A restraint device for preventing support pipe from becoming unstable

Abstract

The present invention discloses a restraint device for preventing a support tube from becoming unstable, which includes a pad fixedly arranged on a vertical container cylinder near the middle of the support tube. The technical key points are: a mounting plate with mounting holes is fixedly arranged on the pad by a web and a rib plate, and the mounting plate is close to the inner side of the support tube; a U-bolt is mounted on the support tube, and the two ends of the U-bolt pass through the mounting holes on the mounting plate and are fixed by a locking nut to form a closed ring structure; a gasket for adjusting the installation error is also installed between the support tube and the mounting plate. In order to ensure the adjustability of the restraint position and the reliability of the restraint, the installation error along the radial direction of the cylinder is adjusted by the gasket; the installation error perpendicular to the radial direction is adjusted by the oblong hole on the mounting plate. By adjusting the tightening torque of the locking nuts on both sides of the mounting plate, the required friction force can be obtained, so that the U-bolt does not move relative to the mounting plate when it is compressed by the deformation of the support tube. The locking nut does not loosen during service.

Description

Technical Field

[0001] The invention relates to the technical field of pressure vessels, in particular to a restraining device for preventing a support pipe from becoming unstable on an ear seat of a vertical pressure vessel. Background Art

[0002] As we all know, pressure vessels can be installed in two main ways: horizontal and vertical. The main feature of the vertical structure is its small footprint. Vertical vessel supports are divided into four types: leg-type, ear-type, support-type, and skirt-type. Leg-type, support-type, and skirt-type supports are generally welded to the lower part of the vessel body. Leg-type and support-type supports are generally used for tanks; tall towers often use skirts with strong load-bearing capacity. Unlike the above-mentioned supports, ear-type supports are mostly located in the upper middle of the equipment and have good stability. They are a commonly used structural form for vertical vessels, especially shell-and-tube heat exchangers, and are usually installed on concrete or steel platforms. However, when no platform is available, a separate support structure should be designed.

[0003] The use of an independent steel pipe support structure offers advantages such as a small footprint, easy installation, and reduced investment. Vertical vessel lug supports typically require consideration of deadweight, eccentric loads, seismic forces, and wind loads. Because lug supports rely on steel pipes for support, they are subject to compression, which, in terms of material mechanics, is a problem of slender rod buckling under compression.

[0004] According to the relevant theories of material mechanics, when the material of the steel pipe has been determined, increasing the diameter of the supporting steel pipe or changing the constraint conditions of the steel pipe can increase the critical pressure of the steel pipe instability.

[0005] Increasing the steel pipe diameter may be limited by the size of the (already standardized) ear supports, and this will also increase installation costs. In this case, the only viable measure is to use restraints to limit the deformation of the steel pipe and increase the critical instability pressure of the supporting steel pipe. Generally, the restraints are installed in the middle of the steel pipe for the best effect.

[0006] The current support and restraint systems for vertical shell-and-tube heat exchanger vessels primarily utilize the high rigidity of the shell (approximately a rigid body) to achieve restraint through a set of components connected to the shell and clamping the steel tube. However, this restraint system has two significant drawbacks that remain unaddressed. First, during installation and removal, the gap between the two clamping plates must be pried open enough to allow the steel tube to pass through (the rectangular base plates welded to each end of the steel tube have a diagonal dimension larger than the outer diameter of the steel tube and are generally assembled in advance), which severely damages the clamping plates. Second, there is no way to adjust for installation errors along the radial and vertical directions of the shell. Forced installation can pre-load the steel tube with lateral loads perpendicular to its axis, which not only fails to increase the ultimate load-bearing capacity of the supporting steel tube, but can actually reduce it, which is highly detrimental.

[0007] Therefore, if a new restraint device is designed, the above disadvantages must be addressed and the cost must be controlled. Summary of the Invention

[0008] The present invention aims to provide a restraint device for supporting steel pipes, which uses U-bolts to prevent them from becoming unstable. Installation and removal are easy and do not damage the U-bolts. Within the maximum adjustment range, the device allows for stepless adjustment both radially and perpendicularly to the cylinder. Using dual U-bolts and paired locknuts for secure positioning, the restraint device maintains its initial installation state during operation.

[0009] The present invention is achieved through the following technical solution: a restraint device for preventing a support tube from becoming unstable, comprising a vertical container body, a support tube, and a pad fixedly arranged on the vertical container body near the middle of the support tube, characterized in that: a mounting plate with mounting holes is fixedly arranged on the pad by a web and a rib plate, and the mounting plate is close to the inner side of the support tube; a U-shaped bolt is mounted on the support tube, and the two ends of the U-shaped bolt pass through the mounting holes on the mounting plate and are then fixed by a locking nut to form a closed ring structure; a gasket for adjusting the installation error is also installed between the support tube and the mounting plate.

[0010] The present invention also includes a rectangular groove on the mounting plate near the support tube for mounting a gasket. The gasket is composed of multiple overlapping inverted L-shaped metal sheets that can be adjusted to the required thickness. The vertical portion of the gasket is used to limit the support tube, and the horizontal portion is placed in the groove of the mounting plate to prevent it from falling out.

[0011] The present invention enables adjustment in both radial and perpendicular directions. Double U-bolts and paired locknuts provide secure positioning, ensuring safety, reliability, and maintenance-free operation. This invention overcomes the difficulties of assembly and disassembly in existing technologies, including the fragility of the clamping plate and the inability to perform follow-up adjustments. It offers precise positioning, reliable restraint, and maintenance-free operation.

[0012] To ensure the adjustability and reliability of the restraint position, installation errors along the cylinder's radial direction are adjusted using a gasket set; installation errors perpendicular to the radial direction are adjusted using the oblong holes in the mounting plate. Adjusting the tightening torque of the locknuts on both sides of the mounting plate provides the required friction, preventing the U-bolt from moving relative to the mounting plate when subjected to pressure from the support tube's deformation. The locknuts remain in place during service.

[0013] The double U-bolts are installed with their openings facing the cylinder axis, making installation and removal easy and space-saving. Each U-bolt is secured with four locking nuts, effectively preventing deformation of the support tube. Adjusting the tightening torque of the locking nuts on both sides of the mounting plate provides the required friction, preventing the U-bolts from moving relative to the mounting plate when subjected to deformation of the support tube. The locking nuts remain in place during service.

[0014] The present invention provides the following advantages: 1. It is extremely easy to assemble and disassemble, without damaging the restraining parts, and provides strong restraint for the support tube. Existing restraint devices, however, require prying the gap between the two clamping plates open sufficiently to allow the steel tube to pass through during assembly and disassembly. (The rectangular base plates welded to the ends of the steel tube have a diagonal dimension larger than the outer diameter of the steel tube and are typically pre-assembled, which can cause significant damage to the clamping plates. To avoid excessive damage and avoid excessive force during prying, the clamping plates cannot be too thick, which can result in insufficient restraint strength. 2. It can be adjusted dynamically based on the position of the support tube, using a shim assembly along the radial direction of the cylinder and an oblong hole perpendicular to the radial direction. Existing technologies lack this adjustment feature. If installation errors are large, forcing the assembly will not only fail to strengthen the support tube, but will also reduce its ultimate load-bearing capacity (even to below the load-bearing capacity without restraint). 3. Proper anti-loosening measures eliminate the need for maintenance. Paired locknuts secure the restraint device in place, ensuring it remains in its original installation state throughout operation. Existing technologies, however, use only conventional nuts, which inevitably loosen during operation, reducing restraint strength.

[0015] The above comparison shows that the restraint structure of the present invention is significantly superior to the existing structure. This is mainly reflected in the ease of assembly and disassembly; the restraint can be adjusted according to the installation position of the support tube; and the restraint state remains unchanged from beginning to end, eliminating maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the installation structure of the present invention;

[0017] Figure 2 yes Figure 1 A-A local cross-section diagram;

[0018] Figure 3 yes Figure 1 Schematic diagram of the local section along the BB direction.

[0019] The serial numbers of the main components in the accompanying drawings are as follows: 1 vertical container cylinder, 2 support tube, 3 pad, 4 rib plate, 5 web, 6 mounting plate, 7 U-bolt, 8 locking nut, 9 gasket set, 10 oblong mounting hole, 11 rectangular groove.

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. DETAILED DESCRIPTION

[0021] like Figure 1-3, where 1 is the vertical container cylinder, 2 is the support tube, and 3 is a pad fixedly arranged on the vertical container cylinder 1 near the middle of the support tube. A mounting plate 6 with an oblong mounting hole 10 is fixedly arranged on the pad 3 through a web 5 and a rib 4. The mounting plate is close to the inner side of the support tube 2; a U-bolt 7 is mounted on the support tube, and the two ends of the U-bolt are passed through the oblong mounting hole 10 on the mounting plate and fixed by a locking nut 8 to form a closed ring structure; a gasket group 9 for adjusting the installation error is also installed between the support tube 2 and the mounting plate 6.

[0022] A rectangular groove 11 is also provided on the mounting plate near the support tube side for mounting the gasket set 9. The gasket is composed of multiple overlapping inverted L-shaped metal sheets that are adjusted to the required thickness. The vertical portion of the gasket is used to limit the support tube, and the horizontal portion is placed in the groove of the mounting plate to prevent it from falling off.

[0023] The U-bolt 7 in this structure has an inner diameter identical to the outer diameter of the support tube to ensure a tight fit. Typical bolt specifications are M16 or higher. The locking nut 8 provides anti-loosening protection and is recommended to comply with GB / T6187.1 and GB / T6185.1 standards. The gasket assembly 9 is an inverted L-shaped sheet metal component, with the vertical portion used for gap adjustment and the horizontal portion for anchoring in the mounting plate groove to prevent it from falling out. It can be made of 0.1-1.0 mm thin steel plate (ordinary carbon steel or austenitic stainless steel can be used depending on the environment. The minimum adjustable gap depends on the minimum sheet thickness. For example, for a 3.1 mm gap, three 1.0 mm and one 0.1 mm gap can be used). The mounting plate, the core component of this invention, is machined with an oblong mounting hole 10 and a rectangular groove 11 for position adjustment and anchoring the inverted L-shaped gasket assembly, respectively. Together with the web, rib, backing plate, and cylinder, it forms the mounting base. Its thickness is usually ≥16mm; support pipe, bearing all the load of vertical container, the number is ≥3, the specifications are determined by the ear support load according to the steel structure specification, the outer diameter specification is generally ≥ φ The unilateral adjustment distance set by the present invention is 5mm (which can be expanded according to specific needs).

[0024] Installation can be performed as follows: ① After the support tube is installed with the foundation and the vertical vessel ear support, insert the required overlapping gasket set according to the gap between the support tube and the mounting plate. The thickness of the gasket set should be equal to the gap. ② Screw the locknut near the arc of the U-bolt into the U-bolt that matches the support tube (the threaded section of the U-bolt must pass through the support tube before screwing the nut in. Pay attention to the orientation so that it is located between the support tube and the mounting plate). ③ Insert the U-bolt with the locknut into the oblong hole of the mounting plate and adjust the position of the locknut so that the arc of the U-bolt aligns with the outer diameter of the support tube. ④ With the arc of the U-bolt aligned with the outer diameter of the support tube, install the locknut near the cylinder and rotate it until it aligns with the mounting plate, paying attention to the orientation of the locknut. ⑤ Rotate the locknut near the arc of the U-bolt until it aligns with the mounting plate. ⑥ Use a torque wrench to simultaneously tighten the locknuts on both sides of the mounting plate to reach the required torque to complete the installation.

[0025] Since the locking nut used has an anti-loosening function, the entire restraint device is maintenance-free during its service life.

[0026] When the vertical container is repaired or replaced, simply unscrew the lock nut on the U-bolt completely, then pull out the U-bolt and gasket assembly to complete the disassembly. The U-bolt and gasket assembly can also be reused.

Claims

1. A restraining device for preventing a support tube from becoming unstable, comprising a vertical container body (1), a support tube (2), and a pad (3) fixedly arranged on the vertical container body (1) near the middle of the support tube (2), characterized in that: A mounting plate (6) with mounting holes is fixedly provided on the backing plate (3) via a web plate (5) and a rib plate (4), and the mounting plate (6) is close to the inner side of the support tube (2); a U-shaped bolt is mounted on the support tube (2), and both ends of the U-shaped bolt pass through the mounting holes on the mounting plate (6) and are then fixed by a locking nut (8) to form a closed loop structure; a gasket for adjusting mounting errors is also installed between the support tube (2) and the mounting plate (6); The mounting hole is an oblong hole used to adjust the mounting error perpendicular to the radial direction of the cylinder; A rectangular groove (11) for mounting a gasket is also formed on the mounting plate (6) near the support tube (2); The gasket is composed of a plurality of overlapping inverted L-shaped metal sheets for adjusting the required thickness. The vertical portion is used to limit the support pipe (2), and the horizontal portion is placed in the rectangular groove (11) of the mounting plate (6) to prevent it from falling off.

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