JPH0447725B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a floating oil embankment for offshore oil storage tanks.

[Conventional technology]

Conventionally, in the case of offshore oil storage tanks, in preparation for an oil spill accident, the sea surface around the offshore storage tank has been set at multiple heights h as shown in the partial plan view of Figure 13 and the partial front view of Figure 14. The floating oil embankments 1 are surrounded by floating oil embankments 1, and both ends of each floating oil embankment 1 are movable up and down according to the tide along the grooves at the top of pedestals 2 established on the seabed at appropriate intervals. Installed.

The mounting structure is, for example, as shown in the partially enlarged front view of FIG. 15 and the partially enlarged plan view of FIG. When a large roller 7 pivotally attached to roller shafts 6 protruding from the upper and lower ends of both ends of the floating oil embankment 1 is inserted into the rigid grooves 5 of the pillar 2. In addition, a small roller 8 protruding through a protrusion between the upper and lower large rollers 7, 7 rolls along the bottom of the hard groove 5 to move each floating oil embankment as the tide rises. Projections are provided on the sides of the protrusions 9 at both ends of the floating oil embankment in order to smoothly raise and lower the oil embankment 1 and to contain the spilled oil inside the floating oil embankment in case of oil spillage from the offshore storage tank. By abutting the hard seal 10 thus formed against the opposing seal surfaces 11 of the U-shaped guide groove of the pedestal 2, a slidable seal is created between the floating oil embankment 1 and the pedestal 2.

In such a floating oil embankment, the floating oil embankment can be raised and lowered in a liquid-tight manner relative to the pillars, and even if a head difference occurs between the inner and outer sea surfaces due to spilled oil, the floating oil embankment Embankments can contain oil spills.

[Problem that the invention seeks to solve]

However, in such floating oil embankments, steel is generally used for the sealing surface, so
Marine organisms such as barnacles adhere to the seal rubber, causing abnormal wear, shortening the seal's service life and reducing sealing performance. In the event of a fire, the seal rubber may burn and lose its sealing effect.

The present invention was proposed in view of the above circumstances, and an object of the present invention is to provide a floating oil embankment for an offshore oil storage tank that ensures sealing performance, is safe against fire, and is highly reliable. .

[Means for solving problems]

To this end, the present invention establishes a plurality of pedestals on the seabed so as to surround an offshore oil storage tank, and extends a floating oil embankment between the upper parts of the adjacent pedestals, projecting laterally from both ends of the pedestal. By bringing the sealing member extending in the rigid direction into contact with the opposing seal surfaces of the guide grooves of the pillars, each floating oil dike can be raised and lowered relative to each pillar in a liquid-tight manner according to the tide level, thereby creating an offshore oil storage tank. In this device, oil leaking from the floating oil levee is contained inside the floating oil levee, and a rigid lip seal is installed at each end of the floating oil levee and protrudes laterally and extends in the rigid direction, and A rigid metal blade is provided on each section of the lip seal and has a height slightly lower than that of the lip seal, and is attached to the opposite surface of the guide groove on the upper part of the column and is at least partially liquid-tight in the lateral direction. a hard seal plate that is retractably attached to the lip seal and always comes into contact with the tip of the lip seal; and a hard seal plate that is attached to the pedestal and at least a portion of the hard seal plate is made to protrude laterally as necessary, and is attached to the top of the metal blade. It is characterized by comprising a hard seal plate moving means that is brought into contact with the tip.

[Effect]

With such a configuration, it is possible to obtain a floating oil embankment for an offshore storage tank that ensures sealing performance, is safe against fire, and has a long life.

〔Example〕

Embodiments of the present invention will be explained with reference to the drawings. FIG. 1 is a partial plan view showing the seal portion of the first embodiment, FIG. 2 is a vertical sectional view of FIG. 1, and FIG. 3 is a second embodiment thereof. 4 is a longitudinal sectional view of FIG. 3, FIG. 5 is a partial plan view of the sealing portion of the third embodiment, and FIG. 6 is a longitudinal sectional view of FIG. 5. , FIG. 7 and FIG. 8 are partial plan views showing a modified example of the metal blade shown in FIG. 5, FIG. 9 is a partial plan view showing a seal portion of the fourth embodiment, and FIG. Cross-sectional view along line X-X in Figure 1
Figure 1 is a partially enlarged view showing the seal part in Figure 9.
FIG. 2 is a partially exploded perspective view showing the seal plate of FIG. 11.

First, in the first embodiment shown in FIGS. 1 and 2,
The same symbols as in Figures 13 to 16 are shown in Figures 13 to 16, respectively.
The same members as in Fig. 16 are shown, and 119 is a seal fixing member protruding from the protrusion 9 of the floating oil embankment, and 120 is a seal fixing member that is sandwiched between a lip seal pressing plate 121 and a metal seal blade plate 122 and is inserted through the seal fixing member 119. A rubber lip seal protruding from the protrusion 9, 1
Reference numeral 23 denotes a rotary seal plate pivotally connected to the rotary plate support member 125 via the vertical rotation shaft 124, 126 a stopper surface of the rotary seal plate, and 127 a stopper surface protruding from the rotary plate support member 125. , 128 is a rubber seal affixed to the outer periphery of the pivot end of the rotary seal plate 123, 129 and 130 are mounting screws, and 131
132 is a bearing provided on the seal structure lower lid 131 and pivots the lower end of the vertical rotation shaft 124; 133 is a seal structure upper lid; 134 is a vertical rotation shaft provided on the seal structure upper lid 133. 1
24, 135 and 137 are coupling rings that coaxially connect the upper end of the vertical rotation shaft 124 and the lower end of the worm wheel shaft 138 via the elastic torsion plate 36, and 139 projects on the vertical rotation shaft 124. A thrust bearing plate 140 is provided, and a thrust bearing 141 is provided protrudingly on the upper lid 133 of the seal structure.
is the middle cover, 142 is the upper cover, 143,1
44 is a bearing, 145 is a worm wheel fitted on the worm wheel shaft 138, 146
is a worm that meshes with the worm wheel 145,
147 is a worm shaft.

In such a seal structure, the rotary seal plate 123 rotates around a rotation shaft 124, and the rotation shaft 124 is connected to the seal upper lid 133 and the seal lower lid 1.
Positioning is performed by bearings 134 and 132 fixed to the rotating shaft 124, and a thrust receiving plate 139 is protruded from the upper part of the rotating shaft 124.
The dead weight of 23 is transferred from the thrust bearing plate to the thrust bearing 1.
40 to the seal upper lid 133, and further the rotation shaft 124 is connected to the coupling rings 135, 141.
and is connected to a drive device via an elastic torsion plate 136.

As the drive device, a worm wheel 145 and a worm 146 are used that can output a large torque with a small torque and are capable of automatic locking, and are equipped with a motor drive and a manual drive that automatically operate in response to an abnormal oil spill signal. and performs the following actions.

(1) Normally; Normally, the lip seal 120 is connected to the rotary seal plate 12.
It always slides in contact with 3 under a light load, and if a small amount of oil leaks out, a lip seal 120 and a rubber seal 128 perform a sealing action.

(2) In an emergency; In an emergency such as when a large amount of oil spills or a fire occurs, the rotary seal plate 123 rotates around the rotary shaft 124 and contacts the metal seal blade plate 122. When they come into contact and rotate further, the surfaces of the stoppers 126 and 127 come into contact and stop rotating, and the contact pressure of the sealing surfaces is made to be higher than the static pressure of the oil layer.

According to such a seal structure, the following effects can be achieved.

(1) The lip seal is always in contact with the rotating seal plate,
By sliding, living things such as barnacles can be prevented from adhering, and the sealing surface can be maintained in good condition.

(2) In an emergency, the seal contact pressure becomes higher than the head difference between the oil and seawater, which can prevent oil spills.

(3) Even in the event of a fire, the sealing surfaces come into contact with the metal surfaces, so sealing performance can be maintained.

(4) The rotary plate drive device operates by an electric method or a manual drive method that can be driven quickly by catching an abnormal signal, and if it malfunctions,
Even if the emergency situation is lifted, you can quickly recover.

Next, in the second embodiment shown in FIGS. 3 and 4,
The same symbols as in the first embodiment indicate the same members as in the first embodiment, and 219 is a seal fixing member;
20 is a rubber lip seal, 221 and 222 are metal stopper blades, 223 is a spacer, 224 is a mounting bolt, 225 is a pop-out seal plate, 226 is an extrusion shaft, and 227 is a lateral support at the inner end of the extrusion shaft 226. A protruding stopper, 228 a rotating shaft, 229 a rotating shaft 228
230 is a pop-out seal plate support member, 231 is a guide bearing,
232 is a spring, 233 and 234 are seals, 23
5 is a back plate, 236 is a mounting screw, 237 is a seal structure lower cover, 238 is a bearing, 239 is a seal structure upper cover, 240 is a bearing, 241 is a thrust plate, 2
42 is a thrust bearing, 243 is a coupling, 2
44 is a worm wheel shaft, 245 is a bearing support plate, 246 is a bearing, 247 is a drive device cover, 2
48 is a worm wheel, 249 is a worm, 2
50 is a pin, 251 is a guide plate, 252 is a slide plate, 253 is a gear, 254 is a linear bearing, and 255 is a bearing.

In such a structure, the worm wheel shaft 244 is connected to the rotation shaft 22 through the coupling 241.
8 and is pivotally supported by bearings 246 and 255, and a worm wheel 248 is fitted therein, and a pin 250 is provided on the worm wheel 248 to project downward.

The pin 250 is normally inserted into the slide plate 252, but in an emergency, the gear 253 is driven by a motor or manually moved down along the guide plate 251 to move the slide plate 252 into the pin 250.
When the pin 250 is pulled away from the pin 250, the pin 250 is unlocked, the rotation shaft becomes free to rotate, and the pop-out seal plate is caused to protrude outward due to the spring force.

(1) Normally; Normally, the sealing surface of the pop-out seal plate 225 is
without coming into contact with the metal stopper blades 221, 222 attached to the seal fixing member 219.
The lip seal 220 is set in such a position that it is always in contact with the lip seal 220.

A spring 232 is attached to the back of the pop-out seal plate 225.
The spring 232 is pre-compressed so that even when the pop-out seal plate pops out and comes into contact with the metal stopper blades 121, 122, the compressive force necessary for the sealing action is generated.

Push-out shaft 22 fixed to the pop-out seal plate
A stopper 127 is fixed to the end of the rotary shaft 228, and the stopper 227 is normally locked by a stopper receiver 129 fixed to a rotating shaft 228 to prevent the pop-out seal plate from popping out due to spring force.

Normally, the lip seal 220 always comes into contact with the protruding seal plate 225 under a light load, and slides due to fluctuations in the tide level, etc., and even if a small amount of oil spills out, the lip seal 220 performs a sealing action.

The inflow of seawater and oil to the rear surface of the pop-out seal plate is sealed by a rubber seal 234 and a seal 223 made of a flame-retardant material such as graph oil.

(2) In an emergency: In an emergency such as when a large amount of oil spills or a fire breaks out, the locking mechanism of the drive device is released, the rotation shaft 228 is free to rotate in the R direction, and the stopper receiver 229 and The contacting stopper 227 is also unlocked, the push-out shaft 226 and the pop-out seal plate 225 are pushed outward by the spring force, and the pop-out seal plate 225 comes into contact with the metal stopper blades 221, 222 to perform a sealing action.

After the emergency state is released, the worm wheel 248 and the worm 249, which are not normally in mesh with each other, are brought into mesh with each other, and the worm wheel shaft and rotation shaft 228 are reversed by driving the worm wheel 249, and the pop-out seal plate 225 is moved. Return to normal state.

After returning to the normal state, insert the slide plate into the pin 250 again to lock the worm 24.
9 releases the meshing with the worm wheel 248.

According to such a structure, the following effects can be achieved.

(1) The lip seal pops out and constantly contacts and slides against the seal plate, which prevents living organisms such as barnacles from adhering to it and maintains a good seal surface.

(2) In an emergency, oil spillage can be prevented by setting the contact pressure between the pop-out seal plate and the metal stopper blade to be higher than the head difference between the oil and seawater.

(3) Even in the event of a fire, the sealing surfaces are made of flame-retardant material such as graph oil, with metal surfaces in contact with each other and very narrow gaps, so oil leakage can be prevented and sealing performance can be maintained.

(4) By catching an emergency signal, the pop-out seal plate drive device can be used as either an electric drive method or a manual drive method, which quickly drives the device, and can quickly recover even if it malfunctions or if the emergency situation is lifted.

Furthermore, in the third embodiment shown in FIGS. 5 to 8, 319 is a seal fixing member, 320 is a lip seal, 321 and 322 are metal stopper blades, 323 is a spacer, 324 is a mounting bolt, 325 is a pop-out seal plate, 326 is an extrusion shaft, 327 is a cam receiving plate, 328 is a cam shaft, 3
29 is a cam, 330 is a pop-out seal plate support member, 331 is a guide bearing, 332 is a spring, 333
is a seal, 334 is an O-ring, 335 is a back plate, 3
36 is a mounting screw, 337 is a seal structure lower lid,
338 is a bearing, 339 is a seal structure upper lid, 34
0 is a bearing, 341 is a thrust plate, 342 is a thrust bearing, 343 is a coupling, 344 is a worm wheel shaft, 345 is a center cover, 346 is a bearing, 347 is an upper cover, 348 is a worm wheel, 349 is a worm, 350 is a bearing , 351
is the bottom cover.

In such a structure, the camshaft 328 is connected to the wormwheel shaft 34 via the coupling ring 343.
A worm wheel 348 is fixed to the worm wheel shaft 344, and the worm wheel meshes with a worm 349.

Normally, the worm wheel and worm are in mesh, so rotation of the worm wheel shaft is restricted, but in an emergency, the worm is driven by a motor or manually and the worm wheel shaft and cam shaft are rotated 180 degrees.

(1) Normally: Normally, the sealing surface of the pop-out seal plate 325 is in a position where it always contacts the lip seal 320 without contacting the metal stopper blades 321 and 322 protruding from the seal fixing member 319. A spring 332 is loaded on the back of the pop-out seal plate, and the spring 332 is set so that the compressive force necessary for the sealing action is generated even when the pop-out seal plate pops out and comes into contact with the metal stoppers 321 and 322. is in a pre-compressed state.

Push-out shaft 32 fixed to the pop-out seal plate
A cam receiving plate 327 is fixed to the end of 6, and in order to prevent the seal plate from popping out due to spring force, the cam receiving plate 327 is held opposite the sealing surface by an eccentric cam 329 of a camshaft 328. It is in a state of being pushed to the side.

Normally, the lip seal 320 always comes into contact with the protruding seal plate 325 under a light load and slides due to movement due to changes in the tide level, etc., and even if a small amount of oil spills out, the lip seal 320 performs a sealing action.

(2) Emergency: In an emergency such as when a large amount of oil spills or a fire breaks out, the camshaft 328 is moved by the drive device.
The cam receiving plate 327 rotates 180 degrees, and since the spring 332 exerts a tensile force in the direction of the sealing surface, the cam receiving plate 327 moves in the direction of the sealing surface as the camshaft rotates.
25 similarly moves toward the sealing surface, and the protruding sealing plate comes into contact with the metal stopper blade to perform a sealing action.

After the emergency state is released, the normal state can be restored by reversing the worm 180 degrees.

According to such a structure, the following effects can be achieved.

(1) The lip seal pops out and constantly contacts and slides against the seal plate, which prevents living organisms such as barnacles from adhering to it and maintains a good seal surface.

(2) In an emergency, oil spillage can be prevented by setting the contact pressure between the pop-out seal plate and the metal stopper blade to be higher than the head difference between the oil and seawater.

(3) Even in the event of a fire, the sealing surfaces are in contact with metal surfaces and are sealed with flame-retardant material in very narrow gaps, which prevents oil spills and maintains sealing performance.

(4) By catching an emergency signal, the pop-out seal plate drive device can be used for both electric or manual drive methods, which can be driven quickly, and can be easily restored even in the event of a malfunction or when the emergency situation is lifted.

Incidentally, since the metal stopper blades 321 and 322 shown in FIG. 5 are always in a seawater atmosphere, they are subject to biological attachment such as potholes and seawater corrosion.
In an emergency situation, there is a risk of seal failure, so
As shown in Fig. 7, a rubber cover or a copper-based metal cover 352 to which living organisms do not easily adhere is attached to the metal stopper blade, and if it comes into contact with the seal plate that pops out in an emergency, the contact pressure will By having a structure in which the cover 352 is cut, sealing performance can be improved.

In addition, as shown in Fig. 8, the tips of the metal stopper blades 321 and 322 are made of a material with good flame retardancy and seawater resistance, such as neoprene rubber, ethylene propylene rubber, graph oil, etc., as well as the lip seal material. A seal 353 is fitted to perform a sealing action when a large amount of oil spills in an emergency.

Since this seal does not cause metal-to-metal contact even when a large amount of oil spills and acts as a seal, abnormal wear of the seal portion can be prevented.

Furthermore, even if the sealing material burns in the event of a fire, the sealing action is still possible due to the contact between the metal stopper blade and the pop-out sealing plate.

Finally, in the fourth embodiment shown in FIGS. 9 and 10, the same symbols as in FIGS.
5 to 16 show the same members, 404 is a protruding seal plate attached to the sealing surface facing the protrusion 450 of the guide groove member 405, 406 is a bearing metal fitted into the center hole of the large roller 7, 407
408 is a seal ring that is fitted onto the roller shaft 6 and seals the center hole of the large roller 7; 408 is a seal cover that seals the outer end of the center hole of the large roller 7;
11 is a seal, 412 is a spring, 413 is an O-ring, 414 is a support rod, 415 is a seal plate support member, 416 is a diaphragm seal, 417 is a metal seal blade, 418 is a pin, 419 is an upper lid,
450 is a protrusion.

In such a structure, the pop-out seal plate 4
A spring 412 is loosely inserted into a support rod 414 protruding from the inner recess of 04, and the inner end of the support rod 414 is slidable and liquid-tight into the mounting hole of the seal plate support member 415 via an O-ring 413. The support rod 41
4 is a spring 41 via a penetrating lock pin 418.
2 is locked to the seal plate support member 415 in a compressed state, and the gap between the outer periphery of the pop-out seal plate 404 and the recessed opening of the seal plate support member 415 is liquid-tightly and flexibly sealed by a diaphragm seal 416. The upper end of the seal plate support member 415 is closed by an upper lid 419.

On the other hand, a seal 411 and a metal seal blade 417 made of copper or the like with a sharp tip are attached to the protrusion 450.

Although not shown, the pin 418 is urgently removed in response to an oil leakage signal, and the restoring force F of the spring 412 allows the seal plate 404 to press the seal 411 while measuring the distance S until it abuts the metal seal blade 417. Moving.

According to such a structure, the following effects can be achieved.

(1) By adopting a sealing mechanism that prevents oil from flowing out to the ocean only in the event of an oil leakage, there is usually no wear on the seal due to light contact, improving durability and reliability.

(2) Integrating the seal plate, support member, etc. makes maintenance easier.

(3) By providing the diaphragm seal 416 and the top cover 419 on the moving seal plate 404,
Seawater does not enter between the seal plate 404 and the support member 415, marine microorganisms do not adhere to the moving surface, and movement in an emergency becomes smooth.

(4) Move the emergency seal plate and attach it to Seal 4.
11 to seal the oil, and even in the unlikely event that the oil catches fire, the non-flammable metal seal can seal the oil.

(5) To prevent marine microorganisms from affecting the sealing surface,
The seal 411 constantly contacts with low sealing surface pressure to prevent the generation of microorganisms, and the metal seal blade has a sharp shape that destroys microorganisms generated on the sealing surface when it comes into contact with the sealing surface, thereby creating a good sealing surface. It can be effective.

(6) By inserting two or more guide rollers into the U-shaped guide groove to support the floating oil embankment, the wave force and wobbling acting on the floating oil embankment are reduced and the sealing performance is stabilized. .

〔Effect of the invention〕

In short, according to the present invention, a plurality of pedestals are established on the seabed so as to surround an offshore oil storage tank, and a floating oil embankment is placed between the upper parts of the adjacent pedestals, and a floating oil embankment is provided at both ends of the pedestal that protrudes laterally. By bringing a sealing member extending in the rigid direction into contact with the opposite sealing surface of the guide groove of the pedestal, each floating oil embankment can be raised and lowered in a liquid-tight manner opposite to each pedestal according to the tide level. In a device designed to contain oil leaking from a storage tank inside a floating oil embankment, there are hard lip seals that project laterally at both ends of the floating oil embankment and extend in the rigid direction, and a floating oil embankment. A rigid metal blade is provided at both ends of the pedestal and protrudes parallel to the lip seal and has a height slightly lower than the height of the lip seal, and a hard metal blade is attached to the opposing surface of the guide groove at the top of the pillar and at least a portion thereof extends in the lateral direction. A hard seal plate is attached to the lip seal so as to be retractable in a liquid-tight manner and is always in contact with the tip of the lip seal; A long-life and safe float for offshore oil storage tanks that prevents oil from leaking to the outside even in the event of an oil spill or fire, as it is equipped with a rigid seal plate moving means that comes into contact with the tip of the made blade. Since oil embankments can be obtained, the present invention is extremely useful industrially.

[Brief explanation of the drawing]

FIG. 1 is a partial plan view showing a sealing portion of a first embodiment of the present invention, FIG. 2 is a vertical sectional view of FIG. 1, and FIG. 3 is a partial plan view showing a sealing portion of a second embodiment of the present invention.
4 is a longitudinal sectional view of FIG. 3, FIG. 5 is a partial plan view showing the seal portion of the third embodiment, and FIG.
The vertical cross-sectional views in the figure, Figures 7 and 8 are respectively
A partial plan view showing a modification of the metal blade shown in the figure.
Fig. 9 is a partial plan view showing the seal portion of the fourth embodiment, Fig. 10 is a cross-sectional view taken along line X-X in Fig. 9, and Fig. 11 is a partially enlarged view showing the seal portion of Fig. 9. 12 is a partially exploded perspective view showing the seal plate of FIG. 11. Fig. 13 is a partial plan view showing a known floating oil embankment for offshore oil storage tanks, Fig. 14 is a partial front view of Fig. 13, and Fig. 15 shows a seal portion of the floating oil embankment shown in Fig. 14. Partially enlarged longitudinal sectional view, No. 16
The figure is a plan view of FIG. 15. 1... Floating oil embankment, 2... Pillar, 3, 4... Guide steel, 5... Hard groove, 6... Roller shaft, 7...
Large roller, 8...Small roller, 9...Protrusion, 1
0...Hard seal, 11...Seal surface, 119...
Seal fixing member, 120... Rubber lip seal, 121... Lip seal presser plate, 122...
Metal seal blade plate, 123... Rotating seal plate, 124... Rotating shaft, 125... Rotating plate support member, 126... Stopper surface, 127... Stopper surface, 128... Rubber seal, 129 ,13
0...Mounting screw, 131...Seal structure lower lid,
132...Bearing, 133...Seal structure upper lid,
134... Bearing, 135... Coupling, 13
6...Elastic torsion plate, 137...Cup ring,
138... Worm wheel shaft, 139... Thrust receiving plate, 140... Thrust bearing, 141...
...Middle cover, 142...Top cover, 143,
144... Bearing, 145... Worm wheel,
146... Worm, 147... Worm axis, 2
19... Seal fixing member, 220... Rubber lip seal, 221, 222... Metal stopper blade, 223... Spacer, 224... Mounting bolt, 225... Pop-out seal plate, 22
6... Extrusion shaft, 227... Stopper, 22
8...Rotation axis, 229...Stopper receiver, 23
0... Pop-out seal plate support member, 231... Guide bearing, 232... Spring, 233, 234...
Seal, 235...Back plate, 236...Mounting screw, 237...Seal structure lower cover, 238...Bearing, 239...Seal structure upper cover, 240...Bearing, 241...Thrust plate, 242...Thrust Bearing, 243... Coupling, 244... Worm wheel shaft, 245... Bearing support plate, 246
... Bearing, 247 ... Drive device cover, 248 ...
...worm wheel, 249...worm, 25
0... Pin, 251... Guide plate, 252... Slide plate, 253... Gear, 254... Linear bearing, 255... Bearing, 319... Seal fixing member, 320... Lip seal, 321, 32
2...Metal stopper blade, 323...Spacer, 324...Mounting bolt, 325...
Pop-out seal plate, 326... Push-out shaft, 32
7...Cam receiving plate, 328...Cam shaft, 329...
...Cam, 330...Protrusion seal plate support member,
331...Guide bearing, 332...Spring, 333
... Seal, 334 ... O-ring, 335 ... Back plate, 336 ... Mounting screw, 337 ... Seal structure lower lid, 338 ... Bearing, 339 ... Seal structure upper cover, 340 ... Bearing, 341 ... ... Thrust plate, 342 ... Thrust bearing, 343 ... Coupling, 344 ... Worm wheel shaft, 345
... Central cover, 346 ... Bearing, 347 ... Upper cover, 348 ... Worm wheel, 349
... Worm, 350 ... Bearing, 351 ... Lower cover, 352 ... Cover, 353 ... Seal,
404... Protruding seal plate, 405... Guide groove member, 406... Bearing metal, 407... Seal ring, 408... Seal cover, 411...
Seal, 412... Spring, 413... O-ring,
414... Support rod, 415... Seal plate support member, 416... Diaphragm seal, 417...
Metal seal blade, 418...Lock pin, 4
19...Top lid, 450...Protrusion.

Claims (1)

[Claims] 1 A plurality of pedestals are established on the seabed to surround an offshore oil storage tank, and a floating oil embankment is installed between the upper parts of the adjacent pedestals, and a seal is provided at both ends of the dam that protrudes laterally and extends in the rigid direction. By contacting the members with the opposing seal surfaces of the guide grooves of the pedestals, each floating oil dike can be raised and lowered relative to each pedestal in a liquid-tight manner according to the tide level, and oil leaking from offshore oil storage tanks can be removed. In the oil embankment, which is to be contained inside the floating oil embankment, there are hard lip seals that protrude laterally at both ends of the floating oil embankment and extend in the rigid direction, and the lip seals are provided at both ends of the floating oil embankment, respectively. A hard metal blade that protrudes parallel to the lip seal and has a height slightly lower than the height of the lip seal, and is attached to the opposing surface of the guide groove at the top of the pedestal so that at least a part of the blade can protrude and retract laterally in a liquid-tight manner. a hard seal plate that is always in contact with the tip of the lip seal; and a hard seal plate that is attached to the pillar and at least a portion of the hard seal plate is made to protrude laterally as necessary so as to come into contact with the tip of the metal blade. A floating oil embankment for an offshore petroleum storage tank characterized by comprising a hard seal plate moving means.