B-type cabin drop plate structure

Abstract

The application discloses a B-type cabin drip tray structure, which comprises a drip tray arranged at the bottom of a liquid cargo cabin; the liquid cargo cabin comprises an outer shell and a heat preservation layer arranged outside the outer shell; a leakage channel is arranged between the outer shell and the heat preservation layer; a support member for supporting the liquid cargo cabin is arranged on a ship body structure, an insulation member is arranged between the support member and the outer shell, an outer wall of the insulation member is provided with a flow guide groove, and the upper end of the flow guide groove is communicated with the leakage channel; the drip tray is connected to the insulation member through a fastener; and the lower end of the flow guide groove is communicated with the inner cavity of the drip tray. The application has the advantages of great flexibility in arrangement, fast natural evaporation, high safety redundancy and reduced construction difficulty.

Description

Technical Field

[0001] This invention relates to the field of marine technology, and in particular to a B-type tank drip tray structure. Background Technology

[0002] According to the International Maritime Organization (IMO) Code on the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (hereinafter referred to as the IGC Code), gas carriers using Type B tanks are required to be equipped with drip trays to address the issue of maintaining the structural safety of the hull even 15 days after a leak of cryogenic liquid cargoes such as liquefied natural gas. The drip trays referred to in this specification are classified as partial secondary bulkheads in the IGC Code. A secondary bulkhead refers to the liquid-tight outer layer of the cargo containment system designed to temporarily contain liquid cargo that may leak from the main bulkhead.

[0003] Liquefied natural gas (LNG) carriers using Type B tank technology include the MOSS spherical tank type and the SPB prismatic type. With the gradual arrival of the low-carbon and zero-carbon era, Type B tank technology has also begun to be applied to the transportation of liquid cargoes such as liquid ammonia and ethylene.

[0004] Designing the drip tray capacity is one of the challenges in the design of the B compartment. Classification societies mandate a minimum leakage rate of 100 liters per hour, resulting in a total leakage of 36,000 liters over 15 days. Typically, LNG carriers have about six drip trays symmetrically arranged at the bow, stern, and midway points of the tank. Each drip tray needs to account for a total leakage of 6,000 liters. However, the distance between the LNG tank and the bottom of the hull is generally about 1 meter. A drip tray measuring 3 meters long, 2 meters wide, and 1 meter high is obviously difficult to arrange, necessitating alternative methods to reduce the drip tray capacity, such as electric heating, pumping, or forced evaporation. These methods introduce additional challenges to the drip tray design.

[0005] If the drip tray collects liquefied natural gas (LNG), the temperature can reach -163°C, making direct welding to the hull impossible. A separate rack is required, with insulating pads placed on the rack before the drip tray is positioned. This prevents low-temperature damage to the hull in the event of a LNG leak. The rack needs to be installed before hoisting into the Type B tank, necessitating additional protection. Furthermore, the alignment of the drain pipe welded to the tank side with the drip tray must be precise during hoisting, demanding high hoisting accuracy.

[0006] Because the diversion pipe is directly welded to the bottom of the liquid cargo tank, and the part of the diversion pipe that extends out of the insulation is exposed to the air, when the liquid cargo tank is fully loaded for transportation, the low temperature is transferred to the outside, which poses a risk of icing.

[0007] Patent publication number US4488500A disclosed the earliest design of a prismatic B-type liquid tank drip tray, in which LNG liquid slowly drips into a U-shaped drip tray arranged on a shelf on the bottom plate of the hull. It also mentioned an electrically heated method. The prismatic LNG ship drip trays have now evolved from this design.

[0008] Utility model patent CN219406816U discloses a fully enclosed drip tray to address the risk of liquid leakage from traditional open-type liquid collection boxes when a ship's static heel angle is 30 degrees during operation. The drip tray is mounted on a shelf and secured with bolts and nuts. One end of a guide pipe is welded to the bottom of the tank, and the other end extends into the drip tray through a through-hole above it.

[0009] Patent application CN113401284A discloses a leaking liquid storage device with an independent liquid tank. This device improves the shelf design of the drip tray, changing the drip tray itself from an open type to a semi-enclosed type.

[0010] The invention patent CN108146583B discloses a type B LNG tank containment system, which sets valves on the flow guide pipes, fully seals the drip trays and sets suction ports, so that leaked cryogenic liquids are directly pumped away.

[0011] The aforementioned prior art has the following disadvantages:

[0012] 1. In existing technologies, the capacity of a single drip tray is relatively large. How to arrange the drip trays to minimize low-temperature damage to the hull is a major challenge. To address this, methods such as pumping, electric heating, and natural evaporation are employed to accelerate the evaporation of the leaked liquid.

[0013] 2. In view of the characteristics of existing technologies, such as a small number of drip trays, large capacity, and difficulty in arrangement.

[0014] 3. In the existing technology, the support structure of liquid cargo tank has many elbow plates, making it difficult to arrange drip trays between the supports.

[0015] 4. Existing technologies use closed drip trays, which increases the amount of equipment required and results in low redundancy in system safety and reliability.

[0016] 5. In the existing technology, the drip tray and the liquid cargo tank support structure are independent functional structures, which are difficult to construct. Summary of the Invention

[0017] In order to overcome the above-mentioned defects in the existing technology, the present invention provides a B-type chamber drip tray structure.

[0018] The present invention solves the above-mentioned technical problems through the following technical solution:

[0019] A type B cargo tank drip tray structure includes a drip tray located below the cargo tank; the cargo tank includes an outer shell and an insulation layer located outside the outer shell; a leakage channel is provided between the outer shell and the insulation layer; a support member is provided on the hull structure to support the cargo tank, and an insulating member is provided between the support member and the outer shell; a guide groove is provided on the outer wall of the insulating member, and the upper end of the guide groove is connected to the leakage channel; the drip tray is connected to the insulating member by fasteners; the lower end of the guide groove is connected to the inner cavity of the drip tray.

[0020] Furthermore, the sidewall of the drip tray is attached to the insulating component, and the sidewall of the drip tray is provided with a through hole communicating with the guide groove.

[0021] Furthermore, the insulating component is provided with multiple flow channels, each of which is connected to a drip tray.

[0022] Furthermore, the guide channels are vertically distributed.

[0023] Furthermore, the fastener is a screw.

[0024] Furthermore, the insulating component is laminated wood.

[0025] Furthermore, the laminated wood is in the shape of a cuboid, and each of the four outer walls of the laminated wood is provided with a guide groove and a drip tray is connected to each of the four outer walls of the laminated wood.

[0026] Furthermore, the drip tray is attached to the laminated wood, and low-temperature adhesive is applied between the drip tray and the laminated wood.

[0027] Furthermore, the drip tray is made of low-temperature plastic.

[0028] Furthermore, the depth of the guide channel is 1–10 mm.

[0029] The beneficial effects of this invention are as follows: The drip tray is made of low-temperature plastic, which is lightweight and low-cost. This invention eliminates the need for a separately configured insulation layer, reducing construction costs; it also eliminates the need for a separately configured shelf, further reducing costs; and it eliminates the need for a separately configured drainage pipe, further reducing costs. The drip tray features a modular design, facilitating screw installation; and it can be used to retrofit and install drip trays on older LNG carriers. This invention solves the drawbacks of traditional drip trays, which are few in number but have large individual capacities; and it addresses the problem of numerous elbow plates on traditional support seats, making it difficult to arrange the drip trays. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view of a preferred embodiment of the present invention.

[0031] Figure 2 for Figure 1 Enlarged diagram of section C.

[0032] Figure 3 for Figure 2 Schematic diagram of sectional view AA.

[0033] Figure 4 for Figure 2 Schematic diagram of the BB section. Detailed Implementation

[0034] The present invention will be described more clearly and completely below with reference to a preferred embodiment and the accompanying drawings.

[0035] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a type B cargo tank drip tray structure includes a drip tray 10 located below the cargo tank 20; the cargo tank 20 includes an outer shell 21 and an insulation layer 22 located outside the outer shell; a leakage channel 23 is provided between the outer shell 21 and the insulation layer 22.

[0036] The hull structure 27 is provided with a support member 24 for supporting the liquid cargo tank, and an insulating member is provided between the support member 24 and the outer shell 21. The insulating member is laminated wood 25.

[0037] The outer wall of the laminated wood 25 is provided with flow channels 26. The flow channels 26 are vertically distributed. The depth of the flow channels is 1 to 10 mm.

[0038] The upper end of the guide channel 26 is connected to the leakage channel 23; the drip tray 10 is connected to the laminated wood 25 by fasteners 11; the fasteners 11 are screws.

[0039] The lower end of the guide channel 26 is connected to the inner cavity of the drip plate 10.

[0040] The side wall of the drip tray 10 is attached to the laminated wood 25, and the side wall of the drip tray 10 is provided with a through hole 12 that communicates with the guide groove.

[0041] The laminated wood 25 is provided with multiple flow channels 26, and each flow channel 26 is connected to a drip tray 10.

[0042] The laminated wood 25 is rectangular in shape, with guide grooves on all four outer walls and drip trays connected to all four outer walls.

[0043] The drip tray 10 is attached to the laminated wood 25, and low-temperature adhesive is applied between the drip tray and the laminated wood 25. The drip tray 10 is made of low-temperature plastic.

[0044] In this design, load and heat are transferred between the cargo tank 20 and the hull structure 27 via supporting members 24 and laminated wood 25. The main shield wall is the outer shell 21 of the cargo tank. When the outer shell 21 of the cargo tank has cracks, the leaking cryogenic liquid flows through the leakage channel 23 into the drip trays 10 on the left, right, or front and rear sides of the laminated wood 25. An insulation layer 22 is provided on the outside of the leakage channel 23.

[0045] Numerous support components 24 are arranged along the ship's length, and front and rear drip trays 10 are installed on the laminated wood 25. The guide channels and drip trays are corresponding, with each guide channel equipped with one drip tray.

[0046] The drip tray is fixed to the laminated wood 25 with screws, and the bottom of the through hole 12 of the drip tray is aligned with the bottom of the guide channel. Low-temperature adhesive can be applied to the mating surface of the drip tray and the laminated wood for fixation. The drip tray 10 has an open plate only at the top, and the other surfaces are liquid-tight.

[0047] Compared with the prior art, the present invention has the following advantages:

[0048] 1. The drip tray is made of low-temperature plastic, which is lightweight and low-cost;

[0049] 2. The conventional separate insulation layer for drip trays has been eliminated, reducing construction costs;

[0050] 3. The conventional separate shelf for drip trays has been eliminated, reducing construction costs;

[0051] 4. The conventional drip tray with its separately configured drainage tube has been eliminated, reducing construction costs;

[0052] 5. Modular design of the drip tray for easy screw installation;

[0053] 6. This plan can also be used to retrofit and install drip trays on older liquefied natural gas (LNG) ships;

[0054] 7. It solves the drawbacks of traditional drip trays, which have a small number of trays but a large capacity per tray;

[0055] 8. It solves the problem of traditional support seats having many elbow plates, making it difficult to arrange the drip tray.

[0056] This invention solves the problems of existing prismatic B-compartment drip trays, such as large capacity, difficult installation, and the risk of icing in the guide pipes. This invention proposes a design concept of numerous drip trays, small individual capacity, and modular installation. The small-capacity drip trays proposed in this invention can be installed on the supporting structure, greatly increasing layout flexibility. The drip trays used in this invention do not require guide pipes or other equipment. The large number of drip trays leads to rapid natural evaporation and high safety redundancy. This invention integrates the drip trays with the supporting structure, reducing construction difficulty.

[0057] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A type B cargo tank drip tray structure, comprising a drip tray disposed below a cargo tank; the cargo tank comprising an outer shell and an insulation layer disposed outside the outer shell; a leakage channel provided between the outer shell and the insulation layer; a support member for supporting the cargo tank provided on the hull structure, and an insulating member provided between the support member and the outer shell; characterized in that, The outer wall of the insulating component is provided with a guide groove, the upper end of which is connected to the leakage channel; the drip tray is connected to the insulating component by fasteners; the lower end of the guide groove is connected to the inner cavity of the drip tray; the side wall of the drip tray is attached to the insulating component, and the side wall of the drip tray is provided with a through hole that communicates with the guide groove; the guide grooves are vertically distributed; the insulating component is laminated wood; the laminated wood is cuboid in shape, and each of the four outer walls of the laminated wood is provided with a guide groove, and each of the four outer walls of the laminated wood is connected to a drip tray; the drip tray is attached to the laminated wood, and low-temperature adhesive is applied between the drip tray and the laminated wood.

2. The B-type chamber drip tray structure as described in claim 1, characterized in that, The insulating component is provided with multiple flow channels, and each flow channel is connected to a drip tray.

3. The B-type chamber drip tray structure as described in claim 1, characterized in that, The fastener is a screw.

4. The B-type chamber drip tray structure as described in claim 1, characterized in that, The drip tray is made of low-temperature plastic.

5. The B-type chamber drip tray structure as described in claim 1, characterized in that, The depth of the guide channel is 1 ~ 10 mm.

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