Manufacturing method for manufacturing a thermally insulated storage tank for storing liquid or bulk material

Abstract

The application relates to a manufacturing method (100) according to an embodiment for manufacturing a thermally insulated storage tank (302) for storing liquid or bulk material. The manufacturing method comprises forming (122) an uppermost shell structure (224) of an essentially circular cylindrical shell (210) of the storage tank, formed from essentially ring-shaped shell structures (212, 224, 242, 248), by attaching steel plates (214) essentially in the form of a sector arc side by side to each other. The manufacturing method further comprises jacking (138) the formed shell structure (224) upward by at least one shell structure height (H) and forming (140) a next shell structure (242) below the uppermost shell structure by attaching steel plates essentially in the form of a sector arc to a bottom edge (AR) of the previous jacked-up shell structure (224) and to each other side by side. The manufacturing method further comprises completing (150) the shell by attaching the shell formed by the jacked-up, interconnected shell structures (224, 242, 248) at its lower edge (AR) to an installation structure (206) and forming (128, 146, 152) thermal insulation (230) for the storage tank by attaching insulation elements (232) to an outer surface (UP) of the shell. The manufacturing method further comprises forming (128, 146, 152) an essentially circular cylindrical protective sheet metal cladding (236) for the storage tank by attaching thin metal sheets on top of the thermal insulation so that the thermal insulation is between the shell and the protective sheet metal cladding. During or after the formation of the next shell structure, thermal insulation is formed (146, 152) on an outer surface (UP) of the previous jacked-up shell structure by attaching the insulation elements to the jacked-up shell structure and to each other before jacking up the next formed shell structure or before attaching the shell formed by the jacked-up, interconnected shell structures to the installation structure.

Description

[0001] Manufacturing method for manufacturing a thermally insulated storage tank for storing liquid or bulk material

[0002] Technical field

[0003] The application concerns in general a manufacturing method for manufacturing a thermally insulated storage tank for storing liquid or bulk material.

[0004] Background

[0005] Large steel-structured, thermally insulated storage tanks are used, e.g., in the paper and pulp industry for storing liquid or bulk materials.

[0006] Storage tanks are manufactured by forming a foundation and erecting, on top of the foundation, from the bottom up, a circular cylindrical steel shell for the storage tank using welded steel plates. As the height of the steel shell increases, builders need scaffolding to be installed around it, the height of which increases as the steel shell is erected, up to the so-called eave height of the storage tank. Once the steel shell is complete, a roof structure is installed on top of it.

[0007] With the steel shell complete, thermal insulation for the storage tank is formed on its outer surface using insulation elements, working from the bottom up. The insulation elements are protected from rain by forming a protective cladding made of profiled steel sheets in a similar manner from the bottom up, allowing builders to utilise the scaffolding around the storage tank, erected during the construction of the steel shell, in the installation of both the thermal insulation and the protective sheet metal cladding.

[0008] Summary

[0009] One of the objectives of the invention is to solve problems in the prior art and to provide a method for manufacturing a thermally insulated storage tank for storing liquid or bulk material, wherein providing the thermal insulation is combined with (integrated into) a construction of the storage tank carried out by means of jacking, i.e., using jacks of a jacking system. Thanks to the manufacturing method, a scaffolding required for the construction of the storage tank does not need to be erected up to an eave height, which significantly reduces construction costs and speeds up the construction of the storage tank, as an amount of work required to erect the scaffolding is reduced.

[0010] One of the objectives of the invention is achieved by the manufacturing method and storage tank according to the independent claims.

[0011] Embodiments of the invention comprises the manufacturing method and storage tank according to the independent claims.

[0012] In a manufacturing method for producing a thermally insulated storage tank for storing liquid or bulk material, an uppermost shell structure of an essentially circular cylindrical shell (jacket) of the storage tank, formed from essentially ring-shaped shell structures, is formed by attaching steel plates essentially in the form of a sector arc side by side to each other. The manufacturing method further comprises jacking the formed shell structure upward by at least one shell structure height and forming a next shell structure, to be placed below the uppermost shell structure, by attaching steel plates essentially in the form of a sector arc to a bottom edge of the previous jacked-up shell structure and side by side to each other. The manufacturing method further comprises completing the shell by attaching the shell formed by the jacked-up, interconnected shell structures at its lower edge to an installation structure and forming thermal insulation for (of) the storage tank by attaching insulation elements to an outer surface of the shell, and forming an essentially circular cylindrical protective sheet metal cladding for the storage tank by attaching thin metal sheets on top of the thermal insulation so that the thermal insulation is between the shell and the protective cladding. The manufacturing method further comprises, during or after the formation of the next shell structure, forming thermal insulation on an outer surface of the previous jacked-up shell structure by attaching the insulation elements to the jacked-up shell structure and to each other before jacking up the next formed shell structure or before attaching the shell formed by the jacked-up, interconnected shell structures to the installation structure. A thermally insulated storage tank for storing liquid or bulk material manufactured by using the above-mentioned manufacturing method comprises a shell, a roof structure, a bottom, thermal insulation and protective (sheet metal) cladding formed from protective sheet metal layers corresponding to a height of shell structures of the shell. Brief description of the figures

[0013] In the detailed description of the figures, embodiments of the invention are described, by way of example, in more detail with reference to the following figures:

[0014] fig. 1 shows steps of manufacturing method for manufacturing a thermally insulated storage tank

[0015] fig. 2a shows an embodiment for a construction of a roof structure in a vicinity of a installation structure

[0016] fig. 2b shows an embodiment with an uppermost shell structure lifted above a lowest shell structure functioning as the installation structure using jacks of a jacking system

[0017] fig. 2c shows roof and shell structures attached to each other and supported by jacks

[0018] fig. 2d shows the completed roof structure and the uppermost shell structure, partially thermally insulated and covered by protective sheet metal cladding, before jacking

[0019] fig. 2e shows the jacked-up partially completed top section of the storage tank before a formation of a next shell structure

[0020] fig. 2f shows a second shell structure to be formed on the top section of the storage tank that is partially thermally insulated and covered by protective sheet metal cladding

[0021] fig. 2g shows the completed uppermost shell structure and a third shell structure to be formed on the second shell structure that is partially thermally insulated and covered by protective sheet metal cladding fig. 2h shows a completed lower part of the shell of the storage tank attached to the installation structure, ready for insulation and protective sheet metal cladding

[0022] fig. 3 shows the completed thermally insulated storage tank and its crosssection

[0023] Detailed explanation of the figures

[0024] Figs. 1 to 3 show steps of a manufacturing method 100 for manufacturing a large, thermally insulated storage tank 302 for storing liquid or bulk material, details of the manufacturing method 100, and the completed storage tank 302. The storage tank 302 comprises a flat-bottomed, vertical cylindrical steel tank with a typical capacity of 100 to 20,000 m3, e.g. , 100; 1 ,000; 10,000; 15,000; or 20,000 m3.

[0025] During a foundation step 104, installation structures 206 for the storage tank are constructed at an installation site for the storage tank 302. Necessary earthworks are carried out at the installation site, e.g., levelling the ground and the creating a foundation (foundations) 208 for the storage tank 302, so that the storage tank 302 will be sufficiently stable and the soil will not cause the storage tank 302 to sink or lean to the side.

[0026] Once the foundation 208, e.g., a slab foundation, has been completed, the installation structure 206 of the storage tank 302 is formed (built, assembled) on top of it, essentially comprising a lowest shell structure 212 of a circular cylindrical shell 210 and a jacking system attached to it, comprising at least one jack 225, e.g., one, two, three, four, or more jacks. The shell structure 212 essentially comprises steel plates 214 essentially shaped like sector arcs. The adjacent steel plates 214 are welded together so that the steel plates 214 welded together at their side edges SR form the essentially ring-shaped (circular cylindrical) lowest shell structure 212.

[0027] Each steel plate 214 is made of carbon steel, duplex steel, or stainless (acid-resistant) steel.

[0028] Alternatively, the installation structure 206 comprises, unlike in the figures, just the foundations 208, on top of which the other structures 210, 218 of the storage tank 302 are installed, in which case the installation structure 206 comprises the foundation 208 and a jacking system attached to it. Regardless of whether the installation structure 206 comprises the shell structure 212 or not, a diameter of the foundation 208 essentially corresponds to a diameter of the storage tank 302, such that the diameter is at least equal to or greater than a diameter of the shell 210.

[0029] A manufacturing step 116 comprises manufacturing (building, assembling) a roof structure 218 in a vicinity of the installation site (foundation 208) using levelled elevation supports after the step 104. Load-bearing support structures 220 of the roof structure 218, e.g., roof trusses and other support structures, are welded together and a ceiling structure is attached to the support structures 220. In a formation step 122, an uppermost shell structure 224 of the shell 210 is formed (built, assembled) in the vicinity of the installation site and the formed installation structure 206 after, simultaneously with, or, alternatively, before the step 116. The shell structure 224 essentially comprises sector arc shaped steel plates 214, similar to the lowest shell structure 212. The adjacent steel plates 214 are welded together so that the steel plates 214 welded together at their side edges SR form the essentially ring-shaped uppermost shell structure 224. Once formed, the shell structure 224 is lifted by means of a crane, e.g., a tower crane or a lifting vehicle, on to the installation site, on top of the installation structure 206 where it rests on the jacks 225 of the jacking system.

[0030] Alternatively, the steel plates 210 are lifted by the crane on to the installation site so that they are supported by the jacking system, and the shell structure 224 is formed by attaching the steel plates 214 resting on the jacks 225 to each other.

[0031] In an attachment step 126, the roof structure 218 is lifted by the crane on to the installation site, on top the shell structure 224 supported by the jacks 225, and the roof structure 218 is attached to the shell structure 224 by welding. A formation step 128 comprises beginning, from top down, thermal insulation and cladding of the interconnected roof and shell structures 218, 224 of the storage tank 302 by attaching to the roof structure 218 insulation elements 232, e.g., glass, mineral, or rock wool elements, that constitute thermal insulation 230 and, at the same time, proceeding downwards, forming a roof cladding 234 consisting of sheets of thin metal on top of the attached insulation elements 230.

[0032] Similarly, when the thermal insulation 230 has been formed in the roof structure 218, a thermal insulation of the shell structure 224 of the shell 210 is formed from top down by attaching insulation elements 232 on to an outer surface UP of the steel plates 214. The insulation elements 232, which are installed side by side, are attached to the outer surface UP of the shell structure 224 and to each other with fastening pins, e.g., weldable or self-adhesive wool or insulation pins, vertical fastening bands, or horizontal fastening bands, so that the thermal insulation 230 of the shell 210 forms a uniform whole and there are no vertical or horizontal gaps between the insulation elements 232. While the thermal insulation 230 of the shell structure 224 is being completed, a uniform protective sheet metal layer (protective sheet metal cladding, surface sheeting) 236 is also formed on top of the shell structure 224 and the completed thermal insulation 230 by attaching thin metal sheets, e.g., coated profile steel sheets, with a height essentially corresponding to a height H of the shell structure, e.g., 2, 2.5, 3, 3.5, or 4 m high, so that the thermal insulation 230 is between the shell 210 and the protective sheet metal cladding 236.

[0033] A jacking step 138 comprises jacking the fully thermally insulated and clad roof structure 218 and the partially thermally insulated and clad shell structure 224 by means of the jacks 225 by at least one shell structure height H, e.g., one, one and a half, or two shell structure heights, upwards from the installation structure 206 so that the formation of the shell 210 can be continued.

[0034] A formation step 140 comprises forming a next shell structure 242 below the shell structure 224 by attaching steel plates 214 to a bottom edge AR of the previous jacked-up shell structure 242 and to each other side by side. The shell structure 242 essentially comprises sector arc shaped steel plates 214, similar to the top shell structure 224. The adjacent steel plates 214 are welded so that the steel plates 214 welded to the shell structure 224 at their upper edges YR and to each other at their side edges SR form the essentially ring-shaped shell structure 242.

[0035] If the top section of the shell 210 is not yet at the planned height, a jacking step 144 comprises jacking, by the jacks 225, the fully thermally insulated and clad roof structure 218, the partially thermally insulated and clad shell structure 224, and the newly formed shell structure 242 at least one shell structure height H upwards, so that the thermal insulation and cladding of the shell structures 224, 242 and the formation of the shell 210 can be continued.

[0036] A formation step 146 comprises completing the thermal insulation 230 and protective sheet metal cladding 236 on the outer surface UP of the shell structure 224 and starting the formation of thermal insulation 230 of the shell structure 242 from top down by attaching insulation elements 232 to the outer surfaces UP of the steel plates 214, as in the step 128. As the thermal insulation 230 of the shell structure 242 is being completed, the forming of the protective sheet metal cladding 236 on top of the completed thermal insulation 230 is also begun, as in the step 128. Next, in the formation step 140, the next shell structure 248, to be installed under the shell structure 224, is formed in the same way as the shell structure 242.

[0037] Once the top section of the shell 210 comprises the planned number of shell structures 224, 242, 248, an attachment step 150 comprises lowering the fully thermally insulated and clad roof and shell structures 218, 242, partially thermally insulated and clad shell structure 242 and the newly formed shell structure 248 by means of the jacks 225 so that the roof and shell structures 218, 224, 242, 248 supported by the jacks 225 can be attached to the installation structure 206, i.e., to the lowest shell structure 212 or the foundation at a lower edge AR of the steel plates 214 of the shell structure 248.

[0038] The shell 210 is completed by attaching the top section of the shell 210 formed by the interconnected shell structures 224, 242, 248 to the installation structure 206 at its lower edge by welding, if the installation structure 206 is the lowest shell layer 212, or using mechanical fastening means, if the installation structure 206 is the foundation 208.

[0039] Following the attachment, a formation step 152 comprises completing the thermal insulation 230 and protective sheet metal cladding 236 on the outer surface UP of the shell structure 242 and starting the formation of the thermal insulation 230 of the shell structure 248 and shell structure 212, if the installation structure 206 is the shell structure 212, from top down by attaching insulation elements 232 to the outer surfaces UP of the steel plates 214, as in the steps 128, 146. As the thermal insulation 230 of the shell 210 is being completed, the forming of the protective sheet metal cladding 236 on top of the completed thermal insulation 230 is also begun, similar to the steps 128, 146. Once the thermal insulation 230 and protective sheet metal cladding 236 of the shell 210 are complete, a bottom 356 of the storage tank 302 is formed in a formation step 154 and an edge plate 358, e.g., an edge plate comprising a steel plate, is attached by welding, if the material to be stored in the storage tank 302 requires the bottom 356.

[0040] Only a few embodiments of the invention have been described above by way of example. Naturally, the principle according to the invention can be modified within the scope of protection defined by the claims, e.g., with regard to implementation details and fields of application.

Claims

Claims1. A manufacturing method (100) for manufacturing a thermally insulated storage tank (302) for storing liquid or bulk material, comprisingforming (122) an uppermost shell structure (224) of an essentially circular cylindrical shell (210) of the storage tank, formed from essentially ring-shaped shell structures (212, 224, 242, 248), by attaching steel plates (214) essentially in the form of a sector arc side by side to each other,jacking (138) the formed shell structure (224) upward by at least one shell structure height (H),forming (140) a next shell structure (242) below the uppermost shell structure by attaching steel plates essentially in the form of a sector arc to a bottom edge (AR) of the previous jacked-up shell structure (224) and to each other side by side,completing (150) the shell by attaching the shell formed by the jacked-up, interconnected shell structures (224, 242, 248) at its lower edge (AR) to an installation structure (206),forming (128, 146, 152) thermal insulation (230) for the storage tank by attaching insulation elements (232) to an outer surface (UP) of the shell, and forming (128, 146, 152) an essentially circular cylindrical protective sheet metal cladding (236) for the storage tank by attaching thin metal sheets on top of the thermal insulation so that the thermal insulation is between the shell and the protective sheet metal cladding,characterised in that, during or after the formation of the next shell structure, forming (146, 152) thermal insulation on an outer surface (UP) of the previous jacked-up shell structure by attaching the insulation elements to the jacked-up shell structure and to each other before jacking up the next formed shell structure or before attaching the shell formed by the jacked-up, interconnected shell structures to the installation structure.

2. The manufacturing method according to the previous claim, wherein the insulation elements are attached to outer surface of the shell structures (224, 242, 248) and to each other using fastening pins, vertical fastening bands, or horizontal fastening bands.

3. The manufacturing method according to any one of the previous claims, wherein, during or after the formation of the thermal insulation attached to the outer surface of the previous jacked-up shell structure, a protective sheet metallayer (236) of the thin metal sheets essentially corresponding to the height of the jacked-up shell structure is formed (146, 152) before jacking up the next formed shell structure or before attaching the shell formed by the jacked-up interconnected shell structures to the installation structure.

4. The manufacturing method according to any one of the previous claims, wherein the installation structure comprises a lowest shell structure (212) of the storage tank shell or a foundation (208) of the storage tank.

5. The manufacturing method according to any one of the previous claims, wherein a lowest shell structure (212) of the storage tank shell (210) is formed (104) before forming the uppermost shell structure, when the installation structure comprises the lowest shell structure of the shell.

6. The manufacturing method according to any one of the previous claims, wherein, after forming a last shell structure (248), the shell formed by the jacked-up, interconnected shell structures (224, 242, 248) is attached to the lowest shell structure of the shell at a bottom edge (AR) of the last formed shell structure and, after the attachment, a thermal insulation (230) and a protective sheet metal cladding (236) of the last and lowest shell structures (212, 248) are formed, when the installation structure comprises the lowest shell structure of the shell.

7. The manufacturing method according to claim 4, wherein, after forming the last shell structure (248), the shell formed by the jacked-up, interconnected shell structures (224, 242, 248) is attached to the foundation at a bottom edge (AR) of the last formed shell structure and, after the attachment, a thermal insulation (230) and a protective sheet metal cladding (236) of the last shell structure (212, 248) are formed, when the installation structure comprises the foundation.

8. The manufacturing method according to any one of the previous claims, wherein a roof structure (218) of the storage tank is attached (126) to the uppermost shell structure before the uppermost shell structure is jacked up.

9. The manufacturing method according to claim 8, wherein a thermal insulation (230) and a protective sheet metal cladding (234) of the roof structure are formed (128) in connection with the formation of the thermal insulation of the uppermost shell structure.

10. The manufacturing method according to any one of the previous claims, wherein a bottom (256) of the storage tank is formed (154) after the attachment of the installation structure of the shell.

11. A storage tank (302) manufactured by a manufacturing method (100) according to any one of the previous claims comprises a shell (210), a roof structure (218), a bottom (256), thermal insulation (230), and protective sheet metal cladding (234, 236) formed from protective sheet metal layers (236) essentially corresponding to a height (H) of shell structures (224, 242, 248) of the shell.

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