Deepwater PLET release device

Abstract

The deepwater PLET releasing device comprises a fixing main frame and a hanging bracket main beam, the whole fixing main frame is in a U shape, the top of one end of the fixing main frame is rotationally connected with one end of the hanging bracket main beam, a ladder platform is arranged at the top of the hanging bracket main beam, and a variable-amplitude oil cylinder assembly is rotationally matched with the bottom of the inner wall of the fixing main frame; the output end of the variable-amplitude oil cylinder assembly is rotationally connected with the bottom of the hanging bracket main beam, one end of the hanging bracket main beam is rotationally matched with a lifting oil cylinder assembly, and a left-right adjusting device and a forward adjusting device are arranged in the hanging bracket main beam. By means of the left-right adjusting device and the forward adjusting device, when the hanging bracket main beam is obliquely hoisted, the forward adjusting device supports a hoisted object through a stop lever, the left-right adjusting device pushes the hoisted object to adjust the position, hoisting is kept stable, and the adjustable design can adapt to different working conditions; and normal operation and special heavy load are considered.

Description

Technical Field

[0001] This invention relates to the field of marine engineering lifting equipment technology, specifically to a deep-water PLET release device. Background Technology

[0002] In marine engineering and ship lifting operations, deep-water PLET release devices, as core load-bearing equipment, must withstand complex marine environmental loads and multi-condition operational pressures over long periods. Their performance directly determines operational safety and efficiency. As marine development moves towards the deep sea, the operating environment becomes increasingly harsh, and the technical shortcomings of existing deep-water PLET release devices are becoming increasingly apparent, making it difficult to meet the requirements for high reliability, long lifespan, and multi-condition adaptability.

[0003] Current PLET (Plug and Thruster) release devices are not adequately designed for the dynamic load characteristics of marine operations, resulting in insufficient overall stability. They are prone to swaying under normal operating conditions and may even experience localized instability under special conditions. Furthermore, existing PLETs are mostly designed for single operating conditions, failing to accommodate various scenarios such as normal operations, special heavy loads, and unlimited navigation area deployments, thus limiting operational flexibility. The marine environment, characterized by high salt spray, high humidity, and strong ultraviolet radiation, places extremely high demands on the corrosion resistance of the PLET steel structure. Existing PLETs generally employ single-coating or simple composite coating designs, without differentiated protection schemes for different surface functions. Therefore, there is an urgent need to design a deep-sea PLET release device to address these issues. Summary of the Invention

[0004] The purpose of this invention is to provide a deep-water PLET release device to overcome the aforementioned shortcomings in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The deep-water PLET release device includes a fixed main frame and a gantry main beam. The fixed main frame is U-shaped. The top of one end of the fixed main frame is rotatably connected to one end of the gantry main beam. A ladder platform is provided on the top of the gantry main beam. A luffing cylinder assembly is rotatably fitted to the bottom of the inner wall of the fixed main frame. The output end of the luffing cylinder assembly is rotatably connected to the bottom of the gantry main beam. A lifting cylinder assembly is rotatably fitted to one end of the gantry main beam. A left-right adjustment device and a forward adjustment device are provided inside the gantry main beam. The surfaces of the fixed main frame, gantry main beam, ladder platform, left-right adjustment device, and forward adjustment device are all provided with a composite anti-corrosion structure. The left and right adjustment device includes two adjustment supports respectively installed at the bottom of the left and right sides of the main beam of the hanger, an adjustment cylinder set in the adjustment support, and an adjustment rod installed at the output end of the adjustment cylinder. The two adjustment rods are symmetrically distributed. The forward adjustment device includes two forward push cylinders set in the main beam of the hanger, a rotating shaft rotatably engaged at the output end of the forward push cylinder, and a stop rod rotatably engaged between the two rotating shafts.

[0006] Furthermore, the fixed main frame includes a base, a plurality of base mounting plates disposed around the base, two main beam supports mounted on the top of one end of the base, a hinge assembly disposed on the top of the main beam supports, and two shelf brackets mounted on the top of the other end of the base, wherein the top of the shelf brackets is provided with a limit groove.

[0007] Furthermore, the main beam of the hanger includes two main beams, multiple connecting beams installed between the two main beams, two legs respectively installed at one end of the two main beams, a head beam installed at one end of the two legs, and a head connecting beam installed between the two legs. The legs are distributed obliquely and symmetrically. The bottom of one end of the main beam is rotatably connected to the hinge assembly. The lifting cylinder assembly is rotatably fitted to the top of the head beam. Two luffing cylinder assemblies are provided, and the output end of the luffing cylinder assembly is rotatably connected to the bottom of the main beam.

[0008] Furthermore, the ladder platform includes multiple platforms respectively installed on the opposite outer sides of the two main beams, multiple large platforms installed between the two support legs, two first straight ladders respectively set on the opposite outer sides of the two support frames, an intermediate platform set on the first straight ladders, and two second straight ladders respectively set on the opposite outer sides of the two main beams, the second straight ladders corresponding to the intermediate platforms.

[0009] Furthermore, both the platform and the large platform have drainage holes on their tops, and multiple guardrails are installed around the perimeter of the platforms.

[0010] Furthermore, bushings are provided between the rotating shaft and the output end of the front push cylinder and one end of the stop rod, and retaining rings are provided between the output end of the front push cylinder and one end of the stop rod.

[0011] Furthermore, a mounting base is provided on the top of the main beam of the hanger, the adjusting support is installed on the top of the mounting base, flange gaskets are installed on the opposite ends of the two adjusting rods, a wear-resistant gasket is installed on one side of the flange gasket, a support frame is installed on the top of the main beam of the hanger, and the adjusting rod is slidably engaged on the top of the support frame.

[0012] Furthermore, an extension base is installed between the adjusting support and the mounting base. The extension base is bolted to both the adjusting support and the mounting base. The extension base has different height specifications. A support frame extension seat is installed between the support frame and the main beam of the hanger. The support frame extension seat is bolted to the support frame. The support frame extension seat has different height specifications.

[0013] Furthermore, the composite anti-corrosion structure includes an outer surface coating, an inner surface coating, a galvanized part coating, and a flange mating surface coating. The outer surface coating is a three-layer structure consisting of an epoxy zinc-rich primer, an epoxy thick-film intermediate paint, and a polyurethane thick-film topcoat. The inner surface coating is an epoxy thick-film primer. The galvanized part coating is a three-layer structure consisting of an epoxy primer, an epoxy intermediate paint, and a polyurethane topcoat. The flange mating surface coating is an inorganic zinc-rich primer.

[0014] Furthermore, the outer surface coating and the inner surface coating of the fixed main frame and the main beam of the hanger are respectively coated. Existing high-strength bolts are used at the assembly and connection of each component of the fixed main frame and the main beam of the hanger. The surface of the high-strength bolts is treated with galvanized coating. The flange connection of the device is coated with the flange mating surface coating.

[0015] In the above technical solution, the deep-water PLET release device provided by the present invention has the following beneficial effects: With its left-right and forward adjustment devices, the system allows for adjustable lifting of the main beam at an angle. The forward adjustment device uses a forward-pushing cylinder to move a stop bar, supporting the load and adjusting it to a suitable lower position for lifting. The two adjustment cylinders of the left-right devices use adjusting rods to adjust the position of the load, maintaining lifting stability. This adjustable design adapts to different working conditions, accommodating normal operations, special heavy loads, and unrestricted navigation deployments, thus improving the system's operational flexibility. The composite anti-corrosion structure covers all functional surfaces, adapting to the corrosive marine environment, extending service life, and reducing rust and corrosion at flange contact surfaces and bolt connections. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0017] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the deep-water PLET release device of the present invention.

[0018] Figure 2 This is a schematic diagram of the main beam structure provided for an embodiment of the deep-water PLET release device of the present invention.

[0019] Figure 3 This is a schematic diagram of the ladder platform structure provided in an embodiment of the deep-water PLET release device of the present invention.

[0020] Figure 4 This is a schematic diagram of the lifting cylinder assembly provided in an embodiment of the deep-water PLET release device of the present invention.

[0021] Figure 5 This is a schematic diagram of the forward adjustment device structure provided in an embodiment of the deep-water PLET release device of the present invention.

[0022] Figure 6 Provided for embodiments of the deep-water PLET release device of the present invention Figure 5 Enlarged view of point A in the middle.

[0023] Figure 7 This is a schematic diagram of the left and right adjustment device provided in an embodiment of the deep-water PLET release device of the present invention.

[0024] 1. Fixed main frame; 2. Hanger main beam; 3. Ladder platform; 4. Luffing cylinder assembly; 5. Lifting cylinder assembly; 6. Left and right adjustment device; 7. Forward adjustment device; 8. Adjusting support; 9. Adjusting cylinder; 10. Adjusting rod; 11. Forward push cylinder; 12. Rotating shaft; 13. Stop bar; 14. Base; 15. Base mounting plate; 16. Main beam support; 17. Hinge assembly; 18. Shelf; 19. Main beam; 20. Connecting beam; 21. Outrigger; 22. Head beam; 23. Head connecting beam; 24. Platform; 25. Large platform; 26. First straight ladder; 27. Intermediate platform; 28. Second straight ladder; 29. ​​Bushing; 30. Mounting base; 31. Flange gasket; 32. Wear-resistant gasket; 33. Support frame; 34. Elevated base; 35. Support frame elevated seat. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] like Figure 1-7 As shown, this is a deep-water PLET release device provided in an embodiment of the present invention.

[0027] It includes a fixed main frame 1 and a hanger main beam 2. The fixed main frame 1 is U-shaped. The top of one end of the fixed main frame 1 is rotatably connected to one end of the hanger main beam 2. A ladder platform 3 is provided on the top of the hanger main beam 2. A luffing cylinder assembly 4 is rotatably fitted on the bottom of the inner wall of the fixed main frame 1. The output end of the luffing cylinder assembly 4 is rotatably connected to the bottom of the hanger main beam 2. A lifting cylinder assembly 5 is rotatably fitted on one end of the hanger main beam 2. A left-right adjustment device 6 and a forward adjustment device 7 are provided inside the hanger main beam 2. The surfaces of the fixed main frame 1, the hanger main beam 2, the ladder platform 3, the left-right adjustment device 6, and the forward adjustment device 7 are all provided with a composite anti-corrosion structure. The left and right adjustment device 6 includes two adjustment supports 8 respectively installed at the bottom of the left and right sides of the main beam 2 of the hanger, an adjustment cylinder 9 set in the adjustment support 8, and an adjustment rod 10 installed at the output end of the adjustment cylinder 9. The two adjustment rods 10 are symmetrically distributed. The forward adjustment device 7 includes two forward push cylinders 11 set in the main beam 2 of the hanger, a rotating shaft 12 rotatably engaged with the output end of the forward push cylinder 11, and a stop rod 13 rotatably engaged between the two rotating shafts 12.

[0028] Reference Figure 1 The fixed main frame 1 in this embodiment includes a base 14, a plurality of base mounting plates 15 disposed around the base 14, two main beam supports 16 mounted on the top of one end of the base 14, a hinge assembly 17 disposed on the top of the main beam support 16, and two shelf frames 18 mounted on the top of the other end of the base 14. The top of the shelf frame 18 is provided with a limit groove. The base 14 is the basic load-bearing component for fixing the main frame 1. It bears the weight of the main beam 2 of the gantry, various hydraulic cylinder assemblies, and the working load. Its function is to evenly transfer the distributed load to the mounting base, avoiding local stress concentration that could damage the mounting surface. At the same time, it provides a unified mounting reference surface for the base mounting plate 15, the main beam support 16, and the support frame 18, ensuring the assembly accuracy of each component. This part of the structure, through the coordinated design of base bearing, mounting plate fixing, support support, hinge point rotation, and support positioning, not only meets the power transmission and attitude adjustment requirements during normal operation, but also adapts to the stable support requirements of the dispatch condition. In addition, all components are rigid structures that are welded or bolted together, which meets the safety factor requirements of working condition 1.43 and dispatch condition 1.11 in the "Offshore Mobile Platform Classification Specification", providing a basic guarantee for the multi-condition adaptability of the deep-water PLET release device.

[0029] Reference Figure 2In this embodiment, the main beam 2 of the hanger includes two main beams 19, multiple connecting beams 20 installed between the two main beams 19, two legs 21 respectively installed at one end of the two main beams 19, a head beam 22 installed at one end of the two legs 21, and a head connecting beam 23 installed between the two legs 21. The legs 21 are distributed in an inclined and symmetrical manner. The bottom of one end of the main beam 19 is rotatably connected to the hinge assembly 17. The lifting cylinder assembly 5 is rotatably fitted on the top of the head beam 22. Two luffing cylinder assemblies 4 are provided. The output end of the luffing cylinder assembly 4 is rotatably connected to the bottom of the main beam 19. This structural section employs a collaborative design that integrates main beam load-bearing, connecting beam reinforcement, outrigger force transmission, head concentration, and dual hydraulic cylinder adjustment. This design ensures both the rationality of load transfer paths and the strength and stability of the structure. All welded parts adhere to the process requirements of low-hydrogen welding rods, preheating before welding, and post-weld flaw detection. Core connection parts meet strength calculation standards, ensuring that the structural strength is less than the allowable stress under normal operating conditions, special heavy-load conditions, and dispatch conditions. This meets the safety factor requirements of working condition 1.43 and dispatch condition 1.11 in the "Offshore Mobile Platform Classification Specification," providing core assurance for multi-condition adaptability and operational safety.

[0030] Reference Figure 3 The ladder platform 3 in this embodiment includes multiple platforms 24 installed on the opposite outer sides of two main beams 19, multiple large platforms 25 installed between two support legs 21, two first straight ladders 26 installed on the opposite outer sides of two support frames 18, an intermediate platform 27 installed on the first straight ladders 26, and two second straight ladders 28 installed on the opposite outer sides of two main beams 19, with the second straight ladders 28 corresponding to the intermediate platform 27; drainage holes are provided on the top of the platforms 24 and the large platforms 25, and multiple guardrails are installed around the perimeter of the multiple platforms 24. The ladder platform, through its three-dimensional layout of straight ladders, platforms, and intermediate transitions, constructs a safety maintenance network covering the entire area of ​​the gantry. This ensures that all key components, such as the fixed main frame, gantry main beam, cylinder assembly, and hinge structure, have accessible operating platforms and passageways. Meanwhile, the drainage design of the water-permeable holes and the safety protection design of the guardrails are tailored to the characteristics of the marine C5-level corrosive environment and the dynamic operation of the vessel. This not only protects the personal safety of maintenance personnel but also extends the service life of the ladder platform itself and surrounding structures by reducing water accumulation and corrosion, providing a fundamental guarantee for the long-term stable operation of the deep-water PLET release device.

[0031] Reference Figure 5 , Figure 6In this embodiment, bushings 29 are provided between the rotating shaft 12 and the output end of the front push cylinder 11 and one end of the stop rod 13. Retaining rings are provided at both the output end of the front push cylinder 11 and one end of the stop rod 13. The bushings 29 and retaining rings work together to reduce wear, center, and buffer, while the retaining rings provide limiting, fixing, and sealing, forming a complete rotational connection protection system. This design ensures that the connection between the front push cylinder 11 and the stop rod 13 maintains transmission accuracy and structural stability under long-term dynamic loads and highly corrosive environments. The hinge transmission component meets the calculation standards for strength and wear resistance, providing a core guarantee for the reliable operation of the forward adjustment device.

[0032] Reference Figure 7 In this embodiment, the main beam 2 of the hanger is equipped with a mounting base 30 at its top, and an adjusting support 8 is installed on the top of the mounting base 30. Flange plates 31 are installed at the opposite ends of the two adjusting rods 10, and a wear-resistant pad 32 is installed on one side of the flange plate 31. A support frame 33 is installed on the top of the main beam 2 of the hanger, and the adjusting rods 10 are slidably fitted onto the top of the support frame 33. This newly added component works in conjunction with the original left and right adjusting device. Through the design of the mounting base for positioning and bearing, the flange plate for distributing force, the wear-resistant pad for wear reduction and protection, and the support frame for guiding support, problems such as instability, uneven force transmission, severe wear, and movement deviation during left and right adjustment are solved. All component strength calculations, stability designs, and wear-resistant and corrosion-resistant specifications ensure that the left and right adjusting device can achieve stable, precise, and reliable attitude adjustment under different load conditions, further guaranteeing the multi-condition adaptability of the deep-water PLET release device.

[0033] Reference Figure 7 In this embodiment, a raised base 34 is installed between the adjusting support 8 and the mounting base 30. The raised base 34 is bolted to both the adjusting support 8 and the mounting base 30. The raised base 34 has different height specifications. A support frame raised seat 35 is installed between the support frame 33 and the main beam 2 of the hanger. The support frame raised seat 35 is bolted to the support frame 33. The support frame raised seat 35 has different height specifications. The raised base 34 and the support frame raised seat 35 work together to adjust the height, ensuring that the adjusting rod 10 is in the best horizontal and coaxial force state throughout its entire range. This allows the output force of the adjusting cylinder 9 to be efficiently converted into attitude adjustment force, avoiding force loss or deviation. This collaborative design is particularly suitable for the dynamic loads generated by the rolling and pitching of ships, ensuring the adjustment accuracy and response speed of the left and right adjusting device under complex working conditions. Both are bolted together, and the bolt tension at the connection point is ≤26T, meeting the strength requirements under dynamic loads. At the same time, the modular structure avoids structural stress concentration caused by welding.

[0034] The composite anti-corrosion structure of this embodiment includes an outer surface coating, an inner surface coating, a galvanized part coating, and a flange mating surface coating. The outer surface coating is a three-layer structure consisting of an epoxy zinc-rich primer, an epoxy thick-film intermediate paint, and a polyurethane thick-film topcoat. The inner surface coating is an epoxy thick-film primer. The galvanized part coating is a three-layer structure consisting of an epoxy primer, an epoxy intermediate paint, and a polyurethane topcoat. The flange mating surface coating is an inorganic zinc-rich primer. The composite anti-corrosion structure design achieves full coverage and no blind spots, covering all key parts such as the outer and inner surfaces of the structure, galvanized parts, and flange mating surfaces. The material and structure of each coating are precisely matched to the corrosion risk and functional requirements of the corresponding surface, ensuring that the coating adhesion meets the standards and avoiding protection failure due to insufficient adhesion. The entire anti-corrosion system can not only resist the corrosion of high salt spray, high humidity, and strong ultraviolet rays in the ocean, but also, in conjunction with the structural design, reduce local corrosion caused by water and dust accumulation. This indirectly ensures the structural strength and connection reliability of the deep-sea PLET release device, avoiding safety hazards such as reduced steel strength and loose bolts due to corrosion, and providing a basic guarantee for the stability of multi-condition operation.

[0035] In this embodiment, the inner and outer surfaces of the fixed main frame 1 and the hanger main beam 2 are coated with an outer surface coating and an inner surface coating, respectively. Existing high-strength bolts are used at the assembly and connection of each component of the fixed main frame 1 and the hanger main beam 2. The surface of the high-strength bolts is treated with galvanized coating. The flange connection of the device is coated with a flange mating surface coating. The comprehensive anti-corrosion system achieves seamless corrosion protection for the main frame, main beams of the hangers, and core connection parts through the synergy of external surface coatings, internal surface coatings, galvanized component coatings, and flange mating surface coatings. It is fully adaptable to the highly corrosive marine C5 environment, extending the overall service life of the equipment. The strength performance of the high-strength bolts is combined with the anti-corrosion performance of the galvanized component coatings, and the fastening effect of the flange mating surface coatings is complementary to that of the high-strength bolts. This satisfies the connection stability under dynamic loads and avoids connection failures caused by corrosion, ensuring the structural safety of the equipment under different load conditions from 100T to 300T. All coating types, thicknesses, surface treatment methods, and bolt and flange treatment requirements ensure that the equipment complies with relevant requirements such as the "Offshore Mobile Platform Classification Code" and the "Code for Lifting Equipment of Ships and Offshore Facilities," demonstrating its feasibility and compliance.

[0036] Working Principle: In use, the fixed main frame 1 is first fixed to the mounting surface, serving as the load-bearing foundation for the entire device. This ensures that all operating loads are effectively distributed and transferred to the mounting base. Simultaneously, the ladder platform 3 provides a safe passage for subsequent maintenance operations. Next, the luffing cylinder assembly 4 is activated. Its extension and retraction drive the main beam 2 of the lifting frame around the core hinge point connected to the fixed main frame 1, adjusting it to the target pitch angle within the specified range. When the luffing cylinder assembly 4 extends, the main beam 2 rotates upward to increase the pitch angle; when retracting, it rotates downward to decrease the pitch angle or switches to a resting state. Then, the lifting cylinder assembly 5 is activated. Its extension and retraction directly acts on the lifting device or load-bearing structure, overcoming the resistance of the weight of the load, the inertia of the ship's motion, and wind loads, achieving smooth lifting and lowering of the load. The rotational design of the lifting cylinder assembly 5 can adapt to changes in the force transmission direction under different pitch angles of the main beam 2. Afterward, according to operational needs, if it is necessary to adjust the left and right horizontal posture of the load on the main beam 2, the two symmetrically distributed adjusting cylinders 9 of the left and right adjusting device 6 are activated. The synchronous reverse extension and retraction of the two adjusting cylinders 9... Independent operation drives the adjusting rod 10 to move the hoisted items on the main beam 2 of the gantry by a small angle to adjust their position and counteract the attitude deviation caused by the ship's rolling or load imbalance. If forward limiting or auxiliary load bearing is required, the two forward-pushing cylinders 11 in the forward adjusting device 7 are activated to extend synchronously. Through the rotating shaft 12, the stop rod 13 is moved forward to contact the heavy object or load-bearing structure, sharing the forward inertial force and preventing load shift. Throughout the operation, the fixed main frame 1, the main beam 2 of the gantry, the ladder platform 3, and all adjusting devices are covered. The composite anti-corrosion structure on the surface continuously blocks corrosive media such as salt spray and moisture in the marine environment, ensuring the flexibility and reliability of each component. After the operation is completed, the lifting cylinder assembly 5 is first controlled to retract to smoothly lower the heavy object to the designated position. Then, the luffing cylinder assembly 4 is used to adjust the main beam 2 of the hanger to the resting state. If it is in the dispatching condition, the forward cylinder 11 can be fully extended to lock the stop rod 13, which, together with the fixed main frame 1, enhances the structural stability during the dispatching process. At the same time, each component is inspected and maintained as needed to ensure subsequent performance.

[0037] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A deep-water PLET release device, comprising a fixed main frame (1) and a hanger main beam (2), characterized in that, The fixed main frame (1) is U-shaped. The top of one end of the fixed main frame (1) is rotatably connected to one end of the main beam (2). A ladder platform (3) is provided on the top of the main beam (2). A variable amplitude cylinder assembly (4) is rotatably fitted on the bottom of the inner wall of the fixed main frame (1). The output end of the variable amplitude cylinder assembly (4) is rotatably connected to the bottom of the main beam (2). A lifting cylinder assembly (5) is rotatably fitted on one end of the main beam (2). A left-right adjustment device (6) and a forward adjustment device (7) are provided inside the main beam (2). The surfaces of the fixed main frame (1), the main beam (2), the ladder platform (3), the left-right adjustment device (6), and the forward adjustment device (7) are all provided with a composite anti-corrosion structure. The left and right adjustment device (6) includes two adjustment supports (8) respectively installed at the bottom of the left and right sides of the main beam (2) of the hanger, an adjustment cylinder (9) set in the adjustment support (8), and an adjustment rod (10) installed at the output end of the adjustment cylinder (9). The two adjustment rods (10) are symmetrically distributed. The forward adjustment device (7) includes two forward push cylinders (11) set in the main beam (2) of the hanger, a rotating shaft (12) rotatably engaged at the output end of the forward push cylinder (11), and a stop rod (13) rotatably engaged between the two rotating shafts (12).

2. The deep-water PLET release device according to claim 1, characterized in that, The fixed main frame (1) includes a base (14), a plurality of base mounting plates (15) disposed around the base (14), two main beam supports (16) mounted on the top of one end of the base (14), a hinge assembly (17) disposed on the top of the main beam support (16), and two shelf frames (18) mounted on the top of the other end of the base (14), wherein the top of the shelf frame (18) is provided with a limit groove.

3. The deep-water PLET release device according to claim 2, characterized in that, The main beam (2) of the hanger includes two main beams (19), multiple connecting beams (20) installed between the two main beams (19), two legs (21) respectively installed at one end of the two main beams (19), a head beam (22) installed at one end of the two legs (21), and a head connecting beam (23) installed between the two legs (21). The legs (21) are distributed in an inclined symmetrical manner. The bottom of one end of the main beam (19) is rotatably connected to the hinge assembly (17). The lifting cylinder assembly (5) is rotatably fitted to the top of the head beam (22). There are two luffing cylinder assemblies (4). The output end of the luffing cylinder assembly (4) is rotatably connected to the bottom of the main beam (19).

4. The deep-water PLET release device according to claim 3, characterized in that, The ladder platform (3) includes multiple platforms (24) installed on the opposite outer sides of the two main beams (19), multiple large platforms (25) installed directly on the two support legs (21), two first straight ladders (26) respectively set on the opposite outer sides of the two shelving frames (18), an intermediate platform (27) set on the first straight ladders (26), and two second straight ladders (28) respectively set on the opposite outer sides of the two main beams (19), the second straight ladders (28) corresponding to the intermediate platform (27).

5. The deep-water PLET release device according to claim 4, characterized in that, Both the platform (24) and the large platform (25) have drainage holes on their tops, and multiple guardrails are installed around the perimeter of the multiple platforms (24).

6. The deep-water PLET release device according to claim 1, characterized in that, A bushing (29) is provided between the rotating shaft (12) and the output end of the front push cylinder (11) and one end of the stop rod (13), and a retaining ring is provided between the output end of the front push cylinder (11) and one end of the stop rod (13).

7. The deep-water PLET release device according to claim 1, characterized in that, The main beam (2) of the hanger is provided with a mounting base (30) at the top. The adjusting support (8) is installed on the top of the mounting base (30). Flange gaskets (31) are installed on opposite ends of the two adjusting rods (10). A wear-resistant gasket (32) is installed on one side of the flange gasket (31). A support frame (33) is installed on the top of the main beam (2) of the hanger. The adjusting rod (10) is slidably fitted on the top of the support frame (33).

8. The deep-water PLET release device according to claim 7, characterized in that, An extension base (34) is installed between the adjusting support (8) and the mounting base (30). The extension base (34) is connected and fixed to the adjusting support (8) and the mounting base (30) by bolts. The extension base (34) has different height specifications. An extension support (35) is installed between the support frame (33) and the main beam (2) of the hanger. The extension support (35) is connected and fixed to the support frame (33) by bolts. The extension support (35) has different height specifications.

9. The deep-water PLET release device according to claim 1, characterized in that, The composite anti-corrosion structure includes an outer surface coating, an inner surface coating, a galvanized part coating, and a flange mating surface coating. The outer surface coating is a three-layer structure consisting of an epoxy zinc-rich primer, an epoxy thick-film intermediate paint, and a polyurethane thick-film topcoat. The inner surface coating is an epoxy thick-film primer. The galvanized part coating is a three-layer structure consisting of an epoxy primer, an epoxy intermediate paint, and a polyurethane topcoat. The flange mating surface coating is an inorganic zinc-rich primer.

10. The deep-water PLET release device according to claim 9, characterized in that, The outer surface coating and the inner surface coating are respectively applied to the inner and outer surfaces of the fixed main frame (1) and the hanger main beam (2). Existing high-strength bolts are used at the assembly and connection of each component of the fixed main frame (1) and the hanger main beam (2). The surface of the high-strength bolts is treated with galvanized coating. The flange connection is coated with the flange mating surface coating.

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