JPS5838673B2 - Corner structure of low temperature liquefied gas container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vessel tank or vessel corner structure for storing or transporting cryogenic liquids such as liquefied natural gas (LNG), and the present invention relates to a container tank or ship corner structure for storing or transporting cryogenic liquids such as liquefied natural gas (LNG), and the present invention relates to a container tank or ship corner structure for storing or transporting cryogenic liquids such as liquefied natural gas (LNG), an insulator and one or more liners, preferably of low temperature resistance such as high nickel steel, e.g. low thermal expansion, and a simple but strong support structure for the liner or membrane at the corners. with support structures that are easily fitted into the foam plastic insulation at the corners and that can transfer loads from the liner to the tank wall or hull at various angles with minimal heat transfer to the cold contents. It relates in particular to a corner structure of a vessel, tank or ship of the type mentioned above.

Containers or tankers for storage and/or transportation of cryogenic liquids must be designed to withstand extremely low temperatures.

Generally, containers of this type have an outer wall of rigid construction, a thermally insulating layer provided on the inner surface of such wall, and an inner membrane on the inner surface of such thermally insulating layer.

A few non-metallic, e.g. foamed, thermally insulating layers are often employed, and one or more membranes, especially an inner liner membrane such as a nickel steel liner, are in contact with the cryogenic liquid and-
A waste paper auxiliary secondary liner is placed between the foamed plastic insulation layers.

A primary liner, generally made of a thin, low temperature resistant (low thermal expansion) material such as nickel steel, is maintained in close contact with an adjacent layer of thermal insulation, and the liner transfers the internal pressure exerted by the cold liquefied gas to the vessel or tanker. heat is transferred to the hull of the ship through an insulating layer.

Of particular importance is the thermal strain induced by the cryogenic liquid in the container or its insulation device and by changes in conditions during both cooling and heating cycles due to loading and unloading of the liquid;
and must be able to withstand mechanical strains resulting from displacement of the hull or vessel during operation.

-A crucial part of such cryogenic insulation equipment for supporting the secondary liner is in the corners, where the loads experienced by the liner are transferred to the vessel wall or hull.

In membrane devices of the type described above designed to contain cryogenic liquids, the corners must be mounted so that they are not moved by contraction and deflection of the membrane of the support structure.

These corner structures must withstand loads at various angles and from many different directions with minimal heat transfer to the cold cargo.

However, one of the major difficulties with relatively complex corner structures of conventional methods is the difficulty involved in fitting low temperature insulation devices around the various components forming those corner structures. Additionally, it is the use of complex specially cut pieces of foamed plastic for this purpose that substantially increases the cost of such low temperature insulators.

According to the invention, the invention comprises a container wall having a corner, a low temperature resistant metal liner disposed within the container wall, and a thermally insulating layer disposed between the container wall and the metal liner. , the corner structure of a cryogenic liquefied gas container, wherein the thermal insulation layer comprises at least one fiber-reinforced plastic insulation layer, the corner structure being located corresponding to one of the corners of the container wall; an angle member of low temperature resistant metal consisting of two plate portions intersecting at an angle, each of said plate portions having a free end disposed between said metal liner and said thermally insulating layer; and the chevron member is engaged to the container wall by a plurality of elongated metal strips, each of the metal strips having a
connected to one of said plate parts, said metal strip being substantially parallel to the plane of said plate part to which said metal strip is connected; A corner structure for a cryogenic liquefied gas container is provided, the corner structure forming an extension to transfer loads from the metal liner to the container wall.

The corner structures can be incorporated into various angular corners of the tank.

The corner structure may thus be incorporated into a 90' corner, in which case the gables are 900 gables and the first series of said strips is relative to the second series of said strips. It is located at 900.

If the corner structure of the present invention is incorporated into a corner having an acute angle, the chevrons are correspondingly acutely shaped and the first series of said strips is attached to the second series of said strips. Similarly, it is placed at an acute angle.

If the corner structure of the present invention is incorporated into an obtuse-angled container, said chevron member is shaped with a corresponding obtuse angle and the first
A series of said strips are arranged at an obtuse angle to a second series of said strips.

In some cases, only a series of said strips at the corners are needed, as will be explained in more detail below.

A preferred embodiment includes a corner support panel surrounding the corner structure;
Provisions are made to support foamed plastic insulation at these corners.

Alternatively, the foamed plastic insulation can be bonded directly to the interior walls of the vessel or hull.

The corner structure to support the membrane or liner can be employed with a metal membrane having a low coefficient of thermal expansion to contain cryogenic liquids in any type of vessel or storage vessel, marine or land-based. .

If a metal strip or finger made of a high strength material with low thermal conductivity, such as stainless steel, is used with a membrane made of a material with a low coefficient of expansion, such as nickel steel, the inner metal membrane of the vessel or vessel This results in an effective transfer of longitudinal loads in various directions and angles from the to the external walls and heat loss and breakdown of the foamed plastic insulation can be minimized, thus ensuring that these corner structures and Foam insulation can be easily incorporated around the structure.

The width and/or thickness of the strip or finger can be sized as appropriate for the expected load intensity.

Furthermore, said strips extending in one direction of the corner structure are wider and/or wider than said strips extending in the other direction.
Can be made thicker.

Additionally, if a secondary liner or inner liner, such as a fiberglass liner, is employed with a primary metal liner, a strip or finger may be used in the corner structure of the present invention to connect the secondary liner to the vessel wall or hull. If used, fiberglass liners can pass through the foam insulation at the corner structures, thus ensuring structural continuity of such fiberglass liners.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following description of a few preferred embodiments, taken in conjunction with the accompanying drawings, in which: FIG.

Referring to FIG. 1 of the accompanying drawings, reference numeral 10 designates a cryogenic liquid or LNG tanker having an inner wall 12 of the hull and an insulating device 13 arranged around the inner circumference of the inner wall.

Such an insulating device consists of an outer insulation layer 14 of fiber-reinforced foamed plastic and an inner insulation layer 16 of fiber-reinforced foamed plastic, which are arranged against the inner wall 12.

Such a fiber reinforced foamed plastic insulating layer is preferably a ternary layer of foamed polyurethane reinforced with glass fibers.

Such fiber-reinforced insulation materials have layers of glass fibers, both horizontally and laterally extending fibers, i.e., X and Y reinforcing fibers, and vertically extending fibers, i.e., Z reinforcing fibers. closed cell
ll) type polyurethane foam blocks or blanks (
plank).

FIG. 1A shows a material of the above type having a block 1γ of closed cell foamed polyurethane having embedded therein a layer of glass fibers 19, said layer providing a reinforced polyurethane block 1T to a structural member such as a tank wall. It has exposed fiber ends 21 to facilitate joining.

The polyurethane block 1T has other glass fibers 23 extending vertically with fiber ends 25 exposed to facilitate joining the individual blocks to each other, and other glass fibers 23 extending horizontally and fibers 19.
It has another layer of fibers 21 extending perpendicular to the .

This type of reinforcement is known as X-Y-Z reinforcement.
The X fibers are longitudinal fibers, the Y fibers are transverse fibers, and the X fibers are vertical fibers, and the resulting reinforced foamed plastic is also known as "3D foamed plastic."

Preferably, these 3D foam polyurethane blanks are bonded together as at 13 in FIG. 2 by a suitable adhesive, preferably a polyurethane adhesive, to form an outer insulating layer 14 and an inner insulating layer 16.

Referring to FIGS. 1 and 2, a thin primary or barrier membrane 18 is disposed in contact with and bonded to the 3D polyurethane foam insulating inner layer 16, and a tongue rest 17 is shown.
tongue 15 held in place by the tongue 15 (see Figure 8).
The inner layer may be connected to the inner layer in any suitable manner, such as by a mechanical fastening device consisting of.

Membrane 18 is formed in a series of parallel sections or plates 19P'C'' having upright flanges along each longitudinal edge, the flanges of adjacent plates being interconnected.

A tongue 15 is located between the flanges 21' of adjacent plates 19.

Preferably the primary membrane is a low temperature resistance (low thermal expansion) material such as nickel steel, preferably high nickel steel such as the material sold as Amber®.

Membrane 18 is a fluid-impermeable material and forms a membranous inner container for containing the cryogenic liquid.

The secondary liner 20 is an insulating outer layer 14 made of 3D foamed polyurethane.
and an insulating inner layer 16 made of 3D polyurethane foam.

Such a liner can be a fiberglass cloth liner or a thin metal, such as a combination of aluminum foil and fiberglass cloth, or such a secondary liner can be a fiberglass cloth liner impregnated with a resin, such as a polyurethane resin, - Such a resin-impregnated fiberglass cloth in combination with a polyfluorinated vinyl film commercially available as Tedlar®.

Such a secondary liner consists of an insulating inner layer 16 of polyurethane foam.
The liner can be a non-porous liner that prevents the transmission of cryogenic liquids from the foamed polyurethane insulating outer layer 14 to the foamed polyurethane insulating outer layer 14.

Referring to FIGS. 2 to 5, the corner structure of the present invention is 9
Shown incorporated in the 0° corner.

At these corners, similar to the primary membrane 18, there is provided an angle member 22 of a low temperature resistance material with a low coefficient of thermal expansion, such as nickel steel, preferably a high nickel steel such as invar, which is placed at 24. It is attached to the primary membrane or liner 18, such as by welding.

A support member or backing 26 for the chevron 22 is incorporated into the foamed polyurethane insulating inner layer 16 adjacent to the chevron 22 and adhered thereto at 28.

Such support members or backings 26 are preferably in the form of plywood and include a pair of support members or backings 26 disposed at 90° with respect to each other, each contacting the outer surface of each side of the 90° chevron member 22. The backing members 30 and 32 are protected from each other.

The support member or backing 26 not only serves as a support for the angle member 22, but also serves to stabilize the membrane 18 and provide a base for welding.

The chevron member 22 is attached to a plywood support member or backing 26 by set screws 34.

A first series of metal strips 36 are connected at their respective inner ends to a side 40 of the chevron member 22, such as by welding at 38, and a second series of metal strips similar to the strips 36 4
2 are similarly connected at their respective inner ends to the other side 44 of the chevron member 22, such as by welding at 43.

These strips or fingers 36 and 42 are constructed of a low thermal conductivity (low thermal conductivity coefficient) high strength material, such as stainless steel, to transfer loads from the primary liner 18 to the hull wall 12.

It will be seen in FIG. 3 that the first series of strips 36 and the second series of strips 42 are oriented at 90 degrees with respect to each other.
00, and the first series of strips 36 are in one direction of the primary membrane 18 and the chevrons 22 at the corner substantially in the same plane as the primary membrane 18 and the chevrons 22;
and a second series of strips 42 with the primary membrane 18 and the chevrons 22 at the corners and the primary membrane 18 and the chevrons 22 in the other direction.
be in substantially the same plane as the

With reference to FIGS. 4 and 5, it will be appreciated that the first series of strips 36 comprises a number of parallel, spaced apart strips and the second series of strips 42 is likewise in the form of a number of parallel, spaced apart strips, with the second series of strips alternating with the first series of strips at the corners.

It should be noted that the inner ends of the respective strips 36 and 42 are disposed within the grooves 46 formed in the respective members 30 and 32 of the support member 26 and thus, as previously described.
Support member 26 serves as a base for welding membrane 18 to angle member 22 as shown at 38 and 43.

The fingers 36 and 42 are specifically balanced with respect to the width of the fingers 36 and 42 to accommodate the predetermined load intensity to be transferred from the primary liner 18 to the hull interior wall 12.

The opposite end of finger 36 is attached, such as by welding at 48, to a metal strip 50 which is supported by a mount, such as a T-shaped mount 52, connected to hull wall 12.

Therefore, the strip 50 is placed in a vertical position and the T-shaped fixture 5
2 and held in the same groove by a chevron 56 which abuts the outer surface of the finger 36 and attaches to the bottom of the T-shaped fitting a bolt-nut fastening device 5B. connected by.

The T-shaped fitting 52 is made by welding at 60, etc.
and is connected to the interior hull wall 12 by studs 62, with a metal shim 64 interposed between the flat outer surface of the T-shaped fitting and the adjacent vessel wall or interior hull wall 12.

A similar family of components, including elements 50, 52 and 56-64, is utilized to attach the outer ends of the second series of strips 42 to the interior hull wall 12.

Corner support panels 66 are provided and stands 6 for supporting the foamed polyurethane insulation layers 14' and 16' at the corners.
2 to two T-shaped fixtures 52 at the corners.

It is noted that the corner support panels 66 are formed of metal, such as steel.

A longitudinal support panel 68, preferably made of plywood, is also provided and both inner and outer foamed polyurethane insulation layers 16 and 1 are provided.
T-shaped fittings 52 are connected to bolt-nut fasteners 58 at opposite corners to support the main body of the tank 4 at a distance from the wall of the hull wall 12 along the length and width of the tank.

Insulating layer support panels 66 and 68, which maintain the foamed polyurethane insulation at a distance from the interior walls of the vessel or hull interior wall, may be provided adjacent the sump to the hull interior wall.

Adjacent to the corner, a member 10 incorporated in the foamed plastic adjacent the end of the primary liner is also provided, as seen in FIG. 2, and the same member 70 removes gas from behind the primary liner 1B. It has a large number of gas vent grooves T2.

Such a member γ0 is supported on a member γ4 inserted in a suitable groove T6 in the insulating inner layer 16 of foamed polyurethane, said supporting member 74 being preferably formed of plywood, for example, and adjacent to the foamed polyurethane insulating inner layer 16. insulation inner layer 1
It is glued to 6.

2, it should be understood that two bands or fingers 36 are connected to the chevron member 22 and the T-shaped fixture 52.
The simple construction of the same pattern of the present invention, which is mainly omitted from 42 and 42, surrounds the itch or finger 36 and 42 at the corner and allows the insulating layers 14' and 16'0 to be installed between them, so that the foamed It minimizes breakdown or discontinuity of the polyurethane insulating layer and does not require the installation of specially shaped polyurethane foam strips surrounding the elements as was previously required. .

It will also be understood that the strips or fingers 36 and 42 allow passage of a secondary, e.g., fiberglass cloth membrane 20 between them at the corners, thus ensuring a continuous structure of this membrane. Should.

The corner structure of the present invention, consisting primarily of strips 36 and 42 connected at one end to the chevron member 22 and at the other end to the T-shaped fixture 52, is designed to be tensioned under high uniform loads and -
It is specifically designed to also take the compressive loads applied by the membrane.

These strips or fingers, which are preferably made of a low thermal conductivity, high strength material such as steel, specifically transfer membrane loads in various directions and at various angles relative to the tank or hull wall, allowing the adjacent foam to Minimize breakdown or potential damage to the polyurethane insulation layer.

It is noted that the primary membrane or liner 18 and the angle members 22 are both formed of a material having a very low coefficient of thermal expansion, preferably a high nickel steel such as invar.

In contrast, the strips or fingers 36 and 42 have higher coefficients of thermal expansion but lower coefficients of thermal conductivity and are stronger than the materials of membrane 18 and angle members 22.

This has the advantage that less heat is transferred from the outer tank structure to the primary membrane and the support structure is strengthened to withstand loads and transfer the same loads from the primary membrane to the tank outer wall or hull. .

Another advantage is that by using strips or fingers instead of large single pieces of metal to support the primary membrane at the corners, the load is not applied longitudinally along the strip and thus the strip The shrinkage load at the end of the tube is substantially reduced.

FIG. 6 shows a simple but sturdy corner structure of the invention applied to an obtuse angle tank or tanker.

What should be understood from this figure is that the angle-shaped member γB connected to the -order liner 1B as described above forms an obtuse angle, and that the two series of metal strips 36' and 42/ are connected to the angle-shaped member 18. a first series of metal strips 3 arranged at a similar obtuse angle;
6' is substantially coplanar with one surface 18a at the corner of the primary liner, and a second series of metal strips 42' is substantially coplanar with the other surface 18a at the corner of the primary liner. It is something that is within.

The corner structure of the FIG. 6 embodiment is otherwise similar to the corner structure for the 900 chevron member shown in FIG.

FIG. 1 shows the corner structure of the invention applied to the corner of an acutely shaped tank or tanker.

In this embodiment, a chevron member 8 similar to the chevron member 22 is used.
0 has sharp angles at the corners and the first series of strips 36
"and the second series of strips 42" form a similar angle,
Again, the strips 36'' are substantially coplanar with one side or side 18a of the second liner 18, and the other series of strips 42'' are in the other side or direction 18a of the second liner 18. substantially in the same plane.

What should be noted is the second band, which employs two bands or fingers.
In the corner structure of FIGS. 6 and 1, an upright parallel plate flange 21' on the next inner plate 9' is also seen in FIG. 1 in both directions at the corner of the liner 18. , it should be □ straight to the corner adjacent to the cross section taken at line 2--2 in the figure.

However, - a plate flange in one direction or plane at the corner of the next liner is perpendicular to the corner, and - a plate flange in the other direction or plane at the corner of the next liner is parallel to the corner. In some cases, only a series of fingers need be employed to connect and support the liner section with vertical plate flanges at the corners to the vessel wall or hull.

This is illustrated in FIG. 8, which shows the corner structure at the 135° corner of the tandem of FIG.

It should be noted in this modification that the upright plate flange 21' connected to one side surface 18a' at the corner of the liner 18 is perpendicular to the corner, whereas the other side at the corner of the primary liner 1B is Upright plate flange 21 connected to the direction surface 18a
' can be seen more clearly in FIG.
In the cross section at No. 8, it is arranged parallel to the corner.

Under the latter condition, if we look at FIG. 8, we will see that only a series of metal strips 42" similar to strips 42" are connected to the chevrons 82 and the T-shaped fittings 52' in FIG. A series of metal strips 42'' are substantially coplanar with the surface 18a' of the primary inner cavity, which has perpendicular plate flanges 21' at the corners.

This corner structure employing fingers 42'' supports, for example, the negative liner surface 18a', for example when subjected to shrinkage loads.

However, the other surface, or section 18a, at the corner of the primary liner with plate flanges 21' arranged parallel to the corner absorbs shrinkage loads without the need for support of metal fingers such as 42'' at the corner. and therefore the liner portion 18 at the corner
No metal fingers are used in this modification to connect a to the vessel wall or hull.

The corner structure of FIG. 8 is otherwise comprised of plywood panels 86 with foamed polyurethane insulation layers 14" and 16" in the corners.
The corner structure of FIG. 2 is similar to the corner structure of FIG. 2, employing substantially the same elements, except that metal support panels 66 in FIG. 2 are utilized at the corners to support the .

The holding panel 86 is mounted on a stand 88 connected to the hull wall 12.

It will be appreciated from the foregoing description that the present invention provides an improved corner structure for supporting the primary crevice of cryogenic insulation systems for tanks and ships while substantially reducing the complexity of the pronation structure. A simple structure consisting essentially of a number of parallel strips was employed to transfer the loads in various directions from the primary to the hull walls, reducing heat leakage to the cold contents of the vessel. Especially when it comes to designing.

Although the cryogenic isolation device of the present invention is particularly useful for use on ships, ie, tankers, it can be used on any cryogenic liquid container, including barges, storage tanks, aircraft, or spacecraft.

The thickness of the device's fiber-reinforced 3D foam polyurethane insulation layer can be boil-off (boil-off) depending on special design needs.
off).

Although specific embodiments of the invention have been described above for purposes of illustration, it will be understood that various other modifications will occur to those skilled in the art, and therefore the invention is not limited to the claims hereinbefore claimed. It should be understood that there is no limitation other than by the scope of.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a methane (LNG) vessel or tanker having an insulating device and a corner structure according to the present invention;
Figure A is adopted in the apparatus of Figure 1 and is used herein as a 3D
Figure 2 depicts a preferred form of fiber-reinforced insulation material referred to as foamed plastic insulation; Figure 2 depicts the corner structure of the present invention along line 2--2 of Figure 1 of a tank or tanker at 90; 3 is a diagram showing the corner structure of the present invention adopted in the foamed plastic insulation device shown in FIG. 2, and FIG. 4 is a corner sectional view of the corner structure shown in FIG. 3. 5 is a perspective view showing the alternating or staggered relationship of one series of strips or fingers to another series of strips or fingers in the corner structure; FIG. 6 is a perspective view taken at an obtuse angle with FIG. Figure 7 shows the corner structure of the present invention used at the corner of a tank with an acute angle, similar to FIG. 2 and FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 1 of a corner employing only a series of strips in accordance with the present invention. 10... Tanker, 12... Hull inner wall, 14... Fiber-reinforced foamed plastic insulation outer layer, 16... Fiber-reinforced foamed plastic insulation inner layer. , 18...-Next, ie, breaking, 20...Secondary liner, 22...Chevron member, 24...Welding, 26... ...Supporting member, 34...Set screw, 36°42...
...Metal strip plate, 3B, 43.48...Welding, 5
0... Metal band plate, 52... T-shaped fitting, 56... Chevron member, 58... Bolt nut tightening device, 60... ...Welding, 62...
···stud.

Claims (1)

Claims: 1. A container wall having a corner, a low temperature resistant metal liner disposed within the container wall, and a thermally insulating layer disposed between the container wall and the metal liner. and the corner structure of a low temperature liquefied gas container, wherein the thermal insulation layer comprises at least one fiber-reinforced plastic insulation layer, the corner structure comprising:
It includes a chevron member 22 of low temperature resistant metal consisting of two angularly intersecting plate sections disposed corresponding to one of the corners of the container wall 12, each of said plate sections being connected to said metal. Having a free end disposed between liner 18 and the thermally insulating layer 16, the chevron member 22 is engaged to the container wall 12 by a plurality of elongated metal strips 36,42, the metal Each of the strips 36.42 is connected to one of said plate sections and is substantially parallel to the plane of said plate section to which said metal strip 36.42 is connected;
．． 42 forms an extension of the plate portion to which the metal strip 36.42 is connected and extends from the metal liner 18 to the container wall 1.
A corner structure of a low-temperature liquefied gas container, characterized in that the corner structure is configured to transmit a load to the container. 2. A corner structure according to claim 1, wherein the plurality of metal strips 36,42 include a first series of substantially parallel spaced strips and a second series of substantially parallel spaced strips. parallel spaced strips, said first series of strips being in the plane of one outer surface of said plate portion, and said second series of strips being in the plane of one outer surface of said plate portion. a corner approximately in the plane of the other outer surface of said plate portion, characterized in that at least one of said series of parallel strips is within at least one fiber-reinforced insulation layer 14.16; Structure. 3. A corner structure according to claim 2, characterized in that said second series of strips are arranged alternately with said first series of strips. 4 Any one of claims 1 to 3
In the corner structure according to , the metal strip 36.42
The corner structure is connected to the chevron-shaped member 22 by welding. 5 Any one of claims 1 to 4
In the corner structure according to , the metal strip 36.42
is attached to the container wall 12 by a member including a T-shaped fitting 52.
and having means for connecting said metal strips 36, 42 to said T-shaped fitting 52 and means for connecting said T-shaped fitting 52 to said container wall 12. corner structure. 6 Any one of claims 2 to 5
The corner structure of claim 1, wherein the corner is at a 90' angle, the chevron 22 is at a 900' angle, and the first series of strips is at a 900' angle with respect to the second series of strips. 90°
A corner structure characterized by being arranged at an angle. 1% Any one of claims 2 to 5
In the corner structure described in , the corner has an acute angle, the chevron member 22 has a corresponding acute angle, and the first series of strips is connected to the second series of strips. A corner structure characterized by being arranged at an acute angle to the board. 8 Any one of claims 2 to 5
In the corner structure according to item 1, the corner forms an obtuse angle, the chevron member 22 forms an obtuse angle, and the first series of strips forms an obtuse angle with respect to the second series of strips. A corner structure characterized by being arranged to form a corner structure. 9 Any one of claims 1 to 8
In the corner structure according to item 1, the metal liner 18 and the chevron member 22 are made of a metal having a low coefficient of thermal expansion, and the metal strips 36, 42 are made of a high-strength metal having a low thermal conductivity. A corner structure characterized by being composed of. 10. A corner structure according to claim 9, characterized in that said metal liner 18 is made of high nickel steel and said metal strips 36, 42 are made of stainless steel.