JP2876948B2 - Apparatus for reducing sway of pipe tower in LNG ship - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for reducing the fluctuation of a pipe tower installed in the hold of an LNG ship, and more particularly to a load transmitting member for the device.

[0002]

2. Description of the Related Art FIG. 5 is a longitudinal sectional view of the center of a hull showing a pipe tower installed in the hold of a conventional LNG ship during navigation, and FIG. 6 is an enlarged view of a device for reducing the fluctuation of the pipe tower. It is. In the figure, 1 is an outer shell of a hull, 2 is an inner shell, 3 is a pipe tower whose upper part is held by a dome top cover 7 and suspended in a hold, and 3a is opposed to the inside of the lower end of the pipe tower 3. It is a strut member provided for reducing sway. 4 is a standard panel stretched on the inner surface of the inner shell 2, 5 is, for example, a laminated steel plate, and an anchor panel for an attachment provided on the inner shell 2, 6 is between the strut members 3 a of the pipe tower 3. It is an anti-vibration stopper that is erected and fixed to the anchor panel 5.

The operation of the conventional apparatus for reducing the fluctuation of a pipe tower thus constructed will be described. Since LNG (liquefied natural gas) loaded in the hold of an LNG carrier has a very low temperature of -162 ° C, the temperature change in the hold (+ 25 ° C to -1 ° C)
(62 ° C.), the shrinkage of each member is large, and the difference in shrinkage in the longitudinal direction of the pipe tower 3 may reach 100 mm.
As a corresponding means, a conventional pipe tower sway reduction device is provided with a strut member 3a at a lower portion of a pipe tower 3 suspended in a hold, as shown in the figure.
By sliding the anti-vibration stopper 6 from both sides and sliding it up and down while sliding up and down, the difference in contraction is eliminated.
The a makes contact with the anti-vibration stopper 6 to suppress the swing of the pipe tower 3.

[0004]

The conventional L as described above is used.
In the apparatus for reducing the fluctuation of the pipe tower of an NG ship, when LNG is loaded in the hold and the inside of the hold becomes extremely low temperature, the pipe tower 3 undergoes thermal contraction as shown by the solid line in FIG. The load point applied to the stopper 6 moves upward by L, and the load moment applied to the anchor panel 5 increases by that amount, which causes a problem that breakage is likely to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and LNG is loaded in the hold of an LNG ship, and the temperature in the hold changes to an extremely low temperature. It is an object of the present invention to provide a pipe tower sway mitigation device for an LNG ship in which the swaying load acting point of the pipe tower due to the sway of the ship can be kept low and the load applied to the anchor panel is kept low to prevent breakage of the anchor panel. It is the purpose.

[0006]

According to the present invention, there is provided an apparatus for reducing the fluctuation of a pipe tower in an LNG ship, comprising: a groove-shaped connecting member provided to face a lower girder of a pipe tower installed in a hold of the LNG ship; The central part is rotatably supported by a plurality of ribs installed on the anchor panel, and both ends are supported so as to be displaceable in horizontal and downward directions, and both ends slide on the connecting member. And a load transmitting member which is fitted as possible.

[0007] The above-mentioned load reaching member is constituted by a trunk portion which is bifurcated at the center portion and is expanded in the width direction, and arms provided on both sides of the trunk portion.

[0008]

According to the present invention, since both ends of the load transmitting member supported by the rib provided on the anchor panel are fitted into the groove of the connecting member attached to the lower girder of the pipe tower, the inside of the hold is kept at a very low temperature. Even if the temperature of the pipe tower shrinks and deforms each member of the pipe tower, the connecting member moves up and down in a state of being fitted to both ends of the load transmitting member, so that a dimensional change due to shrinkage of the pipe tower can be eliminated. In addition, the sway of the pipe tower is suppressed by the connecting member abutting on the load transmitting member, and the reaction force due to the difference in height when the sway load of the pipe tower acts on the anchor panel via the pin is exerted on the anchor panel. The load can be reduced.

[0009]

FIG. 1 is a perspective view of a lower portion of a pipe tower showing one embodiment of the present invention, and shows a partially cut-away state in order to clarify the structure of a fluctuation reducing device. 2 is a plan view of FIG. 1, and FIG. 3 is a side view of FIG. In the drawing, reference numeral 8 denotes a lower girder of the pipe tower 3, 9 denotes a bracket provided on the lower surface of the opposite cross girder of the lower girder 8, and 10 denotes a connection reinforced by the bracket 9 and attached to the lower surface of the lower girder 8 so as to face the lower girder. The member has a groove shape that is opened on the inner surface side.

Reference numeral 11 denotes a load transmitting member, which comprises a trunk portion 11a extending in the width direction with a central portion forked, and arms 11b provided on both sides of the trunk portion 11a. The portion 11a is pivotally supported by a rib 12 installed on the anchor panel 5 by a center pin 14 provided at the center thereof, and the vicinity of both ends of the arm 11b is
The pins 17a and 17b support the ribs 15a and 15b provided on the anchor panel 5, and the ends thereof are slidably fitted into the grooves of the connecting member 10, respectively.

The center pin 14 and the pins 17a,
17b is provided on the substantially same plane below the lower edge of the load transmitting member 11. The pin hole 13 provided in the rib 12 is formed so that the center pin 14 of the load transmitting member 11 can be rotatably fitted therein, and the pin holes 16a, 16b provided in the ribs 15a, 15b are provided.
Is formed in a special shape so that the pins 17a and 17b can be displaced horizontally and downward. Pin holes 13, 16
When the load transmitting member 11 contracts due to the extremely low temperature of the LNG, the load transmitting member 11 contracts around the center portion where the center pin 14 is provided, and the arm portion 11b has the pin hole 16a. , 16b, so that no internal stress is generated.

In the apparatus for reducing the fluctuation of the pipe tower of the LNG ship of the present invention configured as described above, the horizontal swing load of the pipe tower 3 due to the rolling of the LNG ship during voyage is reduced by the load via the connecting member 10. Transmission member 1
Transmitted to the first arm portion 11b, as shown in FIG. 4, it acts a horizontal load P ₁ in the longitudinal direction of the load transmitting member 11,
This is because the horizontal load P is applied to the rib 12 via the center pin 14.
It works as ₂ . At this time, both horizontal loads P ₁ and P ₂
The reaction force R ₁ is generated by the difference L ₁ in the height direction of the
₁ acts upward on the rib 15b and downward on the rib 12.

As described above, the ribs 15a and 15b near both ends of the load transmitting member 11 apply the horizontal load P due to rolling.
Would be subject to a reactive force R ₁ upward without being _1, the ribs 12 are made to undergo horizontal load P _2, acting reaction force R ₁ downward against the ribs 12 as described above it means that the force acting is distributed load moment due to horizontal load P ₁ to the anchor panel 5 through the rib 15b and the rib 12, the force exerted on the rib 12 is reduced.

[0014] Further, these effects are caused by the fact that the temperature inside the hold of the LNG ship becomes extremely low and the pipe tower 3 contracts, and the connecting member 10
Of the horizontal load P _{1 received} by the load transmitting member 11 and the center pin 14 and the pin 17
a, the difference in height of 17b L _1, and the height L ₂ of from anchor panel 5 of the point of application of force of the horizontal load P ₂ acting on the rib 12
Is constant without change, so that the load moment applied to the anchor panel 5 by the contraction of the pipe tower 3 does not increase.

Next, the swing load before and after the pipe tower 3 due to the pitching of the LNG ship is received by the side walls of the arm 11b of the load transmitting member 11 via the connecting member 10, and this is received by the trunk of the load transmitting member 11. 11a and a plurality of ribs 12, 15a and 15b installed before and after the arm 11b.
Does not increase the load moment.

Further, as shown in this embodiment, the center portion of the load transmitting member 11 is bifurcated and expanded in the width direction (longitudinal direction of the ship) so that the rib 12 and the center pin 14 Not only disperse the load points applied to the anchor panel 5 by increasing the number of pivot points, but also by widening the load points back and forth, it is possible to improve the effect of suppressing the back and forth swing of the pipe tower 3. .

The present invention is constructed as described above.
Even when the temperature inside the hold of the NG ship becomes low and the pipe tower shrinks and the connecting member rises, the point of application of the swaying load of the pipe tower due to the swaying of the ship can always be kept low.

Further, the horizontal load applied to the load transmitting member due to the motion of the ship is dispersed, so that the force transmitted to the anchor panel can be reduced. That is, by the load moment generated in the load transmitting member by the horizontal load,
Of the vertical forces (compressive or tensile) acting on the anchor panel, the anchor panel is not damaged by the compressive force, but may be broken by the tensile force. In the present invention, the tensile force due to the load moment is received at the center of the load transmitting device. However, since the moment due to the horizontal load is small, the tensile force is small and does not adversely affect the anchor panel.

[0019]

As is apparent from the above description, the apparatus for reducing the fluctuation of the pipe tower in the LNG ship according to the present invention is provided with a groove provided opposite to the lower girder of the pipe tower installed in the hold of the LNG ship. The central part is rotatably supported by a plurality of ribs installed on the anchor panel, and the vicinity of both ends is supported so as to be displaceable in the horizontal and downward directions, and both ends are the same. Since the load transmission member is slidably fitted to the connecting member, LNG is loaded in the hold of the LNG ship, and the temperature in the hold changes to a very low temperature, so that even if the pipe tower contracts and deforms, The height of the point of application of the oscillating load of the pipe tower does not change,
In addition, the load applied to the anchor panel can be kept low.

Further, since the configuration is as described above, the following effects can be obtained. (1) A plywood having a high heat-insulating effect, which has not been used conventionally because of insufficient strength, can be used as a material for an anchor panel. (2) Conventionally, when loading LNG, it was only possible to fill the LNG liquid volume to the hold to reduce sloshing. However, the fluctuation of the pipe tower can be reduced reliably and stably. Can be freely selected.

Further, since the above-mentioned load transmitting member is constituted by a body portion which is axially expanded with a central portion forked, and arms provided on both sides of the body portion, the load transmission member is applied to the anchor panel. Not only can the load points be dispersed, but also the swinging of the pipe tower back and forth can be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a lower girder portion of a pipe tower according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a side view of FIG. 1;

FIG. 4 is an enlarged view of the load transmitting member of FIG. 3;

FIG. 5 is a hull center cross-sectional view showing a state of a pipe tower of a conventional LNG ship.

FIG. 6 is an enlarged view of a conventional apparatus for reducing the motion of a pipe tower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer shell 2 Inner shell 3 Pipe tower 5 Anchor panel 8 Lower girder 9 Bracket 10 Connecting member 11 Load transmission member 12, 15a, 15b Rib 14 Center pin 17a, 17b Pin

Claims (2)

(57) [Claims] 1. A pipe tank installed in a hold of an LNG ship.
The central part is formed by a groove-shaped connecting member facing the lower girder of the work and a plurality of ribs installed on the anchor panel.
Are rotatably supported, and the vicinity of both ends is horizontal and
It is supported so that it can be displaced in the downward direction, and both ends are the connecting portions.
And a load transmitting member slidably fitted to the material.
Of sway of pipe tower in LNG ship
apparatus. 2. A method load transmitting member, central portion and the extended barrel portion <br/> width direction I Do bifurcated, provided on both sides of the body portion
Upset mitigation apparatus of the pipe tower in LNG carriers according to claim 1, characterized by being configured by an arm portion.