any of the claims 2 - 10, wherein the bottom mount (7) comprises an inlet attachment part (14) and at least one fastening means ( 15 ) .

An inlet stratification device (1) according to claim 11, wherein a first end (17a) of the inlet attachment part (14) extend inside the tank (3) and is arranged for being attached to one end of the inlet stratification pipe (2), and an opposite second end (17b) of the inlet attachment part (14) extends outside the storage tank (3), and is arranged for securing the inlet attachment part (14) to the tank (3) by means of the at least one fastening means

(15) .

An inlet stratification device (1) according to claim 11 or 12, wherein the first end of the inlet attachment part (14) has a substantially oval, circular or round cross- section .

An inlet stratification device (1) according to any of the claims 2 - 13, wherein the bottom mount (43,50) is arranged for ensuring that the inlet stratification pipe (2) can not be rotated during the mounting in the storage tank ( 3 ) .

An inlet stratification device (1) according to claim 14 wherein the bottom mount comprises a fastening means (47), a flange which is attached to the inlet pipe, and a treaded connection (46)

An inlet stratification device (1) according to any of the claims 2 - 15, wherein the top mount (9, 9', 9'', 9' ' ') comprises a top attachment part (19), arranged for attaching the flexible inlet stratification pipe (2) to the top mount (9, 9', 9'').

An inlet stratification device (1) according to any of the claims 2 - 16, wherein the top mount (9, 9', 9'') comprises a second fastening means (22,38,41), arranged for attaching the top mount (9, 9', 9'') to the upper part (10) of the tank ( 3 ) . An inlet stratification device (1) according to any of the claims 2 - 16, wherein the top mount (9''') comprises a retention means (55), arranged for attaching the top mount (9''') to the upper part (10) of the tank (3) by means of friction .

A method of providing an inlet stratification device (1) according to any of the claims 1 - 18, said method comprises

providing a flexible inlet stratification pipe (2) comprising a number of openings,

providing a storage tank (3) with an inlet opening (12) at a bottom part (8) of the storage tank (3), and a top opening (24) in a top part (10) of the storage tank (3), guiding an installation means (30) via the top opening

(24), through the tank (3) and out of the inlet opening

(12) ,

attaching the top section (38) of the flexible inlet stratification pipe (2) to the installation means (30), pulling the installation means (30) in the reverse direction through the storage tank (3), until the flexible inlet stratification pipe (2) is disposed at the predetermined stretched vertical position between the inlet opening (12) and the top opening (24), and

attaching the inlet stratification pipe (2) to the top and bottom parts (10,8)of the storage tank (3).

A method according to claim 19, wherein the top opening (24) after attachment of the inlet stratification pipe (2) to the upper part (10) of the storage tank (3), is closed with a cap or lid member (26) .

A storage tank (3) for use in the method according to any of the claims 19 - 20, wherein said storage tank (3) comprises an inlet tube (12) and a top opening (24) .

22. An installation means (30) for use in the method according to any of the claims 19 - 21, said installation means (30) is substantially elongated and is arranged for being guided through the top opening (24), the storage tank (3) and out of the inlet tube (12), and comprises an attachment means (35) for securing the inlet stratification pipe (2) or the top mount (9, 9', 9'') to the installing means (30) .

23. The installation means (30) according to claim 22, wherein said installation means (30) cannot rotate about its own axis during operation.

24. The installation means (30) according to claim 22 or 23, wherein said installation means (30) comprises a handle (31) and a visual marking arranged for indicating when the inlet stratification pipe (2) has reached the predetermined stretched position in the storage tank (3) .