Vertical mounting method for super-large-diameter pressure vessel

Abstract

The invention provides a vertical mounting method for a super-large-diameter pressure vessel, which is convenient in butt joint, small in occupied field and low in hoisting cost, and relates to the technical field of mounting of pressure vessels. The vertical installation method of the super-large-diameter pressure container comprises the following steps that the container is divided into at least two sections in the height direction; when the container is assembled, the lowermost section is fixedly installed on a container installation foundation, then the other sections are sequentially welded to the lowermost section in a butt joint mode from bottom to top so as to complete assembling of the container, and in the installation process, every two adjacent sections are connected in a butt joint mode. The upper coaming of the upper section is matched with the alignment guide surface of the lower section to guide the upper section to be aligned with the lower section, and the upper coaming is in contact with the supporting surface of the lower section to perform axial positioning, so that a welding groove is formed between the butt joint end surfaces of every two adjacent sections; and after the container is assembled, carrying out hydrostatic test and nondestructive inspection on the container until the container is qualified, and completing the installation of the container.

Description

Technical Field

[0001] The invention relates to the technical field of pressure vessel installation, and in particular to a vertical installation method for an ultra-large diameter pressure vessel. Background Art

[0002] Pressure vessels such as hydrogenation reactors are commonly used equipment in the chemical industry and are generally made of stainless steel. With the continuous improvement of the production capacity of refining and chemical plants, the diameter and weight of its core equipment, hydrogenation reactors, are constantly increasing. For ultra-large diameter pressure vessels with a diameter greater than 5000mm, the thickness is generally greater than 300mm, the length is generally greater than 70000mm, and the weight exceeds 2000 tons. In order to facilitate accurate docking, assembly and welding, the more commonly used method is to carry out horizontal assembly in sections on site. During the welding process, natural gas or liquefied petroleum gas is used for direct heating to preheat, and a local heat treatment furnace fueled by natural gas or liquefied petroleum gas is used for stress relief and local heat treatment. Finally, the overall water pressure test is carried out at the welding station, and the overall hoisting is carried out after passing the test. This method requires a large welding site on site during assembly, and the total weight of the equipment and water during the water pressure test is large, which places high load-bearing requirements on the welding site. In addition, large-scale hoisting equipment is required for overall hoisting, which is expensive. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a vertical installation method for an ultra-large diameter pressure vessel which is convenient for docking, occupies a small site and has a low hoisting cost.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a vertical installation method of an ultra-large diameter pressure vessel, comprising the following steps:

[0005] The container is divided into at least two sections in the height direction; except for the uppermost section, the inner sides of the upper end surfaces of the remaining sections are provided with lower enclosure plates arranged along the circumference thereof, the upper end surface of the lower enclosure plates forms a support surface for supporting the upper adjacent section, the inner side of the support surface is provided with radial limiting protrusions arranged along the circumference thereof, and the outer side surface of the radial limiting protrusion is gradually inclined toward the outer side of the section from top to bottom to form an alignment guide surface; except for the lowermost section, the inner sides of the lower end surfaces of the remaining sections are provided with upper enclosure plates arranged along the circumference thereof and the end surface can abut against the support surface of the lower adjacent section;

[0006] First, the lowest segment is installed and fixed on the container installation foundation, and then the remaining segments are butt-welded on the lowest segment in order from bottom to top to complete the assembly of the container. In the installation process, between two adjacent segments, the upper segment is aligned with the lower segment by using the upper enclosure plate of the upper segment and the alignment guide surface of the lower segment to guide the upper segment to align with the lower segment, and the upper enclosure plate is in contact with the support surface of the lower segment to perform axial positioning, so as to form a welding groove between the butt end faces of the two adjacent segments;

[0007] After the container is assembled, it is subjected to water pressure test and non-destructive testing until it passes the test, and the container installation is completed.

[0008] Furthermore, except for the uppermost segment, the upper end surfaces of the other segments are gradually inclined downward from the outside to the inside; except for the lowermost segment, the lower end surfaces of the other segments are gradually inclined upward from the outside to the inside.

[0009] Furthermore, the adjacent segments are butt-welded using the following method:

[0010] Install insulation blankets on the inner walls of the segments;

[0011] Preheat the welding grooves between adjacent sections. The preheating temperature of the welding grooves should be ≥180℃ to ensure that the interlayer temperature is between 180 and 280℃.

[0012] A plurality of welding guns are evenly distributed around the welding groove, and the welding guns are used to perform welding construction on the welding groove simultaneously and synchronously along the same circumferential direction of the welding groove.

[0013] Furthermore, along the circumferential direction of the welding groove, the gun heads of the welding guns are arranged alternately downward and upward in sequence;

[0014] During welding, a welding gun with the gun head facing upward is used to weld with the end face on the upper side of the welding groove to form an upper weld bead, and a welding gun with the gun head facing downward is used to weld with the end face on the lower side of the welding groove to form a lower weld bead.

[0015] Furthermore, there are four welding guns.

[0016] Furthermore, the welding grooves of adjacent segments are preheated from the outside using a medium frequency induction heating coil.

[0017] Furthermore, the medium frequency induction heating coil is formed by at least two sections which are sequentially spliced ​​end to end.

[0018] The beneficial effects of the present invention are as follows: the vertical installation method of the ultra-large diameter and ultra-large wall thickness container of the present invention divides the container into multiple segments, and then adopts a vertical assembly method of installing each segment one by one on the basis of the container installation, and finally performs a water pressure test. This method occupies a small space and does not require additional site processing. During the installation process, the lifting equipment only needs to meet the load-bearing requirements of lifting a single segment 11. Compared with the horizontal assembly and installation method, it greatly saves the lifting equipment cost and installation cost. In addition, the invention provides a lower enclosure plate, an alignment guide surface and other structures on the inner side of the upper end surfaces of the remaining segments except the top segment, and provides an upper enclosure plate and other structures on the inner side of the lower end surfaces of the remaining segments except the bottom segment, which are circumferentially enclosed and whose end surfaces can abut against the supporting surfaces of the adjacent segments below. During vertical assembly, the upper enclosure plate of the upper segment cooperates with the alignment guide surface of the lower segment to gradually guide the upper segment to align with the lower segment, and the upper enclosure plate contacts the supporting surface of the lower segment for axial positioning, so as to form a welding groove between the butt end surfaces of the two adjacent segments, thereby ensuring the rapid and accurate alignment and installation of the adjacent upper and lower segments, solving the problem of inconvenient butt joint in vertical assembly of containers, and improving assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the docking and positioning of adjacent segments of a container;

[0020] Figure 2 It is a schematic diagram of the setting of the medium frequency induction heating coil;

[0021] Figure 3 It is a schematic diagram of the arrangement of welding guns;

[0022] Figure 4 It is a schematic diagram of the weld bead of the welding groove;

[0023] As shown in the figure: container 1, welding gun 2, medium frequency induction heating coil 3, segment 11, lower enclosure 12, upper enclosure 13, radial limiting protrusion 14, supporting surface 15, welding groove 16, paired positive guide surfaces 17, lower weld bead 161, and upper weld bead 162. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, the vertical installation method of the ultra-large diameter pressure vessel of the present invention comprises the following steps:

[0026] Step 1, dividing the container into at least two segments 11 along the height direction; except for the uppermost segment 11, the inner sides of the upper end surfaces of the remaining segments 11 are provided with lower enclosure plates 12 arranged along the circumferential direction thereof, the upper end surface of the lower enclosure plate 12 forms a support surface 15 for supporting the upper adjacent segment 11, the inner side of the support surface 15 is provided with radial limiting protrusions 14 arranged along the circumferential direction thereof, and the outer side surface of the radial limiting protrusions 14 is gradually inclined from top to bottom toward the outer side of the segment 11 to form an alignment guide surface 17; except for the lowermost segment 11, the inner sides of the lower end surfaces of the remaining segments 11 are provided with upper enclosure plates 13 arranged along the circumferential direction thereof and the end surface can abut against the support surface 15 of the lower adjacent segment 11;

[0027] Step 2: first install and fix the lowest segment 11 on the container installation foundation, and then butt-weld the remaining segments 11 on the lowest segment 11 in order from bottom to top to complete the assembly of the container. In the installation process, between two adjacent segments 11, the upper segment 11 is aligned with the lower segment 11 by using the upper enclosure 13 of the upper segment 11 and the alignment guide surface 17 of the lower segment 11 to guide the upper segment 11 to align with the lower segment 11, and the upper enclosure 13 is in contact with the support surface 15 of the lower segment 11 for axial positioning, so as to form a welding groove 16 between the butt end faces of the two adjacent segments 11;

[0028] Step 3: After the container is assembled, perform a water pressure test and non-destructive testing on the container until it passes the test. The container installation is completed.

[0029] The vertical installation method of the extra-large diameter and extra-large wall thickness container of the present invention divides the container into a plurality of segments 11, and then adopts a vertical assembly method of installing each segment 11 one by one on the container installation foundation, and finally performs a water pressure test. This method occupies a small space, and uses the container installation foundation to perform the water pressure test. The container installation foundation itself is required to have the ability to bear a full load of the container, and no additional site processing is required. During the installation process, the lifting equipment only needs to meet the load-bearing requirements of lifting a single segment 11. Compared with the horizontal assembly and installation method, it greatly saves the lifting equipment cost and installation cost. In addition, according to the present invention, except for the uppermost segment 11, the inner sides of the upper end surfaces of the remaining segments 11 are provided with structures such as a lower enclosure plate 12 and an alignment guide surface 17. Except for the lowermost segment 11, the inner sides of the lower end surfaces of the remaining segments 11 are provided with structures such as an upper enclosure plate 13 which is circumferentially enclosed and whose end surfaces can abut against the support surface 15 of the adjacent segment 11 below. During vertical assembly, the upper enclosure plate 13 of the upper segment 11 cooperates with the alignment guide surface 17 of the lower segment 11 to gradually guide the upper segment 11 to align with the lower segment 11. The upper enclosure plate 13 contacts the support surface 15 of the lower segment 11 for axial positioning, so as to form a welding groove 16 between the butt end surfaces of the two adjacent segments 11, thereby ensuring rapid and accurate alignment and installation of the adjacent upper and lower segments, solving the problem of inconvenient butt joint in vertical assembly of containers, and improving assembly efficiency.

[0030] For the convenience of welding, in the embodiment of the present invention, except for the uppermost segment 11, the upper end surfaces of the other segments 11 are gradually tilted downward from the outside to the inside, and except for the lowermost segment 11, the lower end surfaces of the other segments 11 are gradually tilted upward from the outside to the inside. In some embodiments, the end surfaces of both sides of the welding groove 16 are also arranged horizontally.

[0031] like Figure 2 , Figure 3 As shown, in the present invention, the adjacent segments 11 are welded and butted in the following manner:

[0032] Install a thermal insulation blanket on the inner wall of the segment 11 to insulate the material around the welding groove 16 of the segment 11;

[0033] Preheat the welding groove 16 between adjacent segments 11, and the preheating temperature of the welding groove 16 is ≥180°C to ensure that the interlayer temperature during welding is between 180 and 280°C;

[0034] An even number of welding guns 2 are evenly distributed around the welding groove 16 , and the welding guns 2 are used to perform welding construction on the welding groove 16 simultaneously and synchronously along the same circumferential direction of the welding groove 16 .

[0035] In the embodiment of the present invention, four welding guns 2 are evenly distributed around the welding groove 16. In some embodiments, the number of welding guns 2 is 2, 6 or 8.

[0036] The circumferential direction along the welding groove 16 may specifically be a clockwise direction or a counterclockwise direction along the circumferential direction of the welding groove 16 .

[0037] The specific welding process of the welding gun is as follows: in the first circumferential cycle, the first welding gun welds the first layer of welds, the second welding gun welds the second layer of welds, the third welding gun welds the third layer of welds, and the fourth welding gun welds the fourth layer of welds. Then, the welding gun position is adjusted to perform the second circumferential cycle, the first welding gun welds the fifth layer of welds, the second welding gun welds the sixth layer of welds, the third welding gun welds the seventh layer of welds, and the fourth welding gun welds the eighth layer of welds, and so on, until the welding liquid fills the welding groove 16. Since the welding guns 2 move synchronously along the same circumferential direction of the welding groove 16 at the same time, the welding guns always maintain a relative position between the two, which can reduce the possibility of problems such as segment skewness caused by welding deformation during vertical butt welding.

[0038] The above method can better ensure the weld quality and welding speed by heat preservation, preheating and arranging an even number of welding guns for simultaneous welding construction.

[0039] In some embodiments, the welding grooves 16 of adjacent segments 11 are preheated by gas heating. Figure 3 As shown, in the embodiment of the present invention, the medium frequency induction heating coil 3 is used to preheat the welding groove 16 of the adjacent segments 11 from the outside. This method does not have a fire source and is safer.

[0040] The medium frequency induction heating coil 3 can be an integral structure. The medium frequency induction heating coil 3 adopts an integral structure, and the medium frequency induction heating coil 3 needs to be put on from the upper end of the container. The medium frequency induction heating coil 3 is inconvenient to disassemble and assemble, especially when there is a nozzle on the container, the nozzle is easy to interfere with the medium frequency induction heating coil 3. In one embodiment of the present invention, the medium frequency induction heating coil 3 is formed by at least two sections spliced ​​end to end in sequence. The medium frequency induction heating coil 3 adopts a split structure formed by at least two sections spliced ​​end to end in sequence. The medium frequency induction heating coil 3 does not need to be put on from the upper end of the container, and only needs to be assembled at the corresponding installation position, which is more convenient for the disassembly and assembly of the medium frequency induction heating coil 3.

[0041] In order to better ensure the welding quality, in the present invention, optimally, the gun head of the welding gun 2 is alternately arranged downward and upward in sequence along the circumferential direction of the welding groove 16; during welding, the welding gun 2 with the gun head facing upward is welded to the end face on the upper side of the welding groove 16 to form an upper weld bead 162, and the welding gun 2 with the gun head facing downward is welded to the end face on the lower side of the welding groove 16 to form a lower weld bead 161.

[0042] The inner side surface of the radial limiting protrusion 14 can be a straight surface. In the embodiment of the present invention, the inner side surface of the radial limiting protrusion 14 is an inclined surface that gradually tilts from top to bottom toward the inner side of the segment 11. The inner side surface of the radial limiting protrusion 14 is an inclined surface that gradually tilts from top to bottom toward the inner side of the segment 11, which can make it easier to dock and align the upper and lower segments.

Claims

1. A vertical installation method for an ultra-large diameter pressure vessel, characterized in that: The following steps are involved: The container is divided into at least two segments (11) along the height direction; except for the uppermost segment (11), the inner sides of the upper end surfaces of the remaining segments (11) are provided with a lower enclosure plate (12) which is arranged along the circumference thereof, the upper end surface of the lower enclosure plate (12) forms a support surface (15) for supporting the upper adjacent segment (11), the inner side of the support surface (15) is provided with a radial limiting protrusion (14) which is arranged along the circumference thereof, the outer side surface of the radial limiting protrusion (14) is gradually inclined from top to bottom toward the outer side of the segment (11) to form an alignment guide surface (17); except for the lowermost segment (11), the inner sides of the lower end surfaces of the remaining segments (11) are provided with an upper enclosure plate (13) which is arranged along the circumference thereof and the end surface of which can abut against the support surface (15) of the lower adjacent segment (11); First, the lowest segment (11) is installed and fixed on the container installation foundation, and then the remaining segments (11) are butt-welded to the lowest segment (11) in order from bottom to top to complete the assembly of the container, wherein, during the installation process, between two adjacent segments (11), the upper segment (11) is aligned with the lower segment (11) by using the upper enclosure (13) of the upper segment (11) and the alignment guide surface (17) of the lower segment (11) to guide the upper segment (11) and the lower segment (11) to align, and the upper enclosure (13) is contacted with the support surface (15) of the lower segment (11) to perform axial positioning, so as to form a welding groove (16) between the butt end surfaces of the two adjacent segments (11); After the container is assembled, it is subjected to water pressure test and non-destructive testing until it passes the test, and the container installation is completed.

2. The vertical installation method of the super-large diameter pressure vessel according to claim 1, characterized in that: Except for the uppermost segment (11), the upper end surfaces of the other segments (11) are gradually inclined downward from the outside to the inside; except for the lowermost segment (11), the lower end surfaces of the other segments (11) are gradually inclined upward from the outside to the inside.

3. The vertical installation method of the super-large diameter pressure vessel according to claim 1, characterized in that: Adjacent segments (11) are butt-welded using the following method: Installing a thermal insulation blanket on the inner wall of the segment (11); Preheating the welding groove (16) between adjacent segments (11), wherein the preheating temperature of the welding groove (16) is ≥180°C to ensure that the interlayer temperature is between 180°C and 280°C; An even number of welding guns (2) are evenly distributed around the welding groove (16), and the welding guns (2) are used to simultaneously and synchronously perform welding construction on the welding groove (16) along the same circumferential direction of the welding groove (16).

4. The vertical installation method of the super-large diameter pressure vessel according to claim 3, characterized in that: Along the circumferential direction of the welding groove (16), the gun head of the welding gun (2) is alternately arranged downward and upward in sequence; During welding, a welding gun (2) with its gun head pointing upward is used to weld the upper end surface of the welding groove (16) to form an upper weld bead (162), and a welding gun (2) with its gun head pointing downward is used to weld the lower end surface of the welding groove (16) to form a lower weld bead (161).

5. The vertical installation method of the super-large diameter pressure vessel according to claim 3, characterized in that: There are four welding guns (2).

6. The vertical installation method of the super-large diameter pressure vessel according to claim 3, characterized in that: A medium frequency induction heating coil (3) is used to preheat the welding grooves (16) of adjacent segments (11) from the outside.

7. The vertical installation method of the super-large diameter pressure vessel according to claim 6, characterized in that: The medium frequency induction heating coil (3) is formed by at least two sections being spliced ​​end to end in sequence.

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