DE2546477C2 - Ship tank for storing or transporting a pressurized flowable medium - Google Patents

Description

The invention relates to a ship's tank for storing or transporting a pressurized one flowable medium, with a bottom, an upper part, longitudinal side walls, which are made of the same design, to each other parallel shells consist of outwardly convex, partly cylindrical shape, as well as with end walls that consist of convex wall elements of the same design, with an inner framework made of rectangular interpenetrating connecting plates that make the shell connecting elements opposed to each other Connect walls together, the connecting elements between the bottom trays and the inner frameworks are formed by floor inserts with a cross section that is vertical top and lower arms as well as elongated side arms and wherein the connecting elements between the top wall shells and the inner framework are formed by top insert members, with a cross section of the vertical floor arms and upwardly inclined side arms, furthermore with floor supports, which have upper areas, which in turn engage the S-Bodeneinsetzelemente.

LR-PS 34 14 153 shows a tank made of bowl-shaped Walls of part-cylindrical cross-section is constructed. This font suggests the use of internally arranged, interpenetrating plates at right angles.

To use a steel structure inside, for example in the form of tension or connecting plates, is preferable per se, rather than the material in the To accommodate container jacket. Although a bullet is theoretically less weight than an equivalent Having bowl tank, the difference is almost reversed in practice This goes back to the higher one hydrostatic pressure of the ball, on the fact that the thickness tolerance and the welding factor on the whole Containers are applicable (but not to inner panels in bowl tanks) to the need of meridional reinforcement of the ball for the purpose of supporting or carrying as well as due to an internal gear, which does not have to be present in the bowl-shaped tank.

In the tanks constructed from shells according to US-PS 30 92 063, US-PS 36 45415, US-PS 36 40 237 and US-PS 35 28 582, as well as according to FR-PS I i 16 193 are connecting plates penetrating each other at right angles intended. US-PS 35 28 582 proposes to provide under the bottom of the tank supports which are welded along the intermediate shells to nodes of the tank bottom. However, such tanks have not yet been implemented. The reason is that such a tank is disadvantageous in practice. A major disadvantage arises from the fact that its weight is significantly greater than that of other tanks. The tanks according to US-PS 35 28 582 and according to US-PS 34 14 153 are constructed from self-supporting shells that only have floor supports. Such designs also lead to high weights.

It must also be taken into account that the hold of a ship is by no means absolutely rigid, but rather in particular is subject to considerable deformation during transport at sea. A self-supporting, out Shell built tank with internally arranged connecting plates is very rigid, which is with the mentioned flexibility of the ship's hold not tolerated The problem is therefore tiarin, a rigid The tank can be accommodated in a flexible hold without undue stress on the tank during use or loading space.

US-PS 33 14 567 describes a constructed from shells Tank in a ship without considering the issue of under-support. The ones mentioned there However, tanks are used to hold goods at atmospheric pressure. Such tanks are unsuitable for picking up goods under pressure. This would therefore require further considerations and further measures need. These are very special tank constructions, with the tanks in their own designed supporting structures rest or hang that provide the necessary rigidity. Is the tank in the When the cargo hold of a ship is introduced, a support frame assigned to the tank rests on the floor of the cargo hold; Further supports can be found below the tank at the nodes between the Provide trays and between the hold and the tank

side supports are also arranged at the nodes attack between the shells. Such a tank structure with a double wall and associated (attached) supporting structure leads to high weight. In addition, there is only a very limited Relative movement to the relatively flexible ship hold is possible.

The invention is based on the object of building the tank itself to be relatively rigid, which is the case with Pressurized goods is required, but despite the relative flexibility of the ship's hold, none to allow impermissible tensions to act on one of the named elements, namely the cargo space or tank, furthermore to design the tank so that it is essentially secured as a whole during operation at sea is

This object is achieved by the characterizing features of claim 1

Further features within the scope of the invention are characterized in the dependent claim

The invention will now be explained in more detail with reference to the drawing, in which exemplary embodiments are shown will. It shows

F i g. 1 is a pictorial representation, partially cut away, of a tank, the end walls of which are made of dome-shaped Share,

F i g. FIG. 2 is a detailed illustration showing how the tank of FIG. 1 is produced,

F i g. 3 is a pictorial representation of a lower support for the tank;

F i g. 4 the lower beam according to FIG. 3 in cross section and

F i g. 5 shows an upper support for the tank in cross section.

The first with reference to FIG. Tank shown 1 is intended for mounting in a ship the mass transport of liquefied natural gas, or natural gas at a pressure of 5-10 atmospheres, the compared reduced cooling requirements (-115 ° C 135 ⁰ C) with the transport of liquefied natural gas at atmospheric pressure (- 161 ° C). When installed on a ship, the tank will be one of a series of tanks housed in the hold of the hull, the tanks being tapered or tapered at the bow and stern. The same tank construction can, however, be used for final storage or disposal on land or in barges, barges, sloops and the like.

The tank is made of 9% nickel steel and is generally rectangular in cross-section. the The skin or shell of the tank consists of an upper part, a lower part and elongated side walls, composed of outwardly convex part-cylindrical parallel shells 11, which are horizontally Extend from one end to the other of the tank. Although there are only four bowls in the tank shown 11 are present across the width and three in depth of the tank, it goes without saying that this is a simplification for the sake of illustration and that in practice a larger number of trays 11 will usually be present. The shells 11 each have an arc of about 65 °, with the exception of the corner shells 11a, the have much larger arcs of about 155 ° to join the sides of the tank to the top and bottom. The end walls of the tank are composed of domes 12 with a square base, being part-spherical Joints or knuckles 12a the shells 11 of the tank sides, the top and bottom of the Complete refueling ends. All shells 11, domes 12 and elbows 12a have the same radius of curvature on; and in the tank shown, the module size is, so to speak, the chord length of a each shell 11 (with the exception of the corner shells 11a / die same in all four long walls. For a cone

. migen or conical bow or stern tank changes however the module size along the tank.

At the overlap or intersection levels

ίο the shells 11 are, so to speak, the branch points or nodes between successive ones Cup arches, inner connecting plates 13,14 are fitted in horizontal and vertical parallel rows, which run along the tank and thereby the interior of the tank in a plurality of longitudinally extending Divide cells or square tunnels or channels 15. The full structure or Construction is welded at every intersection or intersection and at every inter-shell node so that the skin sides or casing shell sides are laterally cross-connected and the top side and underside of the housing jacket are connected to one another perpendicularly. The inner panels are on theirs Ends are also connected to the intermediate coupling nodes or junction points so that the ends of the Tanks are interconnected lengthways in a similar manner. The ones through the inner tunnels formed axial channels must be interconnected for fluid flow during loading and Unloading of the tank and other reasons, and this is done by oval or otherwise rounded openings near the ends of all connecting plates 13, 14 are provided in areas be where the main stresses or main loads to minimal loads or stresses fall off so that the openings do not require any compensation or equalization.

The F i g. Figure 2 shows the manner in which the tank structure is manufactured. At the overlaps or Crossings of the horizontal and vertical inner connecting plates 13, 14 become the connections produced in that connecting pieces 16 are welded with a cruciform cross-section. Insert elements 17 generally fork-shaped cross-sections are used to weld joints between to manufacture the connecting plates 13,14 and shells 11 of the shell or skin of the tank, and in this The case, the insert elements 17 are larger. Where external tank girders or supports are provided to

so the tank at the intermediate shell junction points or tying knots, as will be described below, become cruciform ground insert elements 17a used instead of the fork-shaped insert elements 17 and, if one uses the lower cross-shaped Bodeneinsetzelement 17a z. Considered, for example, the side arms 17f> of the cruciform bottom insert members 17a are lowered to the same angular positions like the arms of the fork-shaped insert elements 17 for adapting to the ends of the shell arches. The construction shown allows free access to both sides of all welds, whereby 100% through-welding is ensured without the use of support plates and subsequent X-ray inspection the weld seams is facilitated. As the angle of the bowl arches increases above 70 °, the Welding accessibility increasingly difficult.

As previously stated, the inner connecting plates extend 13, 14 up to the intersection

nien or nodes or branch points of the part-spherical domes 12 with a square base the tank ends, and it is essential that the inner anchors extend continuously from one Extend the end of the tank to the other in that way. The construction of the tank can thus all pressures caused by stresses due to elongation or tensile stresses in the cladding of the tank and the internal anchoring structure. If you z. B. a shell 11 is considered the force on this shell 11 depends on the shell radius and the pressure inside the tank. This force is held by the connecting plates that run across run to the tank and which are directly stressed in terms of tension. The real protection or the real one Safety on the tank lies in the form of tension loads in partially cylindrical shells, with no bending stresses occur or be exercised.

As far as the ends are concerned, similar considerations apply. Here is the load or burden, which must be supported by a dome 12, the compressive force on the area by a part spherical Dome 12 is covered, and this is sustained by the longitudinal connecting plates, which connect create with the single dome 12.

The panels running in the longitudinal direction bear their main loads from top to bottom and from side to side accordingly. The end load, however, is borne in the longitudinal direction by the vertical and horizontal connecting plates 13, 14 together and the upper part-lower part-side shells together at approximately half the transverse load. Due to the resulting constant energy of the deformation effect, the main stress or main load in all connecting plates 13, 14 and shells 11 is _{reduced by j / V 2} and the required thickness is reduced accordingly.

The weight of a tank constructed as described can be less than that of a conventional one spherical or cylindrical tanks for the same pressure and for the same capacity present construction, the charge is held or received while by the internal structures this is taken up by the jacket in a conventional tank; and a tolerance or oversized thickness must be provided in the case of cladding, while this is for the internal structure of the present tank is not necessary As already mentioned, the cladding can be thinner The smaller the radius of the shells 11 and domes 12 is. A great advantage of the thinner cladding is to reduce the depths of welds required to build the tank will.

To provide a tank that is tapered or tapered and into the hull end of a ship with decreasing cross-section, it is when the shells 11 run in the longitudinal direction in the ship, only necessary to increasingly reduce the arc length of the shells 11 while maintaining the same Shell radius.

For example, in a typical construction, the inner plates could be 11 mm thick and may be cladding 7 mm thick. Such a tank can be designed by appropriate selection of the relative plate thicknesses be that in the inner plates and in the housing shell different levels of stress or stress or tension are present. It can in certain In some cases it may be advantageous to have lower stress levels or levels in the cladding or shell cladding than in the internal anchorages or struts. For this low temperature application that is Metal nickel steel, however any other suitable alloy may be used.

In such a tank, the inner plates in it act as a tank for the transport of liquids this eliminates the problem of contamination or spillage of the liquid cargoes in the tanks -

and also the risk of the load rolling over.

Although, as discussed herein, the construction described is intended for tanks containing internal pressure, it goes without saying that such tanks can also be used where the internal fluid is is under atmospheric pressure.

Instead of the ends being composed of domes 12, the tank can be made with lobed ends will. One type of construction has vertical tabs on one end and horizontal tabs on the other, however, the preferred embodiment or arrangement has horizontal lobes followed by horizontal Plates of reduced width are held together. Since in this construction longitudinal lobes and End tabs will collide or converge in node connections or T-connections special fillers or roundings on the tank legs or edges are required to make these connections. The arrangement bypasses or avoids end tabs that can relieve main plate stresses or stresses have to follow, and allows a closing of the vertical panels on the lower part or on the floor in order to to improve the ship's stability when carrying part loads. The arrangement is a little heavier than when in use curved ends, but it is easier to manufacture.

Such a tank is free-standing and has a very large size Strength and rigidity in the longitudinal direction and is borne or supported by the lower part, together with structurally provided stabilizing supports on the sides and / or the top, without significant bending loads or stresses are exerted on the tank.

The F i g. 3 and 4 of the drawings show the lower support for the tank of FIGS. 1 and 2. A grooved Element 20 of roughly triangular cross-section runs the length of the ship and is cut through in sections Steel A-frame 21 to which the lower edge of the element 20 is welded. The top edge of the Elements 20 in turn is associated with the lower arm of a corresponding cruciform floor insert element 17a of the tank bottom connected; if a tongue and groove joint is used at this point, will these allow the longitudinal contraction and expansion of the tank, but a welded connection is also possible, provided that relative movements of the tank and the hull are somehow balanced. The base or base plate 22 of each A-frame 21 is down on an elongated thermally insulating Block 23 of hardened wood attached e.g. B. synthetic resin impregnated pressed wood, which is in turn attached to the tank top 24 on the hull floor of the ship by means of brackets 25

The lateral position of the tank is fixed and firm because the tank shells themselves are sufficiently flexible to accommodate expansion and contraction of the tank. If desired, this form of support can be arranged to allow longitudinal expansion and longitudinal contraction movements are possible without the tank movements on the upper floor of the ship

can be transferred by providing longitudinal holes for the fastening bolts. At the end of the tank a certain overhang can be allowed, if desired, because the tank, although flexible in the transverse direction, is extremely strong and rigid in the longitudinal direction.

So that bends or deflections of the ship's hull do not exert any bending loads on the tank sealed hydraulic pads or buffers 26 between the tank top 24 of the ship and the blocks 23 made of hardened wood.

Similar supports can be provided on the sides of the tanks if required. However, these are merely anchorages, and there won't be any need for a permanent connection between the tank and the The fuselage should be provided as the tank contracts away from them when it cools, but the tank will preferably a lateral support is given by means of upper supports, for example such as in FIG. 5 are shown. These top supports are like the inverted bottom supports with tongue and groove joints, as at 28 to allow relative vertical movement. There is no need for any to provide relative movement between the frame 27 and the ship deck 28 to which it is attached and hydraulic buffers or pads are not required.

Corner saddles can be provided on the lower edges of the tank, which extend lengthways, to take overhead loads, with each saddle being carried by the ship's hull on two V-frames, which are arranged near the ends of the saddle. Such saddles on the edges or corners provide lateral support or lateral limitation, just as they carry the weight loads overhanging the main floor beams. Another way to take overhanging loads, however, is that the internal horizontal Surfaces are locally stiffened. This may be necessary because of the flexibility of the tank in the transverse plane. If the floor beams or lower beams are not welded to the tank, there is a way of securing that the tank does not move physically or as a whole lengthways in the ship, in it, the ends of the To provide floor beams or lower beams with upward-facing bugs to rest against the ends of the tank.

The tank, if installed in the manner described above, can be block or injection molded Plastic insulation are insulated, which are attached to all surfaces of the container hold. For the purpose of easy access to the tank, gaps are advantageous everywhere between the insulation and the tank intended.

in tanks of the design described are all Stresses or stresses are not just tensile or elongation stresses, but are the loads or tensions or stresses in the connecting plates 13, 14 and shells 11 are the same and the flexibility of the cups 11 resembles the tank contraction and expansion in the manner of a tire or a clamp, and the main vertical loads do not exert any bending stresses on the tank. In some Cases it can be advantageous to have higher loads or stresses in the central connecting plates 13,14 than to have in bowls 11.

Although the case in which the shells of the longitudinal walls and the inner tunnels or channels are perpendicular, not discussed in particular or in detail this represents a construction that is remarkable is in terms of bracket or support, as such a tank is just welded floor beams or lower beams required.

For this purpose 3 sheets of drawings

Claims (2)

Patent claims: 1. Ship's tank for storing or transporting a pressurized flowable medium, with a bottom, an upper part, long side walls, which consist of identically designed, parallel shells of outwardly convex, partially cylindrical shape, as well as end walls, which consist of identically designed convex end wall elements consist, with an inner framework of right-angled penetrating connecting plates, which interconnect the shell-connecting elements of opposing walls, wherein the connecting elements between the bottom shells and the inner framework are formed by bottom-insert elements with a cross-section, the vertical upper and lower arms as well having downwardly drawn side arms and wherein the connecting elements between the upper wall rails and the inner framework are formed by upper insert elements, with a cross-section having vertical bottom arms and upwardly inclined side arms, further with Bo the supports having upper portions which in turn engage the bottom insert members, characterized in that the bottom supports comprise upper grooved members (20) which slide on the bottom arms of the bottom insert members (17a) to allow the tank to expand horizontally, and that the upper supports are arranged at a level above the upper side of the tank and have downwardly extending regions which engage in recesses which are formed on the tank in the region of its upper side, namely on the connecting elements between adjacent shells (H) wherein the upper supports include links (28) which also allow relative sliding movement. 2. Tank according to claim 1, characterized in that the upper supports comprise the triangular frames (27) which are attached to the underside of the deck (281) of the ship and which comprise grooved connecting elements (28) which engage slidably on upper arms, provided on some of the upper insert members (17) of the tank.