Patent Application
20080053993
The embodiments will be described in detail with reference to the accompanying drawings.
First, there will be described an anchor member and an anchor structure placed in an LNG storage tank according to the present invention with reference to
Referring to
The anchor member 110 has a frustoconical body 111 attached to a lower securing part 112. The anchor member 110 is secured to an inner surface of a storage tank 10, that is, an inner wall 12 or a partition 14, as will be described as follows with reference to
Although the securing part 112 is illustrated as having a ring shape formed along the lower outer circumference of the body 111 of the anchor member 110, it should be noted that the securing part 112 may be partially formed along the lower outer circumference so as to have a continuous arc-shape or a plurality of non-continuous arc-shape.
In this embodiment, the ring-shaped securing part 112 is produced as a separate member, and then welded to the lower end of the body 111 of the anchor member 110.
In addition, the securing part 112 has a plurality of through-holes 112a formed at constant intervals such that a plurality of stud bolts 61 can be inserted into the through-holes 112a and fastened by nuts 62.
The anchor member 110 has a step on the top surface of the frusto-conical body 111 so that the two junction parts (i.e., first junction part 113 and second junction part 114) are formed to have a predetermined height difference therebetween. First and second sealing walls 51, 52 are welded to the first and second junction parts 113, 114, as will be described below with reference to
In this embodiment, the first and second junction parts 113, 114 are produced separately and then welded to the upper end of the body 111 of the anchor member 110, thereby closing the upper end of the body 111 of the anchor member 110.
Referring to
The first sealing wall 51 directly contacting the LNG in the cryogenic state, and the second sealing wall 52 spaced from the first sealing wall 51 may have corrugation to endure temperature variations resulting from the loading and unloading of the LNG.
The first and second sealing walls 51, 52 are connected to the inner wall 12 or the partition 14 of the marine vessel 1 via a plurality of anchor structures 100. Thus, the first and second sealing walls 51, 52 cannot be moved with respect to the hull.
A heat insulating wall is arranged between the second sealing wall 52 and the inner wall 12 or the partition 14 to form a heat insulating layer therebetween. The heat insulating wall is made up of a corner structure (not shown) placed at a corner of the storage tank 10, the anchor structure 100 including the anchor member 110, and a planar structure 200 placed on a planar section of the storage tank 10. In other words, the overall heat insulating layer of the storage tank 10 may be formed by the corner structure, anchor structure 100, and planar structure 200.
The anchor structure 110 supports the first and second sealing walls 51, 52, whereas the planar structure 200 supports only the load of the LNG exerted on the first and second sealing walls 51, 52, and works independently of the anchor structure 110.
Here, the anchor structure 100 includes the anchor member 110 directly connected between the first and second sealing walls 51, 52 and the hull to secure the first and second sealing walls 51, 52 to the hull, and a heat-insulating material 103 formed of polyurethane foam or reinforced polyurethane foam to surround the anchor member 110.
Plywood 105 may be attached to one or both of the upper and lower ends of the heat-insulating material 130. Although the plywood is illustrated as being attached to the upper end of the anchor structure 100 and the upper and lower ends of the planar structure 200 in
The anchor heat-insulating material 103 in the anchor structure 10 has a density of about 35˜45 kg/m3, which is lower than the density of the planar heat-insulating material 203 of the planar structure 200 (about 115˜125 kg/m3). In this regard, although the density of the anchor heat-insulating material 103 is lower than that of the planar heat-insulating material 203, the anchor structure 100 can maintain a sufficient strength due to the anchor member 110 embedded therein.
The anchor structure 100 constructed as above is secured to the inner surface of the storage tank 10 via the securing part 112 formed at the lower portion of the frustoconical body 111 of the anchor member 110.
As described above, the securing part 112 is formed with the plurality of through-holes 112a arranged at constant intervals, and the plurality of stud bolts 61 are inserted through the holes 112a and fastened by the nuts 62.
For this purpose, the anchor heat-insulating material 103 has a lower surface that is substantially coplanar with a lower surface of the securing part 112, and is formed with a plurality of cylindrical hollows 103a (i.e., holes in the heat-insulating material) extending in a vertical direction and aligned with the through-holes 112a of the securing part 112.
The cylindrical hollows 103a may be formed by use of a mold when forming the heat-insulating material at an initial stage, or in such a way that the heat-insulating material is formed in a hexahedral shape around the anchor member 110 and then cut away at portions where the cylindrical hollows 103a are formed.
After positioning the anchor structure 100 such that the stud bolts 61 can be inserted through the through-holes 112a, the nuts 62 are inserted through the cylindrical hollows 103a, and fastened to the stud bolts 61, securing the anchor structure 100 to the inner surface of the storage tank 10.
At this time, a leveling plate 63 may be interposed between the lower surface of the securing part 112 of the anchor member 110 and the inner surface of the storage tank 10 to level off the heat insulating wall, if necessary, as well known in the art. Furthermore, a washer 64 may be interposed between the upper surface of the securing part 112 of the anchor member 110 and the nuts 62 fastened to the stud bolts 61, as well known in the art.
After securing the anchor structure 100 to the inner surface of the storage tank 10 by fastening the nuts 62 inserted through the cylindrical hollows 103a to the stud bolts 61, a cylindrical heat-insulating material 103b having a shape corresponding to that of the cylindrical hollows 103a is inserted into each of the cylindrical hollows 103a.
In addition, as described above, the first junction part 113 and the second junction part 114 are formed to have a predetermined height difference on the top surface of the frustoconical body 111 of the anchor member 110. The first and second sealing walls 51, 52 are welded to the first and second junction parts 113, 114, respectively.
Meanwhile, although the sealing structure is illustrated as having the double structure of the first sealing wall 51 and the second sealing wall 52 in
As such, according to one embodiment of the present invention, the plurality of stud bolts 61 secured to the inner surface of the storage tank are inserted into the plurality of through-holes 112a formed along the ring-shaped securing part 112 of the anchor member, and then fastened by the nuts 62, so that the anchor member 110 and the sealing walls 51, 52 can be secured to the hull.
In this way, attaching the anchor member 110 to the inner surface of the storage tank can be accomplished by a simple operation of nut fastening.
Furthermore, since the anchor member 110 and the inner surface of the storage tank are attached to each other at a plurality of consecutive locations, it is possible to absorb stress resulting from thermal deformation caused by loading and unloading of the LNG or from deformation of the hull caused by an external force such as waves.
As in the above embodiment, the anchor member 130 of the alternative embodiment has a frustoconical body having a planar top surface, which is closed at the upper surface and opened at a lower surface, as shown in
As in the above embodiment, the anchor member 130 comprises a frustoconical body 131, which is integrally formed at a lower portion with a securing part 132 through which the anchor member 130 is secured to the inner surface of the storage tank 10.
The securing part 132 has a plurality of through-holes 132a formed at certain intervals such that a plurality of stud bolts 61 can be inserted into the through-holes 112a and fastened by nuts 62. The intervals may be the same or different.
As in the above embodiment, the frustoconical body 131 of the anchor member 130 is integrally formed at the top surface with first and second junction parts 113, 114, which have a predetermined height difference, and are respectively welded to the first and second sealing walls 51, 52.
The reinforcing plate 135 may be mounted inside an upper end of the anchor member 130 by welding, as shown in
The plurality of through-holes 131a is arranged in a zigzag pattern in the body 131 of the anchor member 130 according to this embodiment. Additionally, by forming the through-holes 131a to have an elliptical shape as well as being arranged in the zigzag pattern on the body 131, there is an effect of extending a transfer path of cold energy from an upper end to a lower end of the anchor member 130, which can prevent loss of the cold energy.
According to the alternative embodiment, the forming of the heat-insulating material to surround the anchor member 130, the forming of the anchor structure with the anchor member 130 and the heat-insulating material, the securing of the anchor structure comprising the anchor member 130 to the hull and the first and second sealing walls 51, 52 are the same as those of the above embodiment, and thus are omitted hereinafter.
In this way, the alternative embodiment not only has the advantages of the above embodiment, but also other advantages as follows. That is, according to the alternative embodiment, since the anchor member can be formed as a single component by pressing, a process of producing the anchor member can become more simple, and since the elliptical through-holes are arranged in the zigzag pattern on the body of the anchor member to increase the transfer path of the cold energy, it is possible to further reduce the loss of the cold energy.
Referring to
In
The movable member 330 is installed to allow a very minute movement in a linear direction with respect to the fixed member (will be described in more detail below) when thermal deformation occurs caused by temperature variation resulting from loading and unloading of the LNG in the cryogenic state or deformation of the hull by waves.
As viewed from the front side, the fixed member 310 has a cross shape (+) wherein four extensions, that is, first to fourth extensions 311a to 311d, cross each other at right angles. Among these first to fourth extensions 311a to 311d, adjacent two extensions, that is, the first and second extensions 311a, 311b, are secured to the inner surface of the storage tank 10, and the remaining two extensions, that is, the third and fourth extensions 311c, 311d, support the movable member 330.
The first to fourth four extensions 311a to 311d may be formed separately, and then welded to each other. Alternatively, the two extensions, that is, the first and second extensions 311a, 311b or the second and fourth extensions 311c, 311d, may be formed as an integrated component, and then joined to another component of the other two extensions by welding or the like.
To enlarge the contact area with respect to the inner surface of the storage tank 10, the first and second two extensions 311a, 311b have a trapezoidal shape (see
Each of the first and second extensions 311a, 311b is formed at a distal end with a securing part 312, as will be described below with reference to
The securing parts 312 may be integrally formed with the first and second extensions 311a, 311b, or may be individually formed and joined thereto by welding and the like.
The securing part 312 has a plurality of through-holes 312a formed at constant intervals such that a plurality of stud bolts 61 secured to the inner surface of the storage tank 10 can be inserted into the through-holes 312a and fastened by nuts 62.
In
The movable member 330 has a substantially L-shape to be placed along the corner of the storage tank 10.
The movable member 330 is formed with two junction parts (i.e., first and second junction parts 331, 332) with a predetermined height difference therebetween. The first and second sealing walls 51, 52 are welded to the first and second junction parts 331, 332.
Each part of the movable member 330 facing the fixed member 310 is formed with a through-hole 334 through which a bolt 309 is inserted and fastened to the fixed member 310, and with a guide protrusion 333 to guide the movable member 330 to allow minute movement in the linear direction along the guide recess 313 of the fixed member 310, as shown in
The two guide protrusions 333 may be made independent of the movable member 330, and welded to locations of the movable member 330 corresponding to the guide recesses 313 of the fixed member 310, as shown in
The movable member 330 of this embodiment is positioned and supported on two fixed members spaced a predetermined distance from each other along the corner of the storage tank 10.
As shown in
In addition, the movable member 330 is coupled at opposite sides to the fixed members 310 by fastening the bolts 309 inserted through the through-holes 334 formed at opposite sides of the movable member 330 and through the through-holes 314 formed in the third and fourth extensions 311c, 311d of the fixed members 310 after positioning the opposite sides of the movable member 330 on the fixed members 310 secured to the inner surface of the storage tank 10, as described above.
Here, the movable member 330 and the fixed members 310 are coupled so as not to avoid a relative movement therebetween. Rather, the movable member 330 is coupled to the fixed members 310 such that the movable member 330 can be linearly moved by the guide recesses 313 of the fixed members 310 and the guide protrusions 333 of the movable member 330, as described above, when the movable member 330 is stretched or compressed in the longitudinal direction.
For this purpose, the through-holes at one side among the through-holes 334 formed at the opposite sides of the movable member 330 and the through-holes 314 formed in the third and fourth extensions 311c, 311d of the fixed member 310 are preferably formed in an elongated shape.
Preferably, the corner member 301 may further include a connection member 320, which is placed in the middle between the fixed members 310 (i.e., in the middle of the movable member 330) and has a shape similar to that of the fixed member 310.
As in the first and second extensions 311a, 311b of the fixed member, the connection member 320 may also have a trapezoidal shape (see
At one end of the connection member 320, the connection member 320 is integrally provided with securing parts 322 in which through-holes 322a are formed. Thus, as in the fixed member 310, the connection member 320 is secured to the inner surface of the storage tank 10 by inserting a plurality of stud bolts 61 secured to the inner surface of the storage tank 10 into the through-holes 322a of the connection member 320, and then fastening the nuts 62 to the stud bolts 61.
Meanwhile, the other end of the connection member 320 may be welded to the movable member 330. The movable member 330 is formed at corresponding locations with welding slots 336 for joining the connection member 320 to the movable member 330 via welding. Thus, even when the movable member 330 is laid on the connection member 320 and the fixed members 310 after mounting the connection member 320 and the fixed members 310 on the inner surface of the storage tank 10, it is possible to join the movable member 330 and the connection member 320 via the welding slots 336.
As such, the movable member 330 is secured to the inner surface of the storage tank 10 via the connection member 320 at the middle of the movable member 330 in the longitudinal direction, while being attached at the opposite ends to the fixed members 310 so as to allow minute movement in the linear direction with respect to the fixed member 310.
The inner peripheral surface of the storage tank 10 is sealed liquid-tight by the first and second sealing walls 51, 52. In other words, the first and second sealing walls 51, 52 define a single storage space with a plurality of metal plates joined together by welding, so that the storage tank 10 can store and transport the LNG without any leakage.
The first sealing wall 51 in direct contact with the LNGin the cryogenic state, and the second sealing wall 52 spaced from the first sealing wall 51 may have corrugation to endure the temperature variation caused by the loading and unloading of the LNG, as known in the art.
The first and second sealing walls 51, 52 are fixedly connected to the inner wall 12 or the partition 14 of the marine vessel 1 by a plurality of the corner structures 300 and anchor structures. Thus, the first and second sealing walls 51 and 52 cannot be moved with respect to the hull.
A heat insulating wall may be placed between the second sealing wall 52 and the inner wall 12 or the partition 14 to form a heat insulating layer therebetween. The heat insulating wall comprises the corner structure 300 placed at the corner of the storage tank 10, the anchor structure 100 including an anchor member, and the planar structures 200 placed on a planar portion of the storage tank 10. As such, the overall heat insulating layer can be formed by the corner structure 300, anchor structure 100, and planar structure 200.
The corner structure 300 and the anchor structure 100 serve to support the first and the second sealing walls 51, 52, whereas the planar structure 200 serves to support the load of the LNG exerted on the sealing walls 51, 52 without being directly coupled to the anchor structure 100 (see
Here, the corner structure 300 comprises the corner member 301 directly connected between the first and second sealing walls 51, 52 and the hull to secure the first and second sealing walls 51, 52 to the hull, and a heat-insulating material 303 integrally formed of polyurethane foam or reinforced polyurethane foam to surround the corner member 310.
Plywood 305 may be attached to one or both of the upper and lower ends of the heat-insulating material 303. Although the plywood is illustrated as being attached to the upper end of the corner structure 300 and the upper and lower ends of the planar structure 200 in
The corner structure 300 of this embodiment is secured to the inner surface of the storage tank 10 via the securing parts 312, 322 of the fixed member 310 and the connection member 320 of the corner member 301.
As described above, the securing parts 312, 322 are formed with the plurality of through-holes 312a, 322a at constant intervals, through which the stud bolts 61 previously secured to the inner surface of the storage tank 10 are inserted and fastened by the nuts 62.
In addition, the leveling plate 63 may be interposed between the plywood 305 and 205 attached to the lower surfaces of the heat-insulating materials 303 and 203 and the inner surface of the storage tank 10 to level off, if necessary, as well known in the art. Furthermore, washers may be interposed between upper surfaces of the securing parts 312, 322 and the nuts 62 fastened to the stud bolts 61, as well known in the art.
In addition, as described above, the first junction part 331 and the second junction part 332 are stepped to have the predetermined height difference therebetween on the top surface of the movable member 330 of the corner member. The first and second sealing walls 51, 52 are welded to the first and second junction parts 331, 332, respectively.
Although the sealing structure is illustrated as having the double structure of the first sealing wall 51 and the second sealing wall 52 herein, the sealing structure may be embodied by a multilayer structure of three or more layers.
As such, according to this invention, the plurality of stud bolts 61 are inserted into the plurality of through-holes 312a, 322a formed in the securing parts 312, 322 of the fixed member 310 and the connection member 320, and then fastened by the nuts 62, so that the fixed member 310 and the connection member 320 can be secured to the hull.
In addition, the movable member 330 joined to the sealing walls 51, 52 is able to be minutely moved in the linear direction with respect to the fixed members by the guide recesses 313 and the guide protrusions 333, and is welded to the connection member 320 via the welding slots 335, so that the sealing walls 51, 52 can be secured to the hull.
According to the present invention, since the fixed members 310 and the connection member 320 making up the corner member 301 are attached to the inner surface of the storage tank at a plurality of consecutive locations, and the movable member 330 can be linearly moved with respect to the fixed members 310, it is possible to absorb the stress resulting from the thermal deformation caused by the loading and unloading of the LNG or from the deformation of the hull caused by an external force such as waves.
In the above embodiments of the anchor member and the corner member, the fixed member and the connection member are described as being secured to the inner surface of the hull by bolts and nuts. However, it should be noted that the present invention is not limited to this structure, and that the securing parts of the fixed member and the connection member can be directly welded to the inner surface of the hull.
Furthermore, the anchor member may have other polygonal cone shapes, such as a triangular pyramid, a quadrangular pyramid, etc., as well as the frustoconical shape.
Although the sealing walls are formed from corrugated stainless steel used for, for example, GTT Mark-III type, according to the embodiments, the sealing walls may be formed from Inva steel used for GTT NO 96.
Furthermore, the present invention can be applicable to an LNG storage tank on land as well as in the hull of a marine vessel.
As apparent from the above description, the anchor structure and the corner structure of the LNG storage tank according to the present invention can provide a simple construction of the heat insulating wall and the sealing walls, and a simple connecting structure therebetween, enabling convenient assembly. In addition, the anchor structure and the corner structure of the invention increase the reliability of sealing while simplifying the assembled structure and manufacturing process of the storage tank, reducing the construction time of the storage tank. Furthermore, the anchor structure and the corner structure of the invention relieve mechanical stress exerted on the storage tank.
It should be understood that the embodiments and the accompanying drawings have been described for illustrative purposes, and the present invention is limited only by the following claims. Further, those skilled in the art will appreciate that various modifications, additions and substitutions are allowed without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0084298 | Sep 2006 | KR | national |
| 10-2006-0084299 | Sep 2006 | KR | national |
