JP2538744Y2 - Dome seal device for low temperature liquefied gas carrier - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dome seal device for a low temperature liquefied gas ship such as an LNG ship.

[0002]

2. Description of the Related Art As shown in an example in FIG. 2, a low-temperature liquefied gas ship has a cargo tank 4 in a hold 2 of a hull 1 via a support 3.
And the mouth 5 of the cargo tank 4 is connected to the upper deck 6 of the hull 1.
It is projected upward from the opening 7, and a gap between the peripheral edge of the dome top plate 9 closing the opening 5 and the opening 8 is sealed by a sealing device.

When the low-temperature liquefied gas ship is an ethylene ship, an example of the above-mentioned sealing device is as shown in FIG. Conventionally, a method in which the bellows 10 is directly mounted has been adopted, and the bellows 10 can ensure the sealing performance, and at the same time, the relative displacement between the warehouse opening edge 8 and the dome top plate 9, that is, , Can absorb the relative displacement between the hull 1 and the cargo tank 4.

[0004]

[Problem to be solved by the invention] However, bellows 1
In the case of a seal device in which the cargo temperature is -104 ° C, the seal device in which the cargo temperature is directly mounted on the dome top plate 9 can be used. Can not be used. That is,
When the bellows 10 is directly attached to the dome top plate 9, there is a problem that the original function cannot be exhibited due to hardening.

Therefore, the present invention provides a dome seal employing a bellows which can exert a reliable sealing function even when employed on an LNG ship and can safely absorb the relative displacement between the hull and the cargo tank. It is intended to provide a device.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention closes a cargo mouth edge of a cargo mouth which is provided in a hold and protrudes the mouth of the cargo tank onto an upper deck and a mouth of the cargo tank. In a dome sealing device for a low-temperature liquefied gas ship that seals between a dome top plate and a peripheral portion thereof, a plywood is attached to a lower surface of a peripheral portion of the dome top plate, and neoprene is provided between the ply plate and the warehouse edge. Alternatively, a configuration is adopted in which bellows made of silicon rubber are mounted.

A bolt for attaching the plywood to the dome top plate is provided with a washer made of a low friction material so as to be in contact with the upper surface of the dome top plate, and a low washer is provided on the upper surface of the plywood so as to be in contact with the lower surface of the dome top plate. It is preferable that a sealing material made of a friction material is provided.

Further, it is preferable that the plywood is provided with tape on the inner and outer peripheral portions.

[0009]

Since the plywood having a heat insulating function is interposed between the dome top plate and the bellows, the cooling heat of the dome top plate is not directly transmitted to the bellows, and the bellows original function is secured.

When the upper and lower surfaces of the dome top plate are sandwiched between a washer made of a low-friction material and a sealing material made of a low-friction material, the dome top plate can slide smoothly during thermal contraction.

Further, when the inner and outer peripheral portions of the plywood are covered with tape,
The airtightness of the hold is ensured.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. As shown in FIG. 2, the port 5 of the cargo tank 4 installed in the hold 2 of the hull 1 projects to the upper deck 6 in the same manner as in FIG. Kuraguchi rim 8
In the low-temperature liquefied gas ship that seals between the dome top plate 9 and the peripheral portion of the dome top plate 9 that covers the opening 5 of the cargo tank 4, a plywood 12 is provided on the lower surface of the peripheral portion of the dome top plate 9.
Are laminated in a required thickness, a holding plate 13 is arranged on the lower surface of the lowermost plywood 12, and a bellows made of neoprene or silicon rubber is provided between the holding plate 13 and the above-mentioned opening 8. 14, the upper end of the bellows 14 is fixed to the dome top plate 9 by bolts 15 penetrating the plywood 12 and the holding plate 13 from the upper surface side of the dome top plate 9, and the lower end of the bellows 14 is fixed. The part is fixed to the above-mentioned opening edge 8 by bolts 16 so that the relative displacement between the hull 1 and the cargo tank 4 can be absorbed by the bellows 14, and further transmitted to the bellows 14 from the dome top plate 9 side. Cold heat can be insulated by the plywood 12.

At the upper end of the bolt 15, a washer 11 made of a low friction material such as Teflon is interposed so as to be in contact with the upper surface of the dome top plate 9, and the uppermost plywood 1
A sealing material 17 made of a low friction material such as Teflon is arranged on the upper surface of the dome 2 so as to be in contact with the lower surface of the dome top plate 9, and the dome top plate 9 is slidably supported by the washer 11 and the sealing material 17. It is like that. Further, from the lower surface of the holding plate 13 to the outer peripheral portion and the inner peripheral portion of the plywood 12, an aluminum tape 1 reinforced with glass cloth is used.
8 is attached so that the sealing property is more reliable.

When LNG is loaded in the cargo tank 4, the dome top plate 9 becomes extremely low temperature, and if this is transmitted directly to the bellows 14, the bellows 14 will harden and lose its function. Since the plywood 12 is interposed between the bellows 14 and functions as a heat insulating material and a sealing material, the bellows 14 does not harden and its original function is not impaired. Displacement can be safely absorbed, and reliable sealing performance can be maintained. Furthermore, since the plywood 12 is pressure-bonded in multiple layers by the bolts 15 via the holding plate 13, high reliability is obtained in terms of sealing performance, and the interior of the hold 2 is held airtight against outside air. can do.

In the above, the dome top plate 9 is
A washer 1 made of Teflon or the like having an excellent low-temperature performance and a small friction coefficient at a portion where the plywood 12 is attached by the bolts 15.
1 and the sealing material 17 such as Teflon, so that the upper and lower surfaces thereof are in contact with each other, so that even if only the dome top plate 9 is thermally contracted at the time of cooling down, it can slide between the washer 11 and the sealing material 17. No excessive force is applied. Further, since the tape 18 is provided on the inner peripheral portion and the outer peripheral portion of the plywood 12, there is an advantage that the sealing performance can be further ensured.

Incidentally, in order to confirm that the slip between the dome top plate 9 and the plywood 12 and the sealing property were maintained, a low-temperature experiment using liquid nitrogen (-196 ° C.) was performed. Good results were obtained. Also, a low-temperature experiment was performed on the tape 18, and good results were obtained.

It should be noted that the present invention is not limited to only the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0019]

As described above, the plywood is attached to the lower surface of the peripheral portion of the dome top plate, and the bellows made of neoprene or silicone rubber is mounted between the plywood and the edge of the warehouse.
The heat insulation function of the plywood can prevent the cold heat from the dome top plate from being directly transmitted to the bellows, safely absorb the relative displacement between the hull and the cargo tank, and secure the sealing performance. This is extremely advantageous because it can be adopted for an LNG ship, and the upper and lower surfaces of the dome top plate are sandwiched between low-friction material washer and seal material at the plywood mounting portion, so that The dome top plate can be slid during thermal contraction of the plate, preventing the generation of unreasonable force. In addition, by placing tape on the inner and outer peripheral portions of the plywood, the airtightness of the hold , Etc. can be more reliably held.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a dome sealing device for a low-temperature liquefied gas ship according to the present invention.

FIG. 2 is a schematic diagram showing an example of a low-temperature liquefied gas ship.

FIG. 3 is a schematic view showing an example of a conventional dome seal device, and is an enlarged view corresponding to a part III in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hull 2 Hold 4 Cargo tank 6 Upper deck 7 Kuraguchi 8 Kuraguchi rim 9 Dome top plate 11 Washer 12 Plywood 14 Bellows 15 Bolt 17 Sealing material 18 Tape

Claims (3)

(57) [Scope of request for utility model registration] 1. A low-temperature liquefied gas ship that seals a space between a rim edge of a garage opening for projecting a mouth of a cargo tank installed in a hold onto an upper deck and a peripheral portion of a dome top plate closing the mouth of the cargo tank. In the dome seal device, a plywood is attached to a lower surface of a peripheral portion of the dome top plate, and a bellows made of neoprene or silicone rubber is mounted between the plywood and the cradle edge. Dome seal device for cryogenic liquefied gas carrier. 2. A bolt for attaching the plywood to the dome top plate is provided with a washer made of a low friction material so as to be in contact with the upper surface of the dome top plate, and a low washer is provided on the upper surface of the plywood so as to be in contact with the lower surface of the dome top plate. 2. The dome sealing device for a low-temperature liquefied gas ship according to claim 1, further comprising a sealing material made of a friction material. 3. The dome seal device for a low-temperature liquefied gas ship according to claim 1, wherein tapes are disposed on an inner peripheral portion and an outer peripheral portion of the plywood.