JPS626157B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tank device for liquid storage, especially natural gas, petroleum gas, ethane gas, ethylene gas,
and land storage tanks for storing toxic gases such as ammonia and chlorine, and other liquefied gases at room temperature or below, and at normal pressure or above normal pressure.

British Patent No. 1522609 and British Patent No. 15830291 disclose a tank formed by connecting a plurality of specially designed shell plates for ships or barges for transporting large quantities of liquefied gas by sea. ing.

From the viewpoint of the shape of the hull of the ship or barge, as well as cost and volume economy, it is preferable for the tank to be generally cylindrical or prismatic. However, from the viewpoint of functional efficiency as a tank, the wall of the tank However, it is preferable to receive only tensile force without receiving bending force.

A tank arrangement design for this purpose is disclosed and claimed in the aforementioned GB 1522609. To be more specific, the tank is made up of a large number of body plates that are connected in the front-rear and vertical directions by appropriate support frames, and the overall shape of the tank made up of these many body plates is generally cylindrical or cylindrical. It has a prismatic shape. On the other hand, British Patent Application No. 37247/76 proposes an improvement to the frame structure for this purpose.

Since the invention relates in particular to land-based storage tanks, as in the case of ships or barges,
There are no restrictions on the shape or dimensions of the tank due to the geometry of the ship's hull, and it is also a primary object of the present invention to provide a tank system having a shell-connected tank that is particularly suitable for use as a land storage tank.

According to the present invention, there is provided a tank having a generally rectangular cross section consisting of a bottom plate, a top plate, and a pair of side walls and end walls facing each other, and having a heat insulating effect as well as withstanding internal pressure; is composed of a plurality of equal-sized body plates, and these body plates are partially cylindrical and convex outward, and their adjacent inward edges along the axial direction are connected to each other. and the end wall is composed of a plurality of truncated end wall elements having a radius of curvature similar to that of the body plate, and each end wall element is connected to each other by adjacent inward edges. and a liquid storage tank device in which the bottom plate, the top plate, the side walls, and the end walls are connected to each other by being connected to the bottom plate, the top plate, and the side walls, wherein each side wall of the tank is connected to the bottom plate, the top plate, and the side walls. , each consisting of one body plate of equal size, with an internal reinforcing member extending from the connection of adjacent body plates of the bottom plate to the connection of the opposing top plate and of the opposite connection of the end wall elements. consisting only of a series of parallel reinforcing plates connecting the end walls to each other in the axial direction, the tank being covered by an outer wall spaced apart from the tank, with a heat insulating material and A generally flat roof filled with an inert gas encloses the tank, the supports of the roof supporting supports of the top plate of the tank supported at connections between adjacent shell plates. and wherein the roof section is supported by the tank.

The connection of two adjacent shell plates is achieved by welding the two side arms of a generally Y-shaped insert, with the central arm protruding from the tank wall towards the inside of the tank. , preferably welding the periphery of each partition to its inner end.

In order to facilitate understanding of the present invention and clarify its characteristics, one embodiment based on the present invention will be described below with reference to the accompanying drawings.

The tank 1 has a generally rectangular or square shape when viewed from above, and is heated under an absolute pressure of 1 to 10 atmospheres.
Large quantities of liquefied natural gas can now be stored.

The tank 1 is made of a type of steel that does not show brittleness at low temperatures, such as 9% nickel-containing steel or stainless steel, or a suitable aluminum alloy, and has a cylindrical shape with a convex outer surface and an arcuate cross section. The tank includes a top plate A, a bottom plate B, two side walls C, and an end wall D, which are formed by connecting a large number of body plates 2 and 3 arranged in parallel over the entire length of the tank.

The planar dimensions can be changed as appropriate depending on the location where the tank is constructed. That is, by increasing the length of the body plates 2 and 3 or by increasing the number of intermediate body plates 3, the length or width of the entire tank can be increased.

According to the present invention, a tank consisting of only one row of body plates is provided, and does not require any frame structure, plate member, or other structure for horizontally connecting the body plates.

The two side walls C form an arc of approximately 270 degrees when viewed in FIG. 1, where a cross section of the tank is shown. Further, the intermediate body plate 3 has a top plate and a bottom plate formed by an arc of about 90 degrees centered on two points offset from the center of the tank.

The end wall D of the tank is made of a mirror plate 4 having a spherical shape, and seals both ends of the body plates 2 and 3 in the front and rear direction. The body plate 3 and the end plate 4 each have the same radius of curvature in the direction perpendicular to the front-rear direction of the tank, and the chord lengths of the intermediate body plates 3 are the same, so these The body plate can be of modular construction.

The radius of curvature of each end plate 4 in the vertical direction is equal to or larger than the radius of curvature in the direction orthogonal to the longitudinal direction of the tank.

Next, the body plate 2 at the side end will be explained with reference to the one on the left in FIG.

The inner half of the body plate 2 indicated by the symbol E is equal to the half of the intermediate body plate 3, and the radius of curvature in the vertical direction of the outer half of the body plate 2 indicated by the symbol F is equal to the center of the end plate 4. It is equal to the radius of curvature of the end plate 4 in the vertical direction on the vertical line passing through.

In particular, as clearly shown in FIG. 3, at the joint of each body plate, that is, at the joint between the arcs of adjacent body plates, there is an annular insertion member 5 having three arms forming a generally Y shape. , is provided as a welded joint member between adjacent shell plates.

As shown, the side arms 6, 7 of the annular insert 5
are arranged so as to align with the edges of the top plate 2, bottom plate 3, and mirror plate 4 of the body plate, and are welded against each other. Moreover, the central arm 8 of the annular insert member is
It penetrates into the tank at right angles to the tank wall.

An important feature of the present invention is that a partition wall 9 made of a flat plate is supported by butt welding over the entire circumference of the inwardly facing free end of each annular insertion member 5.

Thereby, the bulkhead 9 is located inside the tank and plays the role of a reinforcing connecting member, especially against tensile forces, when the tank is empty, and also extends over the entire width of the tank.
Shell plates 2, 3 to form independent storage compartments
It plays the role of dividing the space.

Looking at Figures 1 and 2, it can be seen that the tank is of low size. For safety reasons, it is highly preferred that any land-based storage tank be located at least partially within a dike that is below ground level.

As shown in the figure, the oil dike consists of a lower part formed by excavation and an upper part formed by heaping the remaining soil 12 from the excavation above the ground surface 13. Furthermore, the oil embankment has side walls and end walls made of reinforced concrete.
4, and the tank 1 is successively built inside it.

It will be seen that this construction work can be accomplished extremely easily by using the modular intermediate shell plate 3. In addition, if it is desired to obtain a desired storage capacity, it is sufficient to form an oil barrier having a length and width that can accommodate the required number of end portions and intermediate shell plates 2, 3 having predetermined dimensions.

In this embodiment, the body plates 2 and 3 of the tank are as follows:
It is supported by a pair of bottom support brackets 15 facing in the front-rear direction and provided for each connecting portion between the arcs of the bottom plate. Details of these support brackets will be explained later.

In addition, in order to prevent the end body plate 2 from sagging especially when the tank is not pressurized, the first
As shown, a support band 17 is stretched across the adjacent side wall 14 and the base. Alternatively, a supporting block made of rigid foam glass and having a suitably concave upper surface, as indicated by the dashed line 16, may be provided.

To obtain the required insulation, the space between the tank and the dike must be of sufficient thickness and quality to maintain the stored gas in a liquid state with only a controlled and relatively small pressure increase. It is filled with a heat insulating material 18 comprising. Perlite is suitable as this heat insulating material.

On top it is necessary to protect the insulation material against weather changes. Furthermore, it is necessary to seal the space around the tank so that it can be covered with an inert gas such as nitrogen. To this end, the roof 19 must be sealed against the side walls of the dike.
All you have to do is set it up.

This roof 19 needs to have sufficient strength to withstand weather changes. This purpose
In order to achieve a relatively lightweight construction, the roof is provided with legs 33 which are supported by the upper part of the shell plate connection of the tank. By doing this, you can cover a long section with a roof.

In order to detect gas leaks early and to make it easier to locate them, the space between the tank and the dike is divided into shell plates, and within each section the tank is surrounded. It is also possible to install gas detectors. By doing this, it is possible to discover in which compartment of the tank the gas has leaked by sampling the nitrogen gas in the individual compartments with a suitable detector.

Referring again to Figure 3, the tank bottom support bracket 15 is similar to that disclosed in British patent application no. At the top, there is an upwardly tapered sleeper 24 made of resin-impregnated plywood or hard wood that can withstand loads and has a heat insulating effect.
It is provided via a dish-shaped saddle 23.

As mentioned above, the support brackets are installed at the bottom of the connecting portion of the body plate, facing in the front-rear direction and spaced apart from each other laterally.

In one embodiment of the above tank for storing 230,000 ^m3 of liquefied natural gas at an absolute pressure of 50 atm, the total length and width of the tank is 128 m, and the depth is 16 m.
m, the radius of curvature of the end body plate and end end plate 4 is 8.
m, and the lateral radius of curvature of the top and bottom surfaces of the body plate and the end mirror plate 4 is approximately 5.7 m. The interval between partition walls 9 made of flat plates in the tank 1 is 8 m.

For example, the thickness of an insulating material made of perlite is
It is preferable that the length is approximately 1 m. In this way,
The pressure increase per week will be in a controlled range of less than 1 atmosphere. In other words, the amount of evaporation per day is
This will amount to less than 0.05% of the storage capacity.

As mentioned above, an important feature of the tank according to the invention is its low profile, which allows it to be installed economically, to a large extent or in its entirety, below the surface of the earth. Its unique design also allows the tank to be laterally flexible and expandable in the front-back direction to accommodate thermal expansion or contraction during use.

Another important feature of the tank according to the invention is that it has a bulkhead 9 with a dual purpose. That is, this bulkhead 9 not only serves to stiffen the tank against internal pressure and provide a solid enough structure to hold the tank when it is empty, but also to effectively divide the tank into a number of separate compartments. It is divided into parts to increase its security. As a result, cracks, damage, etc. are limited to only one compartment, and leakage of liquefied natural gas is limited to that compartment.

In use, each compartment will leave some void space even when the tank is filled, and if for any reason there is a leak in one compartment, the liquefied natural gas in that compartment will be immediately drained to its designated location. It can be discharged to an evaporator, combusted, or transported into other compartments using the gas and liquid lines described below.

After this transfer operation, if, for example, there is a significant gas leak, it is necessary to reduce the pressure in the leaking compartment. In that case, a large pressure difference occurs between adjacent compartments, but this pressure difference can be absorbed by elastic deformation of the partition wall 9,
The safety of the leaked compartment and adjacent compartments is maintained.

Since the tank is effectively divided into a number of independent compartments, it is necessary to provide suitable ductwork to connect these compartments. Code 2 in Figure 2
9 and 30 indicate a liquid supply/discharge pipe and a gas pressure adjustment pipe, respectively, which are connected to the valve 3.
4 and 35 to a common liquid header 31 and gas header 32, respectively.

It goes without saying that, in use, the liquid and gas valves are normally open in order to equalize the pressure in all compartments.
Valves also isolate leaky compartments and
Using gas pressure, it is possible to transfer the liquid contents to other compartments or to another predetermined evaporation plant.

In addition, the pressure resistance capacity of the tank is determined by discharging the gas in the space through the gas header 32 and circulating it through the liquid header 31 when filling the tank with liquid.
It will also be readily appreciated that sufficient pressure may be generated to liquefy the gas again.

Another advantage of storing liquefied gas under pressure is that the liquid can be drained and pumped by pumps placed above the ground outside the tank. By doing so, the pump can be easily inspected or repaired.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway longitudinal sectional front view of an embodiment of a storage tank according to the present invention, FIG. 2 is a longitudinal sectional side view taken along the line - in FIG. 1, and FIG. FIG. 3 is a longitudinal section of the tank and an enlarged partial view showing the tank support bracket. A...Top plate, B...Bottom plate, C...Side wall, D...End wall, E
... Inner half of end body plate, F... Outer half of end body plate, 1... Tank, 2, 3... Body plate, 4... Head plate, 5...
Annular insertion member, 6, 7...side arm, 8... central arm, 9...
Partition wall, 12... Remaining soil, 13... Ground surface, 14... Side wall,
15...Support bracket, 16...Support block, 1
7...Support band, 18...Insulating material, 19...Roof,
21... Support leg, 22... Pedestal, 23... Saddle part, 24... Sleeper, 29... Liquid supply and discharge pipe line, 30... Gas supply and discharge pipe line,
31...Liquid header, 32...Gas header, 33
...Leg, 34...Liquid valve, 35...Gas valve.

Claims (1)

[Scope of Claims] 1. A tank device for liquid storage, which has a generally rectangular cross section consisting of a bottom plate, a top plate, and a pair of side walls and end walls facing each other, and has an internal pressure resistance and a heat insulation effect. the bottom plate and the top plate are composed of a plurality of equally sized body plates, the body plates are partially cylindrical and outwardly convex, and are adjacent to each other, and Inward edges along the axial direction are connected to each other, the end wall is composed of a plurality of partially spherical end wall elements having the same radius of curvature as the body plate, and each end wall element is adjacent to each other. The bottom plate, the top plate, the side walls, and the end walls are connected to each other by being connected to each other by their inward facing edges, and being connected to the bottom plate, the top plate, and the side walls,
each side wall of the tank is comprised of a single body plate of equal size, and an internal reinforcing member extends from a joint between adjacent body plates of the bottom plate to a joint between opposing top plates;
and consists only of a series of parallel reinforcing plates that connect the opposing connecting parts between the end wall elements and connect the end walls to each other in the axial direction, and the tank is spaced apart from the tank. a generally flat roof covering and connected to the outer wall, the tank being enclosed by an outer wall filled with insulating material and an inert gas; The apparatus is characterized in that the roof is supported by supporting legs supported by the connecting parts of the top plate. 2. The internal reinforcing plate forms a partition wall that liquid-tightly partitions the inside of each shell plate, and a gas detector is installed around the outer periphery of the partition wall so that leakage from the tank can be detected in each partitioned inner chamber of the tank. 2. A device as claimed in claim 1, characterized in that the device has a structure of: