WO2018189421A1

WO2018189421A1 - An arrangement and a method for recovering chemical substance floating on the surface of a liquid

Info

Publication number: WO2018189421A1
Application number: PCT/FI2018/050260
Authority: WO
Inventors: Timo Siltala
Original assignee: A&T Subsea Oy
Priority date: 2017-04-11
Filing date: 2018-04-11
Publication date: 2018-10-18

Abstract

The invention relates to a transportable and quickly mountable arrangement and a method for recovering chemical substance. The problem of the prior art solutions is the difficulty to adapt quickly capacity for recovering chemical substance in case of a big accidents, for example. The arrangement (100) according to the present invention comprises a supporting structure (102) attachable to a desired site, which supporting structure comprises a protruding part (103), a rack (104) and an extendable jib (106), which are connected in the protruding part (103), and recovering devices, such as a skimmer (108), a pump, an inflatable boom (112), attached to the jib (106) and/or the rack (104), wherein the rack (104) is arranged to be lowered substantially towards the surface of the liquid and the jib (106) is arranged to be protruded from the supporting structure (102) for enabling said recovering devices to recover chemical substance from the surface of the liquid.

Description

AN ARRANGEMENT AND A METHOD FOR RECOVERING CHEMICAL SUBSTANCE FLOATING ON THE SURFACE OF A LIQUID

Technical field Generally, the invention relates to an arrangement and a method for recovering chemical substance floating on the surface of a liquid, and more particularly, the invention relates to a transportable and quickly mountable arrangement.

Background technology Recovering pollution, such as spilled oil or other chemicals, from the surface of the water has basically two different main concepts: The first concept uses dedicated special vessels having built-in devices and openable hull hatch door(s) in the water- line. The extreme solution in this family of concepts is a vessel, which is split into two halves. Although efficient, this concept has serious drawbacks: best cargo ca- pacity in amidships is permanently lost for the recovery chamber and removal apparatus, the devices are continuously exposed to sea water suffering from heavy corrosion and the maintenance of partly submerged components and structures is difficult. Side hatch system with inflatable chemical booms also uses a separate jib which requires own pedestal on the main deck and a crane for its handling. Because of its size and weight, the jib is typically stored loose onshore, often dismantled. These requirements together reduce the usability of a dedicated vessel in other tasks.

The other main concept is based on a large number of separate loose devices to be installed onboard a ship when needed. Ships tended for recovery have to be equipped with special fixings and attachments beforehand, including a pedestal for the jib. Equipment hanging on sides of the ship requires protruding attachments which are easily damaged when the ship leans against a dock. Transportability of mentioned loose devices is implemented by containers, into which the loose devices are usually packed. The heaviest items, typically power packs, can be permanently installed into a container which empty space is used for storing loose items like a boom reel and also personal devices. Jib needed for stretching out the boom is stored typically in a separate flat rack container. Installing a heavy jib require also in this concept a crane, which is typically another loose item if the ship itself has none. Preparation and setup of such system can take time, may be laborious and consume valuable deck space.

Both concepts have a common problem concerning the collected chemical storage. The vessel has to have dedicated tanks to store collected mixture of chemical and water, which many vessels, otherwise suitable for the recovery operation, don't have. If the chemical has high viscosity, rapid unloading even from dedicated storage vessels is very difficult and hardly possible without getting to a harbor. This slows down radically the recovery process out in the sea and forces the storage vessels to sail from collection site to suitable harbor which can be far away. In case of a major spill accident, all available storage vessels onboard and onshore is rapidly exhausted and will slow down the spill recovery. Few if none countries have enough reserve volume for a supertanker size accident.

Some dedicated vessels have control stands for the operators, loose equipment system almost never has. This makes it very wearing for the personnel operating the devices, especially in harsh weather and cold sea. The result is understandably reduced recovery rate after operators been freezing days in open deck.

Summary of the invention

It is an objective of the present invention to implement such a solution, that the pre- viously mentioned drawbacks of the prior art could be diminished. In particular, the invention is implied to solve how to provide a transportable and rapidly installable chemical substance recovering arrangement.

The objective of the invention is met by the features disclosed in the independent patent claims. An arrangement for recovering chemical substance floating on the surface of a liquid according to the present invention is characterized by the features of claim 1.

A method for recovering chemical substance floating on the surface of a liquid is characterized by the features of claim 10.

According to an embodiment of the present invention, an arrangement for recover- ing chemical substance floating on the surface of a liquid comprises a supporting structure attachable to a desired site for mounting the arrangement to the proximity to a liquid, which supporting structure comprises a protruding part, a rack and an extendable jib, which are connected in the protruding part, and recovering devices, such as a skimmer, a pump, an inflatable boom, attached to the jib and/or the rack, wherein the rack is arranged to be lowered substantially towards the surface of the liquid and the extendable jib is arranged to be protruded from the supporting structure for enabling said recovering devices to recover chemical substance from the surface of the liquid.

The extendable jib can be advantageous, because it may be able to keep the boom and the recovering devices in a certain distance from the site and thus improve the recovering of chemical substance, without a need to use heavy cranes.

In one embodiment, the supporting structure further comprises one or more fixing points compatible with a standard container for transportation, handling and/or fixing the arrangement on to the site. Fixing points compatible with a standard container can be advantageous, because it may enable easy transportation and handling of the arrangement with equipment typically used for standard containers. In addition, it may provide fast, easy and reliable fixing of the arrangement for example vessels having standard container lashing points on a deck.

In one embodiment, the supporting structure further comprises at least one sliding rail enabling the protruding part to be protruded from the site towards a space above said liquid. By using the sliding rail, it may be possible to arrange the recovering devices and/or the jib into a better position above the liquid in order to recover chemical substance from the liquid.

In one embodiment, the rack comprises turning means, such as one or more hinges, for enabling the rack to be lowered by turning it down around the turning means. This embodiment may provide easy and fast way to arrange the recovering devices in connection with the rack near to the surface of the liquid.

In one embodiment, the rack comprises a main hose connector comprising two compatible parts, which are lockable together by turning said rack in its lowered position. The embodiment in question may eliminate a need to turn swivel joints etc. arranged in hoses, and it may help to radically reduce pumping back pressure and to prevent a harmful wearing of the components, such as hoses and connector parts.

In another embodiment, the rack further comprises a sliding part arranged to move upwards and/or downwards in said rack for providing a heave compensation to the recovering devices, which may extend the rack in order to reach the surface of the liquid better and enable the recovering devices to locate on the surface of the liquid in such way that the recovering devices are able to follow the surface, when the sliding part moves up and down according to the waves. In an embodiment, the arrangement further comprises an operator booth arranged in the protruding part for providing a shelter for a user of said arrangement. The operator booth may provide a warm and safe place for a user and a window/windows arranged in it can offer direct visibility to the recovery devices, which may help to control the recovery operation. In addition, the operator booth can provide a safe space to place additional devices, such as a camera, for example.

In an embodiment, the arrangement further comprises a storage bag, which can be connected to the recovery devices. Advantageously, the storage bag can be arranged into a standard container. Preferably, the storage bag is a flexible bag made of chemical resistant material. The storage bag may rapidly be installed to any stand- ard sea container. Typically, the storage bag has a necessary connector for a hose/hoses of the recovery devices, which connector/connectors may be easily installed to the container.

Further, in an embodiment, the arrangement further comprises a filling level gauge arrange to be in connection with said storage bag for providing filling level infor- mation relating to said storage bag. The filling level gauge can be arranged to send filling level information to the operator of the arrangement, which may be in the operator booth, preventing overloading accidents due to high pumping pressures with high viscosity fluids, for example. The filling level gauge may also provide a possibility to load numerous storage bags in appropriate order. Another optional function of the filling level gauge is sending loading, location and speed information to a recovery control center with suitable time intervals, which may increase the operation overall efficiency.

Some preferable embodiments of the invention are described in the dependent claims. Significant advantages can be achieved with the present invention when compared to prior art solutions. The arrangement according to the present invention may be easy to transport and mount to the desired site to the proximity to a liquid, which will be recovered from chemical substance. In a storage position, the arrangement with all its parts and devices may be possible to arrange in a small and compact space. In addition, in the storage position, the arrangements can be piled one upon the other, because of the correspond size of a standard sea container both for a recovery unit and a storage container of the arrangement.

The arrangement may be rapidly mounted to the desired site and it does not require an external crane for deployment. The arrangement orientation on the site can be longitudinal, transversal or something in between these in a possibly curved area of the site, and when mounted on a vessel, the arrangements can be on either or both sides of the vessel, which can make it suitable for different size and types of vessel, for example. Many vessels have container lashings in their cargo decks and container handling hoists and cranes, enabling unloading of filled containers from recovery vessels on site and loading empty ones instead. This enables usage of vessels not having dedicated cargo tanks in recovery process, extending available fleet remarkably. Also installation of storage bags according to the present invention can be rapid and may provide storage and on shore transportation capacity in areas not having suitable hardware for spill chemicals.

Multiple arrangement can be onboard a vessel, for example. One or more arrangement can be arranged as slave units, controlled remotely form one or more arrangements acting as masters. Typically, in a vessel having two arrangements onboard, for example, one side is a master arrangement whereas the opposite side being a slave.

In the present document, the term "chemical substance" has been used in a wide meaning, referring to oil, chemicals and/or other particles, which in the present case are floating on the surface of water or another liquid. In the present document, the term "liquid" has been used in a wide meaning, referring typically to water, such as a sea, an ocean or a lake, but in a wider meaning to any liquid that may require recovering from chemical substance.

In the present document, the term "desired site" has been used in a wide meaning, referring to a deck of a multiple kinds of vessels, a pier, a barge, a pontoon, for ex- ample.

In the present document, the terms "up" or "upwards" refer to direction substantially upwards perpendicular to a site, on which the arrangement is mounted, and, re- spectively, the terms "down" or "downwards" refer to direction substantially downwards perpendicular to the site.

The expression "a number of refers herein to any positive integer starting from one (1), e.g. to one, two, or three. The terms "a" and "an", as used herein, are defined as one or more than one.

Short description of the drawings

Next, the invention is described in more detail with reference to the appended drawings, in which Fig. 1 illustrates a perspective view of an arrangement according to an embodiment of the present invention in a transportation and storage condition,

Fig. 2a illustrates a perspective view of the arrangement in Fig. 1 in an operational condition onboard a vessel,

Fig. 2b depicts an enlarged side view of the area denoted as "A" in FIG. 2a. Fig. 3 illustrates a perspective view of a longitudinally mountable arrangement according to an embodiment of the present invention in an operational condition onboard a vessel,

Fig. 4 illustrates a perspective view of an operator booth and some main components of the arrangement according to an embodiment of the present invention, Fig. 5 illustrates a perspective view of a storage container according to an embodiment of the present invention,

Fig. 6 illustrates a perspective view of a storage container connector according to an embodiment of the present invention,

Fig. 7 illustrates a perspective view of an overall arrangement installed onboard a vessel according to an embodiment of the present invention,

Fig. 8 is a flowchart of a method according to an embodiment of the present invention, and Fig. 9 is a detailed flowchart of an exemplary method according to an embodiment of the present invention.

Detailed description of the embodiments The presented figures are not to scale, and component dimensions vary according to requirements in different applications.

Same numbers are used in different Figs to denote the similar kind of objects, although they do not have to be identical as a skilled person understands from the embodiments and the contexts. Same numbers are used in several Figs in suitable part to denote similar objects if not otherwise expressly noted. Shown embodiments are shown as examples, without any intention to limit the embodied scope only to the shown examples.

Fig. 1 illustrates a perspective view of an arrangement according to an embodiment of the present invention in a transportation and storage condition, and Fig. 2a in an operational condition onboard a vessel. An arrangement 100 for recovering chemical substance floating on the surface of a liquid comprises a supporting structure 102 attachable to a desired site, which supporting structure comprises a protruding part 103, a rack 104, an extendable jib 106, which the rack 104 and the extendable jib 106 are movably connected in the protruding part 103, and recovering devices, such as a skimmer unit 108, a float 1 10, a pump, a boom 1 12, attached to the jib 106 and/or the rack 104.

Preferably, the size and form of the supporting structure 102 are selected so that it correspond the size of a standard sea container. In one embodiment, walls, a floor and/or a roof is arranged in the suitable part of the supporting structure for covering parts and devices in the supporting structure.

One end or a side of the supporting structure 102 is selected to be the protruding part 103. Components, such as the rack 104 and the extendable jib 106, are connected in the protruding part 103 and the supporting structure 102 is positioned on the site in such way that the protruding part 103 faces towards the direction of the liq- uid. Depending on the embodiment, the arrangement of the present invention can be transversally mountable, i.e. having one end the supporting structure as the protruding part, or longitudinally mountable, wherein one side of the supporting structure forms the protruding part. In an embodiment, the protruding part is arranged at least partially outside of the site, where the arrangement is mounted, in such way that the protruding part is above the liquid. The embodiment in question enables the turning means to be arranged outside of the site, when arranging the arrangement into the operational con- dition.

In an embodiment, the supporting structure further comprises one or more fixing points 1 14, which are compatible with a standard container for making transportation, handling and/or fixing the arrangement on to the site easier. The arrangement can comprise fixing points in every corner both the bottom and the top of the ar- rangement, or the fixing points can be arranged in suitable places, as depicted in Fig. 1 , for example, in three corners at the top of the arrangement. The arrangement can also comprise some additional fixing points in addition to or instead of the fixing points of the standard sea container. For example, in the embodiment, wherein the supporting structure comprises one or more sliding rails, it is advantageous to arrange double fixing points for the sliding rails.

As mentioned above, in one embodiment, the supporting structure 102 comprises at least one sliding rail 1 16 enabling the protruding part 103 to be protruded from the site towards a space above said liquid, when turning the arrangement into the operational condition from the storage condition. The sliding rail can be formed in one rail system, such as a monorail, or the rails can be arranged to the both sides of the supporting structure. Preferably, the one or more sliding rails comprise locking means to lock the protruding part in the suitable position.

The rack 104, which is movably connected in the protruding part 103, as described above, is arranged to be lowered substantially towards the surface of the liquid in operational condition of the arrangement. In the storage condition the rack is arrange against the end of the protruding part, so that the arrangement preferably forms a standard size container, as depicted in Fig.1.

In an embodiment, the rack comprises lowering means, such as rails, arrange in the protruding part. In another embodiment, the rack 104 comprises turning means, such as one or more hinges 1 17, for enabling the rack 104 to be lowered by turning it down around the turning means. The turning means of the present embodiment are arranged to turn the rack 104 substantially 180 degrees, so that after the procedure the rack is outside of a site the arrangement has been assembled, such as a vessel. Fig. 2b depicts an enlarged side view of the area denoted as "A" in FIG. 2a. In one embodiment, the rack comprises a main hose connector comprising two compatible parts 1 19a, 1 19b, which are lockable together by turning the rack 104 in its lowered position. The first main hose connector part 1 19a is arranges in the rack 104 and it is naturally connected to a hose 121 of the recovering devices. The second main hose connector part 1 19b is arranges in the bottom of protruding part 103 is such a way that when the rack 104 is turned and locked in its lowered position, the main hose connector parts 1 19a, 1 19b will also be locked together.

Yet, in an embodiment, the rack further comprises a sliding part 1 18 arranged to move upwards and/or downwards in the rack 104 in the operational condition of the arrangement. Sliding part 1 18 is preferably arranged inside the rack so that the rack 104 provides natural rails for the sliding part 1 18. The recovery devices are arranged in connection to the rack 104, and preferably in the sliding part 1 18 in those embodiments comprising the sliding part. The rack 104 is locked in the operational condition, but the sliding part 1 18 is enabled to move freely following waves of the liquid in its range. In the storage condition, the sliding part is set inside of the rack.

The extendable jib 106 according to the present invention is movably connected in the protruding part 103 and is arranged to be protruded from the protruding part, as described above. In the storage condition of the arrangement, the jib 106 is arranged in the retracted position stored on a roof recess of the supporting structure.

Preferably, the jib 106 is mounted to the corner of the protruding part 103, so that the corner may protect it in case of a possible support wire failure. A boom towing force caused by vessel movement can turn it backwards without physical damage in that case. In an embodiment the jib 106 comprises its own hydraulics, which is used, when extending the jib 106 into its operational condition. Preferably, the jib comprises means to extend it and to protrude it from the supporting structure. According to one embodiment, the jib 106 comprises a hinge joint 120, an extended telescopic joint 122 and a wrist joint 124 (depicted in Fig. 2a). In one embodiment, the jib has mechanical contact surfaces, which make it rigid, when straightened into the operational condition, both in the hinge joint 120 and in the extended telescopic joint 122.

In one embodiment, a wing float 1 10 is connected to the jib 106 by the wrist joint 124. The wing float 1 10, fixed to the tip of jib 106, is preferably a multi-wing float. The jib 106 provides an active heave compensation lift force to the float 1 10 to prevent it diving in high waves in the operational condition.

The jib recess in the storage condition forms a basin for washing the jib after recovery duty. The float recess forms also a washing basin for cleaning the remainder chemicals.

In an embodiment, a support wire 126 is arranged in connection of the jib or in the wing float 1 10. The meaning of the support wire 126 is to help keeping the jib in the operational condition protruding from supporting structure and to help the jib by carrying the longitudinal loads caused by the boom towing. As described above, the arrangement comprises recovering devices, such as the skimmer unit 108, the float 1 10, the pump, the boom 1 12, attached to the jib 106 and/or the rack 104. The skimmer unit 108 is preferably attached to the rack 104 and more preferably to the sliding part 1 18 of the rack in embodiments comprising the sliding part. The boom 1 12 in preferably inflatable and in the storage condition it is deflated and coiled in a reel. Depending on the embodiment, the boom reel is attached on either of its end to the float 1 10 or sliding part 1 18.

In an embodiment, the boom 1 12 is attached to flexible means, such as a line or a hose, in order to pull the boom out from the reel when the jib is extended. The ar- rangement can also comprise means for inflating the boom.

Fig. 3 illustrates a perspective view of a longitudinally mountable arrangement according to an embodiment of the present invention in an operational condition onboard a vessel. In the present embodiment, the sliding rails are omitted and additional container fixing points are located to railing line to enable protruding installa- tion of the arrangement. Otherwise the arrangement can comprise the same components, only some dimensional changes occur due to different space envelopes available.

In one embodiment, the arrangement further comprises the operator booth 400 arranged in the protruding part 103 for providing a shelter for a user of said arrange- ment. In an embodiment, the operator booth is also protruded outside of the site, such as a vessel, for providing a better view for a user, when using the arrangement. A door 128 (in Fig. 2a) enables safe access into the operation booth 400, which also comprises at least one large perspective windows 130 giving optical visibility to components of the arrangement in the operational condition. Additional viewport at the bottom of control booth gives direct vision to cargo hose and skimmer, in addition to cameras, for example.

Fig. 4 illustrates a perspective view of inside of the operator booth and main com- ponents of the arrangement according to an embodiment of the present invention. The operation booth 400 can be equipped with necessary safety and comfort apparatus. For example, a power pack 402 is encapsulated and insulated on a separable, independently removable pallet 404. The easily removable pallet may enable also easy maintenance separately from the other components of the arrangement and usage of the arrangement without the power pack when the power supply of the site is adequate.

Hydraulic oil and fuel tanks 406 are located on the wall, but they can also be located in the roof of the operation booth 400 to give more free storage space 408 for necessary equipment. The power pack 402 may also be arranged to give supply to possi- ble slave units in case operational conditions do not require full power.

Fig. 5 illustrates a perspective view of a storage container 500 according to an embodiment of the present invention. In one embodiment, the arrangement further comprises a storage bag 502 connectible to the recovery devices, which storage bag 502 is arrangeable into a standard container 504 as a storage container 500. The storage bag 502 has one or more connectors 506, which can be arrange at the top of the standard container 504 and/or at one or more sides of the standard container 504.

A certain shape hole can be cut at the top, side and/or end surfaces of a standard container 504, from which hole the connector can be pushed out. The connector can be fixed to its place with few tag welds or screws. This procedure is fast and enables on site conversion of an ordinary container to a storage container.

Fig. 6 illustrates a perspective view of a storage container connector 506 according to an embodiment of the present invention. The connector 506 has a frame bowl 508, which shape is such that it fits through a suitable shape of cutout in a standard container. When the frame bowl 508 is turned flat, it covers the cutout hole and can be fixed with welding, screws or other suitable means to the standard container. The connector 506 has a lid 510 covering a hose connector, a valve and/or an adapter.

In one embodiment, the arrangement further comprises a filling level gauge arranged to be in connection with a storage bag for providing filling level information relating to the storage bag. The filling level gauge 512 can be arranged to provide an overfilling warning to a controller of the arrangement. The filling level gauge 512 can be united with remote data link sending periodically filling condition, speed and coordinate data to a remote operation center responsible for main salvage / re- covery operation, for example.

Fig. 7 illustrates a perspective view of an overall arrangement installed onboard a vessel according to an embodiment of the present invention. In the Figure 7, it is depicted an exemplary arrangement according to the present invention divided as a number of recovery units 702 and a number of storage containers 704. In an embod- iment, the arrangement further comprises a remote valve unit 706, controlled from the operation booth, for example. The remote valve unit 706 can be used when there are more containers 704 than connectors in the recovery unit 702. In combination with the filling level gauges the remote valve unit 706 is enabled to control loading of the storage containers 704, and essentially maintaining the vessel stability and keeping hull moments in acceptable levels during loading.

In an embodiment comprising multiple recovery units 702, at least one recovery unit is selected as a master and the functions of the arrangement comprising slave recovery units and/or storage containers are preferably activated and/or controlled by means of the master unit. The person skilled in the art will understand that it is possible to arrange the arrangements according to the present invention onboard a vessel one upon the other. Especially useful it is to load storage containers one upon the other.

Fig. 8 is a flowchart of a method according to an embodiment of the present invention. In an embodiment, a method for recovering chemical substance floating on the surface of a liquid comprises at least following steps:

- Start, i.e. turning the arrangement into the operational condition 800

- lowering said rack substantially towards the surface of the liquid 802,

- protruding said extendable jib from said supporting structure for enabling said recovering devices to recover chemical substance from the surface of the liquid 804.

In one embodiment, when executing the step 804, the boom is reeled out from the reel by means of a line connected to the jib and the boom. In another embodiment, the method further comprises steps of inflating then boom and tensioning the support wire after this.

In another embodiment, the method further comprises a step of initializing said arrangement by moving said protruding part from said supporting structure towards the space above the liquid 801.

Fig. 9 is a more detailed flowchart of an exemplary embodiment of a method according to the present invention. The most steps of the flowchart have been explained above in the description of the Figures showing the arrangement embodiments. The flowchart also shows steps for monitoring weight load distribution pref- erably with a load control system. A load control system is usually readily available in ships. Preferably the ship data and the storage data are input in the load control system. If the load moment approaches a maximum value, the system gives a warning, indicating that the tank or the container should then be changed to an empty one. It is also possible to monitor filling level instead or in addition to the weight load and moment.

The scope of the invention is determined by the attached claims together with the equivalents thereof. The skilled persons will again appreciate the fact that the explicitly disclosed embodiments were constructed for illustrative purposes only, and the scope will cover further embodiments, embodiment combinations, manufactur- ing processes, and equivalents that better suit each particular use case of the invention.

Claims

1. An arrangement for recovering chemical substance floating on the surface of a liquid comprising: - a supporting structure attachable to a desired site, such as on a deck of vessel or on a pier, for mounting said arrangement to the proximity to a liquid, which supporting structure comprises a protruding part, a rack connected in said protruding part, an extendable jib connected in said protruding part, - recovering devices, such as a skimmer, a pump, an inflatable boom, attached to said jib and/or said rack, wherein said rack is arranged to be lowered substantially towards the surface of the liquid and said extendable jib is arranged to be protruded from said supporting structure for enabling said recovering devices to recover chemical substance from the surface of the liquid.

2. An arrangement according to claim 1, wherein said supporting structure further comprises one or more fixing points compatible with a standard container for transportation, handling and/or fixing the arrangement on to the site.

3. An arrangement according to any preceding claims, wherein said supporting structure further comprises at least one sliding rail enabling said protruding part to be protruded from the site towards a space above said liquid.

4. An arrangement according to any preceding claims, wherein said rack comprises turning means, such as one or more hinges, for enabling said rack to be lowered by turning it down around said turning means.

5. An arrangement according to claim 4, wherein said rack comprises a main hose connector comprising two compatible parts, which are lockable together by turning said rack in its lowered position.

6. An arrangement according to any preceding claims, wherein said rack further comprising a sliding part arranged to move upwards and/or downwards in said rack for providing heave compensation to the recovering devices.

7. An arrangement according to any preceding claims, wherein said arrangement further comprises an operator booth arranged in said protruding part for providing a shelter for a user of said arrangement.

8. An arrangement according to any preceding claims, wherein said arrange- ment further comprises a storage bag connectible to said recovery devices, which storage bag is arrangeable into a standard container.

9. An arrangement according to claim 8, wherein said arrangement further comprises a filling level gauge arrange to be in connection with said storage bag for providing filling level information relating to said storage bag.

10. A method for recovering chemical substance floating on the surface of a liquid by using an arrangement of any of claims 1-9, wherein said method comprises at least following steps:

- lowering said rack substantially towards the surface of the liquid,

- protruding said extendable jib from said supporting structure for enabling said recovering devices to recover chemical substance from the surface of the liquid.

1 1. A method according to claim 10 further comprising a step of initializing said arrangement by moving said protruding part from said supporting structure towards the space above the liquid.

12. A method according to claim 10 further comprising a step of monitoring weight load distribution on the ship and based on monitored load approaching its maximum value, preferably giving a warning in order to avoid overloading.