Axial expansion joint

Abstract

The utility model relates to axial expansion joint belongs to expansion joint technical field. Including upper telescopic joint seat, lower telescopic joint seat and filler, upper telescopic joint seat sliding insertion is in the inside upper end of lower telescopic joint seat, the inboard wall upper end of lower telescopic joint seat is fixedly connected with the ring seat for the support filler, and the filler is clamped between upper telescopic joint seat and lower telescopic joint seat with ring seat, and the upper end of lower telescopic joint seat is connected with the filler gland for the axial pressure tightness of the filler and is applied to, and the filler gland movable sleeve sets up in the outside of upper telescopic joint seat. The utility model discloses through setting up the upper telescopic joint seat and lower telescopic joint seat of slidable telescopic, when axial expansion telescopic, upper telescopic joint seat can be relative lower telescopic joint seat axial sliding. In the sliding process, the filler can form effective sealing to the sliding gap of both, improves the rigidity and pressure -bearing capacity of overall structure while guaranteeing the leakproofness, makes it can effectively bear frequent telescoping and system vibration.

Description

Technical Field

[0001] This utility model relates to the field of expansion joint technology, and in particular to axial expansion joints. Background Technology

[0002] In industries such as metallurgy, high-temperature flue ash collected by waste heat boilers is discharged through the outlet below the ash collection hopper and then conveyed to a screw conveyor via a connecting device. Because the boiler experiences thermal displacement due to temperature changes during operation, an expansion joint must be installed between the ash collection hopper and the screw conveyor to compensate for axial displacement.

[0003] Currently, the industry generally uses square or round bellows expansion joints, which mainly rely on the flexible structure of the bellows to achieve axial expansion and contraction and a certain degree of displacement compensation.

[0004] However, such expansion joints have many inherent defects in practical applications: 1. To meet expansion and contraction requirements, the material thickness of the corrugated part of square or round corrugated expansion joints is usually controlled below 2mm. This results in low structural strength, poor fatigue resistance, and easy cracking and failure due to frequent expansion and contraction and system vibration; 2. The flue gas emitted by waste heat boilers has a high temperature (about 350℃) and contains corrosive flue gas such as sulfur dioxide, which may condense to form sulfuric acid dew point corrosion. The thin-walled material used in the corrugated pipe is difficult to effectively resist this harsh corrosive environment, resulting in a fast corrosion perforation rate and an extremely short overall service life; 3. When the corrugated part of the square corrugated expansion joint is partially damaged or the seal fails, leakage occurs, requiring the replacement of the entire expansion joint, resulting in high maintenance costs. Summary of the Invention

[0005] To solve the above-mentioned technical problems, this utility model provides an axial expansion joint. The technical solution of this utility model is as follows: An axial expansion joint includes an upper expansion joint seat, a lower expansion joint seat, and packing. The upper expansion joint seat is slidably inserted into the upper inner end of the lower expansion joint seat. An annular seat for supporting the packing is fixedly connected to the upper inner wall of the lower expansion joint seat. The packing and the annular seat are sandwiched between the upper and lower expansion joint seats. A packing gland for applying axial clamping force to the packing is bolted to the upper end of the lower expansion joint seat. The packing gland is movably sleeved on the outer side of the upper expansion joint seat, and there is a radial gap between the inner hole of the packing gland and the outer wall of the upper expansion joint seat.

[0006] Optionally, a flange plate one is fixedly connected to the upper end of the outer side wall of the upper telescopic joint seat, and a flange plate three is fixedly connected to the lower end of the outer side wall of the lower telescopic joint seat.

[0007] Optionally, a second flange is fixedly connected to the upper end of the outer side wall of the lower telescopic joint seat. The packing gland includes a fourth flange and a clamping ring. The clamping ring is fixedly connected to the lower surface of the fourth flange. The second flange and the fourth flange are fixedly connected by bolts. The lower end face of the clamping ring applies an axial clamping force to the packing under the action of the bolts.

[0008] Optionally, multiple sets of reinforcing ribs are fixedly connected between the outer wall of the lower telescopic joint seat and the lower surface of the flange plate two.

[0009] Optionally, the upper surface of the ring seat is a guide slope that slopes downward inward, and the lower surface of the packing is provided with a corresponding slope that cooperates with the guide slope.

[0010] Optionally, the inclination angle of the guide ramp is 30 degrees.

[0011] Optionally, the minimum wall thickness of the upper telescopic joint seat and the lower telescopic joint seat is 6mm.

[0012] Optionally, there is a radial gap between the outer diameter of the clamping cam and the inner wall of the lower telescopic joint seat.

[0013] Optionally, the radial clearance between the inner hole of the packing gland and the outer wall of the upper telescopic joint seat is 1 mm, and the radial clearance between the outer wall of the clamping ring and the inner wall of the lower telescopic joint seat is 1 mm.

[0014] Optionally, the packing material is graphite packing.

[0015] All of the above optional technical solutions can be combined arbitrarily, and this utility model does not provide a detailed description of the structure after each combination.

[0016] The beneficial effects of this utility model through the above solution are as follows: 1. This utility model, by setting up a sliding and telescopic upper telescopic joint seat and a lower telescopic joint seat, allows the upper telescopic joint seat to slide axially relative to the lower telescopic joint seat during axial expansion and contraction. During the sliding process, the packing can effectively seal the sliding gap between the two, ensuring sealing while improving the rigidity and pressure-bearing capacity of the overall structure. This enables it to effectively withstand frequent expansion and contraction and system vibration, fundamentally overcoming the defect of bellows in the prior art that is prone to cracking and failure due to thin walls.

[0017] 2. Since the upper and lower expansion joint seats are axially slidingly fitted, their wall thickness is not limited by the expansion and contraction requirements. Therefore, the wall thickness can be reasonably set according to the on-site working conditions to meet the corrosive environment and extend its service life.

[0018] 3. By setting a packing gland, when the packing seal fails, the packing can be removed and replaced simply by separating the packing gland from the lower expansion joint seat, without the need for a complete replacement, which greatly reduces maintenance costs.

[0019] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 A schematic diagram of the overall appearance structure of the axial expansion joint provided by this utility model; Figure 2 An exploded view of the axial expansion joint provided by this utility model; Figure 3 A front sectional view of the axial expansion joint provided by this utility model; Figure 4 for Figure 3 A magnified structural diagram of point A in the middle.

[0021] The following are the labels in the diagram: 1. Upper expansion joint seat; 11. Flange 1; 2. Lower expansion joint seat; 21. Flange 2; 22. Flange 3; 23. Reinforcing rib; 3. Packing; 4. Ring seat; 41. Guide slope; 5. Packing gland; 51. Flange 4; 52. Pressing ring. Detailed Implementation

[0022] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0023] Please see Figure 1-4 This utility model provides an axial expansion joint, including an upper expansion joint seat 1, a lower expansion joint seat 2, and a packing 3. The upper expansion joint seat 1 is slidably inserted into the upper part of the lower expansion joint seat 2. An annular seat 4 for supporting the packing 3 is fixedly connected to the upper part of the inner side wall of the lower expansion joint seat 2. The packing 3 and the annular seat 4 are sandwiched between the upper expansion joint seat 1 and the lower expansion joint seat 2. The upper end of the lower expansion joint seat 2 is connected by bolts to a packing gland 5 for applying axial clamping force to the packing 3. The packing gland 5 is movably sleeved on the outside of the upper expansion joint seat 1.

[0024] This invention features a sliding and telescopic upper telescopic joint seat 1 and a lower telescopic joint seat 2. During axial expansion and contraction, the upper telescopic joint seat 1 can slide relative to the lower telescopic joint seat 2. During this sliding process, the packing 3 effectively seals the sliding gap between the two, ensuring sealing while improving the rigidity and pressure-bearing capacity of the overall structure. This allows it to effectively withstand frequent expansion and contraction and system vibration, fundamentally overcoming the defect of bellows in the prior art that is prone to cracking and failure due to thin walls.

[0025] Secondly, since the upper telescopic joint seat 1 and the lower telescopic joint seat 2 are axially slidingly fitted, their wall thickness and material are not limited by the telescopic requirements. Therefore, the wall thickness can be reasonably set according to the on-site working conditions, and high-temperature resistant and corrosion-resistant materials can be reasonably selected to meet the on-site corrosive environment and extend their service life.

[0026] In addition, by setting the packing gland 5, when the seal of the packing 3 fails, the packing gland 5 can be separated from the lower expansion joint seat 2 to remove and replace the packing 3 without the need for overall replacement, which greatly reduces maintenance costs.

[0027] Specifically, by setting up a sliding and telescopic upper telescopic joint seat 1 and a lower telescopic joint seat 2, the axial expansion range of the device is significantly increased. The axial expansion range mainly depends on the depth to which the upper telescopic joint seat 1 is inserted into the lower telescopic joint seat 2. As long as the lower end face of the upper telescopic joint seat 1 is lower than the lower surface of the ring seat 4, an effective seal can be achieved, thereby meeting the axial expansion requirements.

[0028] It should be noted that, during transportation, to prevent the upper telescopic joint seat 1 from detaching from the upper opening of the lower telescopic joint seat 2, a stop can be fixed to the lower periphery of the upper telescopic joint seat 1 by bolts or by welding (not shown in the figure) after assembly. When the upper telescopic joint seat 1 slides to the upper limit position of the lower telescopic joint seat 2, the stop can firmly abut against the lower surface of the ring seat 4, thereby achieving the limiting function.

[0029] Furthermore, there is a radial gap between the inner hole of the packing gland 5 and the outer wall of the upper expansion joint seat 1, and the radial gap between the inner hole of the packing gland 5 and the outer wall of the upper expansion joint seat 1 is 1 mm.

[0030] Specifically, the radial clearance ensures that when the packing gland 5 is pressing the packing 3, its inner hole will never come into contact with or rub against the outer wall of the upper telescopic joint seat 1, which moves up and down, thereby ensuring that the upper telescopic joint seat 1 slides freely and will not get stuck.

[0031] Furthermore, a flange plate 11 is fixedly connected to the upper end of the outer side wall of the upper telescopic joint seat 1, and a flange plate 22 is fixedly connected to the lower end of the outer side wall of the lower telescopic joint seat 2.

[0032] Specifically, flange 11 is fixedly connected to the upper expansion joint seat 1 by welding, and flange 22 is fixedly connected to the lower expansion joint seat 2 by welding.

[0033] Furthermore, a flange 21 is fixedly connected to the upper end of the outer side wall of the lower expansion joint seat 2. The packing gland 5 includes a flange 4 51 and a clamping ring 52. The clamping ring 52 is fixedly connected to the lower surface of the flange 4 51. The flange 21 and the flange 4 51 are fixedly connected by bolts. The lower end face of the clamping ring 52 applies axial clamping force to the packing 3 under the action of the bolts.

[0034] Specifically, when the packing 3 fails to seal or is damaged, the bolts used to fix the connecting flange 21 and flange 51 can be removed, and then the packing gland 5 can be removed from the lower expansion joint seat 2 to replace the packing 3.

[0035] Furthermore, multiple sets of reinforcing ribs 23 are fixedly connected between the outer wall of the lower expansion joint seat 2 and the lower surface of the flange plate 21. The reinforcing ribs 23 can be triangular plates to enhance the overall structure between the lower expansion joint seat 2 and the flange plate 21.

[0036] Furthermore, the upper surface of the ring seat 4 is a guide slope 41 that slopes downward inward, and the lower surface of the packing 3 is provided with a corresponding slope that cooperates with the guide slope 41.

[0037] Specifically, under the tightening force of the bolt, the clamping ring 52 can apply axial pressure to the packing 3. At this time, the axial pressure will be decomposed into axial clamping force and radial inward clamping force, thereby forcing the packing 3 to adhere more tightly to the outer wall of the upper telescopic joint seat 1, thus significantly enhancing the sealing effect on the sliding surface.

[0038] Furthermore, the tilt angle of the guide ramp 41 is 30 degrees.

[0039] Specifically, when the sliding angle between the guide slope 41 and the lower surface of the packing 3 is 30 degrees, it can ensure the effective transmission of force and make the cooperation between the sliding angle of the lower surface of the packing 3 and the guide slope 41 smoother, thereby effectively converting the axial pressing force into the radial sealing force.

[0040] Furthermore, the minimum wall thickness of the upper telescopic joint seat 1 and the lower telescopic joint seat 2 is 6mm.

[0041] Specifically, the 6mm wall thickness effectively withstands the long-term operation of the waste heat boiler at a high temperature of 350 degrees Celsius, while also resisting corrosive media. This ensures stable structural strength and sealing performance even under extreme working conditions, significantly extending the service life of the components. Furthermore, the wall thickness can be adjusted according to the actual on-site environment and operating conditions to cope with different temperatures, pressures, or corrosive media, thereby ensuring long-term reliable operation of the equipment in various complex environments.

[0042] Furthermore, there is a radial gap between the outer diameter of the clamping ring 52 and the inner wall of the lower telescopic joint seat 2, and the radial gap between the outer wall of the clamping ring 52 and the inner wall of the lower telescopic joint seat 2 is 1mm.

[0043] Specifically, the radial clearance ensures that when the packing gland 5 is pressing the packing 3, the outer wall of the pressing ring 52 will never come into contact with or rub against the inner wall of the fixed lower telescopic joint seat 2.

[0044] Furthermore, packing 3 uses graphite packing.

[0045] Specifically, graphite packing can withstand temperatures ranging from -100°C to approximately 800°C and maintain excellent sealing performance under pressures of 0.4 MPa. Due to its excellent high-temperature resistance, corrosion resistance, and heat resistance, graphite packing is particularly suitable for environments containing corrosive gases such as sulfur dioxide and high dust levels, effectively coping with harsh operating conditions. Graphite packing is not only resistant to acids and alkalis but also possesses self-expanding properties under high-temperature conditions, allowing for a tighter fit to the sealing surface, further improving the sealing effect, preventing media leakage, and thus ensuring the long-term stable operation of the equipment.

[0046] It should be noted that, depending on the specific operating conditions and media of the axial expansion joint, other types of packing 3 can also be selected, such as asbestos rope or oil-impregnated packing. Asbestos rope is suitable for low-temperature environments, while oil-impregnated packing is more suitable for operating conditions at normal temperature and pressure.

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit 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 technical principles 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. An axial expansion joint, characterized in that: The device includes an upper telescopic joint seat (1), a lower telescopic joint seat (2), and a packing (3). The upper telescopic joint seat (1) is slidably inserted into the upper part of the lower telescopic joint seat (2). The upper part of the inner side wall of the lower telescopic joint seat (2) is fixedly connected to an annular seat (4) for supporting the packing (3). The packing (3) and the annular seat (4) are sandwiched between the upper telescopic joint seat (1) and the lower telescopic joint seat (2). The upper end of the lower telescopic joint seat (2) is connected by bolts to a packing gland (5) for applying axial pressure to the packing (3). The packing gland (5) is movably sleeved on the outside of the upper telescopic joint seat (1), and there is a radial gap between the inner hole of the packing gland (5) and the outer wall of the upper telescopic joint seat (1).

2. The axial expansion joint according to claim 1, characterized in that, The upper side wall of the upper telescopic joint seat (1) is fixedly connected to a flange plate one (11), and the lower side wall of the lower telescopic joint seat (2) is fixedly connected to a flange plate three (22).

3. The axial expansion joint according to claim 1, characterized in that, The upper end of the outer side wall of the lower telescopic joint seat (2) is fixedly connected to a flange plate two (21). The packing gland (5) includes a flange plate four (51) and a clamping ring (52). The clamping ring (52) is fixedly connected to the lower surface of the flange plate four (51). The flange plate two (21) and the flange plate four (51) are fixedly connected by bolts. The lower end face of the clamping ring (52) applies axial clamping force to the packing (3) under the action of the bolts.

4. The axial expansion joint according to claim 3, characterized in that, Multiple sets of reinforcing ribs (23) are fixedly connected between the outer wall of the lower expansion joint seat (2) and the lower surface of the flange plate (21).

5. The axial expansion joint according to claim 1, characterized in that, The upper surface of the ring seat (4) is a guide slope (41) that slopes downward inward, and the lower surface of the packing (3) is provided with a corresponding slope that cooperates with the guide slope (41).

6. The axial expansion joint according to claim 5, characterized in that, The guide ramp (41) has an inclination angle of 30 degrees.

7. The axial expansion joint according to claim 1, characterized in that, The minimum wall thickness of the upper telescopic joint seat (1) and the lower telescopic joint seat (2) is 6 mm.

8. The axial expansion joint according to claim 3, characterized in that, There is a radial gap between the outer diameter of the clamping ring (52) and the inner wall of the lower telescopic joint seat (2).

9. The axial expansion joint according to claim 8, characterized in that, The radial gap between the inner hole of the packing gland (5) and the outer wall of the upper telescopic joint seat (1) is 1 mm, and the radial gap between the outer wall of the clamping ring (52) and the inner wall of the lower telescopic joint seat (2) is 1 mm.

10. The axial expansion joint according to any one of claims 1-9, characterized in that, The packing material (3) is graphite packing.

Images