Movable ladder for checking prismatic liquid cargo tank

Abstract

The invention discloses a prismatic movable ladder for liquid cargo tank inspection. The prismatic movable ladder is arranged outside a liquid tank. An inspection channel platform is also arranged outside the liquid tank; the vertical ladder comprises a vertical straight ladder and an inclined straight ladder; the inclined straight ladder is hinged to the top of the vertical straight ladder; a track is arranged on the inspection channel platform, and the vertical straight ladder is arranged on the track; a roller matched with the track is arranged at the bottom of the vertical straight ladder; crawler wheels are connected to the inclined straight ladder and abut against the outer surface of the liquid tank. Insulation of the inclined plane of the upper part of the liquid tank can be checked in a closer distance through climbing, and the device is simple in structure, easy to manufacture and low in manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of marine technology, and in particular to a movable ladder for inspecting prism-shaped liquid cargo tanks. Background Technology

[0002] According to the specifications for the construction and equipment of ships transporting liquefied gases in bulk, at least one side of the hull structure should be visually inspectable without moving any fixed structures or installations. When arranging cargo holds, empty spaces, liquid cargo tanks, and other spaces classified as hazardous areas, consideration should be given to the ability of personnel wearing protective clothing and carrying respirators to enter and inspect any of these spaces.

[0003] The general visual inspection distance is 4 to 5 meters. The insulation layer in a normal location can be reached through the inspection channel. However, there is a slope on the inspection channel leading to the top of the prism-shaped liquid tank. Due to the special location of the tank, it is difficult to visually inspect it from the inspection channel. Therefore, a ladder needs to be set up to facilitate the inspection personnel to reach the tank and inspect its insulation.

[0004] Existing inspection methods mostly involve inspectors using portable ladders hung on pre-welded ear plates to climb to a certain height for inspection or leaning out from the top of the liquid tank for inspection.

[0005] The existing technology has the following drawbacks: the inspector is still some distance from the inspection surface, and the inspection line of sight is limited; the passageway inside the cargo area is narrow, and it is inconvenient for inspectors to carry an extra ladder to pass through; the safety of climbing the portable ladder cannot be guaranteed. Summary of the Invention

[0006] In order to overcome the above-mentioned defects in the prior art, the present invention provides a movable ladder for inspecting prism-shaped liquid cargo tanks.

[0007] The present invention solves the above-mentioned technical problems through the following technical solution:

[0008] A movable ladder for inspecting a prism-shaped liquid cargo tank is provided outside the tank. An inspection passage platform is also provided outside the tank. The ladder includes a vertical ladder and an inclined ladder. The inclined ladder is hinged to the top of the vertical ladder. A track is provided on the inspection passage platform, and the vertical ladder is placed on the track. Rollers adapted to the track are provided at the bottom of the vertical ladder. Tracked wheels are connected to the inclined ladder and abut against the outer surface of the tank.

[0009] Further inspection revealed that the access platform was fixed to the ship's structural components.

[0010] Furthermore, the distance between the hull structural components and the vertical ladder shall not be less than 380mm.

[0011] Furthermore, as the vertical ladder moves along the track, the inclined ladder moves along with the vertical ladder under the support of the track wheels.

[0012] Furthermore, the rollers at the bottom of the vertical ladder have grooves that engage with the track.

[0013] Furthermore, the track is fixed to the inspection channel platform.

[0014] Furthermore, the track is located at the edge of the top of the inspection channel platform.

[0015] Furthermore, the liquid tank is a prismatic liquid tank.

[0016] Furthermore, the vertical ladder does not come into contact with the liquid tank.

[0017] Furthermore, the inclined ladder does not come into contact with the liquid tank.

[0018] The beneficial effects of this invention are as follows: This invention enables the inspection of hard-to-reach areas on the upper part of a prismatic liquid tank using a straight ladder; the inspection channel platform serves as the ladder's moving track, allowing the ladder to move back and forth along the liquid tank; it allows direct access to the top of the liquid tank from the inspection channel platform, eliminating the need to detour to either end of the tank. In this invention, several tracked wheels are installed on the inclined straight ladder, facilitating ladder movement while providing support, and avoiding damage to the insulating surface. Using this ladder, inspection personnel entering cargo areas do not need to carry an additional ladder. The ladder of this invention is relatively fixed, reducing the safety risks of climbing portable ladders. The ladder of this invention has a supported base, making it more stable and safer than portable ladders. Using this ladder, the insulation of the inclined surface of the upper part of the liquid tank can be inspected at a closer distance. The ladder of this invention can be installed directly after the liquid tank is installed, without affecting the installation of other structures; the ladder structure is simple, easy to manufacture, and has low manufacturing costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention.

[0020] Figure 2 for Figure 1 Enlarged diagram of part A in the middle.

[0021] Figure 3 for Figure 1 Enlarged schematic diagram of the connection position between the central vertical ladder and the inspection channel platform.

[0022] Figure 4 for Figure 3 Schematic diagram of the BB section. Detailed Implementation

[0023] The present invention will be described more clearly and completely below with reference to a preferred embodiment and the accompanying drawings.

[0024] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a movable ladder for inspecting a prism-shaped liquid cargo tank is located outside the liquid tank 20; an inspection access platform 21 is also provided outside the liquid tank. The inspection access platform 21 is fixed to the hull structure 23.

[0025] The movable ladder for inspecting the prismatic cargo tank includes a vertical ladder 11 and an inclined ladder 12; the inclined ladder 12 is hinged to the top of the vertical ladder 11.

[0026] The inspection channel platform 21 is equipped with a track 22. The track 22 is fixed to the inspection channel platform. The track 22 is located at the top edge of the inspection channel platform.

[0027] A vertical ladder 11 is mounted on a track 22; the bottom of the vertical ladder 11 is provided with rollers 13 that are adapted to the track. The rollers 13 at the bottom of the vertical ladder 11 have grooves that engage with the track 22.

[0028] A tracked wheel 14 is connected to the inclined straight ladder 12, and the tracked wheel 14 abuts against the outer surface of the liquid tank 20.

[0029] As the vertical ladder moves along the track, the inclined ladder moves along with it, supported by track wheels.

[0030] The distance between the hull structural component 23 and the vertical ladder 11 shall not be less than 380mm.

[0031] The inspection channel platform 21 does not contact the liquid tank 20. The vertical ladder 11 does not contact the liquid tank 20. The inclined ladder 12 does not contact the liquid tank 20.

[0032] The liquid tank is a prismatic type.

[0033] In use, inspectors can climb the vertical ladder to the inclined ladder to reach the top of the prismatic liquid tank for inspection. The vertical ladder moves along the track, and the inclined ladder moves accordingly, allowing access to different areas of the upper part of the prismatic liquid tank.

[0034] The outer surface of the liquid tank is an insulating part, and the inclined straight ladder uses tracked wheels to contact the insulating surface, which can prevent the inclined straight ladder from damaging the insulation of the liquid tank.

[0035] This invention enables the inspection of hard-to-reach areas on the upper part of a prismatic liquid tank using a straight ladder. The inspection channel platform serves as the ladder's moving track, allowing the ladder to move back and forth along the liquid tank; it provides direct access to the top of the tank without having to detour to either end.

[0036] In this invention, several tracked wheels are installed on the inclined straight ladder, which facilitates the movement of the ladder and provides support for the straight ladder. The use of tracked wheels can avoid damage to the insulating surface.

[0037] Using the ladder of this invention, inspection personnel entering cargo areas no longer need to carry an additional ladder. The ladder of this invention is relatively fixed, reducing the safety risks of climbing portable ladders. The ladder of this invention has a supported base, making it more stable and safer than portable ladders.

[0038] Using the ladder of this invention, the insulation of the upper slope of the liquid tank can be inspected more closely by climbing it.

[0039] The ladder of this invention can be installed directly after the liquid tank is installed without affecting the installation of other structures. The ladder has a simple structure, is easy to manufacture, and has low manufacturing cost.

[0040] 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 movable ladder for inspecting a prism-shaped liquid cargo tank, located outside the tank; the outside of the tank is also equipped with an inspection access platform; characterized in that, It includes a vertical ladder and an inclined ladder; the inclined ladder is hinged to the top of the vertical ladder; the inspection channel platform is equipped with a track, and the vertical ladder is located on the track; the bottom of the vertical ladder is equipped with rollers that are compatible with the track; the inclined ladder is connected to a track wheel, and the track wheel abuts against the outer surface of the liquid tank.

2. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, The inspection channel platform is fixed to the ship's structural components.

3. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 2, characterized in that, The distance between the hull structural components and the vertical ladder shall not be less than 380mm.

4. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, As the vertical ladder moves along the track, the inclined ladder moves along with it, supported by track wheels.

5. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, The rollers at the bottom of the vertical ladder have grooves that engage with the track.

6. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, The track is fixed to the inspection channel platform.

7. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, The track is located at the top edge of the inspection channel platform.

8. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, The liquid tank is a prismatic type.

9. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, The vertical ladder does not come into contact with the liquid tank.

10. The movable ladder for inspecting a prism-shaped liquid cargo tank as described in claim 1, characterized in that, The inclined ladder does not contact the liquid tank.

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