LNG ship side auxiliary hole segmented lifting ring and mounting method thereof

Abstract

The invention discloses an LNG (Liquefied Natural Gas) ship side auxiliary hole segmented lifting ring and a mounting method thereof, and the lifting ring comprises a base material which is an inverted L-shaped plate; the hanging hole is formed in the center of the long edge of the base metal. And the rectangular lifting holes are formed in the short edges of the base metal. The arc grooves comprise the first arc groove formed in the tail end of the long edge of the base material and the second arc groove formed in the intersection position of the long edge and the short edge of the base material. By changing the original lifting ring type, the number of the lifting rings is reduced on the premise that operation is not affected, subsequent mounting work of redundant lifting rings is avoided, the welding workload is reduced, the mounting and dismounting efficiency is improved, and labor hour loss is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of shipbuilding, and in particular to a sectional lifting ring for a process hole on a side of an LNG ship and an installation method thereof. Background Art

[0002] During the construction of LNG ships, it is usually necessary to cut the side sections from the modules during the hull module loading stage, and weld 4 A-type lifting rings on the outer plates of the sections. After the sections are lifted out, the side process holes are reserved to facilitate the entry and exit of personnel and materials. After the installation of the insulation layer of the cargo tank is completed, the side sections are lifted to the side process holes. At this time, the previous sections must be turned over, cut, extended, and other pre-processed before lifting. The lifting of the sections must meet both the vertical lifting of the crane and the side pulling force. At this time, the design of the lifting ring is very important.

[0003] In the prior art, the number of lifting rings and the location of the lifting rings during the segment lifting are determined according to the segment shape and the center of gravity. The lifting of a side segment often requires the welding of 8-10 lifting rings or even more. For the side segment, the installation of the lifting rings must meet the force requirements and reduce the damage to the hull. After the welding of the lifting rings is completed, the welding parts of the lifting rings should also be subjected to PT and MT flaw detection. In the later stage of the lifting ring removal, all the lifting rings need to be cut, polished, and then the MT flaw detection is performed on the lifting ring positions, which makes the installation and removal of the lifting rings time-consuming and labor-intensive. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a segmented lifting ring for the process hole on the side of an LNG ship and an installation method thereof. By changing the original lifting ring type, the number of lifting rings is reduced without affecting the operation, thereby avoiding the subsequent installation of redundant lifting rings, reducing the welding workload, improving the efficiency of installation and removal, and reducing the loss of working hours.

[0005] The object of the present invention is achieved through the following technical scheme: a LNG ship side process hole segmented lifting ring, comprising:

[0006] The parent material is an inverted "L" shaped plate.

[0007] The hanging hole is set at the center of the long side of the base material.

[0008] Rectangular hanging holes are set on the short side of the base material.

[0009] The arc groove comprises a first arc groove arranged at the end of the long side of the base material and a second arc groove arranged at the intersection of the long side and the short side of the base material.

[0010] Preferably, a crack-stop hole is provided at one end of the second arc groove close to the short side of the base material.

[0011] Preferably, a tooth-like structure is provided on a side of the short side of the base material close to the second arc groove.

[0012] Preferably, the hanging holes arranged on the long sides of the mother material include a first hanging hole and a second hanging hole.

[0013] Preferably, the base material is made of E-grade steel.

[0014] Preferably, the segmented lifting rings of the process holes on the side of the LNG ship are welded to the segmented T-rows or bulb flat steels on the side.

[0015] In addition to providing a LNG ship side process hole segmented lifting ring, the present invention further provides an installation method of the above-mentioned lifting ring, which is as follows:

[0016] Step 1: Weld the section lifting rings of the process holes on the side of the LNG ship to the section T-row or bulb flat steel on the side, lift the section to the dock and use the A-type lifting ring to turn the section over, and cut the A-type lifting ring after the section is turned over;

[0017] Step 2: After the scaffolding of the LNG carrier's liquid cargo tank is removed, before lifting, install lifting rings corresponding to the positions of the side section lifting rings at the T-row frame above the side process hole. During lifting, the lifting rings at the corresponding positions of the section and the hull are used in pairs.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] The present invention provides a LNG ship side process hole segmented lifting ring and its installation method. The segmented segmented by the lifting ring is a semi-stereoscopic side segmented segmented, which is a segmented segmented at the side process hole in the later stage of liquid cargo tank sealing of LNG ship construction. The segmented segment is provided with an A-type lifting ring and a special lifting ring of the present invention. The lifting ring provided in the present invention is a structural lifting ring, which is installed on the T-shaped frame of the process hole segmented, and the lifting holes for the hand chain hoist and the lifting hook are reserved on the lifting ring. The use of the lifting ring provided by the present invention can effectively avoid the need to weld two lifting rings at the same time during the lifting of the side segmented, because the needs of the hand chain hoist and the lifting hook are met at the same time, which reduces the loss of man-hours, reduces the damage to the segmented parent material, makes the lifting point more accurate and effective, and improves the safety of lifting. The present invention can reduce the number of welding of the lifting rings for the side segmented lifting, reduces the damage to the hull caused by welding and oxygen cutting of multiple lifting rings, and can also be used for the lifting of the process holes on the side of other ship types in the sealing stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the segmented lifting ring structure of the process hole on the side of the LNG ship in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the installation of a single lifting ring at a T row in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the use of the lifting ring in the embodiment of the present invention;

[0023] Figure 4 It is a schematic side view of the side section in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the final state of the side segmented dock before hoisting in an embodiment of the present invention;

[0025] Figure 6 It is a side section cross-sectional view in an embodiment of the present invention;

[0026] Figure 7 It is a schematic diagram of the side section lifting in an embodiment of the present invention.

[0027] In the figure, 1 is the first arc groove; 2 is the second arc groove; 3 is the rectangular hanging hole; 4 is the first hanging hole; 5 is the second hanging hole; 6 is the crack-stopping hole; 7 is the tooth-like structure; and 8 is the fixing rod. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0029] The technical solution of the present invention provides a LNG ship side process hole segmented lifting ring, comprising:

[0030] The parent material is an inverted "L" shaped plate;

[0031] The hanging hole is set at the center of the long side of the parent material;

[0032] The rectangular hanging hole 3 is arranged on the short side of the base material.

[0033] The arc groove comprises a first arc groove 1 arranged at the end of the long side of the base material and a second arc groove 2 arranged at the intersection of the long side and the short side of the base material.

[0034] like Figure 1 As shown, in one embodiment of the present invention, a crack-stopping hole 6 is provided at one end of the second arc groove 5 close to the short side of the base material.

[0035] In one embodiment of the present invention, a toothed structure 7 is provided on a side of the short side of the base material close to the second arc groove 2 .

[0036] In one embodiment of the present invention, the hanging holes arranged on the long sides of the base material include a first hanging hole 4 and a second hanging hole 5 .

[0037] In one embodiment of the present invention, the parent material is made of E-grade steel, which can meet the requirements of simultaneous hooking operation of the hand winch and the lifting equipment during lifting.

[0038] In one embodiment of the present invention, the LNG ship side process hole segmented lifting ring is welded on the side segment T row or bulb flat steel. The installation area belongs to the semi-stereoscopic side segment, which is located on the side of the ship in the later stage of ship construction. The installation position of the lifting ring needs to avoid the segment frame while meeting the pulling force upward and toward the inside of the hull. There are A-type lifting rings and Figure 1 to Figure 2 The lifting ring shown is a structural lifting ring. In this embodiment, the parent material is 560mm long, 200mm wide, and 22mm thick. There are two first lifting holes 4 and second lifting holes 5 with R 20mm in the middle of the lifting ring, and a rectangular lifting hole 3 with a size of 90mm*140mm is provided at the other end. The first arc 1 and the second arc 2 with R50mm and R70mm are provided at the end and the middle of the lifting ring, respectively, and a crack stop hole 6 (stress release) is provided to effectively reduce the damage of the lifting ring to the hull weld and the T-shaped frame while meeting the lifting strength. When lifting the sections, the sections need to be lifted to the specified height and then pulled into the hull from the side. Therefore, the lifting ring needs to meet the upward pulling force of the crane while meeting the pulling force from the outside to the inside of the hand winch. In order to prevent the sliding speed of the sections from being too fast during lifting due to the tilt of the ship, we often add a reverse pulling force and provide a position for hooking at the same time at the lifting ring.

[0039] In addition to providing a LNG ship side process hole segmented lifting ring, the technical solution of the present invention further provides an installation method of the above-mentioned lifting ring, which is as follows:

[0040] Step 1: Weld the section lifting rings of the process holes on the side of the LNG ship to the section T-row or bulb flat steel on the side, lift the section to the dock and use the A-type lifting ring to turn the section over, and cut the A-type lifting ring after the section is turned over;

[0041] Step 2: After the scaffolding of the LNG carrier's liquid cargo tank is removed, before lifting, install lifting rings corresponding to the positions of the side section lifting rings at the T-row frame above the side process hole. During lifting, the lifting rings at the corresponding positions of the section and the hull are used in pairs.

[0042] like Figures 3 to 7As shown, in one embodiment of the present invention, the lifting ring is installed on the side process hole segment of the LNG ship, which is a side semi-stereoscopic segment, and the hull segment is a liquid cargo tank process hole segment located on the starboard side of the ship reserved during the loading of a conventional ship. The side segment is provided with an A-type lifting ring and the lifting ring provided in this embodiment. When the segment is still on the tire frame, the relevant technicians mark the side segment cutting line and the workers cut it. At this time, it is necessary to weld the A-type lifting ring on the side segment for lifting the side segment. At this time, the side segment belongs to the deck facing down. The lifting ring provided in this embodiment is welded on the T-row or bulb flat steel of the side segment. After the segment is lifted to the dock, this lifting ring and the A-type lifting ring can be used at the same time to turn the segment over for pre-processing. After the segment is turned over, the A-type lifting ring is cut. The lifting ring provided in this embodiment is reserved for the later segment lifting.

[0043] Specifically, four lifting rings in this embodiment are installed on the hull and the segment respectively. The lifting rings at the corresponding positions of the segment and the hull are in pairs. The arc design of the first arc groove 1 and the second arc groove 2 can avoid the fillet weld between the hull and the T row during the installation and removal of the lifting ring, reducing the damage to the hull weld caused by the installation of the lifting ring. The first lifting hole 4 is used for the lifting hook during the segment lifting stage. The rectangular lifting hole 3 can add a lateral tension to the segment while meeting the vertical lifting requirement. The second lifting hole 5 is used to increase the lifting strength when the lifting rings are welded on the segment and the hull. The crack stop hole 6 is used to release the stress of the lifting ring. The design of the toothed structure 7 can reduce the damage to the T row caused by welding. When the lifting ring is made, rubber pads are set at the rectangular lifting hole 3, the first lifting hole 4 and the second lifting hole 5 to reduce the wear of the lifting ring on the sling during lifting. During the installation stage of the lifting ring, due to the provision of the first arc groove 1 and the second arc groove 2, the lifting ring and the T-row joint position can be welded to increase the strength of the lifting ring.

[0044] During the assembly of ship sections, it is necessary to cut the side sections from the assembly sections in advance. In order to facilitate the lifting of the sections by lifting equipment, four A-type lifting rings need to be welded on the deck in advance. When the ship is built in the later stage, the sections are transported to the dock, and four lifting rings provided in this embodiment are installed at the corresponding positions of the T row. Before the final lifting of the sections, the sections are rotated and turned over by the lifting rings, and the sections themselves are pre-treated before lifting, such as cutting off the A-type lifting rings, painting the cargo hold surface, opening bevels at the frame, extending, and grinding.

[0045] In actual production, in order to shorten the loading cycle, the side segments are often hoisted and assembled before the segments are cut. The side segments need to be cut and hoisted on the ship. At this time, the hoisting ring provided in this embodiment can be used to pull the segments out of the side process holes. Figure 6 To lift the sections out for the front section view, lifting rings are installed at the corresponding positions of the hull and sections.

[0046] After the scaffolding of the liquid cargo tank of the LNG ship is dismantled, the corresponding compartments are hoisted on the side sections according to the production progress of the workshop and the production plan formulated by the production department. Before hoisting, four lifting rings corresponding to the positions of the side section lifting rings are installed at the T-row structure above the side process hole. During hoisting, the lifting rings at the corresponding positions of the section and the hull are used in groups of two. Before hoisting, four hand chain hoists for pulling the sections are hung at the rectangular lifting hole 3 positions, and the lifting slings are fixed at the rectangular lifting hole 3 positions on the side section near the outer plate (to withstand a lifting upward pulling force), and the first lifting hole 4 is used to fix the hook of the hand chain hoist at the process hole (to withstand a pulling force on the side of the hand chain hoist). After the side section welding is completed, the special lifting rings on the hull and the sections are cut off, the sections are cut flat and polished, and the roots are left on the hull. Specifically, Figure 7 shown.

[0047] The LNG ship side process hole segmented lifting ring and its installation method provided by the present invention have the following advantages:

[0048] (1) It reduces the number of lifting rings to be installed, and also reduces the labor and materials consumed in the installation, cutting, and flaw detection of the lifting rings, making it safer and more reliable.

[0049] (2) The problem of the lifting ring having to meet the requirements of the upward lifting of the lifting equipment and the pulling force of the hand winch on the hull during the segmented lifting is solved.

[0050] (3) It is convenient to turn over the side segments, and the segments can be turned over by the lifting ring provided by the present invention.

[0051] (4) The installation of the lifting ring is convenient and simple, the welding is convenient, the welding position space is large, the angle is good, the welding quality is improved, and the welding time is shortened.

[0052] (5) The lifting ring provided by the present invention can meet the needs of side segmented lifting of various ships.

[0053] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A sectional lifting ring for a process hole on the side of an LNG ship, characterized in that: The lifting ring comprises: The parent material is an inverted "L" shaped plate; The hanging hole is set at the center of the long side of the parent material; The rectangular hanging hole (3) is arranged on the short side of the parent material. The circular arc groove comprises a first circular arc groove (1) arranged at the end of the long side of the base material and a second circular arc groove (2) arranged at the intersection of the long side and the short side of the base material.

2. The LNG ship side process hole segmented lifting ring according to claim 1, characterized in that: A crack-stop hole (6) is provided at one end of the second arc groove (5) close to the short side of the parent material.

3. The LNG ship side process hole segmented lifting ring according to claim 2, characterized in that: A tooth-shaped structure (7) is provided on the side of the short side of the parent material close to the second circular arc groove (2).

4. The LNG ship side process hole segmented lifting ring according to claim 3, characterized in that: The hanging holes arranged on the long sides of the parent material include a first hanging hole (4) and a second hanging hole (5).

5. The LNG ship side process hole segmented lifting ring according to claim 4, characterized in that: The parent material is made of E-grade steel.

6. The LNG ship side process hole segmented lifting ring according to claim 5, characterized in that: The LNG ship side process hole segmented lifting rings are welded on the side segmented T-rows or bulb flat steels.

7. A method for installing a segmented lifting ring for a process hole on the side of an LNG ship, characterized in that: The method is used to install the segmented lifting ring of the process hole on the side of the LNG ship according to any one of claims 1 to 6, and is specifically as follows: Step 1: Weld the section lifting rings of the process holes on the side of the LNG ship to the section T-row or bulb flat steel on the side, lift the section to the dock and use the A-type lifting ring to turn the section over, and cut the A-type lifting ring after the section is turned over; Step 2: After the scaffolding of the LNG carrier's liquid cargo tank is removed, before lifting, install lifting rings corresponding to the positions of the side section lifting rings at the T-row frame above the side process hole. During lifting, the lifting rings at the corresponding positions of the section and the hull are used in pairs.

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