Low-pressure reboiler and assembly process thereof

Abstract

The invention discloses a low-pressure reboiler and an assembly process thereof, and belongs to the technical field of low-pressure reboilers in air separation.The low-pressure reboiler comprises a double-core body which is arranged in a tower body and provided with an open channel, and the double-core body is formed by welding two single core bodies; each single core body comprises a first side plate, a second side plate and a core body main body, the first side plate and the second side plate are oppositely arranged, the core body main body is arranged between the first side plate and the second side plate, a middle connecting plate is arranged at each of the four corners of the side, deviating from the core body main body, of the first side plate, and the middle connecting plates between the two single core bodies are attached in a one-to-one correspondence mode and are beveled, welded and fixed. The invention relates to an assembly process of a low-pressure reboiler, which is used for assembling the low-pressure reboiler. The two single core bodies with the open channels can be effectively connected after brazing deformation.

Description

Technical Field

[0001] The invention belongs to the technical field of low-pressure reboilers in air separation, and in particular relates to a low-pressure reboiler and an assembly process thereof. Background Art

[0002] In the chemical, air separation and refrigeration industries, the low-pressure tower reboiler uses the temperature difference between two media of different temperatures to perform heat exchange and achieve energy transfer. Specifically, an aluminum plate-fin heat exchanger is installed in the tower body of the low-pressure tower reboiler as the core component of the heat exchange.

[0003] The plate-fin heat exchanger includes two cores A with open channels assembled into one body. The core includes seals, fins, baffles and two outer plates. The seals, fins, baffles and two outer plates are brazed to form the core. A rectangular plate C is welded on both sides of one side B of the outer plate. Figure 1 Then the rectangular plates between the two cores are correspondingly bonded and welded to form a double core.

[0004] Since the core body itself is brazed by a seal, a fin, a partition and two outer aluminum plates through a brazing process, the core body is deformed due to brazing, making it difficult to accurately control the size, and the thickness of the outer plate is only 6 mm. A rectangular plate C is welded on the outer plate. Due to the long welding length of the rectangular plate, the core body will be severely deformed when welded to the outer plate. When the two deformed cores are assembled into a double core body, the rectangular plate of one core body will be difficult to match the rectangular plate of the other core body. There is also a problem of difficulty in welding between the rectangular plates. Even if they can be barely matched and welded, the assembled double core cannot guarantee that it meets the size requirements for installation in the tower body. Summary of the invention

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a low-pressure reboiler, comprising a double core body arranged in a tower body and having an open channel, wherein the double core body is formed by welding two single core bodies;

[0006] The single core body includes a first side plate and a second side plate arranged opposite to each other and a core body arranged between the first side plate and the second side plate. The first side plate is respectively provided with an intermediate connecting plate at the four corners of the side facing away from the core body. The intermediate connecting plates between the two single core bodies are fitted one by one and fixed by beveling and welding.

[0007] Specifically, the core body has a first side to which the first side plate is fixed by brazing, a second side to which the second side plate is fixed by brazing, and a third side and a fourth side which are arranged opposite to each other.

[0008] Specifically, a plurality of core connecting plates opposite to each other are welded on the circumference of the double core, and the core connecting plates include a first core connecting plate and a second core connecting plate, the first core connecting plate is welded to the second side plate, the second core connecting plate is welded to the third side or the fourth side of the core body, and the second core connecting plate of one single core is fixed to the second core connecting plate of another single core by welding.

[0009] Specifically, an open channel is provided on the top of the double core, and a surrounding plate is provided on the top of the double core. The surrounding plate includes a plurality of plates connected end to end, and the bottom surface of the plate is welded to the core body or the second side plate.

[0010] Specifically, the enclosure plate is provided with a drain pipe penetrating the plate body thereof, and the drain pipe is used to discharge the liquid oxygen retained at the top.

[0011] Specifically, the intermediate connecting plates include a first intermediate connecting plate and a second intermediate connecting plate, the upper ends of which extend out of the core body, and a sealing component is arranged between the first intermediate connecting plate and the second intermediate connecting plate, and the sealing component is used to close the gap between the two single cores.

[0012] Specifically, the sealing assembly includes a first sealing plate, a second sealing plate and a third sealing plate. A first sealing plate is welded on each of the core bodies on both sides of the gap, a second sealing plate is welded on the first sealing plate, and a third sealing plate is welded between the two second sealing plates.

[0013] Specifically, the single core body also includes a head plate and a head. The head plate is welded on the second side plate, and heads are welded on the third and fourth sides of the core body. An intermediate connecting plate is welded at one end of the head, and the head plate is welded at the other end.

[0014] Specifically, the single core further includes an ear plate welded on the second side plate and a lifting ear assembled on the ear plate.

[0015] A low-pressure reboiler assembly process is used to assemble the low-pressure reboiler. The assembly process of the low-pressure reboiler includes taking two single cores, welding the two single cores with one side of the intermediate connecting plates relatively to each other, wherein the four intermediate connecting plates on one single core correspond to the four intermediate connecting plates on the other single core, eliminating the gap between the two corresponding intermediate connecting plates by machining to ensure that the two are completely fitted, and opening a groove to weld and fix the two corresponding intermediate connecting plates to obtain a double core, and hoisting the double core into a tower body.

[0016] The technical solution provided by the present invention has the following advantages compared with the prior art:

[0017] 1. Short intermediate connecting plates are arranged at the four corners of the side plates. Compared with the rectangular plates, the amount of welding between the intermediate connecting plates and between the intermediate connecting plates and the first side plates is reduced, and the deformation of the first side plates and the intermediate connecting plates themselves due to welding is reduced; at the same time, the fitting parts between the intermediate connecting plates and between the intermediate connecting plates and the first side plates are reduced, and the fitting degree is improved. Even if the single core is deformed due to brazing, the facing surfaces between the intermediate connecting plates can be easily machined and leveled into horizontal planes or inclined planes and then fully matched, ensuring that the intermediate connecting plates are fully fitted, reducing the difficulty of docking and welding between the intermediate connecting plates, improving the connection strength between the intermediate connecting plates, and ensuring that the size of the double core meets the size requirements for installation in the tower body.

[0018] 2. A circle of core connecting plates is arranged around the double core to further restrict the size change of the double core and improve the structural stability.

[0019] 3. A panel is set on the top of the double core with an open channel to form a structure for liquid oxygen overflow and evaporation, and to seal the gap between the two single cores, so that the double core has good heat exchange performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the installation diagram of the rectangular parallelepiped plate in the background technology of the present invention;

[0021] Figure 2 This is a diagram of a dual core structure in an embodiment of the present invention;

[0022] Figure 3 is an exploded view of a double core in an embodiment of the present invention;

[0023] Figure 4 is a structural diagram of the first side and the third side of the core body in an embodiment of the present invention;

[0024] Figure 5 is a cross-sectional view of a sealing assembly in an embodiment of the present invention;

[0025] Figure 6 is a structural diagram of the second side and the fourth side of the core body in an embodiment of the present invention;

[0026] Figure 7 is a structural diagram of two first intermediate connecting plates after welding in an embodiment of the present invention;

[0027] Figure 8 is a cross-sectional view of two first intermediate connecting plates after welding in an embodiment of the present invention;

[0028] Fig. 9 is a cross-sectional view of the welding of the enclosure and the core body in an embodiment of the present invention;

[0029] Fig.10 It is a cross-sectional view of the enclosure end face after welding in an embodiment of the present invention.

[0030] As shown in the figure:

[0031] 10. Double core; 20. Core connecting plate; 21. First core connecting plate; 22. Second core connecting plate; 30. Open channel; 40. Enclosure; 41. Drain pipe; 50. Single core; 51. Core body; 52. First side plate; 53. Middle connecting plate; 531. First middle connecting plate; 532. Second middle connecting plate; 533. Third middle connecting plate; 534. Fourth middle connecting plate; 54. Sealing assembly; 541. First A sealing plate; 542, a second sealing plate; 543, a third sealing plate; 55, a second side plate; 56, an ear plate; 57, a head plate; 571, a first head plate; 572, a second head plate; 573, a third head plate; 58, a head; 581, a first head; 582, a second head; 583, a third head; 584, a fourth head; 59, a pipe support pad; 60, a reserved pipe; 61, a clamp; 62, a lifting ear;

[0032] a, first side; b, second side; c, third side; d, fourth side. DETAILED DESCRIPTION

[0033] For ease of understanding, the low-pressure reboiler and its assembly process are described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation and positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] like Figure 2As shown, the low-pressure reboiler in this embodiment includes a tower body (not shown in the figure) and a double core body 10 built into the tower body, 8 tower body connecting plates (not shown in the figure) are arranged on the inner wall of the tower body, 12 core connecting plates 20 are welded on the circumference of the double core body 10, and the 12 core connecting plates 20 are divided into a first core connecting plate 21 and a second core connecting plate 22 according to the different positions of welding on the double core body 10, and every 6 core connecting plates 20 are arranged in a circle end to end, and the ends of the second core connecting plate 22 of one single core body 50 are opposite to the second core connecting plate 22 of another single core body 50 and are fixed by welding, and each tower body connecting plate is connected to a corresponding core connecting plate 20.

[0037] Continue as Figure 2 As shown, the double core 10 is provided with an open channel 30 at the top and a surrounding plate 40, which is used to prevent liquid oxygen from overflowing. The double core 10 is welded by two single cores 50, and the single core 50 includes a first side plate 52 and a second side plate 55 arranged opposite to each other and a core body 51 arranged between the first side plate 52 and the second side plate 55. The core body 51 includes fins, seals, partitions and guide vanes, and the single core 50 also includes a head plate 57, a head 58, an ear plate 56 and a lifting ear 62. The thickness of the surrounding plate 40 meets the welding requirements between the two single cores 50, and does not cover the open channel 30. The height of the surrounding plate 40 is determined according to the amount of liquid oxygen overflow to be achieved, the size of the core body 51 and a certain margin. The enclosure 40 includes six plates connected end to end, the bottom surfaces of which are welded to the core body 51 or the second side plate 55. One of the plates is provided with a drain pipe 41 penetrating the plate body, and the drain pipe 41 is used to discharge the liquid oxygen retained in the enclosure 40 to avoid the accumulation of liquid oxygen and the potential safety hazard.

[0038] like Figure 3 As shown, the two core bodies 51 respectively have a first side a and a second side b disposed opposite to each other, and a third side c and a fourth side d disposed opposite to each other. In the dual core 10, the first side a of one core body 51 faces left, the second side b faces right, the third side c faces forward, and the fourth side d faces backward. The first side a of the other core body 51 faces right, the second side b faces left, the third side c faces backward, and the fourth side d faces forward.

[0039] like Figure 3 and Figure 4As shown, the first side a of the core body 51 is brazed with a first side plate 52. The first side plate 52 is provided with an intermediate connecting plate 53 at the four corners of the side facing away from the core body 51. The intermediate connecting plates 53 between the two single core bodies 50 are welded and fixed with grooves corresponding to each other. The intermediate connecting plates 53 include a first intermediate connecting plate 531, a second intermediate connecting plate 532, a third intermediate connecting plate 533 and a fourth intermediate connecting plate 534. The upper ends of the first intermediate connecting plate 531 and the second intermediate connecting plate 532 extend out of the core body 51. Among the four intermediate connecting plates 53, the length of the first intermediate connecting plate 531 is longer than the length of the remaining three intermediate connecting plates 53. The length of the intermediate connecting plate 53 depends on the diameter of the end cap 58 to be welded and the number of the end cap 58. The first intermediate connecting plate 531, the second intermediate connecting plate 532 and the third intermediate connecting plate 533 are all welded with the end cap 58, and the fourth intermediate connecting plate 534 is not welded with the end cap 58. A sealing assembly 54 is disposed between the first middle connecting plate 531 and the second middle connecting plate 532 . The sealing assembly 54 is used to seal the gap between the two single core bodies 50 .

[0040] like Figure 5 As shown, the sealing assembly 54 includes a first sealing plate 541, a second sealing plate 542 and a third sealing plate 543. A first sealing plate 541 is welded to the core body 51 on both sides of the gap, a second sealing plate 542 is welded to the first sealing plate 541, and a third sealing plate 543 is welded between the two second sealing plates 542.

[0041] like Figure 3 and Figure 6 As shown, a second side plate 55 is brazed on the second side b of each core body 51. Two first core connecting plates 21, two ear plates 56 and three end plates 57 are welded on the side of the second side plate 55 away from the core body 51. The two first core connecting plates 21 are located in the middle of the second side plate 55 and are parallel to the short side of the second side plate 55. The two ear plates 56 are respectively located at the upper and lower ends of the second side plate 55, and each ear plate 56 is equipped with a lifting ear 62. The side of the second side plate 55 away from the core body 51 is rectangular, and the rectangular surface has four corners, and a head plate 57 is welded to each of the three corners. The three head plates 57 are respectively the first head plate 571, the second head plate 572 and the third head plate 573. Among the three head plates 57, the length of the first head plate 571 is longer than the length of the remaining two head plates 57.

[0042] Continue as Figure 3 and Figure 4As shown, each core body 51 is welded with two second core body connecting plates 22 and two heads 58 on the third side c. The two second core body connecting plates 22 are located in the middle of the third side c. The two heads 58 are located at the two ends of the third side c, respectively. The two heads 58 are a first head 581 and a second head 582. The first head 581 is located at the upper end of the third side c, and the second head 582 is located at the lower end of the third side c. The diameter of the first head 581 is smaller than the diameter of the second head 582. One end of the first head 581 is welded with the second middle connecting plate 532, and the other end is welded with the second head plate 572. One end of the second head 582 is welded with the third middle connecting plate 533, and the other end is welded with the third head plate 573. The force bearing area of ​​the core body 51 is increased, the force bearing condition of the core body 51 is optimized, and the structural stability of the core body 51 can be maintained under long-term operation conditions.

[0043] Continue as Figure 3 and Figure 6 As shown, each core body 51 is welded with two second core body connection plates 22, two end caps 58 and a pipe support pad 59 on the fourth side d. The two second core body connection plates 22 are located in the middle of the fourth side d. A pipe support pad 59 is located between the two second core body connection plates 22. The two end caps 58 are located at the upper end of the fourth side d. The two end caps 58 are respectively a third end cap 583 and a fourth end cap 584. The diameter of the third end cap 583 is smaller than the diameter of the fourth end cap 584. The diameter of the end cap 58 depends on the opening size of the guide vane in the single core body 50. The first intermediate connection plate 531 is welded to one end of the third end cap 583 and the fourth end cap 584, and the first end cap plate 571 is welded to the other end. The fourth end cap 584 is connected to a reserved pipe 60. A clamp 61 is assembled on the pipe support pad 59, and the reserved pipe 60 is fixed by the clamp 61.

[0044] The assembly process of the low-pressure reboiler in this embodiment is used to assemble the low-pressure reboiler. The assembly process of the low-pressure reboiler includes the following steps:

[0045] S1: in a brazing furnace, brazing the first side plate 52 to the first side a of the core body 51 , and brazing the second side plate 55 to the second side b of the core body 51 ;

[0046] S2: Weld an intermediate connecting plate 53 at each of the four corners of the first side plate 52, and the upper ends of the first intermediate connecting plate 531 and the second intermediate connecting plate 532 extend out of the core body 51. The intermediate connecting plates 53 between the two single core bodies 50 are attached one by one and welded and fixed with an outer groove, such as Figure 7 and Figure 8As shown, before welding, the groove surface is processed on the edge of the intermediate connecting plate 53 to be welded. After the two intermediate connecting plates 53 are attached, the two groove surfaces form a groove with a V-shaped cross section and the V-shaped opening direction facing outward, and the groove is an outer groove;

[0047] S3: Weld the first core connecting plate 21 on the second side plate 55, and weld the second core connecting plate 22 on the third side c and the fourth side d of the core body 51, ensuring that one end of the second core connecting plate 22 is aligned with the first core connecting plate 21, and the other end is aligned with the second core connecting plate 22 on another single core 50, and weld the end portion where the second core connecting plate 22 is connected to the second core connecting plate 22 on another single core 50;

[0048] S4: The enclosure 40 is welded on the top of the core body 51, the bottom of the enclosure 40 is welded to the core body 51 or the second side plate 55, and the ends are welded to the ends of the adjacent plates, such as Fig. 9 and Fig.10 As shown, the sealing structure is welded between the first middle connecting plate 531 and the second middle connecting plate 532, the bottom of the sealing structure is welded to the core body 51, one end of the sealing assembly 54 is welded to the first middle connecting plate 531, and the other end is welded to the second middle connecting plate 532, as shown in FIG. Figure 5 and Figure 7 As shown;

[0049] S5: Weld the ear plate 56 and the head plate 57 to the corresponding positions of the second side plate 55, weld the pipe support pad 59 to the fourth side d of the core body 51, and then assemble the lifting ear 62, the head 58 and the reserved pipe 60;

[0050] S6: hoisting the double core 10 into the tower body, and welding the tower body connecting plate to the core connecting plate 20.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-pressure reboiler, characterized in that: It comprises a double core body arranged in a tower body and having an open passage, wherein the double core body is formed by welding two single core bodies; The single core body includes a first side plate and a second side plate arranged opposite to each other and a core body arranged between the first side plate and the second side plate. The first side plate is respectively provided with an intermediate connecting plate at the four corners of the side facing away from the core body. The intermediate connecting plates between the two single core bodies are fitted one by one and fixed by beveling and welding.

2. A low-pressure reboiler according to claim 1, characterized in that: The core body comprises a first side to which the first side plate is fixed by brazing, a second side to which the second side plate is fixed by brazing, and a third side and a fourth side which are oppositely arranged.

3. A low-pressure reboiler according to claim 2, characterized in that: The double core is welded with a plurality of core connecting plates which are opposite to each other end to end on the circumference thereof, wherein the core connecting plates include a first core connecting plate and a second core connecting plate, wherein the first core connecting plate is welded to the second side plate, and the second core connecting plate is welded to the third side or the fourth side of the core body, and the second core connecting plate of one single core is fixed to the second core connecting plate of another single core by welding.

4. A low-pressure reboiler according to claim 1, characterized in that: An open channel is arranged on the top of the double core, and a surrounding plate is arranged on the top of the double core. The surrounding plate includes a plurality of plates connected end to end, and the bottom surface of the plate is welded to the core body or the second side plate.

5. A low-pressure reboiler according to claim 4, characterized in that: The enclosure plate is provided with a drain pipe penetrating the plate body thereof, and the drain pipe is used to discharge the liquid oxygen retained at the top.

6. A low-pressure reboiler according to claim 1, characterized in that: The intermediate connecting plates include a first intermediate connecting plate and a second intermediate connecting plate, the upper ends of which extend out of the core body. A sealing component is arranged between the first intermediate connecting plate and the second intermediate connecting plate, and the sealing component is used to close the gap between the two single cores.

7. A low-pressure reboiler according to claim 6, characterized in that: The sealing assembly comprises a first sealing plate, a second sealing plate and a third sealing plate. A first sealing plate is welded to each core body on both sides of the gap, a second sealing plate is welded to the first sealing plate, and a third sealing plate is welded between the two second sealing plates.

8. A low-pressure reboiler according to claim 1, characterized in that: The single core body also includes a head plate and a head. The head plate is welded on the second side plate, and heads are welded on the third and fourth sides of the core body. One end of the head is welded to the middle connecting plate, and the other end is welded to the head plate.

9. A low-pressure reboiler according to claim 1, characterized in that: The single core further comprises an ear plate welded on the second side plate and a lifting ear assembled on the ear plate.

10. A low-pressure reboiler assembly process, used for assembling the low-pressure reboiler according to any one of claims 1 to 9, characterized in that: The assembly process of the low-pressure reboiler includes taking two single cores, fitting the two single cores with one side having intermediate connecting plates welded thereon relatively, wherein the four intermediate connecting plates on one single core correspond to the four intermediate connecting plates on the other single core, eliminating the gap between the two corresponding intermediate connecting plates by machining to ensure that the two are completely fitted, and opening a groove to weld and fix the two corresponding intermediate connecting plates to obtain a double core, and hoisting the double core into a tower body.

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