Corrosion-resistant bellows compensator for fan

Abstract

The present invention belongs to the technical field of corrugated compensators, and specifically relates to a corrosion-resistant corrugated compensator for a fan. The inlet end and the outlet end of the corrugated pipe are respectively fixedly connected to the air duct cylinder body. The outer side of the air duct cylinder body is fixedly connected with a flange for connecting the main pipeline of the fan. A buffer ring is arranged inside the corrugated convex circle of the corrugated pipe. The buffer ring is a foamed honeycomb structure and is made of an elastic polyurethane material. A flow guide cylinder is arranged inside the corrugated pipe. The diameter of the air duct cylinder body fixedly connected to the inlet end of the flow guide cylinder is matched with that of the inlet end of the corrugated pipe and is hermetically welded. There is a radial gap between the outlet end of the flow guide cylinder and the air duct cylinder body fixedly connected to the outlet end of the corrugated pipe. The flow guide cylinder is arranged in a necking structure, and the necking position is adjacent to its inlet end. The flow guide cylinder is assembled by a plurality of arc-shaped tiles, and pressing plates are arranged on the outer walls of the arc-shaped tiles forming the flow guide cylinder. The pressing plates are in surface contact with the buffer ring. The corrugated pipe corrosion-resistant compensation structure provided by the present invention can effectively reduce the corrosion degree of corrosive gas on the corrugated pipe and extend the service life of the corrugated pipe.

Description

Technical Field

[0001] The present invention belongs to the technical field of corrugated compensators, and specifically relates to a corrosion-resistant corrugated compensator for a fan. Background Art

[0002] The waste flue gas from the drying section, preheating section, and front roasting section of the roasting machine is discharged through a fan after purification. The waste flue gas in the main pipeline of the fan contains corrosive SO2 gas. The SO2 content at the pipeline inlet is 578 mg / Nm 3 , the humidity is 6.5%, and the inlet temperature is 140 °C. The corrugated pipe is installed on the main pipeline of the fan for axial deformation compensation of the long pipeline.

[0003] In the prior art, the internal anti-corrosion structure of the corrugated pipe is: a guiding sleeve is installed inside the corrugated pipe. The inlet end of the guiding sleeve is welded to the inlet air pipe of the corrugated pipe, and a radial gap of 5 mm is reserved between the other end and the outlet air pipe to reserve the deformation amount for axial compensation. The high-temperature sulfur-containing gas flows at high speed from the inlet of the internal guiding sleeve to the outlet side. Due to the positive pressure environment inside the guiding sleeve, some sulfur-containing corrosive gas is pressed into the space between the corrugated pipes through the gap. This part of the corrosive SO2 gas is outside the flow field range and cannot leave the cavity of the corrugated pipe with the driving force of the air flow. The SO 2的 The abrasive waste flue gas directly contacts the inner wall of the corrugated pipe, and the overall vibration of the corrugated pipe caused by the air flow pressure accelerates the corrosion process, resulting in corrosion and even rust penetration at the lower low point position of the corrugated pipe. The corrugated pipe is large in size (diameter about 2 m), high in cost, and requires a large amount of financial resources, manpower, and time for installation and replacement. Therefore, how to improve the service life of the corrugated pipe is a very economically valuable topic in this field. Summary of the Invention

[0004] The technical problem to be solved by the present invention is the problem that the pipe wall of the existing corrugated compensator is easily corroded and has a short service life.

[0005] To solve the above problems, the technical solution adopted by the present invention is:

[0006] A corrosion-resistant corrugated compensator for a fan, including a corrugated pipe. The inlet end and the outlet end of the corrugated pipe are respectively fixedly connected to the air pipe cylinder. A flange for connecting with the main pipeline of the fan is fixedly connected to the outside of the air pipe cylinder. A guiding cylinder is arranged inside the corrugated pipe, and the guiding cylinder is assembled by a plurality of arc-shaped tiles; the diameter of the air pipe cylinder fixedly connected to the inlet end of the guiding cylinder is matched with that of the inlet end of the corrugated pipe and is sealed and welded; a radial gap is provided in the air pipe cylinder fixedly connected to the outlet end of the guiding cylinder and the outlet end of the corrugated pipe; the guiding cylinder is arranged in a necking structure, and the necking position is adjacent to its inlet end.

[0007] The present invention adopting the above technical solution, compared with the prior art, has the following beneficial effects:

[0008] The corrosion-resistant compensation structure of the bellows provided by the present invention can effectively reduce the corrosion degree of the bellows by corrosive gases and extend the service life of the bellows.

[0009] Preferably, a further technical solution of the present invention is as follows:

[0010] A buffer ring is provided inside the corrugated convex circle of the bellows. The buffer ring is a foamed honeycomb structure and is made of elastic polyurethane material. The buffer ring prevents the accumulation of abrasive substances such as condensed water at the lowest point of the bellows, blocking the direct contact between the abrasive gas and the pipe wall at the easily corroded position, thereby protecting the bellows.

[0011] Pressure plates are provided on the outer walls of the arc-shaped tiles that make up the flow guide cylinder, and the pressure plates are in surface contact with the buffer ring. In this structure, the pressure plates prevent the buffer ring from falling off from the corrugated convex circle and continuously compact the buffer ring into the corrugated convex circle along with the vibration of the flow guide cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0013] Figure 2 is a schematic structural diagram of a single-piece arc-shaped tile of the present invention;

[0014] Figure 3 is a schematic structural diagram of the flow guide cylinder setting.

[0015] In the figure: 1 transportation pull rod, 2 support plate, 3 flange, 4 gap, 5 flow guide cylinder, 6 high-temperature and high-sulfur gas, 7 air duct cylinder body, 8 pressure plate, 9 buffer ring, 10 bellows, arc-shaped tile 5-1, corrugated convex circle 10-1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The present invention will be further described below in conjunction with embodiments, and the purpose is only to better understand the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0017] See Figure 1 , the corrosion-resistant corrugated compensator for a fan includes a stainless-steel bellows 10 installed on the main pipeline of the fan and used to compensate the axial deformation of the long pipeline. The inlet end and the outlet end of the bellows 10 are respectively welded to the air duct cylinder body 7. The outer end of the air duct cylinder body 7 is fixedly connected to the flange 3. The flanges 3 at both ends are connected to the support plate 2, and the support plate 2 has reserved bolt holes for installing the transportation pull rod 1. The inlet end of the flow guide cylinder 5 is fixedly welded to the inlet-side air duct cylinder body 7, and a radial gap 4 is reserved between the outlet end of the flow guide cylinder 5 and the outlet-side air duct cylinder body 7 for the axial compensation of the stainless-steel bellows 10.

[0018] The present invention adopts a segmented streamline inner flow guide cylinder 5, which is assembled by a plurality of arc-shaped tiles 5-1. The structure of multiple tiles combined is convenient for installation and fixation inside the bellows 10. Specifically, seeFigure 2 , Figure 3 , the draft tube 5 is composed of 9 arc-shaped tiles 5-1 in total. The central angle of each arc-shaped tile 5-1 is 30º, and each tile is spaced 10º apart, and they are circumferentially evenly distributed inside the corrugated tube body.

[0019] A buffer ring 9 is arranged inside the corrugated convex circle 10-1 of the corrugated tube 10. A buffer ring 9 is arranged inside the corrugated convex circle 10-1 of the corrugated tube 10. The buffer ring 9 is a foamed honeycomb structure, and it is a polyurethane material with elasticity. On the one hand, the corrosion-resistant honeycomb buffer ring 9 slows down the vibration of the corrugated tube 10 and reduces the vibration corrosion of the corrugated tube 10; on the other hand, it blocks the high-temperature corrosion effect of the high-temperature and high-sulfur gas 6 inside the tube on the corrugated tube 10, and prolongs the service life of the stainless steel corrugated tube 10. The close contact between the buffer ring 9 and the inner wall of the corrugated tube 10 isolates the contact between the most easily corroded position of the corrugated tube 10 and the high-temperature and high-sulfur gas. The position where the corrugated tube 10 is easily corroded is generally at the lowest point of the corrugated tube. After the high-temperature and high-sulfur gas 6 diffuses into the corrugated tube 10 from the gap of the draft tube 5, the air flow inside the corrugated tube 10 is almost in a static state. The static high-temperature and high-sulfur gas 6 will produce some condensate, and the condensate accumulates at the lowest point of the corrugated tube, and this position will soon be corroded through and leaked. The surface of the buffer ring 9 in contact with the corrugated tube 10 is a curved surface that completely fits the corrugated convex circle, and the inside is a foamed honeycomb structure, which effectively isolates the direct contact between the corrosive substance and the inner wall of the corrugated tube 10, thereby reducing the accumulation of harmful substances at the lowest point and achieving the purpose of reducing corrosion.

[0020] The draft tube 5 is arranged with pressing plates 8 corresponding to each corrugated convex circle 10-1 and buffer ring 9 along the circumferential outer side. Combining with the embodiment shown in the attached Figure 3 of the present invention, 3 rows of pressing plates 8 are axially arranged on each arc-shaped tile 5-1, and 2 pieces in each row (corresponding to two corrugated convex circles). The pressing plate 8 is used to strengthen the radial pressing force of the buffer ring 9 on the corrugated tube and relieve the vibration and corrosion suffered by the stainless steel corrugated tube 10. Because of the material quality characteristics of the buffer ring 9 itself, it does not have the ability to adsorb each other with the corrugated tube 10, and it has a certain weight. Without continuous pressure fixation, the buffer ring 9 will separate from the corrugated convex circle 10-1 due to the frequent oscillation of the corrugated tube 10 during use and cannot ensure close contact. The above structure of the pressing plate 8 can effectively continuously apply radial pressure to the buffer ring 9, so that the buffer ring 9 remains pressed against the corrugated convex circle 10-1. The specific principle is that the high-temperature and high-sulfur gas 6 passes through the draft tube 5. During the gas flow process, the disturbance of the fluid causes the arc-shaped tile 5-1 to expand outward due to the pressure inside the draft tube 5, and when expanding, it pushes the pressing plate 8 to press the buffer ring 9.

[0021] Further, to ensure that the pressing plate 8 exerts an effective pressure on the buffer ring 9, the flow guide cylinder 5 is provided with a necking structure. The gas enters the necking position from the inlet and flows from the necking position to the outlet end. The necking structure converts the circumferential lift force inside the arc-shaped tile 5-1 into a radial pressure, causing the arc-shaped tile 5-1 to expand outward. The radial force received by the arc-shaped tile 5-1 increases, and the disturbance amplitude increases, so that the pressing plate 8 increases the pressing force on the buffer ring 9.

[0022] The pressing plate 8 is in surface contact with the buffer ring 9. The pressing plate 8 is a whole-piece T shape or a flat plate structure. If a flat plate structure is adopted, it is integrally welded to the arc-shaped tile through a support rod.

[0023] When the high-temperature and high-sulfur gas 6 is sucked into the inlet of the bellows compensator due to the negative pressure of the fan, since the flow channel from the inlet to the outlet of the flow guide cylinder 5 first narrows and then gradually increases, a lift force from the inside to the outside is generated along the radial direction of the cylinder body of the flow guide cylinder 5. A radial gap 4 is reserved at the outlet end of the flow guide cylinder 5. On the one hand, it reserves an axial expansion amount for the bellows 10, and on the other hand, it reserves a radial force for each arc-shaped tile 5-1 of the flow guide cylinder 5.

[0024] Under the existing operating conditions, through the streamlined flow guide cylinder 5 structure, the maximum radial force can be obtained in the waste flue gas transmission. The position of the maximum equivalent stress of the flow guide cylinder 5 appears at the combination position of the flow guide cylinder 5 and the pressing plate 8, reaching 5*10 4 Pa. The pressing plate 8 is uniformly stressed, and the equivalent stress is about 1*10 4 Pa. The waste flue gas flow velocity of 6.2 m / s generates a radial thrust of about 240 N on each piece of the inner flow guide cylinder 5. At the maximum radius position of each ring of the bellows 10, the buffer ring 9 is radially fixed by 3*10 pressing plates (the radial force of a single piece is 60 N), and the buffer ring 9 is tightly pressed against the corrugated convex circle 10-1 position of the bellows 10, effectively protecting the original most corroded position of the bellows.

[0025] The radial lift force of the flow guide cylinder 5 along the radial direction of the cylinder body is transmitted to the buffer ring 9 by the pressing plate 8, exerting a pressing effect on the buffer ring 9 to make it tightly adhere to the easily corroded position of the stainless steel bellows 10. The buffer ring 9 can effectively buffer and decompose the vibration transmitted from the flow guide pipe to the bellows caused by the high-speed flow of the high-temperature and high-sulfur gas 6.

[0026] The above are only the preferred and feasible embodiments of the present invention, and do not limit the scope of rights of the present invention accordingly. All equivalent changes made by using the content of the specification and drawings of the present invention are included within the scope of rights of the present invention.

Claims

1. A corrosion-resistant corrugated compensator for a fan, comprising a corrugated pipe, the inlet end and the outlet end of the corrugated pipe are respectively fixedly connected to the air duct cylinder body, and a flange for connecting the main pipeline of the fan is fixedly connected to the outer side of the air duct cylinder body, and it is characterized in that: A buffer ring with elasticity is provided inside the corrugated convex circle of the corrugated pipe; a flow guide cylinder is provided inside the corrugated pipe. The diameter of the air duct cylinder body fixedly connected to the inlet end of the flow guide cylinder is matched with the inlet end of the corrugated pipe and is sealed and welded. There is a radial gap between the outlet end of the flow guide cylinder and the air duct cylinder body fixedly connected to the outlet end of the corrugated pipe; the flow guide cylinder is set as a necking structure, and the necking position is adjacent to its inlet end; the flow guide cylinder is assembled by a number of arc-shaped tiles, and pressing plates are arranged on the outer walls of the arc-shaped tiles forming the flow guide cylinder, and the pressing plates are in surface contact with the buffer ring.

2. The corrosion-resistant corrugated compensator for a fan according to claim 1, wherein: The buffer ring is a foamed honeycomb structure made of polyurethane material.

3. The corrosion-resistant corrugated compensator for a fan according to claim 1, characterized in that: The flow guide cylinder is composed of a total of 9 arc-shaped tiles. The central angle of each arc-shaped tile is 30º, and each piece is spaced 10º, and is circumferentially evenly distributed inside the corrugated pipe cylinder body.

4. The corrosion-resistant corrugated compensator for a fan according to claim 1, wherein: The pressing plates are axially arranged in 3 columns on each arc-shaped tile, with 2 pieces in each column, and each pressing plate corresponds to the corrugated convex circle position.

5. The corrosion-resistant corrugated compensator for a fan according to claim 1, characterized in that: The pressing plate adopts a flat plate structure and is integrally welded with the arc-shaped tile through a support rod.

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