Lifting device for tubular air preheater tube box

Abstract

This utility model relates to a hoisting device for a tubular air preheater tube box, and pertains to the field of tubular air preheaters. The technical solution involves hoisting devices installed at the four inner corners of the tube sheet of the tubular air preheater tube box. Each hoisting device includes square nuts welded to hoisting through holes at the four inner corners of the tube sheet, as well as a first support plate and a second support plate. Bolts or threaded pins for hoisting extend from the outside of the tube sheet into the hoisting through holes and are threadedly connected to the square nuts to facilitate hoisting operations with external hoisting equipment. In this configuration, the hoisting through holes can be sealed with threaded plugs after hoisting, avoiding the use of hot work with steel plates to seal the through holes in existing technologies. When the entire tube box needs to be hoisted for inspection, maintenance, or replacement later, the threaded plugs can be removed, allowing the original hoisting through holes to be reused without causing any damage. This facilitates the installation and maintenance of the tube box, improves construction safety, and reduces the difficulty of construction operations.

Description

Technical Field

[0001] This utility model relates to the field of tubular air preheater technology, and in particular to a hoisting device for a tubular air preheater tube box. Background Technology

[0002] The air preheater tube box, as the core component of the tubular air preheater for heat exchange between flue gas and air, has a complex structure and large size. It is integrated from a large number of thin-walled heat-receiving surface tube bundles, bracing tubes, tube sheets, and auxiliary reinforcement supports. Not only is the overall weight large, but the thin-walled structure also makes it vulnerable to deformation. This characteristic means that the tube box must rely on specialized lifting equipment for handling, loading and unloading, installation, maintenance, and replacement. Improper lifting operations can easily cause problems such as tube bundle bending, tube sheet deformation, or weld cracking, which will lead to a significant decrease in the heat exchange efficiency between flue gas and air, and even cause waste of heat energy or safety hazards during boiler operation. However, the design and operation of the lifting equipment faces multiple challenges. It is necessary to accurately match the structural center of gravity of the tube box to avoid uneven loading, select the lifting path according to the spatial constraints of the installation location, and adapt to the operating requirements of the complex on-site environment. This makes it difficult to reliably achieve safe and efficient lifting operations.

[0003] Currently, existing pipe box hoisting schemes have significant limitations. Although some pipe boxes are equipped with symmetrically arranged dedicated lifting lugs or hoisting through holes to balance the force, these dedicated lifting lugs must be cut off on-site after the pipe box is installed in place; otherwise, they will hinder the assembly of subsequent connecting parts. This directly leads to the complete failure of the original hoisting points when the pipe box is repaired or replaced after the boiler is put into operation, necessitating the redesign of a temporary hoisting structure, which increases operating costs and risks. The scheme relying on hoisting through holes also has drawbacks. After the pipe box is installed, the through holes at the four corners need to be sealed with steel plates. This process involves hot work operations such as flame cutting and welding, which is not only time-consuming and labor-intensive but may also affect the material properties of the pipe box due to high temperatures. More importantly, if the through holes need to be used for hoisting again during later repairs or replacements, the sealing steel plates must be removed first. This not only damages the original sealing structure but may also damage the surrounding structure of the through holes due to secondary processing, further reducing the reliability of the pipe box. Summary of the Invention

[0004] The purpose of this invention is to provide a hoisting device for a tubular air preheater box to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A hoisting device for a tubular air preheater tube box, wherein the hoisting device is provided at each of the four inner corners of the tube sheet of the tubular air preheater tube box, and the hoisting device includes:

[0007] A square nut, welded to the lifting through holes at the four corners of the inner side of the tube sheet, with its threaded through hole coaxial with the lifting through hole; and

[0008] The first support plate and the second support plate are respectively attached to the two adjacent sides of the square nut near the inner corner of the tube plate. They are perpendicular to each other and to the tube plate. They are connected to the tube plate by welding.

[0009] The bolts or threaded pins used for hoisting extend from the outside of the tube sheet into the hoisting through hole and are threadedly connected to the square nut to cooperate with the hoisting operation of external hoisting equipment.

[0010] In one possible implementation, the first support plate and the second support plate are further welded with support feet on the side away from the square nut, for supporting the tubular air preheater tube box during turnover, loading and unloading, and installation, and for preventing the thin-walled tube bundles on the inner side of the tube sheet from being squeezed and damaged.

[0011] In one possible implementation, the first support plate and the second support plate are further welded with reinforcing angle steel on the side away from the square nut, for auxiliary positioning and reinforcement of the tube sheets on both sides when assembled with the thin-walled tube bundle of the heated surface, and for external collision protection of the tubular air preheater tube box during turnover, loading and unloading, and installation.

[0012] In one possible implementation, the support foot protrudes from the outer side of the reinforcing angle steel.

[0013] In one possible implementation, the diameter of the threaded through hole of the square nut is smaller than the diameter of the lifting through hole.

[0014] In one possible implementation, the length of the bolt or threaded pin used for hoisting, after being threadedly connected to the square nut, protruding from the outside of the tube sheet, meets the connection requirements of the hoisting wire rope.

[0015] In one possible implementation, the head diameter of the bolt used for hoisting is larger than the diameter of the screw.

[0016] In one possible implementation, the head of the threaded pin for hoisting has a hoisting hole.

[0017] The beneficial effects of the technical solution provided by this utility model include at least the following:

[0018] This technical solution includes lifting devices at the four inner corners of the tube sheet of the tubular air preheater box. Each lifting device comprises a square nut welded to the lifting through-holes at the four inner corners of the tube sheet, with its threaded through-hole coaxial with the lifting through-hole; a first support plate and a second support plate, respectively attached to adjacent sides of the square nut near the inner corner of the tube sheet, perpendicular to each other and to the tube sheet, and connected to the tube sheet by welding. Bolts or threaded pins for lifting extend from the outside of the tube sheet into the lifting through-hole and are threadedly connected to the square nut to facilitate lifting operations with external lifting equipment. In this configuration, the lifting through-hole can be sealed with a threaded plug after lifting, avoiding the use of hot work with steel plates to seal the through-hole in existing technologies. When the entire tube box needs to be lifted for inspection, maintenance, or replacement later, the threaded plug can be removed, allowing the original lifting through-hole to be reused without damage. This facilitates the installation and maintenance of the tube box, improves construction safety, and reduces the difficulty of construction operations. Attached Figure Description

[0019] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.

[0020] Figure 1 A schematic diagram of the structure of the hoisting device for the tubular air preheater box provided in an exemplary embodiment of the present invention is shown.

[0021] Figure 2 It shows Figure 1 A partial view in direction A.

[0022] Figure 3 It shows Figure 2 BB section view.

[0023] In the picture:

[0024] 1. Lifting device; 2. Tube sheet; 3. Lifting through hole;

[0025] 11. Square nut; 12. First support plate; 13. Second support plate; 14. Support foot; 15. Reinforcing angle steel. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings of this utility model, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component, respectively. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more.

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Figure 1 This diagram illustrates the structure of a hoisting device for a tubular air preheater box provided in an exemplary embodiment of the present invention. Figure 2 It shows Figure 1 A partial view in the middle, Figure 3 It shows Figure 2 In the BB section view, lifting devices 1 are provided at the four inner corners of the tube sheet 2 of the tubular air preheater box. The lifting device 1 includes: a square nut 11, which is welded to the lifting through hole 3 at the four inner corners of the tube sheet 2, and its threaded through hole is coaxial with the lifting through hole 3; and a first support plate 12 and a second support plate 13, which are respectively close to the two adjacent sides of the square nut 11 near the inner corner of the tube sheet 2. The two are perpendicular to each other and both are perpendicular to the tube sheet 2. The two are connected to the tube sheet 2 by welding. The bolts or threaded pins used for lifting extend from the outside of the tube sheet 2 into the lifting through hole 3 and are threadedly connected to the square nut 11 to cooperate with the lifting operation of external lifting equipment.

[0030] In this embodiment, the square nut 11 is welded to the lifting through holes 3 at the four corners of the inner side of the tube sheet 2, and the threaded through hole is coaxial with the lifting through hole 3. This arrangement allows bolts or threaded pins to be inserted from the outside of the tube sheet 2 during tube box hoisting, ensuring precise screwing into the square nut 11 and guaranteeing that force transmission occurs along the central axis, thus preventing damage to the tube box structure from eccentric loading. The first support plate 12 and the second support plate 13 are respectively tightly attached to the adjacent sides of the square nut 11 and welded perpendicularly to the tube sheet 2. This not only strengthens the connection between the square nut 11 and the tube sheet 2, preventing the nut from loosening or falling off due to excessive force during hoisting, but also utilizes the stability principle of triangular supports to effectively disperse stress during hoisting, reducing localized stress concentration on the tube sheet 2 and minimizing the risk of deformation. In this configuration, it can efficiently cooperate with external hoisting equipment to achieve safe and stable hoisting operations for the tube box.

[0031] In an optional embodiment, the first support plate 12 and the second support plate 13 are further welded with support feet 14 on the side away from the square nut 11, for supporting the tubular air preheater tube box during turnover, loading and unloading, and installation, and for preventing the thin-walled tube bundles on the inner side of the tube sheet 2 from being squeezed and damaged.

[0032] In this embodiment, the support foot 14 is welded to the side of the first support plate 12 and the second support plate 13 away from the square nut 11. During the turnover, loading, unloading and installation of the pipe box, the support foot 14 can directly contact the ground or the bearing surface to bear part of the weight of the pipe box and avoid the pipe plate 2 from being directly deformed by force.

[0033] In an optional embodiment, a reinforcing angle steel 15 is welded to the side of the first support plate 12 and the second support plate 13 away from the square nut 11. This is used for auxiliary positioning and reinforcement of the tube sheets 2 on both sides when they are assembled with the thin-walled tube bundle of the heated surface, as well as for external collision protection of the tubular air preheater tube box during turnover, loading and unloading, and installation.

[0034] In this embodiment, the reinforcing angle steel 15 is welded to the side of the first support plate 12 and the second support plate 13 away from the square nut 11. During the assembly of the tube sheet 2 with the thin-walled tube bundle of the heated surface, the reinforcing angle steel 15 serves as a reference, assisting in calibrating the relative positions of the tube sheets 2 on both sides, reducing assembly deviations, and enhancing the overall structural stability. Simultaneously, its angular metal structure forms a physical barrier during the tube box's turnover, loading, unloading, and installation processes, buffering external impact forces and preventing direct impact damage to the tube sheet 2 and the inner thin-walled tube bundle. This dual-functional design improves assembly accuracy and strengthens the tube box's impact resistance, reducing the risk of structural damage during multi-stage operations.

[0035] It is worth mentioning that the support foot 14 protrudes from the outer side of the reinforcing angle steel 15, which can maintain a safe distance from the thin-walled tube bundle inside the tube sheet 2, preventing the tube bundle from bending or breaking due to compression or collision when the tube box is placed or moved, providing extra protection for the thin-walled components and improving the structural safety of the tube box in the non-hoisting state.

[0036] It should be noted that the diameter of the threaded through hole of the square nut 11 is smaller than the diameter of the lifting through hole 3. After the bolt or threaded pin used for lifting is threadedly connected to the square nut 11, the length of its protrusion outside the tube plate 2 meets the connection requirements of the lifting wire rope. The head diameter of the bolt used for lifting is larger than the diameter of the screw. The head of the threaded pin used for lifting has a lifting hole.

[0037] In this embodiment, the diameter of the threaded through hole of the square nut 11 is smaller than that of the lifting through hole 3, allowing for a gap to prevent friction between the bolt or pin and the hole wall when it is inserted, ensuring smooth assembly. The length of the bolt or pin protruding from the outside of the tube plate 2 after connection provides sufficient connection space for the lifting wire rope, ensuring a stable connection between the lifting point and external equipment. The setting of the lifting hole with a bolt head diameter larger than that of the screw and the threaded pin head facilitates the adaptation of wire rope connection.

[0038] Next, the working principle of the hoisting device for the tubular air preheater box involved in the embodiments of this utility model will be explained.

[0039] During the prefabrication stage, square nuts 11 are first welded to the lifting through holes 3 at the four corners of the inner side of the tube sheet 2 to ensure that the threaded through holes are coaxial with the through holes, providing a reference for the lifting connection parts. Then, the first support plate 12 and the second support plate 13, which are perpendicular to each other, are welded to the side of the square nuts 11 and the tube sheet 2 to form a triangular support structure. The load-bearing capacity of the nuts is enhanced by dispersing stress. Optional support feet 14 and reinforcing angle steel 15 are simultaneously welded to the end of the support plate, which are used for tube box support and structural reinforcement, respectively.

[0040] In the non-hoisting state, the support foot 14 provides support when the pipe box is placed, while the reinforcing angle steel 15 assists in positioning the pipe plate and resists external collisions.

[0041] During hoisting, bolts or threaded pins are inserted into the hoisting through-hole 3 from the outside of the tube sheet 2 and threadedly connected to the square nut 11. The hoisting load is transferred by the synergistic force of the nut and the support plate, avoiding local deformation of the tube sheet. The bolt head or the pin hoisting hole is connected to the external hoisting tool, and balanced force is achieved through symmetrical hoisting points.

[0042] Finally, after the tubular air preheater box is installed on site, the first support plate 12, the second support plate 13, and the support foot 14 can be cut off. Then, a threaded plug that matches the threaded through hole of the square nut 11 is used to seal the lifting through hole 3. When the box needs to be hoisted and inspected or replaced later, the threaded plug can be unscrewed and the original lifting through hole 3 can be reused for hoisting. The operation is extremely convenient, greatly simplifying the installation and maintenance process of the box, improving the safety of the construction process, and effectively reducing the difficulty of construction operations.

[0043] In summary, this technical solution provides lifting devices at the four inner corners of the tube sheet of the tubular air preheater box. The lifting devices include square nuts welded to the lifting through holes at the four inner corners of the tube sheet, with the threaded through holes coaxial with the lifting through holes; and a first support plate and a second support plate, which are respectively attached to the adjacent two sides of the square nuts near the inner corners of the tube sheet. The two support plates are perpendicular to each other and to the tube sheet, and are connected to the tube sheet by welding. Bolts or threaded pins for lifting extend from the outside of the tube sheet into the lifting through holes and are threadedly connected to the square nuts to facilitate lifting operations with external lifting equipment. In this case, the hoisting through hole can be sealed with a threaded plug after hoisting, avoiding the use of hot work with steel plates to seal the hoisting through hole in the existing technology. When the pipe box needs to be hoisted, inspected, or replaced later, the original hoisting through hole can be reused after removing the threaded plug, without causing any damage to the original hoisting through hole. This facilitates the installation and maintenance of the pipe box, improves construction safety, and reduces the difficulty of construction operations.

[0044] In the embodiments disclosed in this utility model, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this utility model according to the specific circumstances.

[0045] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A hoisting device for a tubular air preheater box, characterized in that, The hoisting device (1) is provided at each of the four inner corners of the tube sheet (2) of the tubular air preheater box. The hoisting device (1) includes: A square nut (11) is welded to the lifting through holes (3) at the four corners of the inner side of the tube sheet (2), and its threaded through hole is coaxially arranged with the lifting through hole (3); and The first support plate (12) and the second support plate (13) are respectively attached to the two adjacent sides of the square nut (11) near the inner corner of the tube plate (2). They are perpendicular to each other and both are perpendicular to the tube plate (2). They are connected to the tube plate (2) by welding. The bolts or threaded pins used for hoisting extend from the outside of the tube sheet (2) into the hoisting through hole (3) and are threadedly connected to the square nut (11) to cooperate with the hoisting operation of external hoisting equipment.

2. The hoisting device for the tubular air preheater box according to claim 1, characterized in that, The first support plate (12) and the second support plate (13) are also welded with support feet (14) on the side away from the square nut (11) for supporting the tubular air preheater tube box during turnover, loading and unloading, and installation, and to prevent the thin-walled tube bundles on the inner side of the tube sheet (2) from being squeezed and damaged.

3. The hoisting device for the tubular air preheater box according to claim 2, characterized in that, The first support plate (12) and the second support plate (13) are also welded with reinforcing angle steel (15) on the side away from the square nut (11) for auxiliary positioning and reinforcement of the tube sheet (2) on both sides when it is assembled with the thin-walled tube bundle of the heated surface, and for external collision protection of the tubular air preheater tube box during turnover, loading and unloading and installation.

4. The hoisting device for the tubular air preheater box according to claim 3, characterized in that, The support foot (14) protrudes from the outer side of the reinforcing angle steel (15).

5. The hoisting device for the tubular air preheater box according to any one of claims 1 to 4, characterized in that, The diameter of the threaded through hole of the square nut (11) is smaller than the diameter of the lifting through hole (3).

6. The hoisting device for the tubular air preheater box according to any one of claims 1 to 4, characterized in that, After the bolt or threaded pin used for hoisting is threadedly connected to the square nut (11), the length of the bolt or threaded pin protruding from the outside of the tube sheet (2) meets the connection requirements of the hoisting wire rope.

7. The hoisting device for the tubular air preheater box according to claim 6, characterized in that, The head diameter of the bolt used for hoisting is larger than the diameter of the screw.

8. The hoisting device for the tubular air preheater box according to claim 6, characterized in that, The head of the threaded pin used for hoisting has a hoisting hole.

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