KR101076265B1 - Rotation grinding apparatus and method for manufacturing stl cone structure of lng lng regasification ship - Google Patents

Abstract

The present invention relates to the manufacture of STL cone structure of LNG regasification vessel, and an object of the present invention is to provide a rotary grinding device of a structure particularly suitable for grinding removal of the part of the processing margin in the final manufacturing process of the STL cone structure.

According to the present invention, there is provided a rotary grinding device for manufacturing the STL cone structure of the LNG regasification vessel, the rotary grinding device according to the present invention, which is fixed to the bottom, the base located inside the STL cone structure, and A rotary support vertically rotatably mounted to the base, at least one rotary arm connected to the rotary support and adjacent to at least a portion of the STL cone structure, and provided near the end of the rotary arm, And a grinding tool for grinding at least a portion of the STL cone structure.

STL cone, machining margin, base, rotary support, rotary arm, grinding tool

Description

ROTATION GRINDING APPARATUS AND METHOD FOR MANUFACTURING STL CONE STRUCTURE OF LNG LNG REGASIFICATION SHIP}

1 is a view schematically showing a part of an LNG regasification ship, showing a state in which the seabed is docked to the turret.

2 is a cross-sectional view showing a turret installed in the LNG regasification vessel.

3 is a cross-sectional view showing an STL cone structure installed in the turret portion.

Figure 4 is an enlarged cross-sectional view showing an upper ring and a lower ring to which processing margin is granted for quality control according to an embodiment of the present invention.

5 to 7 are views for explaining the main manufacturing process of the STL cone structure according to an embodiment of the present invention.

8 is a view showing a rotary grinding device for collectively grinding the upper and lower rings given processing margin in the STL cone structure according to an embodiment of the present invention.

Description of the Related Art

2: turret 7: seabed

20: STL cone structure 21: block

200: STL cone 220: lower ring

260: upper ring C: chamfer

500: rotary grinding machine 510: base

520: rotation support 540: lower rotary arm

560: upper rotary arm 542, 562: grinding tool

The present invention relates to the manufacture of STL cone structures of LNG regasification vessels, and more particularly, to a rotary grinding apparatus and method of a structure particularly suitable for grinding removal of the processing margin portion in the final manufacturing process of the STL cone structure.

In recent years, the consumption of natural gas is rapidly increasing worldwide. Natural gas is transported in a gaseous state through onshore or offshore gas piping, or to a remote consumer while stored in an LNG carrier (especially an LNG carrier) in the form of liquefied natural gas. Liquefied natural gas is obtained by cooling natural gas at cryogenic temperatures (approximately -163 ° C), and its volume is reduced to approximately 1/600 of that of natural gas, making it well suited for long-distance transport through the sea.

The LNG Carrier is designed to unload liquefied natural gas to the land requirements by loading the liquefied natural gas into the sea, and for this purpose, an LNG storage tank (commonly referred to as a 'cargo') that can withstand the cryogenic temperature of the liquefied natural gas. It includes. Normally, such LNG transport ships unload liquefied natural gas in LNG storage tanks as they are liquefied, and the unloaded LNG is regasified by LNG regasification facilities installed on land and then transported through gas piping to consumers of natural gas. do.

Such onshore LNG regasification facility is known to be economically advantageous when installed in a place where there is a demand for natural gas because the natural gas market is well formed. However, in the case of natural gas demand where the demand for natural gas is seasonal, short-term or periodic, it is economically disadvantageous to install LNG regasification facilities on land due to the high installation cost and management cost.

In particular, if a land LNG regasification facility is destroyed due to a natural disaster or the like, even if an LNG carrier arrives at a required destination, the LNG cannot be regasified. Holding it.

Accordingly, for example, LNG regasification vessels have been developed for providing LNG regasification facilities in LNG carriers, regasifying liquefied natural gas at sea, and supplying natural gas obtained through regasification to land. Further, prior arts related to such LNG vessels include Korean Patent No. 0569621 (ExxonMobil Oil Corporation, Method and System for Gasification of Liquefied Natural Gas on Transport), and US Patent No. 6,546,739 (Exmar Offshore Company, Method and apparatus for offshore) LNG regasification, US Pat. No. 6,578,366 (Moss Maritime AS, Device for evaporation of liquefied natural gas), US Pat. No. 6,688,114 (El Paso Corporation LNG CARRIER, US Pat. No. 6,598,408 (El Paso Corporation, Method and apparatus for transporting) LNG), Korean Patent No. 0467963 (Kang Do-wook, R & G Alv operation method), US Patent No. 6,945,049 (Hamworthy KSE as, Regasification system and method), Korean Patent No. 0504237 (Daewoo Shipbuilding & Marine Co., Ltd., bottom) Vessels equipped with shielding means to block the openings), Korean Patent No. 0474522 (Daewoo Shipbuilding & Marine Engineering Co., Ltd., seawater heating system) Patent Publication No. 2003 -0090686 (Life Hoeg Unt.A.S., Ship and Unloading System), US Patent Publication No. 2005-0061002A (Shipboard regasification for LNG carriers with alternate propulsion plants), Korean Patent Publication No. 2004- 0105801 (Excelate Energy Limited Partnership, Improved LNG Carrier) and Korean Utility Registration No. 0410836 (Samsung Heavy Industries Co., Ltd., Liquefied Natural Gas Regasification System).

The LNG regasification vessel is equipped with a regasification facility, such as a vaporizer, for regasification of the liquefied natural gas stored in the LNG storage tank. The LNG regasification vessel is provided with a turret leading from the ship to the bottom of the ship, and the turret is provided with an STL cone docked with a seabed buoy. The turret and subsea buoy are one means of connecting the gas piping of the LNG regasification vessel to the subsea piping leading to the land.

Here, the STL cone and the structure including the same must be able to completely block the seawater when docking with the seabed buoy, therefore, the STL cone structure requires precise quality control during its design and manufacture. For the production of the STL cone structure, a process of cutting the metal sheet material, bending the cut metal sheet materials, and assembling the curved metal sheet material by a welding method is required. However, deformations such as sagging occur in the metal sheets in these processes, especially in the bending process. Member deformation of the STL cone structure caused during the manufacturing process results in an error above the tolerance that inhibits seabed buoyancy and reliable docking and prevents precise installation of the STL cone to the turret.

In the conventional STL cone structure, since the manufacture is completed without considering deformation of individual members, it is not easy to find a part that causes an error after the completion of manufacture, and therefore, conventionally, the machining of the STL cone structure after manufacturing is performed. Resolving errors was not easy, and even if it was possible, complicated and laborious efforts were required. Furthermore, there could be cases where the error could not be eliminated even through machining. In addition, in the past, the STL cone structure was generally manufactured by an outsourcing company, not a builder of an LNG regasification vessel, which causes more errors when installing the STL cone structure in ships, and also eliminates the error.

Accordingly, the present inventors set the processing margin in consideration of the deformation until the assembly process is completed through the curved processing process in advance in the part requiring quality control, and the part requiring the quality control as much as the predetermined processing margin after the assembly process is completed. It was proposed a technique for machining a, and in particular, to develop a rotary grinding device of the structure suitable for the machining.

Accordingly, it is an object of the present invention to provide an apparatus for simply and conveniently grinding parts of an STL cone structure which is located inside the STL cone structure completed until the assembling process and which requires quality control and a grinding method using the device. will be.

In addition, another object of the present invention, including an upper ring and a lower ring and located inside the STL cone structure completed by the assembly process, the device capable of simultaneously grinding the upper ring and the lower ring, which is essential for quality control; It is to provide a grinding method using the apparatus.

In order to achieve the above object, there is provided a rotary grinding device for manufacturing the STL cone structure of the LNG regasification vessel, the rotary grinding device according to the present invention, the base which is fixed to the bottom, located inside the STL cone structure A rotational support vertically rotatably mounted to the base, and at least one rotational arm connected to the rotational support and having an end thereof adjacent to at least a portion of the STL cone structure; And a grinding tool provided near an end of the rotating arm to grind at least a portion of the STL cone structure.

Preferably, the at least one rotary arm comprises a lower rotary arm and an upper rotary arm corresponding to the lower ring and the upper ring of the STL cone structure having the part of the processing margin. The lower rotary arm and the upper rotary arm are horizontally movable. It is preferable that the lower and upper guide blocks to be installed are provided, and grinding tools for grinding the lower and upper rings are respectively installed on the lower and upper guide blocks. In the lower guide block, for grinding the inclined lower ring, it is preferable that the grinding tool is installed to be able to slide up and down inclinedly. In the upper guide block, it is preferable that two grinding tools for grinding the inner, outer, and upper and lower ends of the upper ring are installed to be slidable up and down.

Preferably, the base is fixed horizontally to the floor by an anchor, and the rotary grinding apparatus according to the embodiment of the present invention is installed to correspond to each other at the bottom and the bottom of the lower rotary arm to support the lower rotary arm at a rotation radius. It is preferable to further include a rail device. The rail device preferably includes a roller fixed to the lower portion of the lower rotating arm and a rail fixed to the bottom by an anchor to form a circular path for guiding the roller.

Preferably, the lower arm and the upper arm are provided with a platform for an operator, and the rotation support is disposed to coincide with the central axis of the above-described STL cone structure, and the STL cone structure is fixed by a pedestal. It is preferably arranged away from the floor.

According to another aspect of the present invention, a grinding tool provided respectively near a base, a rotary support vertically installed to drive rotation to the base, lower and upper rotary arms connected to the rotary support, and end portions of the lower and upper rotary arms, respectively. Provided is a method for grinding a portion of the lower ring and the upper ring of the STL cone structure of a LNG regasification vessel using a rotary grinding device comprising a rotary grinding device comprising the base fixed to the base and the base thereof. Positioning the device in the inner center of the STL cone structure; Rotating the rotary support and the lower and upper rotary arms connected thereto to grind the lower ring and a portion of the upper ring with a grinding tool provided at the ends of the lower and upper rotary arms.

Example

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a state in which the seabed 7 is docked to the turret 2 of the LNG regasification vessel 1. Referring to FIG. 1, the LNG regasification vessel 1 is configured to regasify liquefied natural gas in a ship regasification facility including a vaporizer 4 and the like, and to supply the regasified gas to the land through a subsea pipeline or the like. It is composed. To this end, the LNG regasification vessel 1 includes a turret portion 2, and the STL cone structure 20 to which the seabed portion 7 is docked is installed below the turret portion 2. The seabed buoy 7 is connected to a riser 8, which is a flexible pipe connected to a pipeline and a pipeline of a seabed terminal (not shown) or a seabed. Accordingly, after docking of the seabed buoy 7, another riser (not shown) provided in the regasification facility of the LNG regasification ship 1 is connected to the seabed buoy 7 by a pipeline to deliver the regasified gas from the ship. It can be supplied as. At this time, the LNG regasification vessel 1 includes a traction winch 6 for raising the seabed buoy 7 by hooking the seabed buoy 7 to a wire rope called a 'messenger line'. Since this is not directly related to the present invention, a detailed description thereof will be omitted.

2 shows a turret portion 2 in which an STL cone structure 20 is installed, and FIG. 3 shows an enlarged view of the STL cone structure 20. As shown in Figures 2 and 3, the STL cone structure 20 according to the present embodiment is the STL cone 200 and the STL cone 200 that accommodates the subsea buoy (see Fig. 1) docked And a block 21 welded to the turret portion 2 of the ship at the same time as the support.

Referring to FIG. 3, the STL cone 200 generally has a cone shape corresponding to the sea bottom buoy 7 (see FIG. 1). The STL cone 200 includes a conical frame 240 that defines a space for accommodating the seabed buoy 7. The lower and upper ends of the conical frame 240 are provided with a lower ring 220 and an upper ring 260 that substantially face the seabed portion 7 (see FIG. 1) to contact and block the vessel from seawater. The upper ring 260 is vertically assembled, and a horizontal ring 262 and an inclined ring 264 supporting the upper ring 260 are provided around the upper ring 260. In the following description of the embodiment, the lower ring 220 and the upper ring 260, which is particularly required for quality control, will be described in more detail with respect to other parts.

4 (a) and (b) are views showing the processing margin applied to the lower ring 220 and the upper ring 260 described above.

Referring to Figure 4 (a), in the STL cone structure in which all the manufacturing process is completed, the lower ring 220 having a radius R1 is given a processing margin (R1-R2) in the design stage, the radius of R2 smaller than the radius R1 It is designed to have a radius. In the process of cutting, bending, etc., the metal plate material which is made after the design, an error (± d) is generated from the originally designed radius R2. However, since the lower ring 220 is designed to have a machining margin (R1-R2) larger than the error (± d), grinding the machining margin part with the dimensions obtained by subtracting or adding the error to the machining margin (R1-R2). By doing so, the lower ring 220 having the desired radius R1 can be manufactured. At this time, as shown by the virtual line in Fig. 4 (a), it is preferable that not only the inside of the lower ring 220 but also the outside in the area of the processing margin. At this time, since the radius of the cone-shaped lower ring 220 is different depending on the height, the reference point for determining the radius is predetermined.

Referring to FIG. 4B, in the STL cone structure 1 in which all the manufacturing processes are completed, the upper ring 260 having the radius R3 is provided with a processing margin R3-R4 at the design stage, so that the radius R3 is greater than the radius R3. It is designed to have a radius of small R4. In a process such as cutting, bending, welding, or the like of a metal plate material after the design, an error (± D) occurs from the originally designed radius R4. However, since the upper ring 260 is designed to have a machining margin (R3-R4) larger than the error (± D), grinding the machining margin part with the dimensions obtained by subtracting or adding the error to the machining margin (R3-R4). By doing so, the lower ring 260 having the desired radius R3 can be manufactured.

As indicated by the virtual line in Figure 4 (b), the area of the processing margin includes not only the inner side of the upper ring 260 but also the outer side, and also includes the top and bottom of the upper ring 260. Therefore, it is preferable that the upper part, the lower part and / or the outer margin of the upper ring 260 are also ground.

Hereinafter, the manufacturing method of the above-described STL cone structure 20 will be described in order.

In order to assemble the lower ring 220, in consideration of the processing margin of the lower ring 220 as described above, the metal plate material used for the assembly of the lower ring 220 is cut and curved is prepared. Then, a chamfer is formed in the metal plate member after the cutting of the metal plate member and before the processing of the cut metal plate member.

FIG. 5A is a perspective view illustrating a metal plate 220a in which a cutting process and a chamfer forming process are completed, and FIG. 5B is a cross-sectional view of FIG. 5A taken along I-I. As shown, the metal plate 220a is obtained by cutting long so as to form an arc of the lower ring 220 (see FIG. 3) through a later processing. Inclined chamfers (C) are formed on the upper and lower portions of the cut metal plate (220a) to face opposite to each other. The upper end and the lower end of the metal plate 220a are formed to have a relatively small thickness by the chamfer C, and the conical frame ( 240; see FIG. 3).

FIG. 6A is a plan view of the metal plate 220a that is bent in an arc by curving. By bending a straight metal sheet (shown by a virtual line), an arc-shaped metal sheet 220a as shown in Fig. 6A is prepared, and this arc-shaped metal sheet 220a is shown in Fig. 3. The circular lower ring 220 is formed in one arc. Then, the arc-shaped metal sheet 220a is connected to the side of the other arc-shaped metal sheet 220a neighboring by welding (W), as shown in FIG. Form a ring 220 (see FIG. 3). In this case, deflection deformation occurs in the arc-shaped metal sheet 220a by the curved processing, and this deflection deformation may be particularly severe in a portion where the chamfer C is formed.

In order to assemble the upper ring 260, in consideration of the processing margin of the upper ring 260, the metal plate used for the assembly of the upper ring 260 is cut and bent is prepared. Figure 7 (a) shows a metal plate 260a for the upper ring 260 prepared by cutting long, Figure 7 (b) shows a metal plate 260a bent in the form of an arc in a curved process. . As shown in (c) of FIG. 7, the arc-shaped metal sheet 260a obtained by curved processing is connected to another adjacent metal sheet 260a by welding (W), and the above-described upper ring ( 260 (see FIG. 3). Although not shown in detail, other metal sheets are also cut and bent to prepare the above-described conical frame 240 (see FIG. 3).

Then, in each of the lower ring 220, the upper ring 260 and the conical frame 240, the arcuate unit metal sheets and the metal sheets forming the block 21 supporting them are assembled by welding, An STL cone structure 20 as shown in FIG. 3 is obtained. At this time, each of the lower ring 220 and the upper ring 260 is connected to the side of the metal plate (220a or 260a) by welding in advance, which has already been described with reference to FIGS. 6 and 7.

Then, for the STL cone structure 20 having the integrated block 21 and the STL cone 200, grinding is performed on the parts to which the working margin is given, and the grinding is performed by rotary grinding described below. By the device 800.

8 illustrates a rotary grinding apparatus 500 according to an embodiment of the present invention provided to simultaneously grind the lower ring 220 and the upper ring 260 of the STL cone structure 20 described above. As shown in FIG. 8, the rotary grinding apparatus 500 according to the present embodiment has a lower ring 220 and an upper ring 260 of the STL cone 200 at an inner center of the STL cone of the STL cone structure 20. It is arranged to grinding. At this time, the bottom of the block 21 of the STL cone structure 20 is supported by columnar pedestals 501.

The rotary grinding apparatus 500 according to the embodiment of the present invention includes a horizontal base 510 fixed to the floor (ie, workshop floor) by the anchors 511. In addition, one rotation support 520 is vertically rotatably installed by the power source 521 at the center of the base 510. Meanwhile, the lower rotation arm 540 and the upper rotation arm 560 are connected to the rotation support 520 in the radial direction, respectively, to rotate together with the rotation support 520. In addition, an end of each of the lower rotary arm 540 and the upper rotary arm 560 is adjacent to the lower ring 220 and the upper ring 260 of the STL cone 200, each of the ends of the lower Grinding tools for grinding the processing margins of the ring 220 and the upper ring 260 are respectively installed. In this case, the rotation support 520 is disposed to coincide with the central axis of the STL cone structure 20 described above.

The lower grinding tool 542 connected to the lower rotary arm 540 moves up and down in an inclined state by the inclined guide part 544a provided to be inclined on the outer surface of the lower guide block 544, and the inclined lower ring 220. The surface of can be reliably ground. The guide block 544 is slidably installed in the lower rotating arm 540 in a horizontal direction by a horizontal guide part 544b to grind the surface of the lower ring 220 to a desired thickness. On the other hand, the lower rotary arm 540 is provided with a platform 541 so that the operator can climb.

Grinding tool 562 is also installed in the upper rotary arm 560, the grinding tool 562 of the upper rotary arm 560 in the horizontal direction along the upper rotary arm 560 by a horizontal guide portion 564b. The upper guide block 564 is slidably moved. In addition, the upper guide block 564 is provided with a vertical guide portion 564a for moving the grinding tool 562 up and down. Accordingly, the grinding tool 562 is to grind the upper and lower ends of the upper ring 260 and the inner and outer peripheral surfaces of the upper ring 260 while moving vertically and horizontally by the guide parts 564a and 564b. I can process it. In addition, the lower rotary arm 560 is also provided with a platform 561 so that the operator can climb. In addition, the ladder 521 is provided on the rotary shaft 520 so that an operator can climb up to the platform 561 of the lower rotary arm 260.

In addition, the rotary grinding apparatus 500 according to the present embodiment further includes a rail device 570 installed on the bottom and the bottom of the lower rotary arm 540 to support the lower rotary arm 540 at a radius of rotation. do. The rail device 570 is fixed to the bottom by a roller 572 fixed to the lower portion of the lower rotary arm 540 and the anchor 574a, a circular path for guiding the roller 572 It includes a rail 574 to form a. Here, the rail device 570 is configured such that the roller 572 is installed so that the sliding drive up and down with respect to the rail 574 is installed, the height is adjusted.

The rotary grinding device 500 described above is preferably rotated without the phenomenon that the lower rotary arm 540 and the upper rotary arm 560 integrated with the lower rotary arm 540 by the rotary support 520 is not oriented in one direction. As a result, the grinding tools provided at the ends of the rotary arms 540 and 560 can reliably grind the part of the STL cone. Here, since the structure for grinding the part of the processing margin of the STL cone has already been described in the description of FIG. 4, the description thereof will be omitted.

 While the invention has been described above with reference to specific embodiments, various modifications, changes, or modifications may be made in the art within the spirit and scope of the appended claims, and thus, the foregoing description and drawings illustrate It should be construed as illustrating the present invention, not limiting the technical spirit of the invention.

According to the present invention, the STL cone or the STL cone structure can be precisely manufactured and installed on a ship by the grinding process of convenient and precise final stage. In addition, it is possible to precisely form the upper and lower rings where quality control is particularly required, enabling the STL cone or its structure to reliably dock with the seabed.

In addition, according to the present invention, the upper and lower rings of the STL cone structure provided with the processing margin due to the necessity of the quality control can be collectively ground, thereby making it simpler, more convenient, and faster. It can contribute greatly to manufacturing STL cone structure.

Claims (15)

delete delete A base fixed to the floor and positioned inside the STL cone structure; A rotary support vertically installed to the base to be rotatable; At least one rotating arm connected to the rotating support and having an end thereof adjacent to at least a portion of the STL cone structure; A grinding tool provided near an end of the rotary arm, for grinding at least a portion of the STL cone structure; The at least one rotary arm is composed of a lower rotary arm and an upper rotary arm corresponding to the lower ring and the upper ring of the STL cone structure having a processing margin portion, The lower rotating arm and the upper rotating arm are provided with lower and upper guide blocks which are horizontally movable, and grinding tools for grinding the lower ring and the upper ring are installed on the lower and upper guide blocks, respectively. Rotary grinding device for manufacturing STL cone structure of LNG regasification vessel. The rotary grinding device according to claim 3, wherein the lower guide block has a grinding tool installed on the lower guide block so as to be slidable up and down in an inclined manner to grind the inclined lower ring. The rotary grinding device according to claim 3, wherein a grinding tool for grinding the inner, outer, and upper and lower ends of the upper ring is installed to be slidable up and down on the upper guide block. A base fixed to the floor and positioned inside the STL cone structure; A rotary support vertically installed to the base to be rotatable; At least one rotating arm connected to the rotating support and having an end thereof adjacent to at least a portion of the STL cone structure; A grinding tool provided near an end of the rotary arm, for grinding at least a portion of the STL cone structure; The base is a rotary grinding device for manufacturing the STL cone structure of the LNG regasification vessel, characterized in that fixed to the floor horizontally by the anchor. A base fixed to the floor and positioned inside the STL cone structure; A rotary support vertically installed to the base to be rotatable; At least one rotating arm connected to the rotating support and having an end thereof adjacent to at least a portion of the STL cone structure; A grinding tool provided near an end of the rotary arm, for grinding at least a portion of the STL cone structure; The at least one rotary arm is composed of a lower rotary arm and an upper rotary arm corresponding to the lower ring and the upper ring of the STL cone structure having a processing margin portion, Rotating grinding device for manufacturing the STL cone structure of the LNG regasification ship, characterized in that it further comprises a rail device installed on the bottom and the bottom of the lower rotary arm to support the lower rotary arm at a rotation radius. The method of claim 7, wherein the rail device is characterized in that it comprises a roller fixed to the lower portion of the lower rotary arm and a rail fixed to the bottom by an anchor to form a circular path for guiding the roller Rotary grinding device for manufacturing STL cone structure of LNG regasification vessel.  A base fixed to the floor and positioned inside the STL cone structure; A rotary support vertically installed to the base to be rotatable; At least one rotating arm connected to the rotating support and having an end thereof adjacent to at least a portion of the STL cone structure; A grinding tool provided near an end of the rotary arm, for grinding at least a portion of the STL cone structure; The at least one rotary arm is composed of a lower rotary arm and an upper rotary arm corresponding to the lower ring and the upper ring of the STL cone structure having a processing margin portion, The lower rotary arm and the upper rotary arm is a rotary grinding device for manufacturing the STL cone structure of the LNG regasification vessel, characterized in that the platform provided for the operator. A base fixed to the floor and positioned inside the STL cone structure; A rotary support vertically installed to the base to be rotatable; At least one rotating arm connected to the rotating support and having an end thereof adjacent to at least a portion of the STL cone structure; A grinding tool provided near an end of the rotary arm, for grinding at least a portion of the STL cone structure; The rotary support is a rotary grinding device for manufacturing the STL cone structure of the LNG regasification vessel, characterized in that arranged to match the central axis of the STL cone structure. A base fixed to the floor and positioned inside the STL cone structure; A rotary support vertically installed to the base to be rotatable; At least one rotating arm connected to the rotating support and having an end thereof adjacent to at least a portion of the STL cone structure; A grinding tool provided near an end of the rotary arm, for grinding at least a portion of the STL cone structure; The STL cone structure is a rotary grinding device for manufacturing the STL cone structure of the LNG regasification ship, characterized in that disposed by a pedestal from the bottom at a predetermined interval. delete Using a rotary grinding device comprising a base, a rotary support vertically installed to drive rotation to the base, lower and upper rotary arms connected to the rotary support, and grinding tools provided respectively near end portions of the lower and upper rotary arms. As a method of grinding the lower ring and part of the upper ring of the STL cone structure of the LNG regasification vessel, Securing the base to the floor and positioning a rotary grinding device comprising the base at an inner center of the STL cone structure; Rotating the rotary support and lower and upper rotary arms connected thereto, and grinding the lower ring and a portion of the upper ring with a grinding tool provided at the ends of the lower and upper rotary arms. Rotary grinding method for manufacturing STL cone structure of LNG regasification vessel. Using a rotary grinding device comprising a base, a rotary support vertically installed to drive rotation to the base, lower and upper rotary arms connected to the rotary support, and grinding tools provided respectively near end portions of the lower and upper rotary arms. As a method of grinding the lower ring and part of the upper ring of the STL cone structure of the LNG regasification vessel, Securing the base to the floor and positioning a rotary grinding device comprising the base at an inner center of the STL cone structure; Rotating the rotary support and lower and upper rotary arms connected thereto to grind the lower ring and a portion of the upper ring with a grinding tool provided at the ends of the lower and upper rotary arms, The grinding tool is configured to move in a horizontal direction and an inclined vertical direction on the lower rotating arm, thereby rotating the slant cone structure of the LNG regasification vessel, characterized in that the inclined surface of the lower ring is ground to a desired thickness. Grinding method. Using a rotary grinding device comprising a base, a rotary support vertically installed to drive rotation to the base, lower and upper rotary arms connected to the rotary support, and grinding tools provided respectively near end portions of the lower and upper rotary arms. As a method of grinding the lower ring and part of the upper ring of the STL cone structure of the LNG regasification vessel, Securing the base to the floor and positioning a rotary grinding device comprising the base at an inner center of the STL cone structure; Rotating the rotary support and lower and upper rotary arms connected thereto to grind the lower ring and a portion of the upper ring with a grinding tool provided at the ends of the lower and upper rotary arms, The grinding tool is configured to move in the horizontal and vertical directions on the upper rotary arm, so that the inner and outer surfaces and the upper and lower ends of the upper ring are ground to a desired height and thickness for manufacturing the STL cone structure of the LNG regasification vessel. Rotary grinding method.

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