Key information

Title
Scalable pressure vessel
Application number
20230766
Case type
National
Status
14.09.2026 Patent meddelt (B1)
Filed
06.07.2023
Effective date
06.07.2023
Publicly available
07.01.2025
Next annual fee due
31.07.2027
Applicant
LATTICE INTERNATIONAL AS (NO)
Owner
LATTICE INTERNATIONAL AS (NO)
Inventor
Pål G. Bergan (NO)
Agent
BRYN AARFLOT AS (NO)
Granted
14.09.2026
Patent number
350151
Expiry date
06.07.2043

Abstract and drawing

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content.
Scalable pressure vessel comprising an outer, leak-tight pressure shell which contains a pressurized fluid during operation, and at least one opening through the outer shell for loading and unloading of the fluid. With reference to a global, orthogonal coordinate system the pressure vessel is distinguished in that it comprises six external surface panels where two are side panels parallel to the x-z plane, two are side panels parallel to the y-z plane and two are end panels parallel to the x-y plane, constituting the outer leak tight pressure shell as joined together, a plurality of internal panels parallel to the x-y coordinates, arranged for taking up tension forces in two of the three spatial directions associated with pressure on the two external panels parallel to the x-z plane and the two external panels parallel to the y-z plane, further comprising a plurality of parallel tension members or beams, arranged in the z direction, perpendicular to the parallel tension panels for taking up tension in the third spatial direction originating from the pressure on the two external x-y plane end panels, wherein each of the parallel beams is arranged aligned and continue through the parallel panels through one opening in series for each panel for each beam. Method of fabricating said pressure vessel.

Publications

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Documents

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Date
 Date Doc. No. Process Case number In/Out Journal description To/from
 15.09.2026 12-01 Saksbehandling 20230766(350151) UT PT Registreringsbrev nasjonal patent (15) (PT20230766)
07.09.2026 11-02 Saksbehandling 20230766 INN 143298NO-GRANT-ASAP BRYN AARFLOT AS
 07.09.2026 11-01 Saksbehandling 20230766 INN Korrespondanse (Hovedbrev inn) BRYN AARFLOT AS
 04.09.2026 10-01 Saksbehandling 20230766 UT Intention to grant BRYN AARFLOT AS
 04.06.2026 09-05 Saksbehandling 20230766 INN 143298NO-Response letter BRYN AARFLOT AS
 04.06.2026 09-04 Saksbehandling 20230766 INN 143298NO-Norwegian translation of claims BRYN AARFLOT AS
 04.06.2026 09-03 Saksbehandling 20230766 INN 143298NO-Amended claims and description - marked changes BRYN AARFLOT AS
 04.06.2026 09-02 Saksbehandling 20230766 INN 143298NO-Amended claims and description - clean version BRYN AARFLOT AS
 04.06.2026 09-01 Saksbehandling 20230766 INN Korrespondanse (Hovedbrev inn) BRYN AARFLOT AS
 06.03.2026 08-01 Saksbehandling 20230766 UT Substantive examination BRYN AARFLOT AS
04.09.2025 02-01 Endring av søker/innehaver 2025/09413 UT GH Forespørsel BRYN AARFLOT AS
02.09.2025 01-01 Endring av søker/innehaver 2025/09413 INN Generell henvendelse BRYN AARFLOT AS
 02.06.2025 07-01 Saksbehandling 20230766 UT PT Varsel om betaling av første årsavgift (3317) (PT20230766) BRYN AARFLOT AS
 10.07.2024 06-02 Saksbehandling 20230766 INN Response to Office Action BRYN AARFLOT AS
 10.07.2024 06-01 Saksbehandling 20230766 INN Korrespondanse (Hovedbrev inn) BRYN AARFLOT AS
 02.02.2024 05-02 Saksbehandling 20230766 UT PT report 08:44:24
02.02.2024 05-01 Saksbehandling 20230766 UT 20230766_1809168_PT 08 Eng BRYN AARFLOT AS
 26.09.2023 04-02 Saksbehandling 20230766 INN GPOA NO Lattice International AS BRYN AARFLOT AS
 26.09.2023 04-01 Saksbehandling 20230766 INN Korrespondanse (Hovedbrev inn) BRYN AARFLOT AS
 07.07.2023 03-01 Saksbehandling 20230766 UT Formal Examination 1 BRYN AARFLOT AS
 07.07.2023 02-01 Saksbehandling 20230766 UT Informasjon til oppfinner Pål G. Bergan
 06.07.2023 01-05 Saksbehandling 20230766 INN Drawings BRYN AARFLOT AS
 06.07.2023 01-04 Saksbehandling 20230766 INN Description BRYN AARFLOT AS
 06.07.2023 01-03 Saksbehandling 20230766 INN Claims BRYN AARFLOT AS
 06.07.2023 01-02 Saksbehandling 20230766 INN Abstract BRYN AARFLOT AS
 06.07.2023 01-01 Saksbehandling 20230766 INN Søknadsskjema Patent BRYN AARFLOT AS

Description, claims and drawings

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content. Description
3501511SCALABLE PRESSURE VESSELField of the invention5 The present invention relates to storage and transport of fluids under pressure, such as storage and transport of liquid natural gas (LNG), liquid petroleum gas (LPG), liquid carbon dioxide (LCO2), liquid hydrogen (LH2), or in principle any other fluid that should be stored at pressure higher than atmospheric pressure. More specifically, the invention relates to small, medium and large sized storage 10 tanks and transport tanks for pressurized fluid based on a principle of repetitive, geometric scalability. The storage tanks and transport tanks can be of one and the same tank design or a plurality of differently designed tanks with respect to pressure and shape but are in general in the context of the present invention termed a pressure vessel.15Background of the invention and prior artWhen a pressurized fluid is to be stored or transported, several requirements and constraints must be met by the pressure vessel. The pressure vessel must be strong enough to handle the pressure and to sustain dynamic variations of 20 the load on the tank over the operating ranges of the tank. In addition, certain geometrical, size or shape related constraints associated with the field of use must be met. For example, a spherical tank or a cylindrical tank may be weight optimal for containing pressurized fluid, but the tank wall thickness can become too large for practical fabrication. Moreover, due to their shape such shell type 25 tanks usually have a very poor utilization of the surrounding space such as when employed in a ship structure. Size limitation due to shell thickness, need for multiple tanks to be installed for achieving required storage capacity, and space inefficiency represent severe limitations in the use of traditional shell type pressure vessels.30The concept of in principle size independent, shape independent and pressure independent pressure vessels, typically shaped as prismatic or “nearly prismatic” pressure vessels, started with Norwegian patent NO 321892, filed 2002.07.05 and granted 2006.07.17. The concept was later further developed 3501512with a more flexible design for the load bearing structure at KAIST (Korea Advanced Institute of Science and Technology) and described through a series of patents of which reference is made to patent publications WO 2012148154, WO 2014073719, US10145508, WO2006001711 and US2007194051. 5 These patents describe various forms of the outer geometry including rounded side wall, as well as various types of structural components in what is denoted the internal, three-dimensional load-bearing lattice structure; hence the name “Lattice Pressure Vessel” or LPV. Even though the LPV represents state of the art in size independent, shape independent 10 and pressure independent pressure vessels, work has continued to improve the pressure vessels with respect to weight, structural efficiency, ease of fabrication, and overall cost. Patent publication KR 101106895 B1 has been found to be relevant art for the present invention, but do not relate to a pressure tank.15The objective of the present invention is to provide significantly more favorable pressure vessels, in particular relating to structural efficiency, total weight, ease of fabrication and overall cost. An objective of the invention is to contribute towards a more sustainable economy by providing pressure vessels that more 20 efficiently can store and transport gases and fluids such as fuels with lower emissions (e.g. liquid natural gas), liquid hydrogen and hydrogen carriers such as ammonia, and handling and storage of carbon dioxide in the CCS (Carbon Capture and Storage) chain, and more. Such pressure vessel would represent a significant enabler towards the green shift with a particular potential for better 25 handling of environmentally friendly energy carriers and carbon waste. The international community is now at a crossroad regarding choice of environmentally friendly energy solutions. In particular, this is currently experienced in the shipping industry where new regulations and requirements demand that shipping converts to “no” or “low” emissions fueling or,30 alternatively, onboard carbon capture and storage which also requires highly efficient pressurized tank systems. Ship transport of liquid hydrogen and liquid CO2 can take advantage of very large-scale pressure vessels to make transportation economically viable; these are applications where the current new technology offers unique and competitive storage solutions. 3501513Summary of the inventionThe present invention meets the objectives by providing a pressure vessel comprising a leak-tight pressure shell capable of containing a pressurized fluid 5 during operation, and at least one opening through the pressure shell for loading and unloading of the fluid. With reference to a global, orthogonal coordinate system the pressure vessel is distinguished in that it comprises: six external surface panels where two are side panels parallel to the x-z plane, two are side panels parallel to the y-z plane and two are end panels 10 parallel to the x-y plane, constituting the leak tight pressure shell as joined together, preferably via rounded corner sections,a plurality of internal tension panels parallel to the x-y coordinates, arranged for taking up tension forces in two of the three spatial directions associated with pressure on the two external panels parallel to the x-z plane 15 and the two external panels parallel to the y-z plane, arranged as parallel tension panels distributed apart along the z-axis, further comprisinga plurality of parallel tension members or beams, arranged in the z direction, perpendicular to the parallel tension panels for taking up tension in the third spatial direction originating from the pressure on the two external x-y plane 20 end panels, arranged as parallel tension members or beams distributed apart, over the area of and between said end panels,wherein each of the parallel tension members or beams is arranged aligned and continue through the parallel tension panels through one opening in series for each tension panel for each tension member or beam.25Each of the parallel panels comprises a number of passage openings corresponding to the number of parallel tension members or beams.Preferably, wherein the external panels in the x-z and y-z planes are stiffened 30 with spaced beam stiffeners or ribs on the inside of said outer pressure shell parts and running in the z-direction. Preferably the stiffeners or ribs are uniformly arranged on flat pressure shell parts, preferably the stiffeners or ribs are and preferably the stiffeners or ribs are arranged on the inside of the outer flat pressure shell parts. Alternatively, the stiffeners or ribs can be arranged on 3501514the outside of said pressure shell parts, and/or be of non-uniform design.Preferably, the external end pressure panels in the x-y plane are strengthened with beam stiffeners or ribs on the inside of the end pressure panels parallel to 5 the x-y plane aligned with stiffening on the external side panels in the x-z and yz planes and with the positions of the tension members or beams. This means that stiffeners arranged in z- direction are elongated and curved in plane of said stiffener, extending further on the inside of x-y planes (end parts) and crossing where tension members or beams are fastened between the x-y planes (end 10 panels). The stiffeners, also termed beam stiffeners or ribs, preferably are very narrow long plates, preferably with width less than the distance between the ribs, preferably such as width 0, 8; 0,5; 0,3 or 0,2 or 0,1 or 0,05 times the distance between the ribs, which ribs preferably are arranged parallel and perpendicular to the pressure panel.15In many preferable embodiments, pressure shell transition plates between the in most preferred embodiments six external, stiffened and in substance flat panels are cylindrically shaped sections with radius consistent with the stiffening system in the three spatial directions. The parallel tension panels preferably 20 have corners with curvature that match the inside radius of the transition plates of the outer pressure shell.In many preferable embodiments, the outer pressure shell comprises eight corners connecting the cylindrical transition plates, which corners are25 spherically shaped with the same radius as for the cylindrical sections.Some applications may require adaptation of the box-like (cuboid) geometry of the invention to external constraints, such as hopper tanks and wing tanks inside the holds of ships. Such adaptations are highly feasible by “shaving off” 30 corners of the box geometry (cuboid) such that additional prismatic planes become a part of the total geometry. Such adaptations are easily implemented whereby the rib stiffening system is extended to the additional corner planes and the rounded corner concept is also applied to the edges of the additional facets of the tank geometry. The shape of the pressure vessel of the invention 3501515can be adapted freely, deviating from cuboid shape, for example by not having a in substance rectangular shape from a top view or a more or less nonprismatic shape. Preferably, prismatic and/or cylindrical outer pressure shell panels are used extensively, and preferably the longest dimension prismatic 5 and/or cylindrical outer pressure shell panels are sides and top and bottom, preferably being cylindrical by having identical cross-section shape inside any curved ends, and preferably comprising parallel longitudinal stiffeners or ribs, for maximizing the advantages provided by the invention.10 Preferably, all tension panels comprise multiple openings to allow for fluid flow and equalizing of pressures between tank sections formed by the tension panels.Note that the reference to the right-handed x-y-z system is made for simplicity 15 of description of the main components; in practice any of the x, y, or z axis may be the vertical (gravitational) axis. Likewise, denotations like top and bottom external plates, side plates, and end plates may have any orientation in space relating to the axis of gravity.20 Note that “six external surface panels” are defined to describe a full containment within an outer pressure shell, typically comprising six more or less flat surfaces with curved or double curved areas between the more or less flat surfaces. The panels can however be preassembled to include several of said panels in one plate, with more or less flat, curved, and double curved areas. The panels can 25 however be continuously curved or form a cylindrical single curved pressure shell shape as joined, as the person skilled in the art will realize. However, preferable embodiments, maximizing the advantages of the invention, are in substance as described and illustrated.30 The present invention provides a much simplified, modular, and repetitive structural solution as compared with previous patents, without more structure than actually required for containing the pressure. The result is reduced cost and reduced weight, as will be better understood from the further description and illustrated embodiments or details of the pressure 3501516vessel of the invention.The beam stiffeners or ribs on the inside of the external plating may be simple plates with uniform beam height, or having variable beam height, or being other 5 types rolled or extruded beam profiles. With reference to the defined global x-yz system the stiffeners run in the z-direction inside the walls in the x-z planes and y-z planes. In all cases these stiffeners are continuously welded or joined otherwise to the adjacent outer pressure panels, typically pressure shell end panels.10The end panels extending in the x-y planes are also stiffened panels with positioning of stiffeners consistent with those on the side walls. This stiffening may thus be a cross-grid of continuous stiffening from the side walls. The continuity of stiffening also imply that the stiffeners follow around on the inside 15 of the rounded corners of the end walls. The cross-grid on the end panels may in preferred cases consist of some stiffeners with greater stiffness and strength than others where the stronger stiffeners are positioned where the tension members or beams attach to the end panels. In some cases, particularly for small tanks, it may be sufficient to employ stiffening in only one direction 20 between the cross-grid of stronger stiffening connecting with the attached tension members or beams.A key concept of the present invention is that it implies high repetitiveness and is conducive to structural optimization. In most pressure vessel cases the gas 25 pressure is the dominating load component whereas the passive, gravitational (“hydrostatic”) liquid pressure on the tank walls is normally much smaller. The side walls in relation to the vertical direction can thus be optimized for gas pressure plus gravitational fluid pressure, whereas top plate can be optimized for gas pressure and the bottom for gas plus gravitational pressure. For some 30 applications, such as tanks onboard ships, it may also be necessary to account from additional pressures contributions from pressures generated by motion or accidental load conditions. In all cases it may be a benefit to keep the geometry and spacing as repetitive as possible for ease of fabrication. Even more important, the extensive repetitiveness allows for efficient structural optimization 3501517where the key variables are distance between tension panels, plate stiffening spacing, and dimensions of welded plate stiffeners. The primary optimization parameter or objective function will normally be tank weight whereas it is also possible to include parameters relating to fabrication such as total length of 5 welding.In some embodiments, it may be preferable to add stiffening to the tension panels to reduce their flexibility in relation to variable pressure on the two sides, for instance, from dynamic motion of tank and fluid onboard a ship. In such 10 cases the stiffening should preferably align with the positions of the tension members or beams crossing the tension panels.The tension members or beams that traverse the parallel panels can be fastened to panels by joining methods, which may include welding. There may 15 be several reasons for this; in particular, such connections strengthen the transverse stability of the panels during assembly and operation of fluid filled tanks that are transported. Welded connections between tension members or beams and tension panels may also be reinforced with brackets for reasons of mounting and reduction of stress concentrations. Such brackets should also 20 interconnect with stiffeners on the tension panels. Most preferably, in general, continuity of the tension members or beams through passages in the tension panels is essential. The joints between tension members or beams and tension panels can be augmented with stiffening and with support parts that can facilitate ease of mounting when inserting tension beams through the passage 25 openings.It is necessary to ensure that the pressure in liquid and gas is equalized between neighbouring compartments between tension panels. This is particularly important during filling and emptying operations of the tank.30 Pressure uniformity is easily obtained by providing an adequate number of openings in all tension panels. Typically, such openings can be so-called “ratholes” adjacent to the outer stiffened panels. Such openings can also be larger of size, providing multiple “manholes” distributed over the width and height of each tension panel. In addition to providing fluid flow and pressure 3501518equalization such openings provide important access for humans and equipment through the tension panels during assembly and during inspections. Manhole size openings may be structurally reinforced along their edges to prevent weakening of strength.5In addition to playing an important structural role the tension panels are significant for reducing rapid fluid motion and sloshing when applied for transport purposes. This is particularly important for large tanks onboard ships. In fact, the current tank geometry practically eliminates fluid sloshing and 10 thereby also reduces the risk of fatigue significantly.The parallel panels are preferably repetitive and identical panels. Depending on the size of the tank the panels may be made from one steel or metal plate, or by joining several plates together by welding. Very large tension panels may be 15 assembled from several sections and joined during the overall assembly process of the tank Also very large side and end panels may be assembled by joining sections by welding during assembly.The tank will in most cases be supported on multiple support blocks that are 20 positioned in a way that is consistent with the location of the tension panels and structural outline of the underlying structure, such as a ship deck. Normally, wood blocks that provide fixed or sliding support are used for thermally insulated tanks. Additionally, lateral supports at the sides and at the top panel can be employed to provide lateral stability during normal and accidental load 25 conditions including forces during collisions, grounding, heeling, and flooding of surroundings compartment for the case of tanks onboard ships.. Since supports introduce concentrated forces onto the outer and inner panels additional strengthening of the adjacent parts can be introduced without significant modification of the overall design concept of the invention.30The tank of the invention can be made with any material that suitable in terms of strength, joining, assembly and usage requirements. For most applications it is foreseen that a type of carbon steel or alloyed steel, such as low temperature stable austenitic steel, will be preferable. However, other metals may also be 3501519employed in connection with special requirements, such as use of aluminium for low weight. The chemical properties and temperature of the pressurized fluid also play a decisive role for choice of material; for instance, for containments for liquified gases such as liquid natural gas (LNG), liquid petroleum gas (LPG), 5 liquid ammonia, liquid carbon dioxide (LCO2), and liquid hydrogen (LH2). The international gas code (IGC) sets specific requirements for approval of tank materials depending on temperature, chemical composition, and design pressure. Further, the code requirements may also extend to use of specific welding techniques and weld testing, and to heat treatment of the welded tank 10 assembly. Requirements may also extend to maximum plate thickness. Unlike for traditional spherical and cylindrical shell type pressure vessel the current concept provides size scalability without increase of material thickness. In summary, it appears that containment by the current tank invention may satisfy most known code requirements, possibly except for extremely high pressures 15 beyond the order of 10 MPa.The invention also provides a method of fabricating a pressure vessel according to the invention, distinguished by comprising the steps as follows, not20 necessarily in the order as described:building the pressure vessel from efficient fabrication of stiffened panels representing major components such as side panels, end panels, tension panels, and sections of tension members or beams,performing inspection, non-destructive testing and other fabrication 25 acceptance steps on each of the above-mentioned parts,in case of very large tanks the main components may be made by several parts joined during the overall assembly process,applying an assembly process by which the bottom panel including curved corners is laid out and assembled first,30 following steps include sequentially positioning and connecting the tension panels on top of the bottom panels accompanied with inserting and connecting tension members or beams between tension panels to provide connectivity and stability,enclosing the tank mounting and connecting side panels, end panels and 35015110top panel,performing for each assembly and fastening step required testing of welds,executing the above-mentioned assembly steps in an order which gives a 5 best possible access for work, including application of scaffolding and platforms for work and machinery,during the described assembly process install auxiliary systems such as piping, pumps, instrumentation, tank dome and the like,after tank completion carry out pressure testing or any other time of 10 control and measures required by the code.Preferably, structural parts, with or without stiffeners, and any additional stiffening structure, is to a large extent prefabricated by automated cutting and by welding or other joining method feasible for automation and preferably using 15 fixtures or jigs for holding prefabricated components or parts in position before or during joining in the pressure vessel. Ladders and work platforms for use during the assembly or being of permanent nature for later inspection, can easily be connected with or attached to the regular tension panel and tension beam system.20As a suggested reference classification, small sized pressure vessels are in general of size in the range 0,5 to 10 m3, medium sized pressure vessels are in the size range 10-500 m3 while large pressure vessels have the size above 500 m3.25The current invention represents a significant improvement over previous inventions associated with cellular and lattice type internal load bearing systems. This particularly relates to modularity, repetitiveness and simplicity of design, the capabilities for structural optimization, and ease and efficiency of 30 fabrication. Multiple studies have confirmed that the pressure vessel of the invention is at least 20-30 % less expensive to build, weights at least 20 – 30 % less and is much easier to fabricate than earlier prismatic type pressure vessel designs, which already are favorable compared to other known pressure vessels, all of which is surprising and non-obvious. 35015111FiguresFigure 1 illustrates an embodiment of a pressure vessel of the invention with xy-z reference coordinate system5 Figure 2 illustrates a pressure vessel of the invention completed with an external thermal insulation systemFigure 3 illustrates corner solutions between external panelsFigure 4 illustrates joining parts between tension panels and stiffened external side panels10 Figure 5 illustrates sections of tension panels with tension beams and manholes Figure 6 illustrates positioning of support system that allows for thermal contractionFigures 7-12 illustrates how a pressure vessel of the invention can be fabricated by a method of the invention, step by step.15Detailed descriptionReference is made to Figure 1, illustrating somewhat simplified a preferable embodiment of a pressure vessel 1 of the invention with a defined, associated Cartesian x-y-z coordinate system. For descriptive purposes the reference 20 coordinate system has x and y coordinates parallel to the end panels 5 and the internal tension panels 4 indicated inside the outer pressure shell 2. The two external side panels visible, one in the x-z plane and one in the y-z plane, are indicated with 6. Further, the eight curved joining sections between the external panels are denoted with 7 and the eight doubly curved corners are marked with 25 8. It is to be noted that the y-axis may not necessarily be oriented in the same direction as the direction of gravity; for instance, the x-y plane could be horizontal whereas the z axis could point in the vertical direction.A more extensive illustration of an embodiment of the invention is shown in 30 Figure 2. The pressure vessel 1 is shown comprising an outer shell and pressure barrier 2 inside which pressurized fluid is contained during operation, and at least one opening with pipe connection 10 through the pressure shell for loading and unloading pressurized fluid, here extending from a so-called pipe dome structure 11.9 indicates lateral support attachments on the shell surface. 35015112For clarity, one end panel of the pressure shell, and parts of top, bottom and sides of the pressure shell towards said end panel, have been removed to reveal the internal structure of the pressure vessel. The internal structure comprises a plurality of parallel panels 4, arranged for taking tension forces in 5 the x and y spatial directions, further comprising a plurality of parallel tension beams 12, arranged perpendicular to the parallel panels for taking tension in the third spatial direction z. In Figure 2, it is indicated that each of the parallel tension beams 12 connect continuously and aligned through the parallel panels 4 by way of premade passage openings 13 in the tension panels, one opening 10 in series for each panel for each beam. Alternatively, the tension beams could be attached directly to the surface of the tension panels; however, such connections would be weaker and could make it difficult to align the tension beams properly. The tension beams are continuous and aligned from end panel 5 to opposite end panel of the pressure shell.15The parallel panels 4 are fastened on all sides of the outer side external side panels 6, thereby ensuring that the internal pressure on opposite outer side panels 6 is transferred and balanced by way of tension in the tension panels. The stress in the tension panel the x and y directions originating from the 20 internal gas pressure is equal regardless the relative external dimensions of the prismatic tank; the stress in the tension panels only depends on internal pressure, distance between tension panels and thickness of the tension panel including possible stiffeners. Equal stressing of the tension panels in its two directions implies that the plate load bearing capacity is optimally utilized. A key 25 principle for the present invention is that the thickness of the internal load bearing structure is not dependent on the overall size of the tank, thus any degree of scaling in the three spatial directions is feasible. This is clearly a major difference from traditional spherical and cylindrical pressure vessels for which the shell thickness is directly proportional with the size of the radius of 30 curvature. In essence, the invention describes a modular system with equal modular units that can be extended repetitively in the x and y directions and also extended repetitively in the z direction to provide a box-like pressure vessel 35015113of any size.The outer shell 2 is the barrier for internal fluid pressure and as such takes the internal pressure on the inside of the outer shell between the internal tension 5 panels. Clearly, such pressure leads to bending of the outer plate structure since the pressure load must be transferred from the inside of the shell 2 onto the adjacent tension panels. The problem of pressure transfer to the tension panels is dealt with by introducing longitudinal stiffeners or ribs 14 in the zdirection spanning between the tension panels whereby the combined strength 10 and stiffness transfer provides the required load bearing capacity. For simplicity, Figure 2 only shows such stiffeners associated with the modular positions of the tension beams, whereas stiffeners 14 will in the rule be introduced also in between these positions. The dimensions of the stiffened outer shell with stiffeners depend only on internal pressure, distance between tension panels, 15 and distance between longitudinal stiffeners and not on the overall size and dimensions of the pressure vessel itself. Again, this differs principally from traditional shell type pressure vessels where the size of the tank expressed in terms of radius determines the shell thickness and thereby becomes a severe limitation to scaling of the tank.20The “lean” and simple geometry of the invention carries many advantages. It implies that it is rather simple to optimize the load bearing geometry and weight of a tank for a given pressure by varying distance between tension panels, distance between stiffeners, outer plate thickness, height of stiffeners and 25 thickness of stiffeners. Notably, the total amount of material (sum) required for the tension panels is in principle independent of the distance between these, however, the stiffening clearly depends on tension panel spacing. The spacing between tension panels is preferably chosen to be about equal to or nearly the same as the distance between tension beams. For large tanks such distance 30 will normally be between 0.6 and 3 meters where the minimum distance is associated with providing human access. As described, unidirectional stiffening in the z direction is optimal since additional, perpendicular stiffening between tension panels have very little effect on the local load bearing capacity. These 35015114matters distinguish the current invention significantly from prior art.Figure 3a illustrates that the corners between joining external panels are rounded with quarter-cylinder geometry 8 with radius indicated as R. The 5 reason for this smooth transition rather than sharp corners is to avoid stress concentrations. The radius R is preferably chosen to be about equal or of the same order as for the distance between longitudinal stiffeners. Logically, and as seen in Figure 3b, 1/8 spherical and doubly curved geometry with radius R is implemented at the 8 corners where three panels meet.10The end panels 5 are connected to the external side panels and anchored to the opposite end panel by means of the tension beams 12 which balance pressure on the opposite end panels. Longitudinal stiffeners 14 on the external side panels are extended to the end panels such that they form a grid of 15 crossing stiffeners. The anchoring of tension beams 13 is strengthened by a grid of strong stiffeners 14 that connect between the positions of the incoming tension beams. Intermediary longitudinal stiffeners 15 from the side panels extend to a cross-grid on the end panels. In some embodiments of the invention the stiffening on the end panels only requires plate stiffening in one direction 20 spanning the stronger stiffeners 14 in the other direction; this is indicated in Figure 1.The tension panels are not fluid-tight but rather contain a series of openings to ensure that the liquid level is the same across all sections between tension 25 panels and the gas pressure is also even across all sections, see Figure 4. Rathole type openings 16 in the panels should be implemented along the connections between all tension panels 4 and the surrounding shell enclosure 2 as shown in the figure or they could be separate, round holes at a small distance from the joints between the tension panels and the outer shell A 30 particular objective with these edge openings is to ensure that fluid or gas does not get trapped when emptying the tank. Further, larger openings 17, such as man-holes type access openings, are implemented to a large extent in all tension panels. Such openings are of importance to provide access for people and machinery during construction assembly and during inspections and repair 35015115operations. Typical dimensions of manhole type openings are 400 to 600 mm. The effect of weakening of the tension due to these cut-outs can be compensated by common type edge reinforcement of the openings as is common in many types of structures.5Figure 5 provides some further insight into the matter of tension beams that carry most of the pressure loading on the external end panels and must be dimensioned accordingly, A general principle is that the cross-section of the tension beam should preferably be double-symmetric to avoid eccentricities 10 and, as result, occurrence of bending stresses. Double-symmetric crosssections also have the advantage of being well suited for connecting with stiffeners on the tension panels. Figure 5a shows tension beams with so-called X-type cross-section; this may be referred to as an X-beam. Such X-beams may be fabricated by rolling, extrusion, welding of plate strips or joining angle-type 15 cross-sections. The Figure also show possible manholes 17 for access and passage between tension panels. The dotted lines 20 indicate natural locations for tension panel stiffening. Similarly, Figure 5b shows an alternative embodiment where the tension beam has a square, tube type cross-section. This solution is also easy the implement; however, particular attention should be 20 paid to avoid trapped fluid in hollow cross-sections. Many other alternatives may be considered including solid round bars, pipes, I-beams and heavy flange beams that are also feasible with the current invention.Internal pressure in pressure vessels implies elastic expansion whereas cooling 25 of the stored fluid implies contraction. For a large tank the expansion or contraction can be significant. For simplified illustration, assuming a thermal coefficient of expansion equal to 14 *10-6 per degree K the case of 200 degrees cooling gives a contraction of 2.8 mm per m. For a large tank this case may mean several cm of actual contraction from one end to the other. Clearly, the 30 support must be designed for sliding to avoid severe stressing due to external constraints against motion. Fortunately, well-proven technologies are available for sliding type supports, for example use of laminated woodblocks that additionally also provide some degree of thermal insulation. Woodblock supports have been extensively used for type A and Type B (international gas 35015116code classifications) unpressurized prismatic tanks. Such known support solutions can easily be implemented for the current invention. Figure 6 illustrates an example of support implementation for the current invention where woodblocks 21 are place at a number of locations under the internal tension 5 panels. These locations represent particularly strong and stiff structural parts of the pressure vessel that can also easily be locally further strengthened. Figure 6a shows a view from the side whereas Figure 6 b shows a view from below. The double arrows indicate that the supports have a guidance that allows sliding only in the direction of the double arrows, The support in the middle 22 is 10 a fully fixed support. Given significant cooldown of the pressure vessel the contraction at all other support points is constrained towards the fixed support 22.The simple geometry of the invention with large planar surfaces makes it 15 suitable for applying thermal insulation for pressure vessels with a cold internal fluid. Combination of pressurization and cooling is employed for many fluids such as LNG, LPG, LCO2, ammonia and LH2. Well proven insulation systems for A and B type tanks are easily available, such as foam block type and sprayon foam systems. Thermal insulation of liquid hydrogen at temperature -253° C 20 (20 K) is particularly challenging because it requires vacuum insulation to avoid freezing of gas in the insulation layer. The embodiment of pressure vessel 1 of the invention illustrated in Figure 2 also comprises a vacuum insulation system with porous insulation blocks 24 with gaps between 25 attached to the outer shell surface 2 of the pressure vessel. A continuous, flexible, air-tight25 membrane 25 is attached to the outside of the insulation blocks where the membrane has corrugations 26 in two directions allowing for significant contraction due to compression when the inner pressure vessel is cooled down. The geometry of the corrugations is unique in that the compression at the corrugations and their crossing points can take place elastically without yielding 30 stresses in the membrane. The insulation system includes at least one opening and coupling to a vacuum pump for providing vacuum in the insulation. The vacuum insulation is fully scalable, as is the pressure vessel of the invention. 35015117Further reference is made to patent publication WO 2022050848.Pressure vessels of the current invention may be fabricated by specialized pressure vessel manufacturers or, particularly for large ship tanks, by shipyards 5 and offshore yards that have necessary qualifications and certificates.Traditional ship building methods are usually based on a so-called block assembly principle in which box-like structural parts are prefabricated and placed sequentially and joined with its neighboring blocks. The current invention is comprised only of repetitive components of following types; external side 10 panels including bottom panel, external end panels, internal tension panels, and tension beams. This concept implies that the prefabrication by parts comprises panels or sections of panels, and sections of tension members or beams.Figures 7 through 12 illustrate how a pressure vessel of the invention can be fabricated by an embodiment of the method of the invention, step by step. More 15 specifically, 6 steps are illustrated, with step 1 illustrated in Figure 7, and further steps consecutively in the following figures. The Figures include explanatory text and are in principle self-explanatory. Some variations of the method described are feasible considering size of the pressure vessel and deformations and tolerances of parts associated with handling and welding. When studying 20 the figures closely, it is evident that the work can include prefabrication by automized cutting, forming, and joining techniques. The design and manufacturing procedure allows for personnel to work inside the structure during assembly; this results in a far easier fabrication process than earlier prismatic pressure vessel designs. The quantity of materials used is also 25 reduced, and many difficult fabrication steps have been eliminated or made much easier. Very large plate sections, such as large rolled steel plates from the manufacturer, can be used for the various panels; this reduces the amount of welding and the possibility for crack formation in the outer shell.30 The cost of fabricating a complete pressure vessel of the invention is typically 20 - 30 % lower than for prior art prismatic tank designs. The efficient scalability with fully repetitive geometry even makes it weight competitive with traditional cylindrical and spherical pressure vessels because it can replace a battery of traditional pressure vessels with a single prismatic pressure vessel according to 35015118the invention. In some applications the prismatic space efficiency can imply that the fluid cargo capacity onboard a ship can be doubled for a given storage hold. The resulting weight of a pressure vessel of a specific size is also reduced by at least 20 - 30 % allowing for more cargo or load. The total monetary advantage 5 is thus very significant, and the result is facilitating the shift to a more sustainable economy and enabling the transporters using the pressure vessels to achieve an advantage both with respect to economy, energy efficiency, and reduced impact on environment and climate.10List of component numbering on the figures:1 The pressure vessel2 The gas Ɵght outer shell3 X-y-z coordinate system15 4 Tension panels5 End panels (of outer pressure shell)6 Side panels (of outer pressure shell)7 Rounded, cylindrical corners joining external panels8 Doubly curved, spherical sharp corners20 9 Lateral support aƩachment10 Pipe for inlet and outlet11 Pipe dome12 Tension beams13 Passage opening for tension beam in tension panels25 14 Longitudinal sƟffening on side panels15 Intermediary longitudinal sƟffeners16 Rat hole17 Manhole18 Tension beam with X-type cross-secƟon30 19 Tension beam with tubular cross-secƟon20 System lines for possible sƟffening of tension panel21 Support block allowing unidirecƟonal sliding22 Fixed support block23 Porous insulaƟon block35 24 Gap between insulaƟon blocks25 Air-Ɵght flexible membrane26 CorrugaƟons on flexible membrane40
Claims
35015119CLAIMS1.A pressure vessel (1) comprising a leak-tight pressure shell (2) capable of containing a pressurized fluid during operation, and at least one opening 5 through the pressure shell for loading and unloading of the fluid, and with reference to a global, orthogonal coordinate system the pressure vessel is characterized in that it comprises:six external surface panels where two are side panels parallel to the x-z plane, two are side panels parallel to the y-z plane and two are end panels 10 parallel to the x-y plane, constituting the leak tight pressure shell as joined together, preferably via rounded corner sections,a plurality of internal tension panels (4) parallel to the x-y coordinates, arranged for taking up tension forces in two of the three spatial directions associated with pressure on the two external panels parallel to the x-z plane 15 and the two external panels parallel to the y-z plane, arranged as parallel tension panels (4) distributed apart along the z-axis, further comprisinga plurality of parallel tension members or beams (12), arranged in the z direction, perpendicular to the parallel tension panels for taking up tension in the third spatial direction originating from the pressure on the two external x-y plane 20 end panels, arranged as parallel tension members or beams (12) distributed apart, over the area of and between said end panels,wherein each of the parallel tension members or beams is arranged aligned and continue through the parallel tension panels through one opening (13) in series for each tension panel for each tension member or beam.252.Pressure vessel according to claim 1, comprising longitudinal internal stiffeners (14) in the form of longitudinal ribs oriented in z direction and welded or30 fastened otherwise to the inside of the external side panels parallel to x-z and yz planes.3.Pressure vessel according to claim 1 or 2, comprising internal stiffeners, in the35015120form of ribs (15) oriented in the x or y directions or combined both x and y directions and welded or fastened otherwise to the inside of the external end panels in the x-y planes and where the positioning of the stiffening on the end panels is consistent with positioning of longitudinal stiffening on the side panels, 5 wherein the longitudinal stiffening on the side panels continue on the end panels, from one or both of side panels parallel to x-z and y-z planes, via the inside of single curved transitions from side panel to end panel, wherein the inside of the curved transition has curvature of radius R and the outside of the ribs has matching outer curvature of radius R.104.Pressure vessel according to any one of claim 1-3, having parallel tension members or beams positioned consistently with the stiffening on the external panels, wherein tension members or beams are fastened to stiffeners or when 15 stiffeners run in two directions, where the stiffeners are crossing, so as to take up tension between the stiffened end panels.5.Pressure vessel according to claim 1-4, wherein the tension members or beams 20 have a cross-sectional area consistent with the force carried by the tension beam and a cross-sectional geometry consistent with attachments between tension beam and any local stiffening parts around the intersections, wherein for embodiments with longitudinal stiffeners inside the end panels in both x and y direction, comprising tension members or beams having 25 doubly symmetric cross-sections such as orthogonal X cross section shape, and fastened to stiffeners in x and y directions where said stiffeners are crossing.30 6.Pressure vessel according to any one of claim 1-5 where the tension panels have stiffening consistent with the y and/or x positions of the tension members35015121or beams.7.Pressure vessel according to any one of claim 1-6, where the tension panels 5 have a plurality of smaller or larger openings suitable filling and emptying the pressure vessel with fluid and providing access across tension panels for people and machinery in connection with fabrication and inspection.8.10 Pressure vessel according to any one of claim 1-7 where the joining sections between external panels are rounded with cylindrical shape and spherical shape plate geometry with radius R, such as single curved outer pressure shell parts 7 with radius R between flat side, top, bottom and/or end pressure shell parts, and 1/8 double curved spherical corner parts of radius R where flat outer 15 shell parts meet at an outer pressure shell corner.9.Pressure vessel according to claims 1- 8, whereby the initial orthogonal geometry of the pressure vessel is augmented with skew, “cut-off” external 20 panels with rounded corners to accommodate for spatial constraints introduced by the surrounding space such as holds for the pressure vessel onboard a ship.10.Method of fabricating a pressure vessel according to any one of claim 1-9, 25 characterized by:building the pressure vessel from efficient fabrication of stiffened panels representing major components such as side panels, end panels, tension panels, and sections of tension members or beams,performing inspection, non-destructive testing and other fabrication 30 acceptance steps on each of the above-mentioned parts,in case of very large tanks the main components may be made by several parts joined during the overall assembly process,applying an assembly process by which the bottom panel including35015122curved corners is laid out and assembled first,following steps include sequentially positioning and connecting the tension panels on top of the bottom panels accompanied with inserting and connecting tension members or beams between tension panels to provide 5 connectivity and stability,enclosing the tank mounting and connecting side panels, end panels and top panel,performing for each assembly and fastening step required testing of welds,10 executing the above-mentioned assembly steps in an order which gives a best possible access for work, including application of scaffolding and platforms for work and machinery,during the described assembly process install auxiliary systems such as piping, pumps, instrumentation, tank dome and the like,15 after tank completion carry out pressure testing or any other time of control and measures required by the code.11.Method according to claim 10, whereby pressure shell parts, with or without 20 stiffeners, and any additional stiffening structure, is prefabricated by automated welding or other joining method feasible for automation and using fixtures for holding prefabricated components or parts in position before or during joining in the pressure vessel.2535015123Patentkrav1.En trykktank (1) omfattende et ytre, lekkasjetett trykkskall (2) egnet til å inneholde et fluid under trykk under drift, og minst én åpning gjennom det ytre trykkskallet for fylling og tømming av fluidet, og med referanse til et globalt, ortogonalt koordinatsystem, karakterisert ved at trykktanken omfatter:seks ytre overflatepaneler, hvorav to er sidepaneler parallelle med x-z-planet, to er sidepaneler parallelle med y-z-planet og to er endepaneler parallelle med x-yplanet, hvor disse til sammen utgjør det ytre lekkasjetette trykkskallet ved å være sammenføyd, fortrinnsvis via avrundede hjørneseksjoner,et flertall indre parallelle strekkpaneler (4) med x-y-koordinatene, anordnet for å oppta strekkrefter i to av de tre romlige retningene som følger av trykket på de to ytre panelene parallelle med x-z-planet og de to ytre panelene parallelle med y-zplanet, idet strekkpanelene (4) er anordnet som parallelle strekkpaneler (4) med avstand fra hverandre langs z-aksen, og videre omfattendeet flertall parallelle strekkbjelker (12) eller -elementer, anordnet i z-retningen, vinkelrett på de parallelle strekkpanelene, for å oppta strekk i den tredje romlige retningen som følger av trykket på de to ytre endepanelene i x-y-planet, idet strekkbjelkene (12) eller -elementene er anordnet som parallelle bjelker (12) eller elementer med avstand fra hverandre over arealet av og mellom nevnte endepaneler,idet hver av de parallelle strekkbjelkene eller -elementene er anordnet som gjennomgående gjennom de parallelle strekkpanelene via én åpning (13) i serie for hvert strekkpanel for hver strekkbjelke eller -element.2.Trykktank ifølge krav 1, omfattende langsgående innvendige avstivere (14) i form av langsgående ribber orientert i z-retningen og sveiset eller på annen måte festet til innsiden av de ytre sidepanelene parallelle med x-z- og y-z-planene.350151243.Trykktank ifølge krav 1 eller 2, omfattende innvendige avstivere i form av ribber (15) orientert i x- og/eller y-retning, eller kombinert både i x- og y-retning, og sveiset eller på annen måte festet til innsiden av de ytre endepanelene i x-y-planene, og hvor plasseringen av avstivningen på endepanelene samsvarer med plasseringen av den langsgående avstivningen på sidepanelene, hvorved den langsgående avstivningen på sidepanelene fortsetter på endepanelene fra ett eller begge av sidepanelene parallelle med x-z- og y-z-planene, via innsiden av enkeltkrummede overganger fra sidepanel til endepanel, hvor innsiden av den krumme overgangen har krumning med radius R og utsiden av ribbene har tilsvarende ytre krumning med radius R.4.Trykktank ifølge et hvilket som helst av krav 1–3, hvor de parallelle strekkbjelkene eller -elementene er posisjonert i samsvar med avstivningen på de ytre panelene, hvorved strekkbjelkene eller -elementene er festet til avstivere, eller der avstivere løper i to retninger, der avstiverne krysser hverandre, slik at strekk tas opp mellom de avstivede endepanelene.5.Trykktank ifølge krav 1–4, hvor strekkbjelkene eller -elementene har et tverrsnittareal tilpasset kraften som føres av strekkbjelken eller -elementet og en tverrsnittgeometri tilpasset innfestninger mellom strekkbjelke og eventuelle lokale avstivningsdeler rundt krysningspunktene,hvorved, for utførelsesformer med langsgående avstivere på innsiden av endepanelene i både x- og y-retning, omfatter trykktanken strekkbjelker eller -elementer med dobbelt-symmetriske tverrsnitt, slik som en ortogonal X-tverrsnittsform, festet til avstivere i x- og y-retning der nevnte avstivere krysser hverandre.350151256.Trykktank ifølge et hvilket som helst av krav 1–5, hvor strekkpanelene har avstivning som samsvarer med y- og/eller x-posisjonene til strekkbjelkene eller -elementene.7.Trykktank ifølge et hvilket som helst av krav 1–6, hvor strekkpanelene har et flertall mindre eller større åpninger egnet for fylling og tømming av trykktanken med fluid og for å gi adgang på tvers av strekkpanelene for personer og maskiner i forbindelse med fabrikasjon og inspeksjon.8.Trykktank ifølge et hvilket som helst av kravene 1–7, hvor sammenføyningsseksjonene mellom ytre paneler er avrundet med sylindrisk form og sfærisk plategeometri med radius R, slik som enkeltkrummede ytre trykkskall-deler (7) med radius R mellom plane side-, topp-, bunn- og/eller endetrykkskalldeler, og 1/8 dobbeltkrummede sfæriske hjørnedeler med radius R der plane ytre skalldeler møtes i et hjørne i det ytre trykkskallet.9.Trykktank ifølge kravene 1–8, hvor den innledende ortogonale geometrien til trykktanken er utvidet med skrå, «avkappede» ytre paneler med avrundede hjørner for å tilpasses romlige begrensninger innført av omgivende rom, slik som lasterom for trykktanken om bord i et skip.10.Fremgangsmåte for fremstilling av en trykktank ifølge et hvilket som helst av kravene 1–9, karakterisert ved:å bygge trykktanken ved effektiv fremstilling av avstivede paneler som representerer hovedkomponenter slik som sidepaneler, endepaneler, strekkpaneler og seksjoner av strekkbjelker eller -elementer,å utføre inspeksjon, ikke-destruktiv prøving og andre akseptansetrinn i fabrikasjon for hver av de ovennevnte delene,35015126i tilfelle av svært store tanker kan hovedkomponentene være utført av flere deler som sammenføyes under den samlede monteringsprosessen,å anvende en monteringsprosess der bunnpanelet inklusive krumme hjørner legges opp og monteres først,hvor påfølgende trinn omfatter sekvensiell posisjonering og sammenkobling av strekkpanelene oppå bunnpanelet, ledsaget av innføring og tilkobling av strekkbjelker eller -elementer mellom strekkpanelene for å gi sammenheng og stabilitet,å lukke tanken ved å montere og tilkoble sidepaneler, endepaneler og topp-panel, å utføre, for hvert monterings- og innfestningstrinn, påkrevd prøving av sveiser, å gjennomføre de ovennevnte monteringstrinnene i en rekkefølge som gir best mulig tilgang for arbeid, herunder bruk av stillas og arbeidsplattformer for arbeid og maskineri,under den beskrevne monteringsprosessen å installere hjelpesystemer slik som rørføring, pumper, instrumentering, tankkuppel og lignende,etter fullføring av tanken å gjennomføre trykkprøving eller andre kontroll- og måletiltak som kreves i henhold til regelverket.11.Fremgangsmåte ifølge krav 10, hvorved trykkskalldeler, med eller uten avstivere, og enhver ytterligere avstivningsstruktur, prefabrikkeres ved automatisert sveising eller annen sammenføyningsmetode egnet for automatisering, og ved bruk av fiksturer for å holde prefabrikkerte komponenter eller deler i posisjon før eller under sammenføyning i trykktanken.
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Patent classes

IPC classesF17C 1/08F17C 1/02CPC classesF17C 1/08F17C 1/02

Citations

KR 101106895 B1 (B1)KR 20170050047 A (A)WO 2006001711 A2 (A2)WO 2012148154 A2 (A2)

Applicants, owners and inventors

Owners
LATTICE INTERNATIONAL AS
Strandveien 15 1366 LYSAKER NO (BÆRUM Municipality, Akershus county)Org. number: 926628690Inventors
Pål G. Bergan
Ridder Flemmings vei 38 1397 NESØYA NO (ASKER Municipality, Akershus county)

Agent

BRYN AARFLOT AS
BRYN AARFLOT AS

Org. number: 979993269

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Stortingsgata 8 0161 OSLO NO (OSLO Municipality, Oslo county)
Org. number: 979993269
Reference: 143298NO

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