Single-tube-pass floating head type heat exchanger

Abstract

The invention relates to a single-tube-pass floating head type heat exchanger. The single-tube-pass floating head type heat exchanger comprises a shell; the head cover is connected to one end of the shell; a heat exchange tube is arranged in the floating head tube box, the floating head tube box is integrally arranged in the shell, and a medium outlet is formed in the end, close to the head cover, of the floating head tube box. The floating head outlet joint is connected to a medium outlet of the floating head tube box; the heat exchanger is characterized in that the peripheral wall of the side, close to the head cover, of the shell is connected with a tube pass outlet connector in a sealed mode, an inlet of the tube pass outlet connector is formed in the shell, and an outlet of the tube pass outlet connector is formed outside the shell; the single-tube-pass floating head type heat exchanger further comprises an expansion assembly, one end of the expansion assembly is detachably connected with the floating head outlet connector through a first flange assembly, and the other end of the expansion assembly is detachably connected with an inlet of the tube pass outlet connector through a second flange assembly. Compared with the prior art, the device is convenient to assemble and disassemble.

Description

Technical Field

[0001] The invention relates to heat exchange equipment, in particular to a single-tube floating head type heat exchanger. Background Art

[0002] Heat exchangers are devices that transfer part of the heat of hot fluid to cold fluid, also known as heat exchangers. Heat exchangers play an important role in chemical, petroleum, power, food and many other industrial production. In chemical production, heat exchangers can be used as heaters, coolers, condensers, evaporators and reboilers, etc., and are widely used.

[0003] Heat exchangers can be divided into floating head heat exchangers, fixed tube sheet heat exchangers, U-shaped tube sheet heat exchangers, plate heat exchangers, etc. according to their structures. Among them, the structural feature of the fixed tube sheet heat exchanger is that a tube bundle is arranged in the shell, and the tubes are fixed to the tube sheets at both ends of the tube bundle by welding or expansion. The tube sheets at both ends are directly welded to the shell, the inlet and outlet pipes of the shell are directly welded to the shell, the outer circumference of the tube sheet and the head flange are fastened with bolts, the inlet and outlet pipes of the tube pass are directly welded to the head, and several baffles are arranged in the tube bundle according to the length of the heat exchange tube. The tube pass of this heat exchanger can be divided into any number of passes by partitions. The tube sheet at one end of the floating head heat exchanger is fixed to the shell, while the tube sheet at the other end can float freely in the shell. The shell and the tube bundle are free to expand, so when the temperature difference between the two media is large, no temperature difference stress is generated between the tube bundle and the shell.

[0004] The single-pass floating head heat exchanger absorbs the advantages of fixed tube sheet heat exchangers and ordinary floating head heat exchangers. It is suitable for working conditions such as large temperature difference between the shell and tube, solid particles in the medium that easily clog the heat exchange tubes, and the tube bundle can be pulled out for cleaning. Therefore, it is widely used in coal chemical, methanol and other equipment.

[0005] In order to realize the overall detachability of the tube bundle and facilitate the water pressure test, the existing single-pass floating head heat exchanger needs to be equipped with multiple sets of bolt-nut connection joints at the floating head end. This connection structure is relatively complex and inconvenient to disassemble and assemble. In addition, the joint is located inside the shell. Due to structural reasons, it cannot be connected by stud-double nut, but can only be connected by setting a threaded hole on one of the flanges, screwing one end of the stud into the threaded hole, and tightening the other end with a nut. This easily leads to two problems:

[0006] (1) Compared with bolt holes, threaded holes have higher requirements for the centering of the mating flange. A slight radial or circumferential misalignment during assembly may result in a failure to install smoothly.

[0007] (2) Since the threaded hole is located inside the shell, it is easy to rust due to the long-term effect of the corrosive medium inside the shell, which makes it impossible to unscrew the stud during maintenance. Sometimes, the stud must be destroyed before it can be removed. The stud end is stuck in the threaded hole and cannot be removed, causing the threaded hole flange to be scrapped.

[0008] Taking the existing utility model patent "A New Single-pass Floating Head Heat Exchanger" (application number 201420591577.X, authorization number CN204202439 U) as an example, in order to achieve the purpose of pulling out the tube bundle, it is necessary to set a pair of connection structures, namely flange and clamping plate, at the tail end of the floating head outlet joint. In addition, the joint is located inside the shell, and the expansion joint is set on the shell outlet pipe. Due to structural reasons, the flange and the clamping plate cannot be connected by stud-double nut, but only threaded holes can be set on the flange, one end of the stud is screwed into the threaded hole, and the other end is tightened with a nut. Compared with bolt holes, threaded holes have higher requirements for the alignment of the matching flange. A slight radial or circumferential misalignment during the assembly process may lead to a failure to install smoothly. Therefore, when installing the tube bundle, it is necessary to constantly adjust the circumferential relative position of the flange and the clamping plate so that the stud can be normally screwed into the threaded hole, which is time-consuming and labor-intensive. In addition, since the threaded holes are located inside the shell, they are easily corroded by the long-term action of the corrosive medium inside the shell, resulting in the inability to unscrew the studs during maintenance. Sometimes the studs even need to be destroyed for removal. Even if the studs are successfully unscrewed during maintenance, it is difficult to tighten the studs when they are installed again, which is very likely to cause internal leakage of the medium on the shell side.

[0009] For another example, the utility model patent "Similar Floating Head Methanol Inlet and Outlet Tower Heat Exchanger" (application number 201320508279.5, authorization number CN203518706U), the floating head outlet of the utility model is connected to the upper pipe box. In order to achieve the purpose of detachable expansion joint, two connecting flanges are set at both ends of the expansion joint, which respectively form two sets of paired flanges with the shell side shell equipment flange and the flange at the tail end of the inner liner. Due to structural reasons, these two pairs of flanges cannot be connected by studs and double nuts, but can only be provided with threaded holes on the shell side shell equipment flange and the tail end of the inner liner, one end of the stud is screwed into the threaded hole, and the other end is tightened with a nut. Since the equipment shell and the tube bundle are connected by welding, in order to meet the installation requirements of the detachable expansion joint, the circumferential relative position of the two is extremely high during the assembly welding process. Once circumferential misalignment occurs, the expansion joint can only be assembled by forcibly twisting it, which is extremely unfavorable to the expansion joint. In addition, the threaded hole has been corroded by the medium in the pipe for a long time. Once rust occurs, it is difficult to unscrew the stud; sometimes it is even necessary to destroy the stud before it can be removed. The stud end is stuck in the threaded hole and cannot be removed, which causes the threaded hole flange to be scrapped and the threaded hole to be damaged by corrosion. When installing again, the stud is difficult to tighten and is prone to internal leakage. The shell side shell equipment flange and the flange at the tail end of the liner are welded to the shell side shell and the inner cone respectively. Once the threaded hole is corroded and damaged, it is difficult to replace.

[0010] Therefore, it is necessary to improve the expansion assembly and connection structure of the existing heat exchanger. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide a single-pass floating head heat exchanger which is easy to assemble and disassemble in view of the above technical status quo.

[0012] The technical solution adopted by the present invention to solve the above technical problems is: a single-pass floating head heat exchanger, comprising a shell;

[0013] A head cover connected to one end of the shell;

[0014] A floating head pipe box is provided with heat exchange pipes inside. The floating head pipe box is arranged inside the shell as a whole. A medium outlet is provided at one end of the floating head pipe box close to the head cover;

[0015] The floating head outlet joint is connected to the medium outlet of the floating head pipe box;

[0016] The invention is characterized in that: a peripheral wall of the shell close to the head cover is sealed and connected with a pipe-pass outlet joint, the inlet of the pipe-pass outlet joint is arranged inside the shell, and the outlet of the pipe-pass outlet joint is arranged outside the shell;

[0017] The single-tube floating head heat exchanger also includes a bent expansion assembly, one end of which is detachably connected to the floating head outlet joint, and the other end of which is detachably connected to the inlet of the tube-pass outlet joint.

[0018] As an improvement, the expansion assembly includes a bend pipe connected to the inlet of the pipe-side outlet joint.

[0019] Preferably, the elbow is an elbow with an angle of 90 degrees between the inlet and the outlet.

[0020] In order to facilitate compensation for the displacement caused by the temperature difference between the shell and tube, preferably, the expansion assembly also includes an expansion joint connecting the floating head outlet joint and the elbow.

[0021] The elbow does not need to have a 90-degree angle between the inlet and the outlet. The bending angle of the elbow only needs to satisfy the verticality of the inlet and the outlet of the entire expansion assembly.

[0022] In order to make the expansion assembly detachable and facilitate the maintenance or replacement of the expansion joint, preferably, the floating head outlet joint is a first flange, a second flange is provided at one end of the expansion assembly, and the first flange and the second flange are detachably connected by one or more groups of stud nuts; a third flange is provided at the other end of the expansion assembly, and a fourth flange is provided at the inlet of the pipe outlet joint, and the third flange and the fourth flange are also detachably connected by one or more groups of stud nuts.

[0023] In order to allow the expansion assembly to rotate slightly relative to the floating head outlet joint and the pipe outlet joint, preferably, the second flange and / or the third flange are loose flanges, so as to facilitate the adjustment of the relative position of the first flange and the second flange, ensure that the sealing surfaces of the first flange and the second flange are parallel, and / or, facilitate the adjustment of the relative position of the third flange and the fourth flange, ensure that the sealing surfaces of the third flange and the fourth flange are parallel, ensure the reliability of the sealing surfaces, and avoid twisting of the expansion joint due to forced assembly, thereby effectively protecting the expansion joint.

[0024] The head cover can be directly welded to one end of the shell, and a manhole can be set on the head cover in this case. The size of the manhole is sufficient for the expansion assembly to freely enter and exit the shell through the manhole.

[0025] The head cover can also be detachably connected to one end of the shell. When the head cover is removed, the floating head outlet joint of the floating head pipe box and the entire expansion assembly are in a visible position. On the one hand, during the entire pipe hydrostatic test, the operator can check the reliability of all connection joints. On the other hand, when installing the floating head outlet joint and the expansion assembly of the heat exchanger, the operator can simply align them to reduce the difficulty of installation.

[0026] In order to make the detachable connection structure between the shell and the head cover have both convenience of operation and reliability of installation, preferably, a fifth flange is provided at one end of the shell, a sixth flange is provided on the inner side of the head cover, and the fifth flange and the sixth flange are detachably connected by one or more sets of stud nuts.

[0027] Compared with the prior art, the advantages of the present invention are: the pipe-side outlet joint is arranged on the side wall of the shell instead of being connected to the head cover; the operator can see the connection part between the floating head outlet joint and the expansion assembly from the head cover, which is convenient for assembling and disassembling the floating head outlet joint and the expansion assembly; the floating head outlet joint and the pipe-side outlet joint arranged on the side wall of the shell are connected by the bent expansion assembly, the head cover can be disassembled, and the expansion assembly can also enter the shell from the head cover, which is convenient for installation and disassembly and improves assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of a single-pass floating head heat exchanger in Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of the expansion assembly in the first embodiment of the present invention;

[0030] Figure 3 It is a schematic diagram of the structure of a single-pass floating head heat exchanger in Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in further detail below.

[0032] Embodiment 1

[0033] like Figure 1 and Figure 2 The single-pass floating head heat exchanger in this embodiment includes a shell 1, a head cover 2, a floating head tube box 3 and a bent expansion assembly 4. The shell 1 is a hollow tubular body, the head cover 2 is connected to one end of the shell 1, and the other end of the shell 1 is generally connected to the tail cover or the rear tube box. The floating head tube box 3 and the expansion assembly 4 are located inside the shell 1 as a whole.

[0034] The head cover 2 is detachably connected to one end of the shell 1. A fifth flange 13 is provided at one end of the shell 1, and a sixth flange 21 is provided inside the head cover 2, and the fifth flange 13 and the sixth flange 21 are detachably connected through multiple sets of studs-double nuts; in this embodiment, the head cover 2 is a hollow semi-spherical cylindrical structure, and in other embodiments, the head cover 2 can also be a flat cover.

[0035] The floating head tube box 3 is provided with heat exchange tubes inside for heat exchange medium to circulate. One end of the floating head tube box 3 close to the head cover 2 is provided with a medium outlet, and the medium outlet is connected to a floating head outlet joint 31, which is a first flange.

[0036] The bent expansion assembly 4 includes an expansion joint 42 and an elbow 41. The first end of the expansion joint 42 is provided with a second flange 43 that is connected to the first flange. The first flange and the second flange 43 are detachably connected through multiple sets of studs-double nuts, so that the first end of the expansion joint 42 is detachably connected to the floating head outlet joint 31. The elbow 41 is a bend with a 90-degree angle between the inlet and the outlet, and the inlet of the bend 41 is welded to the second end of the expansion joint 42; a third flange 44 is provided at the outlet of the bend 41, and a fourth flange 12 is provided at the inlet of the pipe-side outlet joint 11. The fourth flange 12 is detachably connected to the third flange 44 through multiple sets of studs-double nut structures, so that the second end of the expansion joint 42 is connected to the inlet of the pipe-side outlet joint 11 through the bend 41, and then the inlet of the floating head outlet joint 31 and the inlet of the pipe-side outlet joint 11 are connected through the expansion assembly 4.

[0037] In this embodiment, the second flange 43 and the third flange 44 are loose flanges, so that the expansion assembly 4 can be slightly rotated relative to the floating head outlet joint 31 and the pipe-side outlet joint 11, so as to adjust the relative positions of the first flange and the second flange 43, and the third flange 44 and the fourth flange 12, ensure that the sealing surfaces of the first flange and the second flange 43 are parallel, and the sealing surfaces of the third flange 44 and the fourth flange 12 are parallel, so as to ensure the reliability of the sealing surfaces, and also avoid the expansion joint 42 from twisting due to forced assembly, so as to effectively protect the expansion joint 42. Since the first end of the expansion joint 42 is detachably connected to the floating head outlet joint 31, and the inlet of the pipe-side outlet joint 11 is detachably connected to the outlet of the elbow 41, the entire expansion assembly 4 is detachable, so as to facilitate the maintenance or replacement of the expansion joint 42.

[0038] When assembling the single-pipe floating head heat exchanger in the present embodiment, the head cover 2 is first opened, and the expansion assembly 4 can be pushed into the housing 1 at this time, and then the first flange and the second flange 43 are connected and connected by multiple groups of studs-double nuts, and the fourth flange 12 is connected with the third flange 44 by the stud-double nut structure. The second flange 43 is a loose flange. During the assembly process, the expansion assembly 4 can be slightly rotated around the axis of the second flange 43 to adjust the relative position of the third flange 44 and the fourth flange 12, and the sealing surface connecting the third flange 44 and the fourth flange 12 can be ensured to be parallel without forcibly twisting the expansion joint 42, so as to achieve the purpose of both ensuring reliable sealing and effectively protecting the expansion joint 42. The third flange 44 is a loose flange, and the fourth flange 12 is connected to the housing 1 through the pipe outlet joint 11, so the flange plate connected to the third flange 44 can be slightly rotated to ensure that the bolt holes connecting the third flange 44 and the fourth flange 12 are misaligned, thereby ensuring the reliability of the flange connection and convenient installation.

[0039] After installation, the head cover 2 does not need to be installed. The shell side is kept open, and the tube side can be subjected to a water pressure test separately. The operator can conveniently check the tightness of each connection joint. After the water pressure test is qualified, the head cover 2 is connected to the shell 1 by bolts and nuts.

[0040] The disassembly sequence of the heat exchanger is the reverse of the installation sequence.

[0041] When assembling the shell 1, the expansion assembly 4, and the floating head pipe box 3, the head cover 2 is removed so that the connection between the expansion assembly 4 and the floating head outlet joint 31 and / or the pipe outlet joint 11 is in a visible position. During the entire pipe water pressure test process, the operator can check the reliability of all connection joints.

[0042] Embodiment 2

[0043] like Figure 3As shown, it is another preferred embodiment of the present invention, which differs from Embodiment 1 in that: the shell 1 and the head cover 2 are connected by welding, and a manhole 22 is provided on the head cover 2, and the size of the manhole 22 satisfies that the expansion assembly 4 can freely enter and exit the shell 1 through the manhole 22.

Claims

1. A single-tube floating head heat exchanger, comprising Housing (1); A head cover (2) connected to one end of the shell (1); A floating head pipe box (3) is provided with a heat exchange pipe inside, and the floating head pipe box (3) is arranged as a whole inside the shell (1). A medium outlet is provided at one end of the floating head pipe box (3) close to the head cover (2); A floating head outlet joint (31) connected to the medium outlet of the floating head pipe box (3); Features: The peripheral wall of the shell (1) close to the head cover is sealed with a pipe-side outlet joint (11), the inlet of the pipe-side outlet joint (11) is arranged inside the shell (1), and the outlet of the pipe-side outlet joint (11) is arranged outside the shell (1); The single-tube floating head heat exchanger also includes a bent expansion assembly (4), one end of the expansion assembly (4) being detachably connected to a floating head outlet joint (31), and the other end of the expansion assembly (4) being detachably connected to an inlet of a tube-pass outlet joint (11).

2. The single-pass floating head heat exchanger according to claim 1, characterized in that: The expansion assembly (4) comprises a curved pipe (41) connected to the inlet of the pipe-side outlet joint (11).

3. The single-pass floating head heat exchanger according to claim 2, characterized in that: The curved pipe (41) is a curved pipe with an angle of 90 degrees between the inlet and the outlet.

4. The single-pass floating head heat exchanger according to claim 2, characterized in that: The expansion assembly (4) further comprises an expansion joint (42) connecting the floating head outlet joint (31) and the elbow (41).

5. The single-pass floating head heat exchanger according to claim 2, characterized in that: The inlet and outlet of the expansion component (4) are perpendicular to each other.

6. The single-pass floating head heat exchanger according to claim 1, characterized in that: The floating head outlet joint (31) is a first flange, and one end of the expansion assembly (4) is provided with a second flange (43), and the first flange and the second flange (43) are detachably connected through one or more sets of stud nuts; the other end of the expansion assembly (4) is provided with a third flange (44), and the inlet of the pipe outlet joint (11) is provided with a fourth flange (12), and the third flange (44) and the fourth flange (12) are also detachably connected through one or more sets of stud nuts.

7. The single-pass floating head heat exchanger according to claim 6, characterized in that: The second flange (43) and / or the third flange (44) are loose flanges.

8. The single-pass floating head heat exchanger according to claim 1, characterized in that: The head cover (2) is welded to one end of the shell (1); a manhole (22) is provided on the head cover (2), and the size of the manhole (22) is sufficient for the expansion component (4) to freely enter and exit the shell (1) through the manhole (22).

9. The single-pass floating head heat exchanger according to claim 1, characterized in that: The head cover (2) is detachably connected to one end of the shell (11).

10. The single-pass floating head heat exchanger according to claim 9, characterized in that: A fifth flange (13) is provided at one end of the shell (11), a sixth flange (21) is provided on the inner side of the head cover (2), and the fifth flange (13) and the sixth flange (21) are detachably connected via one or more sets of stud nuts.

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