WO2013113477A1

WO2013113477A1 - Cooling element handling tower for chemical tank ship

Info

Publication number: WO2013113477A1
Application number: PCT/EP2013/000184
Authority: WO
Inventors: Reiner A. JENSEN
Original assignee: Nordic Tankers Marine A/S
Priority date: 2012-01-31
Filing date: 2013-01-22
Publication date: 2013-08-08

Abstract

The present invention relates to a cooling element handling tower (1) for a chemical tank ship (40), said tower (1) comprising a casing (10) defining a storage space (2) for a cooling element (30) for cooling a chemical tank (42) of said chemical tank ship (40), said casing (10) having a bottom opening (15) configured for passage of said cooling element (30) into and out of the casing (10), and for fitting adjacent a deck trunk (43) of a chemical tank (42), said tower (1) having at least one fixation unit for releasably securing said cooling element (30) immovably relative to said casing (10), said tower (1) having a lifting device for moving said cooling element (30), and said tower (10) being configured for attaching said casing (10) to a deck (41) of the chemical tank ship (40).

Description

COOLING ELEMENT HANDLING TOWER FOR CHEMICAL TANK SHIP

The present invention relates to cooling arrangements for cooling a chemical cargo which is stored onboard a chemical tank ship. More particularly the invention relates to an arrangement for inserting or removing a cooling device from a tank of a chemical tank ship. BACKGROUND ART

Chemical tank ships also known as chemical tankers often transport cargos in liquid form that needs to pressurized, heated or cooled en route. One or more liquid chemical cargos may be transported on the same chemical tanker during a transport, the chemical tankers comprising one or more chemical tanks, typically 12-60 tanks, depending on the size (tonnage) of the vessel. Heaters for heating a cargo are usually integrated in the tanks of the chemical tanker, at the bottom of each tank, or a cargo pump typically associated with each tank is used to circulate the fluid cargo through a heater located on the deck of a tank ship. With regard to cooling a chemical cargo, there are practical and legal limitations to the possibility of cooling the liquid cargo contained in a tank of marine vessel. For security reasons, a volatile cargo may not be circulated to deck mounted coolers. Due to this limitation and to the construction of the tank ship, cooling devices are therefore typically permanently arranged in the tanks or tanks by a cooling device located inside the tank. It is however desirable that cargo ships, such as chemical tankers, can carry numerous kinds of cargos rather than being dedicated for specific cargoes. The cooling device or element may be removed from the cargo tank when the tank is used for a chemical which does not require cooling. Further, some chemicals are very sticky and therefore the cargo tanks and cooling elements are difficult to clean. Yet further, the cooling elements can be provided with a casing fitted around the cooling pipe stack in order to improve the efficiency. This casing and/or the cooling pipe stack of the cooling element hampers the cleaning of the cooling device and the tank with the normal type of tank washing machines.

Further, it is desirable to be able to remove the cooling device from the tank for other maintenance purposes, e.g. repairing the circulation pump, typically provided at the bottom of the cooling element. Therefore, and also because the cooled cargo will sink towards the bottom of the tank, contrary to heaters, cooling devices needs to be removably inserted from the top of the tanks.

Thus, cooling elements are removed from the cargo tanks when not used. In prior art systems they may be stored in a deck house (see Fig. 3) provided on the deck of the tanker/tank ship. The cooling elements for commercial chemical tankers are large devices typically in the range of 4-8 meters high and weighing in the order of 400-1000 kg. Therefore, large deck mounted cranes are used for handling the cooling elements on deck (and into and out of the house) , on and off the vessel and into and out of the tanks. This arrangement requires that the vessel's crane can reach the cooling elements and the position of the deck housing where the elements are stored. Chemical tankers are intended for liquid cargos and therefore are not equipped with or designed for large and expensive cranes. Further, special regulations prohibit the use of normal electrically driven or combustion engine driven equipment on the deck, because the cargos are often highly combustible.

The normal design of the deck arrangement onboard a chemical tanker is that one crane is installed on the deck which is used for lifting the cargo hose to a manifold for filling and emptying the tanks, and for lifting spool pipe pieces used at the manifold as these are to heavy and not possible to handle without a crane. Therefore normally the crane has a limited capacity, and cannot reach the forward and the aft cargo tanks but only the central tanks. Therefore, with prior art technology, only approximately 6000 tons of cooled cargo can be carried on a 20000 tonner tanker, typically having 12-30 tanks. This is because a fixed deck crane can reach a very limited number of the cargo tanks.

In some cases it is desirable that all or at least a larger number of the tanks could be fitted with cooling elements, to accommodate for large cargoes of cooled chemicals. An obvious way to accommodate for this would be to install more cranes, or to provide a crane movable along the length of the vessel. However, such cranes are expensive, and they take up space, which is already limited at the deck of chemical tankers. Further, tanker ships are not designed for carrying such equipment. If e.g. movable crane needs to be installed the sides of the ship needs to be specially reinforced, which is costly in new builds, and which may be costly or practically impossible in the case of retrofitting, and which will limit the space available for cargo. DISCLOSURE OF THE INVENTION

On this background, it is an object of the present invention to provide a new, improved, simple and cost efficient equipment for handling cooling elements, i.e. for inserting and removing the cooling elements from the tanks of a chemical tanker. It is also an object to provide a simple, cost efficient equipment for moving cooling elements between chemical tankers of fleet, in a cost efficient and simple way to provide increased flexibility with respect to multiple fluid chemical cargos in need of cooling.

It is also an object of the invention to provide equipment for handling cooling elements that allows flexibility in transporting from 5000 to 60000 m³ cargo each transport. It is also an object of the invention to provide equipment for handling cooling elements enabling removal of a cooling element without using the deck crane and which may also be used as storage protecting the cooling element when not in use, and as protection during transport between chemical tankers.

This object is achieved by providing a cooling element handling tower for a chemical tank ship, said tower comprising a casing defining a storage space for a cooling element for cooling a chemical tank of said chemical tank ship, said casing having a bottom opening configured for passage of said cooling element into and out of the casing and configured for fitting adjacent a deck trunk of a chemical tank, said tower having at least one fixation unit for releasably securing said cooling element immovably relative to said casing, said tower having a lifting device for moving said cooling element, and said tower being configured for attaching said casing to a deck of the chemical tank ship.

With this arrangement the deck crane installations and the additional deck housing normally used for storing the cooling elements can be saved.

The advantage is also that the cooled cargos can be transported in larger quantities because smaller chemical tankers can be used for this type of chemicals and therefore the same service can be offered with two "16000 Tons" vessels compared with four 40000 tons vessels carrying only 6000 tons cooled cargo due to the crane design .

When only using two vessels, a third vessel must be prepared for cooled cargo where the cooling elements and the cooling plant is moved from one vessel to the other. The third vessel is only acting as standby vessels, and can be used for other cargos and business.

Embodiments of the invention are described in dependent claims 2-10. In another aspect, the objects of the invention is achieved by a combination of a cooling element and a cooling element handling tower according to any one of the embodiments mentioned above, i.e. as described in claims 1-10 below.

Embodiments of this aspect of the invention are described in dependent claim 12. In a further aspect, the objects of the invention is achieved by a chemical tank ship with a cooling element handling tower according to any one of the embodiments mentioned above, i.e. as described in claims 1-10 below; the cooling element handling tower mountable or mounted adjacent a deck trunk provided on the deck of the chemical tank ship.

Embodiments of this aspect of the invention are described in dependent claim 15.

Further objects, features, advantages and properties of the cooling element handling tower and the chemical tanker according to the invention will become apparent from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiments shown in the drawings, in which:

Fig. 1 shows a cooling element for cooling a chemical tank of a chemical tanker submerged in a cargo fluid of a chemical tank,

Fig. 2, shows a cooling element connected to a cooling system of chemical tanker,

Fig. 3 shows a prior art deck house for storing cooling elements and the location of the deckhouse on a tanker, Fig. 4, in a partly sectional view, shows a prior art chemical tanker, with chemical tanks and deck mounted cranes , Fig. 5A, in diagram form shows a portion of a deck and a chemical tank of a chemical tanker, and an embodiment of a cooling element handling tower according to the invention, with a cooling element submerged in a chemical tank,

Fig. 5B, in a perspective view shows the cooling element handling tower of Fig. 5A, from below,

Fig. 6, in diagram form shows a portion of a deck and a chemical tank of a chemical tanker, and another embodiment of a cooling element handling tower according to the invention, with a cooling element lifted into the cooling element handling tower, and Fig. 7, in diagram form shows a portion of a deck and a chemical tank of a chemical tanker, and yet another embodiment of a cooling element handling tower according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following detailed description of the cooling element handling tower (1) according to the invention will be described by the preferred embodiments.

Fig. 1 shows a typical cooling element 30. The cooling element is insertable into a tank 42 of a chemical tanker

40. In Fig. 1, the tank 42 is only represented by a section of the deck 41 of the chemical tanker 40, forming an upper wall of the tank 42, and by a liquid cargo 50, contained in the tank 42. In Fig. 1, the liquid cargo is represented by the gray area. A heat exchanging unit in the form of a cooling element

30 is elongate in shape with a top and a bottom, and typically has a circular cross sectional shape, i.e. it is typically formed as a straight cylinder. Typical cooling elements are about 4-8 meters high and weigh about 400-1000 kilograms, without coolant. At the top, the cooling element 30 has a top plate 36, that when the cooling element 30 is inserted in the tank 42 rests on and is secured to, e.g. by bolts, a deck trunk 43. Each tank 42 of the chemical tanker 40 is provided with a deck trunk 43. The deck trunks 43 define openings through the deck 41 of the chemical tanker 40 to the tank 42, and forming an access way to the tank 42. Deck trunks 43 are typically ring shaped elements, i.e. they have a cylindrical portion 44, with a flange 46 provided at a top portion thereof. When a cooling element 30 is not inserted to the tank 42 a hatch 42 covers the opening to the tank defined by the deck trunk 43, the hatch typically being secured to the flange 43' of the deck trunk 43 by bolts. A chemically resistant gasket (not shown) is fitted between the top plate 36 and the trunk 43 (or between the hatch and the trunk 43) to seal the tank 42. Typically, the deck trunk 43 is welded to the deck 41.

The cooling element 30 comprises a pipe stack 31 for circulating a coolant. The coolant enters the pipe stack

31 through at least one connector 32a at a top portion of the cooling element 30. The connector 32a is configured for connection to a source of coolant, via a piping on the deck of the vessel 40, see Fig. 2.

The pipe stack 30 also connects a circulation unit 33 to the top plate 36. It consists of 1-4 spiraling pipes 31' and one central pipe 31' ' (the figure shows an embodiment with three spiraling pipes 31' ) . The cooling medium (coolant) (or a heating medium) is fed down through the spiraling pipes 31' and returns through the central pipe

In Fig. 1, arrows 60 show the passageway for the coolant entering the pipe stack 31, and passing through the pipes 31' arranged as a triple helix. The coolant is returned via the central pipe 31' and exists through connector 32b to a return conduit of a refrigeration system, see Fig. 2. In Fig. 1, arrow 61 indicates the returning coolant.

Further, the cooling element 30 comprises a circulation unit 33 formed at the bottom. The circulation unit 33 circulates the fluid cargo, by creating an upward flow in the tank in order to improve efficiency of the cooling. In Fig. 1, arrows 62 indicate fluid cargo being sucked into and through the circulation unit 33 from below the circulation unit 33. Arrows 63 indicate fluid cargo flowing out of the circulation unit 33. The circulation of the cooling/heating medium through the pipe stack 31 provides power to a small turbine (not shown) . The flow of coolant drives the turbine, which in return drives a propeller (not shown) , coupled thereto, the propeller circulating the fluid cargo. The circulation unit 33 is bolted to the pipe stack 31, and may therefore easily be dismantled for service Further, the cooling element 30 may, as shown, comprise an optional cooling element casing 34. The cooling element casing 34 may be inserted with, and be removed from the tank 42 together with the cooling element 30, or it may be left in the tank 42, thus forming a guide for the cooling element 30 during the insertion and removal thereof. The cooling element casing 34 guides the circulation of cargo and increases the cooling efficiency. The implementation of a cooling element casing allows the use of smaller/shorter cooling elements 30.

A support for holding the cooling element 30 immovably in the tank when inserted therein, in the form of a circular support ring 35 may further be provided. The support ring 35 is secured to the bottom of the tank 40 or close to the bottom of the tank, e.g. by welding, and support ring 35 is sized, shaped and positioned to cooperate with the bottom portion of the cooling element 30, and intended to allow vertical movement of the cooling element 30 (when inserting or removing it) , and to prevent horizontal movement, when the cooling element is fully inserted in the tank 42. Now referring to Fig. 2 a cargo cooling system 100 for a vessel such as a chemical tanker 40 is described. The cargo cooling system 100 comprises cargo heat exchangers or cooling elements 30 as described above. Further, the system 100 comprises one or more refrigeration units 110 (each comprising circulation pump(s) 111, chiller 112, compressor 113 and condenser 114), a header tank 120 and a cooling medium (coolant) storage tank 130. The circulation pump 111 circulates the coolant through the cooling element 30 and thereby also drives the circulation unit 33 therein, as described above.

In the prior art, the cooling elements 30 or heat exchangers are either permanently installed in cargo tanks or they are installed only in a cargo tank, when the content of a cargo tank needs cooling/heating. Fig. 3 shows a prior art storage arrangement for cooling elements 30, when not in use. In this case, when they are not used, the heat exchangers are stored in a housing 200 provided on the deck 41 of the chemical tanker 40. The storage elements must be moved between the tanks 42 and the housing by a deck crane 60, or by a crane external to the ship e.g. when the vessel is in port. Fig. 4 shows an example of a prior art chemical tanker, and illustrates the crane coverage for a typical vessel. The tanker ship 40 has a plurality of tanks 42. The tanks 42 are formed as compartments in the hull of the ship. The walls of the tanks also serve as structural elements of the hull to reinforce the same. On deck transverse hull reinforcement beams 45 may further serve the same purpose. The deck 41 forms the top wall of the tanks 40. The vessel 40 shown has two deck cranes 60. It is obvious from the figure, that the cranes can only reach a few of the tanks 42 of the vessel, i.e. the chemical tank ship 40. Many chemical tank ships only have one deck crane 60. In some cases, vessels also have portal cranes (not shown) moveable on rails along a part or the whole deck. In chemical tankers however, due to the complex and extensive security equipment does not have space for such portal cranes without extensive redesign of the vessel. Further the construction of chemical tankers would require extensive reinforcement of the hull side in order to carry portal cranes . Now turning to Figs. 5A and 5B, a cooling element handling tower 1 according to one embodiment of the invention is described. The cooling element handling tower 1 (tower 1) comprises a casing 10. The casing 10 may as shown be a straight cylindrical structure with a top plate, or it may be formed as a cage or frame (not shown) . The cage or frame may be provided with three, four or more sidewalls provided between vertical bars of the cage or frame. The sidewalls may be fixedly or detachably attached to said cage or frame. In any embodiment the casing 10 defines a storage space 2 for a cooling element 30 for cooling a chemical tank 42 of a chemical tanker 40, i.e. the casing 10 is elongate in shape with a top end 11 and a bottom end 12, and it is sized and shaped such that a cooling element 30 as described above may be contained within the casing 10. Such a cooling element could e.g. be 4-5 meters high (or even up to 8 meters) . Thus the tower may be from 4.5-6 m high. The height of the tower 1 is always adapted to be able to contain a desired cooling element height.

A lifting mechanism comprising a pulley or a set of wheels 13 is arranged inside the top end 11 of the casing 10. A wire 14 is arranged over the pulley or set of wheels 13 and, at a first end 14' attachable to a top portion of a cooling element 30, and at a second end 14'' connectable to a winch 70, such as an air driven (pneumatic) or hydraulic winch. The winch 70 may, as shown, be attached to a part of the vessel 40, such as a transverse hull reinforcement beam 45, or it may be formed in or on the casing 10 of the tower 1. The winch 70 is configured for winding and unwinding the wire 40 to lower or raise a cooling element 30 attached to the first end 14' of the wire 14. In Fig. 5 the wire 14 is shown connected to the winch 70 as well as to the cooling element 30. The casing 10 of the tower 1 has a bottom opening 15 (See fig. 5B) through a lower surface 12' at the bottom 12. The bottom opening 15 is sized and shaped to allow vertical passage of a cooling element 30 (when in upright position) .

The casing 10 further has a bottom flange 16 arranged at the lower end or bottom 12 of the casing, the bottom flange having an opening, which is the bottom opening 15, sized and shaped to allow vertical passage of a cooling element 30 (when in upright position) , and one or more attachment devices 16' for attaching the flange to the deck 41 or to the deck trunk 43. Such attachment devices may, as shown in Fig. 5B, be holes suitable for bolts. Alternatively the attachment devices may be suitable snap locks. Alternatively, attachment devices, e.g. brackets with holes for bolts or brackets with snap lock mechanisms may be provided directly on the casing 10 at the lower part 12 thereof. The casing 10 is mountable to the deck 41, e.g. to flanges or brackets (not shown) installed on the deck 41 in the vicinity of the deck trunks 43 of each tank 42, or to the deck trunk 43 itself. The cooling element handling tower 1 may be secured to the deck brackets/flanges or the deck trunk 43 via bolts, or via one or more snap fittings/locks/mechanisms. The cooling element handling tower 1 is attached such that the bottom opening 15 fits over the deck trunk 43, i.e. such that the bottom opening partly of fully surrounds the deck trunk 43. The cooling element handling tower 1 may further be secured to its position over the deck trunk 43 by 2-6 wires (not show) extending from the top 11 of the cooling element handling tower 1 to positions on the chemical tanker 4, such that the cooling element handling tower 1 is secured to the deck and kept stable under all conditions, e.g. rough seas. The wires may be connected to rings or brackets (not shown) provided at the top portion of the casing 10 of the cooling element handling tower 1. The casing 10 may be provided with a storage space (not shown) for storing the wires and e.g. snap hooks etc. for the stabilizing purpose, such that the necessary equipment is always available for mounting the cooling element handling tower 1. In other embodiments (not shown) , the wires may be fixedly attached to the casing 10, e.g. in roll-out arrangements, e.g. winches.

When the cooling element handling tower 1 is in position adjacent to or over the deck trunk 43, the lifting device 13 connected to the winch 70 allows the lowering of a cooling element 30 contained in the tower into the tank 40. The lifting device 13 with the winch 70 also enables hoisting the cooling element 30 out of the tank and up into the cooling element handling tower for maintenance of the cooling element, cleaning of the tank 42 etc.

The casing 10 further has a side opening 17 at the bottom end 12, and formed as an opening through a side wall of the casing 10. The side opening 17 allows access to the inside of the cooling element handling tower 1, when the cooling element handling tower 1 is mounted on a deck trunk 43. Especially, the side opening 17 allows access to the bottom part of the cooling element 30, when a cooling element 30 is lifted up and contained in the casing 10 of the cooling element handling tower 1. Thereby, especially access to the circulation unit 33 is easily provided. When the cooling element 30 is lowered into the tank, the side opening 17 allows access to secure the top flange 36 of the cooling element 30 to the deck trunk 43, and to mount the relevant tubing to the coolant connectors 32a, 32b. The side opening 17 may be equipped with a side door (not shown) . Such a side door may be hinged or a loose part.

When the cooling element 30 is lifted up and contained within the casing 10, it may be constrained against movement relative to the tower 1, by a bottom fixation unit 80 (see Figs. 6 and 7). The bottom fixation unit 80 is preferably positioned in the bottom part of the tower 1, and provides a connection between the cooling element 30 and the casing 10. Thereby, the cooling element 30 is secured against damages by being prevented from swinging and hitting the casing, e.g. during rough weather, and the cooling element 30 may be fixated during transport of the tower with the cooling element fixated there within between chemical tankers. Alternatively or additionally, the bottom fixation unit 80 may comprise rings or brackets, which may be provided on or in the casing 10 to which bands or wires may be secured, for securing the cooling element30 in the tower 1. The bottom opening 15 may further be closed by a bottom hatch, when detached from the deck 41 or deck trunk 43. The above mentioned bottom fixation unit 80 may be arranged on said bottom hatch, or an additional fixation unit may be provided on said bottom hatch (the first being provided in or on the casing 10 itself) . The bottom hatch may be hinged or otherwise permanently turnably connected to the tower 1. In other embodiments, the bottom hatch may be a loose part. In this case, the casing 10 may be provided with specialized means for storing the bottom hatch, when it is not used to close the bottom opening 15.

In an embodiment the bottom hatch matches, or has connection means matching the top flange 43' of the deck trunk 43, such that the bottom hatch may be used interchangeably with the hatch used to seal a deck trunk, when no cooling element or tower is associated the tank 42.

In fig. 5A, holes 18 are shown in the top 11 of the casing. The holes 18 are configured for and allow the cooling element 30 to be secured against movement relative to the tower, when the cooling element is lifted into the casing 10. Pins or bars (not shown) may be inserted through the holes 18 and match attachment devices (not shown) on the top part of the cooling element 30. Alternatively, or additionally the holes 18 may be used to secure the cooling element 30 by attaching wires or bands/straps. Thus the holes 18 forms part of a top fixation unit. Storage means for said pins or bars may further be provide on or in said casing 10.

A top hatch (not shown) or a side hatch formed in the top portion 11 of the casing 10 may be provided to allow access (when the top hatch or top side hatch is removed) to connection of the cooling element 30 to the holes 18 or another top fixation unit. The tower may also be open towards the top, the pulley or the wheels 13 being provide on a bracket or an arm.

The lifting device in the form of the pulley or wheels 13 may be formed on an arm or bracket (not shown) pivotally connected to the casing 10 such that pulley or wheels 13 may be swung away from its position above the cooling element 30 to provide access to the top fixation means (e.g. holes 18 ) .

In another embodiment the arm or bracket (not shown) on which the lifting device in the form of the pulley or wheels 13 is mounted is a unit detachable from the tower 1. Thereby, one or more such units (lifting device units) can be used in combination with a larger number of towers 1.

Fig. 6 shows another embodiment of the cooling element handling tower 1. The same reference numbers refer to the same parts as in Fig. 5.

The cooling element handling tower 1 in Fig. 6 is shown with a cooling element 30 lifted into an uppermost position therein. It is also, shown how the cooling element casing 34 may be maintained in the tank 42. Thereby it may function as a guide when lifting the cooling element out of the tank or lowering it into the tank 42. This arrangement is optional. The cooling element casing 34 may in other embodiments be lifted into and out of the tank together with the cooling element 30, itself. Further, it is noted that this also apples to the Fig. 5 embodiment. The fig. 6 embodiment differs from the Fig 5 embodiment in that a casing top flange 19 is provided in a top portion 11 of the casing 10. The casing top flange 19 is configured for securing the cooling element 30 against movement relative to the tower. The casing top flange 19 may be bolted or snap fit with cooperating means (e.g. screw bores) on the top flange 36 on the cooling element 30. Thus the top fixating unit on the tower 1 uses the same means as is used to secure a cooling element 30 to a deck trunk 43. The casing top flange 19 thus forms an embodiment of a top fixation unit.

In Fig. 6 it is further shown that the pulley or wheels 13 may be provided above the tower e.g. on a bracket. However, in other embodiments (not shown) , the tower wall or walls may extend further above the casing top flange 19, such that the pulley or wheels 13 are encased in the tower 1 as in Fig. 5. In this case a top hatch (not shown) or a side hatch formed in the top portion 11 of the casing 10 may be provided to allow access to the casing top flange 19 for connection of the cooling unit 30 to the casing top flange 19. The tower may also be open towards the top. The pulley or wheels 13 may be formed on an arm or bracket (not shown) pivotally connected to the casing such that pulley or wheels 13 may be swung away from its position above the cooling element 30 to provide access to the top fixation means (casing top flange 19) . As described in connection with the Fig. 5 embodiment above, the lifting device comprising pulley or wheels 13 provided on a bracket or arm may be detachable. In Fig. 6 it is further illustrated how a bottom fixation unit 80 may secure the cooling element 30 against movement relative to the tower 1. The bottom fixation unit 80 is provided as a ring mounted on a lid 90 on the deck trunk. The ring is sized and shaped to cooperate with and contain and constrain the circulation unit 33 of the cooling element 30. Thereby, the cooling element 30 is secured against movement when lifted into the tower 1. The lid with the bottom fixation unit may be provided with attachment devices such that it may also function as a bottom hatch as described also in connection with the fig. 5 embodiment above. Further, such a bottom fixation unit 80 may also be used in connection with the Fig. 5 embodiments .

In alternative embodiments lifting device 13 of a cooling element handling tower 1 may be provided by e.g. a toothed rail on the inside of the casing and e.g. a pneumatically driven cart attachable to the upper portion of the cooling element, said cart being moveable on said rail to lower or lift said cooling element 30.

Consequently, the invention provides a great variety of possible designs and adaptation of a cooling element handling tower 1 system.

Fig. 7 shows yet another embodiment of the cooling element handling tower 1. The same reference numbers refer to the same parts as in Figs. 5A, 5B and 6. In Fig. 7, a cooling element 30 is not shown.

The embodiment of the coolin element handling tower 1 is in many aspects similar t the embodiments described above. The embodiment in Fig 7 differs from the previous embodiments mainly with respect to the bottom part 12 of the tower 1 has a widened connection portion 20. The connection portion 20 has a widened cross sectional shape or diameter with respect to the cross sectional shape/diameter of the casing 10 of the tower 1. Thereby, improved access is possible for handling the mounting of the cooling element to the deck trunk 43, i.e. in the tank 42, and for handling the bottom of the cooling element 30, when it is lifted up into the internal storage space 2 of the tower 1. The widened connection portion 20 is configured for cooperating with a special deck trunk 43' , see below. The widened connection portion 20 forms a skirt of the casing 10. A bottom flange 16'' is formed in bottom of the widened connection portion 20. The bottom flange 16' ' has attachment devices with are similar and functions in the same way as the bottom flange 16 and attachment devices 16' described in connection with Figs. 5 and 6 above.

The special deck trunk 43' has a cylindrical portion 44' similar to the cylindrical portion 44 of the deck trunks described in connection with Figs. 1-6 above. The cylindrical portion 44' is configured for allowing passage of a cooling element 30 into and out of a tank 42. The diameter of the cylindrical portion 44' special deck trunk 43' may be in the range 30-60 cm. Preferably, the cylindrical portion 44 forms a guide for the passage of the cooling element 30. The special deck trunk 43' has flange 46' mounted on top of the cylindrical portion 44', the flange 46' having a broader diameter than the diameter of the flange 46 described in connection with Figs. 1-6 above. The diameter of the flange 46' of the special deck trunk 43' may be in the range 70-120 cm. The diameter of the flange 46' of the special deck trunk 43' may preferably be approximately 3 times the diameter of the cylindrical portion 44' of the special deck trunk 43' , while the flange 46 described in connection with Figs. 1-6 above only has a diameter which is slightly larger than the diameter of the cylindrical portion 44 of the deck trunks described in connection with Figs. 1-6.

In an outer periphery of the flange 46' of the special deck trunk 43' a plurality of attachment devices are formed. The attachment devices may simply be holes configured for connecting the tower via bolts 47, in the corresponding holes on the flange 16' ' of the widened connection portion 20. In other embodiments, the attachment devices may be snap fittings or other means known in the art.

The special deck trunk 43' further may have a plurality support brackets 48 formed between the deck 41 and an outer peripheral potion of the flange 46' to support the weight of the tower 1, and to prevent or counteract torsional forces between the deck and the cylindrical portion 44' .

Also illustrated in Fig. 7 is that a winch may be mounted on the tower 1, e.g. on a bracket 71 as shown. The winch may be permanently mounted, or it may be detachably mounted. The latter option allows use of one winch at a plurality of towers 1. The pulley or wheels 13 may be formed on an arm or bracket 13' . The bracket may be pivotally connected to the casing such that pulley or wheels 13 may be swung away from its position above the cooling element 30 to provide access to the top fixation means (casing top flange 19) . As shown, and as described in connection with the Fig. 5 embodiment above, the lifting device comprising pulley or wheels 13 provided on a bracket or arm 13' may also be detachable. In Fig 7 it is shown that the bracket or arm 13' is secured to the casing 10 via bolts 13' ' .

In Fig. 7 it is further illustrated how a bottom fixation unit 80 may secure the cooling element 30 against movement relative to the tower 1. The bottom fixation unit 80 is provided as a ring mounted on a lid 90 on the deck trunk 43' . The ring is sized and shaped to cooperate with and contain and constrain the circulation unit 33 of the cooling element 30. Thereby, the cooling element 30 is secured against movement when lifted into the tower 1. The lid with the bottom fixation unit may be provided with attachment devices such that it may also function as a bottom hatch as described also in connection with the fig. 5 embodiment above. Further, such a bottom fixation unit 80 may also be used in connection with the Fig. 5 embodiments. The lid 90 may, as illustrated, further be provided with a valve 95 and connection into the tank in order to allow the entrance of a tank cleaning fluid. The teaching of this invention has numerous advantages. Different embodiments or implementations may yield one or more of the following advantages. It should be noted that this is not an exhaustive list and there may be other advantages which are not described herein. One advantage of the teaching of this application is that it provides a great flexibility in designing and operating a chemical tanker cooling system. Moreover, due to its flexibility and limited space requirement the invention may be utilized in already existing chemical tankers, which do not already have a cooling system for all tanks.

Although the teaching of this application has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the teaching of this application.

The term "comprising" as used in the claims does not exclude other elements or steps. The term "a" or "an" as used in the claims does not exclude a plurality. The single processor or other unit may fulfill the functions of several means recited in the claims.

Claims

CLAIMS:

1. A cooling element handling tower (1) for a chemical tank ship (40), said tower (1) comprising a casing (10) defining a storage space (2) for a cooling element (30) for cooling a chemical tank (42) of said chemical tank ship (40), said casing (10) having a bottom opening (15) configured for passage of said cooling element (30) into and out of the casing (10) and configured for fitting adjacent a deck trunk (43) of a chemical tank (42), said tower (1) having at least one fixation unit for releasably securing said cooling element (30) immovably relative to said casing (10) , said tower (1) having a lifting device for moving said cooling element (30), and said tower (10) being configured for attaching said casing (10) to a deck (41) of the chemical tank ship (40) .

2. A tower according to claim 1, wherein said casing (10) further comprises a side opening (17).

3. A tower according to claim 1 or 2, wherein said casing (10) comprises a frame.

4. A tower (1) according to any one of claims 1-3, wherein said tower (1) comprises a set of side walls.

5. A tower (1) according to claim 4, wherein said sidewalls are detachably attached to said frame.

6. A tower (1) according to any one of claims 1-5, wherein said bottom opening (15) is provided with a bottom hatch.

7. A tower (1) according to claim 6, wherein said bottom opening (15) is configured for cooperation with a top hatch of a chemical tank of a chemical tank ship to close the casing 10 for transport thereof.

8. A tower (1) according to claim 6 or 7, wherein a fixation unit for releasably securing said cooling element (30) immovably relative to said casing (10) is formed on the bottom hatch.

9. A tower (1) according to any one of claims 1-8, wherein at least parts of the lifting device (13) is formed on a pivotal arm.

10. A tower (1) according to any one of claims 1-9, further comprising a pneumatic drive unit (70) for operating the lifting device (13) .

11. A combination of a cooling element (30) and a cooling element handling tower (1) according to any one of claims 1-10.

12. A combination according to claim 11, wherein a top fixation unit formed in the top portion (11) of the tower (1) is configured for cooperation with a top flange (36) formed at a top portion of the cooling element (30)

13. A combination according to claim 10 or 11, wherein a bottom fixation unit is configured to cooperate with a circulation unit (33) of the cooling element (30) .

14. A chemical tank ship (40) with a cooling element handling tower (1) according to any one of claims 1-10 mountable adjacent a deck trunk (42) provided on the deck (41) of the chemical tank ship (40) .

15. A chemical tank ship (40) according to claim 14, wherein at least one mounting bracket is arranged on the deck (41) of the chemical tank ship (40) in the vicinity of a deck trunk (43), the mounting bracket being configured for releasably fixing the cooling element handling tower (1) above tank (42) of the chemical tank ship (40) .