DK147802B - CONTAINER FOR LIQUID GAS - Google Patents

Description

147802

The present invention relates to a container for storing a liquid at a temperature which emits strongly from the ambient, e.g. a cold liquid, such as liquefied gas at a pressure near the atmosphere, comprising a housing (5) of heat insulating material lined with and carrying a thin, flexible, liquid-tight membrane tank (6) of cold-resistant sheet material which is retained against dimensional changes such as due to thermal stresses in that the corners of the membrane tank are anchored to the corners of the insulation.

In a container of the type specified, the effects on the means holding the diaphragm tank against dimensional changes could be considerable. There may be significant loads due to thermal stresses. If the container is mounted in the cargo compartment of a tanker, at least some of the walls of the diaphragm tank will be subject to stresses caused by deformations in the ship when operating in the sea, which will also impose additional loads on the means holding the membrane tank. Therefore, the means holding the membrane tank against dimensional changes due to thermal stresses must be designed to accommodate such additional loads as well. However, when the container is mounted in a tanker, the means holding the diaphragm tank against dimensional changes should preferably not be directly connected to the hull as this would cause a break in the heat insulation and would provide cold bridges which would dangerously cause local temperature reduction. in the hull ·

In designing containers of the type specified, it is necessary to ensure that the insulation is capable of absorbing the hydrostatic loads emanating from the membrane tank and, furthermore, - if mounted in a ship - the deformations caused by its movements in the sea. . The insulation must also be substantially molded under temperature influences and must not have continuous cold bridges. Furthermore, the means that anchor the diaphragm tank against dimensional changes must not reduce the thermal insulation capacity of the insulation. In practice, these requirements present a number of problems ·

Furthermore, for precautionary reasons, and as it is now a statutory requirement, in containers of the specified type, a secondary barrier layer should be provided to prevent fluid leakage in the event of failure of the primary barrier layer, the membrane tank.

Such a secondary barrier layer could take the form of another membrane tank, e.g. of thin metal around the first membrane tank and carried by the insulation. In another known construction, the secondary barrier layer is constituted by the insulation itself which carries the primary membrane tank, or it may take the form of an unmetallic layer, e.g. plywood, incorporated in the insulation material. It will be understood that in this case it is particularly important that the insulation is reliable and not interrupted by cold bridges which could also cause leakage.

3 147802

Various proposals are known for the construction of "containers of the specified type. In one proposal, the container has two identical barrier layers in the form of a primary and a secondary thin-plate membrane tank, each supported by a surrounding wall of insulating material. Each of these walls consists of a frame carrying rigid hollow blocks containing granulated insulation material and mounted loosely o-each other The corners of each of the membrane tanks are anchored by means extending from each corner through the insulation to the supporting sheath. a number of drawbacks, including the fact that the two insulating walls are made up of loose, displaceable blocks. The blocks in each of the insulating walls will be able to displace such that the surfaces carrying the membrane tank in question no longer flush and no longer flush. forms a smooth surface, whereby the membrane tank may break, this will be especially dangerous if the container is mounted in a ship. Another disadvantage is that anchoring the agents in the corners of the membrane tanks form cold bridges through the insulation0

In another proposal, there is a single primary membrane tank supported by a fixed wall of insulation material consisting of rigid wooden panels or blocks which are individually fixed and thus forming a substantially continuous wall, so that the support surfaces of the membrane tank remain in the same plane and constantly form a smooth support surface for the membrane tank. The insulation material is itself or contains an unmetallic secondary barrier layer and each block is substantially fluid tight while the spaces between the panels or blocks are filled with sealing material and closed with strips connecting the panels so that the insulation remains as a liquid tight secondary barrier layer regardless. contraction of the panels. The anchor means for the membrane tank are spaced apart on the insulation along the walls of the membrane tank in such a way that they absorb the loads from the membrane tank along each wall. A disadvantage of this arrangement is that the corners of the membrane tank cannot be held and will fail. According to a further proposal, the diaphragm is held by angular anchoring members of rigid material extending along the corners of the diaphragm tank and secured to a rigid support positioned within the insulating material and secured to the rigid cap. In this arrangement, the disadvantage is that the extra rack results in a complicated construction, and furthermore, as a result of it being fixed to the corners between the insulating walls, the rack will resist the necessary expansion and contraction of the insulation material.

Finally, from the specification of British Patent No. 924,804, an arrangement is known in which the edges of the walls of a membrane tank are attached to rows of small metal plates which are parallel to and at a short distance from the corner lines of the insulation and where the corners of the membrane tank are made of curved metal strips. , which are welded to the tank walls within the anchor plates. In this arrangement, there are the following disadvantages: I. The anchoring plates are attached directly to the insulation by means of nails or screws, thereby reducing the insulation's liquid density.

II. The corner moldings can move freely due to the varying loads resulting from the liquid contained, especially when the tank is used in a tanker, and are therefore subject to fatigue failure.

III. Tensile stresses in the tank walls are absorbed solely as shear stresses behind the anchor plates, which require extremely strong insulation material, at least at the corners of the insulation.

The object of the present invention is to overcome the disadvantages of the known proposals and to solve the above problems by specifying a container of the specified type with an integrated structure in which the individual requirements regarding the insulation, the membrane tank and its anchoring means are united. appropriately.

The container according to the invention is peculiar to the characterizing part of claim 1.

5 147802

In this embodiment, the anchoring members are secured to the insulation by means of supporting blocks which are again attached to the inside of the insulation, and therefore its liquid density does not deteriorate. The corners of the membrane tank are attached directly to the anchoring parts and therefore cannot move at varying loads, thereby significantly reducing the risk of fatigue failure. The anchoring angles act so that tensile stresses in the walls of the membrane tank are distributed over two walls in the insulation, namely as shear stresses and partly as tensile stresses.

The term "corner" shall herein and hereinafter refer to the transition line between two adjacent walls or wall portions, either in the membrane tank or in the insulation or in the container as a whole. The term "wall" shall also include the top and bottom surfaces.

The containers can have any geometric shape. They will usually be prismatic or parallelepipedic, but may also be more complicated in shape with flat walls or with slanted wall parts, for example to fit to the bottom of a cargo hold in a tanker. The container may also have stepped walls so that it has different cross dimensions, e.g. for precise alignment at the front or aft end of a tanker. In any case, the membrane tanks will have corners formed at the junction of adjacent walls or wall parts. A corner between two adjacent walls may take the form of a straight line or edge, but may also take the form of a curved line. Two adjacent walls may form a substantially right angle, but where inclined wall portions exist, a blunt or pointed angle may be formed, depending on the geometric shape of the tank. Uo ging of the corners of a tank can be outwardly i.e. with an internal angle less than 180 °, while e.g. in tanks with stepped walls can be found inward corners, i.e. projecting corners with an angle greater than 180 °. The anchoring angles must be so rigid that they are substantially non-deformable and so as to keep the angle at the corners of the membrane tank substantially unchangeable, i.e. the angle between the walls or wall parts forming the corners, thereby reducing the risk of rupture in the corners of the membrane tank. Although said portions anchor the diaphragm tank to major dimensional changes due to thermal stresses and hence are hereinafter referred to as anchor portions or anchor angles, they will also stiffen and retain the corners of the diaphragm tank against significant changes in the size of the angle between the surfaces of a corner. .

In one embodiment of the invention, the anchoring members are attached to the insulation material a short distance from the intersection line in the inner corners of the insulation material so that these parts will not affect the deformation of these corners during expansion or contraction of the insulation material. Each flange of an anchor angle extends a short distance along the inside of the insulating material away from the corner line and spaced apart from this line, for example, by means of bolts or screws to rigid bearing insulating blocks, e.g. of hard wood which is attached to the insulating material in such a manner, e.g. by adhesive, the liquid density of the insulating material does not deteriorate. The blocks extend or are distributed along each of the edge portions flanking the corner line constituting the corner of the insulation material off a corner of the membrane tank. Since the blocks carrying the two flanges of each anchor angle are spaced from the corner line of the insulation material, there will be a gap between the anchor portions and the corner of the insulation material to accommodate its deformation.

The membrane tank may consist of any suitable cold-resistant flexible material, e.g. a metal that is not subject to cold brittleness at the temperature of liquid gases at atmospheric pressure. The term "metal" here and hereinafter also means alloys. The membrane tank may be of a metal, e.g. stainless steel or an aluminum alloy which does not have a particularly low heat expansion coefficient, but which is designed with expansion areas, such as corrugations or depressions, in two directions so as to provide excess metal to accommodate contraction. Alternatively, the membrane can consist of a metal, such as the 36 nickel steel, which is referred to as "invar", which has a very low coefficient of thermal expansion and therefore may be free of expansion areas.

The anchoring angles may consist of any suitable metal, e.g. stainless steel, an aluminum alloy or invar with such strength and thickness as to obtain the required rigidity. It is important that the material at the anchoring angles must have a coefficient of thermal expansion that matches the material in the membrane tank and that the angles must be weldable to the membrane tank. Preferably, the same metal is used both for the diaphragm and for the anchoring parts, although this is not essential as long as the metals used can be welded together and have corresponding expansion coefficients. To increase the stiffness, the anchoring angles may have outer ribs (claim 4) either formed coherently with the angle or welded thereto.

In an embodiment in which the membrane tank consists of a metal which does not have a low coefficient of thermal expansion and which has expansion areas, such as corrugations, each anchoring member along a corner of the membrane tank is formed as a number of intermittent angles1, which are spaced apart. closed in liquid-tight fashion by thin corner plates forming the corners of the diaphragm tank, connecting and welded to the anchoring angles (19) and formed with expansion areas.

As indicated above, the thermal insulation in the container of the invention is to form rigid load-bearing walls with the required compressive strength to absorb hydrostatic loads against the walls of the membrane tank, and the load-bearing walls must together form a complete structure that remains liquid-tight. Although any suitable material that meets the above criteria can be used, the insulation should preferably consist of blocks or panels, e.g. of balsa wood, which are separately attached to the supporting sheath, and in which the panels forming a wall are joined together to form a total solid wall, but allowing for limited deformation of the parts forming the corners in insulation. Preferably, the insulation is of the kind disclosed in British Patent Specification No. 951,923, in which interspersed blocks or panels are provided with spaces filled with sealing material and closed with strips connecting the panels. Insulation of this form has the sufficient tensile strength and compressive strength for transferring the loads from the anchoring parts to the supporting jacket. Alternatively, insulation of this form can be used to form the corners of the insulation, where high compressive strength and tensile strength are applied, while another heat insulating material having only the required compressive strength is used for the larger wall surfaces. a foamy plastic material.

In the following, some embodiments of the container according to the invention will be described with reference to the drawing, in which: Fig. 1 shows a schematic vertical section through a tanker with a rectangular container consisting of a single membrane tank mounted in a cargo compartment of the ship; in the left half of the figure the diaphragm tank itself is omitted, Figure 2 shows a horizontal section through half of the cargo space shown in Figure 1 at an early stage during assembly, the upper part of the figure showing a quarter of the cargo space with the sprinklers placed while the lower one part of the figure shows a second quarter of the cargo compartment with insulation panels, the supporting wooden blocks and the intermediate bale blocks fitted, Fig. 3 shows similarly the other half of the cargo space, the lower part of the figure shows a quarter of the cargo space with the anchoring angles mounted, the upper part of this figure shows the relevant part of the membrane tank mounted, figure 4 shows a horizontal section in the larger re scale, showing bl. a. The anchoring angles at a corner between two adjacent walls, an anchorage piece in a three-sided corner between two walls and the bottom, and the adjacent portions of the membrane tank and the thermal insulation; 5 is a perspective view, partly in section, of a corner between the bottom and one of the sides; FIG. 6 shows a vertical section, on an even larger scale, through part of the embodiment shown in FIG. 1; FIG. 7 shows a corresponding section at a three-sided corner; FIG. Fig. 8 shows an even larger sectional view showing certain details when attaching the plates to the membrane tank; 9 is a section through a blunt-angled corner of a container with inclined wall portions; FIG. 10 is a perspective view of a container with stepped side walls; FIG. 11 is a sectional view similar to FIG. 6 through an inward corner of a container, while FIG. 12 shows, in perspective, a changed embodiment of an anchor angle.

It should be understood that Figures 1, 2 and 3 are not made with uniform scale conditions, since the various parts of the membrane tank, the anchorage parts, the mounting blocks and the thermal insulation for clarity are shown on a larger scale than the double hull of the tanker.

FIG. Figure 1 shows a cross-section through a seagoing tanker for the transport of liquefied natural gas and equipped with containers consisting of heat insulated cargo tanks built into cargo spaces and designed accordingly. The ship has an outer hull 1 and an inner hull 2. Furthermore, deck plates 3 and in FIG. 2 and 3 transverse bulkhead 4 at the ends of the cargo compartment. Each cargo compartment forms a generally rigid bearing jacket for a container, the cargo compartments being lined internally with walls 5 of load bearing thermal insulation material. Inside the cargo compartment, a primary barrier layer is provided in the form of a thin, flexible, stainless steel sheet membrane tank0. to wood sprinkles 7, forming a smooth surface which serves to support the walls of the membrane tank 6 and to transfer the load to the sheath 2, the plates 3 and the transverse bulkheads 4 respectively.

The insulation layer consists of panels 8 with a core 9 of balsa wood lined with adhesive plywood sheets 10 and 11, fig. 6. The plywood sheet 10 constitutes a secondary barrier layer.

147802 10

The sprinklers 7 are as shown in FIG. 2 attached at regular intervals to the outer sheath, e.g. as shown in FIG. 6 by means of the Nelson threaded pin 7a, and so that the top side of the springs is in the same plane. The spaces between the beds are filled with an insulating material not shown, e.g. fiberglass. The exterior of each panel 8 is adhered to the upper side of one of the straws 7, and adjacent panels are adhered to a common straw, where they are joined to form a liquid-tight joint. During adhesion, the panels are temporarily held in place by Nelson pins not shown welded to the sheath 2, 3 or 4. These pins can either be removed or can be seated.

The secondary barrier layer is designed to remain liquid tight even though the panels 8 contract at low temperature. For this purpose, the edges of adjacent panels 8 are inclined so that between the panels there is a gap which is widest on the inside and filled with foamy plastic material 12 compressed to 90% or less of its free volume. The spaces between the panels 8 are closed at the outside by the sprays and at the inside by moldings 13; 1 and 5, of plywood adhered to the panels on both sides of the assembly.

The panels .8 forming a wall are in this way rigidly joined by the sprinkles and plywood moldings to form an extremely rigid, continuous bearing wall in which the panels cannot move away from the rigid sheath so that their inside will remain. in a fixed position relative to the supporting jacket.

The space at a corner between the panels 8 in two adjacent walls is filled with foamy plastic material 14 corresponding to the mentioned material 12. A corner strip 15, fig. 6 and 7, preferably of plywood, are adhered to the adjacent panels and close together with a filling strip 15a the space between the panels. However, the list 15 allows a limited relative movement and deformation of the panels forming the corner.

11 147802

The membrane tank 6, the primary barrier layer, is as later described in detail made of thin stainless steel flexible sheets 16 which form the walls of the tank and which are joined at its corner edges by stainless steel corner plates 17 and three-sided corners by three-sided corners 17 FIG. 3 and 4.

The plates 16 are formed with expansion areas to provide extra metal for receiving contraction upon cooling. These areas take the form of two sets of corrugations 16a and 16b. "Within each set, the corrugations are parallel and have the same cross-section. The corrugations 16a have larger cross-sectional dimensions than the corrugations 16b. The two sets of corrugations intersect at right angles and all project toward the interior of the tank.

The corners of the diaphragm tank 6 are anchored so that the tank is held against changes in the main dimensions, the corners being held at anchor angles which are arranged along the corner lines of the tank and welded thereto, which are constituted by relatively short pieces 19 of stainless steel, placed in flight and at regular intervals along each corner of the tank. The anchor pieces are secured by bolts 20 to hardwood blocks 21 and 22, which are again attached to the inside of the insulation 5 in such a manner, e.g. by adhesive, the fluid density of the insulation is not affected.

The wooden blocks 21 and 22 are best seen in the lower part of FIG. 2. A plurality of identical blocks 21 are spaced at regular intervals along the edge of the insulation material on the bottom, close to the adjacent side wall. These blocks 21 are generally T-shaped. The narrow shaft of the I * is located close to the edge and the wide crosspiece of the tee lies inward away from the edge. In addition, on the panels lying along the bottom, small blocks 23 of balsa wood are adhered to the spaces between blocks 21. It should be noted that a bale block 23 covers the strip 13 in the insulation layer, as shown in FIG. 1, 2 and 3. As shown in Fig. 2, at the three-sided corner, at the connection between the bottom and two adjacent side walls, there is a larger block 22 of hardwood. This block 22 may be formed integrally with the two adjacent blocks 21.

147802 12

As shown in FIG. 4 and 5, there is a corresponding arrangement of hardwood blocks 21 and 22 and intermediate bale blocks 23 along the lower edge of each of the side walls and aligned with the block on the bottom. Furthermore, there is a corresponding arrangement at the corner lines along the upper side.

One area bounded between blocks 21, 22 and 23 on each of the walls is filled with balsa wood 24, e.g. by adhesive is attached to the panels 8 which make up the wall itself. The bale layer 24 has the same thickness as the blocks and is cut to accommodate the moldings 13 so that its upper surface aligns with the blocks 21, 22 and 23 and together with these provide additional thickness of the insulation 5 and provides a permanent flat surface to support the membrane. Once all layers of the insulation, namely the sprinklers 7, the panels 8, the ball layer 24 and the blocks 21, 22 and 23 are interconnected and attached to the sheath 2, 3 and 4 against movement away from it, the membrane 6 will be permanently supported by this flat surface. .

In the figures described above, rigid anchoring angles 19 were shown in the form of an outward two-sided angle. Each of these angles has a short distance from the ends two ribs 19c, fig. 4 and 5 of thick stainless steel plate and welded to the angle, to increase its stiffness.

Each corner piece is mounted on and attached to the shaft of the T in one of the blocks 21 on each of the two walls forming the corner.

Such as. shown in FIG. 3 and 5, one flange 19a of each angle is secured by four stainless steel bolts 20 to an adjacent block 21 of the adjacent side wall. The shaft of the T-for-. the middle wooden block is cut out so that the top of the flange 19a aligns with the other part of the block 21.

The bolts 20 are inserted into recessed nuts 25 inserted into small holes in the blocks 21 and 22. As best seen in FIG. 2 and 4, there are spaces between the blocks 21 and 23 and the corner blocks 22 for receiving the ribs 19c. In the cross-section of the T-shaped blocks 21, there may be corresponding slots 26 to facilitate mounting 13 147802 and disassembly of the anchor pieces 19. The edges of the walls of the membrane tank 6 are attached in liquid-tight manner to the respective flanges 19a and 19b. 5, at the anchoring angles 19, by welding, e.g. by an arc welded cloth joint.

The corner plates 17 of the diaphragm tank are similar except for the pieces 17 'at the three-sided corners. Each of the plates 17 is of short length and is formed with a corrugation 17a which forms a connection between the corresponding corrugations in the surfaces entering the bears in question. These corrugations can bake different size or shape to connect different sized corrugations. Each bear plate 17 is slightly longer than the anchoring angles 19 and mounted thereon, in such a way that the beaver plate 17 covers two angular pieces 19 with the corrugation across the space between the pieces 19.

Each bear plate 17 covers a substantial portion of the width of the flanges 19a and 19b at a wide angle 19 and is welded close to the edges of the adjacent plates 16, and at one end it is laid over and welded tightly to the adjacent bear plate 17. These overlapping parts are crippled corresponding to plate thickness.

As seen in FIG. 1, 3 and 7, on each of the three-sided bears, there is a corresponding stainless steel anchor piece 19 '. This bore the same thickness as the angles 19, but is shorter and does not bore the ribs 19c on the angles 19®. Each side is attached by four bolts 20 to the wooden block 22 on each of the three insulation walls meeting in the bear. The anchor piece 19 'is thus fixed to three walls. However, it will be noted that there is a gap S, fig. 6, between the inside of the panels up to the bear and the block 22 of the adjoining panel of the adjacent wall, which allows for the contraction and expansion of these portions by such a three-sided bear "On the anchor piece 19 'is mounted a three-sided diaphragm corner piece 17', FIG. 6. This bore three flat flanges without corrugations and these lie up to the inside of the three-sided bear piece 19 * with the edges welded to it. The flanges on the menopiece corner piece 17 'are smaller than the flanges on the anchor piece 19' and 147802 14 are overlapped by the edge portions of the adjacent diaphragm corner plates 17 as shown in FIG. 6. There may be a narrow gap as shown by X in FIG. 6 between the adjacent wall plates 16 and the membrane corner pieces 17 and 17 ', but this gap will be covered in a liquid-tight manner by the underlying part of the anchor piece 191 ·

The supporting anchors are thus welded to the edges of the walls of the membrane and to the corner pieces of the membrane and are firmly connected to the membrane in such a way that the bending loads that may occur can be accommodated, the anchorages are attached to the wooden blocks which is again attached to the insulation 5 but permits deformation thereof.

Cross-thick edges of the T-shaped wooden blocks 21 and 22 support the initial corrugations at the edges of the membrane.

The various steps of building the container in a tanker are shown in the various parts of FIG. 2 and 3. first, the springs 7 are attached to the inner hull 2, the cover plates 3 and the transverse bulkheads 4, as shown in the upper part of FIG. 2. The plywood-coated balsa panels 8 are mounted, after which the joints are filled and covered with moldings. The blocks 21, 22 and 23 and the ball layer 24 in the area within the blocks are mounted as shown in the lower part of FIG. 2. Then the anchor pieces 19 and 19 »are mounted on the blocks 21 and 23 as shown in the lower part of FIG. 3. The diaphragm corners 17 'are welded to the corners 19 * · The plates 16 included in each wall of the diaphragm tank are now placed on top of the insulation material and the edges of the individual plates are welded together as described later. The edges of the plates forming the edges of each wall of the tank are welded to the corner pieces 19o. Finally, the membrane corner plates 17 are brought into place and welded together and to the walls of the membrane tank, thereby completing the container as shown in the upper part of FIG. 3 and in the right side of FIG. First

Alternatively, each anchoring piece can be attached to the two blocks 21 and 22 as a mounting unit, whereupon the blocks are attached to the corner panels 8j either when the latter are brought into place or as a larger mounting unit, doV0s <> before the corner panels are replaced.

147602 15

The plates 16 constituting the walls of the membrane tank are placed on the insulation and welded together appropriately and using suitable retaining means. In FIG. 4 is an example of such an arrangement.

In such an arrangement, in a block of hardwood in the insulation, a nut 27, preferably of stainless steel, is fixed to the screws 28, fig. 8, below the edge of a portion of one plate 16 having a hole next to the nut 27 and over patches of the edge of the adjacent plate 16. A nut 27 at the edges of a wall will be disposed in one of the blocks 21; . 4, while a nut 27 spaced from the edge will be deposited in a wooden block 29 which is deposited in the ball layer 24 and adhered thereto. The edge of the lower plate 16 is temporarily secured by a bolt (not shown) inserted into the nut 27 and formed with a large head. Thus, while the plate is temporarily retained on the insulation, the other edges of the plate 16 are welded to the adjacent plates 16 and to the angles 19. Once this weld is completed, the bolts are successively removed and the plate permanently anchored to the nut 27 by a weld seam 50 along the inner edge. of the hole in the plate 16.

The pen next plate 16 is then positioned so that its edge covers the parts of plate 16 welded to the nuts 27 and the top plate is welded at 31 to the bottom plate 16.

Pig. 9 shows a vertical cross section through another container with inclined wall portions 35 and 36 which together form a blunt-angled corner. The piles 36 can e.g. constitute transition parts at the bottom of a container. The membrane 6 here also consists of plates 16 and corner pieces 17 and 17 '. As the corrugations in the membrane of the membrane at the end walls 37 can be connected to the corrugations in the wall 36, certain parts of the plates 16 on the end wall are cut away and replaced by small plates 38 with curved corrugations 38a which connect to the corrugations in the wall 35 '. The arrangement also corresponds to a right-angled corner, the insulation consisting of panels 8, the spaces of which are covered with strips 13 and 15. The panels are fixed blocks of hardwood and balsa wood. At the edges of the panels forming the corner, hardwood blocks 39 corresponding to the blocks 21 are fixed at a distance from the corner line of the obtuse corner, corresponding to the distances of the blocks 21 from a right-angled corner, and so that a space S 'which allows a slight deformation of the edges of the panels forming the corner * On the blocks 39 is secured an anchor piece 40 corresponding to the anchor piece 19, but with a blunt angle of the correct size. This anchor piece is secured to bolts 20 by bolts 20 and nuts 25. For the spaces between the screw rings at the ends of the small plates 38, the flange 40a on the anchorage piece is somewhat wider than the flange 40b. The anchor piece 40 has a reinforcing rib 40c.

Pig. Figure 10 shows a perspective view of another membrane tank container 41 which, in its longitudinal direction, has an upward tank neck 41a and whose side walls 41b are stepped so that the vertical cross-sectional area of the container varies. The vertices denoted a are inner outward vertices, while the vertices denoted b are inward vertices. Ted the corners a, the anchor parts can be performed as described in connection with Figures 1-8.

Ted the inward corners b an analogous arrangement is used, e.g. that shown in FIG. 11th

In FIG. 11 is the insulation as in FIGS. 1-9, but the outer edges of the panels 8 meeting in an inward corner are rounded and covered with a strip 43, corresponding to the list 15. Blocks 44, corresponding to the blocks 21, in FIG. . 1-8 and 39 of FIG. 9 is attached to the edge portions of the panels 8 up to the corner. The end of one block 44 abuts the side of the other block 44 so that the two blocks together form a rigid rectangular construction.

Outside of the rounded portions of the panels 8, at the corner there is a space S between the panels and the blocks 44, thereby allowing limited deformation of the panels 8 up to the corner.

Attached to the blocks 44 is a right-angled anchor piece 45, similar to the aforementioned anchor piece 19, and retained by bolts 20 which engage the inserted nuts 25 in the blocks 44. The anchor angle 45 has, as previously shown, a reinforcing rib 45c, but is by this example of smaller dimensions so as to fit the spaces between the corrugations 16a and 16b of the plates 16 of the tank walls. Each of the anchor angles 45 can therefore be fixed to each block with only two bolts 20. In all other respects the arrangement corresponds to that of FIG. 1-8 The walls of the membrane tank are connected by inward corner plates 48, each having a corrugation to connect the corrugations in the walls.

The anchor piece 45 at the end wall is formed as a three-sided piece with a wide flange 50 in plane with the end wall. To the flange 50 and the adjacent diaphragm corner plates 17 is welded a small flat plate 49 which forms part of the diaphragm.

FIG. 12 shows a modified embodiment of an anchor angle 46 corresponding to the piece 19. In this case, the angle piece is made of such a thickness that it has the necessary stiffness without ribs. This not only simplifies the design of the angle piece, but also of the blocks 21, as there need not be any spaces between the blocks 21 and 23. 1-8 for recording ribs. Furthermore, as shown in FIG. 12 to be the same length as the angles, instead of being limited to the distance between the ribs. Furthermore, instead of screws through the block perpendicular to the flange, the anchor pieces can be fixed by means of screws not shown parallel to the flange, through special tabs 33.

Claims (4)

18 147802 1. A container for storing a liquid at a temperature which differs greatly from that of the surroundings, e.g. a cold liquid, such as liquid gas at a pressure near the atmosphere, comprising a housing (5) of heat insulating material lined with and carrying a thin, flexible, liquid-tight membrane tank (6) of cold-resistant sheet material retained against dimensional changes such as due to thermal stresses in that the corners of the membrane tank are anchored to the corners of the insulation, characterized in that the corner anchoring arrangement comprises substantially rigid anchoring angles (19) to which the inner surfaces of the corners of the membrane tank (6) are rigidly fixed while the outer surfaces of the anchoring angles rigidly attached, e.g. by bolts (20), to rigid bearing blocks (21, 22), e.g. of hard wood, which blocks are fixed rigidly on the inside of the insulation in such a manner, e.g. by adhesive, the liquid density of the insulation is not degraded, the insulation being rigidly attached to an outer bearing jacket. (2). Container according to claim 1, characterized in that the anchoring angles (19) are fixed to the respective blocks (21, 22) at a distance from the intersecting lines in the respective corners of the insulation, and that these blocks end briefly from the respective corners, so that gaps are formed (S, Fig. 6). Container according to claim 1 or 2, wherein the diaphragm tank consists of a metal which does not have a low coefficient of thermal expansion and wherein the diaphragm tank is formed with expansion areas, such as corrugations (16a, 16b) or indentations which in two directions provide excess metal for contracting, characterized in that each anchoring member along one corner of the diaphragm tank is formed as a plurality of intermittent short angles (19) which are closed in liquid-tight fashion by thin corner plates (17) constituting the corners of the diaphragm tank; and which joins and is welded to the anchoring angles (19) and is formed with expansion regions (17a). Container according to any one of the preceding claims, characterized in