Metal bellows compensator for isolating high-temperature sulfur-containing flue gas

Abstract

The utility model relates to a metal bellows compensator for isolating high-temperature sulfur-containing flue gas, which comprises a compensator main body, two flanges, a purging assembly, a guide cylinder and a monitoring assembly, the two flanges are symmetrically arranged at the front end and the rear end of the compensator main body and used for connecting the metal bellows compensator, the purging assembly is arranged on the compensator main body, and the guide cylinder is arranged on the compensator main body. The flange is arranged on the compensator main body and used for nitrogen purging of the metal bellows compensator, the guide cylinder is arranged on the flange and used for guiding nitrogen, and the monitoring assembly is arranged on the compensator main body and used for monitoring the concentration of SO3 in the metal bellows compensator. And through mutual cooperation of the purging assembly, the flow guide cylinder and the monitoring assembly, the protection performance of the metal corrugated pipe compensator is improved.

Description

Technical Field

[0001] The utility model relates to a metal bellows compensator for isolating high-temperature sulfur-containing flue gas. Background Art

[0002] Metal bellows compensators are used in systems with large thermal stresses. They should not only be able to eliminate mechanical displacement, absorb vibration, and reduce noise, but also provide compensation in a hot and cold alternating environment in a timely manner. In the petroleum and chemical industries, metal bellows compensators are often used as a flexible component in flue gas transmission pipelines. As the quality of crude oil processed in the petrochemical industry tends to deteriorate, the increase in sulfur content in crude oil leads to a large amount of sulfides in the flue gas, making the flue gas highly corrosive. Metal bellows compensators, being mostly thin-walled and having a corrugated structure with a groove shape, are prone to the accumulation of high-temperature sulfur-containing flue gas on the inner wall of the bellows. Moreover, during the shutdown and cooling of the equipment, the high-temperature sulfur-containing flue gas accumulated on the inner wall of the bellows cannot be discharged normally. When the temperature difference of the high-temperature sulfur-containing flue gas changes, the corrosive medium in the flue gas will condense and dew, and as the corrosion products attached to the corrugated inner wall evaporate and concentrate continuously, the corrosiveness gradually increases, eventually leading to perforation and damage of the equipment. Therefore, the metal bellows compensators in the prior art still have the following deficiencies: 1. Metal bellows compensators are not resistant to corrosive flue gas. In particular, flue gas is likely to accumulate inside the bellows. When the outer wall temperature drops, acidic media will condense on the inner wall, causing corrosion and perforation; 2. Metal bellows compensators have a high failure rate in a high-temperature corrosive medium environment. Especially, the high-temperature flue gas accumulated in the expansion joint cavity after shutdown cannot be discharged, forming polythionic acid corrosion. Under the combined action of tensile stress and corrosion, damage is more likely to occur. Content of the Utility Model

[0003] The purpose of this part is to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Simplifications or omissions may be made in this part, as well as in the abstract and the title of the utility model of this application, to avoid obscuring the purpose of this part, the abstract, and the title of the utility model. However, such simplifications or omissions shall not be used to limit the scope of the utility model.

[0004] The technical problem to be solved by the utility model is how to improve the protection performance of the metal bellows compensator.

[0005] To solve the above technical problems, the present utility model provides the following technical solutions: A metal bellows compensator for isolating high-temperature sulfur-containing flue gas, comprising a compensator body, two flanges, a purging assembly, a flow guide cylinder, and a monitoring assembly. The two flanges are symmetrically arranged at the front and rear ends of the compensator body for connecting the metal bellows compensator. The purging assembly is arranged on the compensator body for purging nitrogen of the metal bellows compensator. The flow guide cylinder is arranged on the flange for guiding the flow of nitrogen. The monitoring assembly is arranged on the compensator body for monitoring the concentration of SO3 inside the metal bellows compensator.

[0006] As a preferred embodiment of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas of the present utility model, wherein: The purging assembly includes eight gas pipes, a connecting pipe, a connecting tube, a purging pipe, and a purging head. The eight gas pipes are evenly distributed on the outer wall of the compensator body. The connecting pipe is looped on the top of the eight gas pipes. The bottoms of the eight gas pipes penetrate the inner wall of the compensator body. The connecting tube is arranged at the bottom of the gas pipe. The purging pipe is arranged on the connecting tube. The purging head is arranged on the purging pipe to facilitate purging nitrogen into the interior of the metal bellows compensator.

[0007] As a preferred embodiment of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas of the present utility model, wherein: The purging assembly further includes a flow control valve and a nitrogen heater. The flow control valve is arranged on the connecting pipe to facilitate controlling the flow rate of nitrogen in the connecting pipe. The nitrogen heater is arranged on the flow control valve to facilitate heating the nitrogen entering the connecting pipe and reducing the temperature difference between the inside and outside of the metal bellows compensator.

[0008] As a preferred embodiment of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas of the present utility model, wherein: The monitoring assembly includes a flue gas sampling pipe and a flue gas analyzer. The flue gas sampling pipe is arranged on the compensator body. The bottom of the flue gas sampling pipe extends into the interior of the compensator body to collect the flue gas inside the metal bellows compensator. The flue gas analyzer is arranged on the top of the flue gas sampling pipe to analyze the collected flue gas to monitor the concentration of SO3 in the flue gas and also to monitor the dew point temperature of the flue gas. The flue gas analyzer is electrically connected to the flow control valve and the nitrogen heater respectively to control the temperature and purging amount of nitrogen through the monitoring results of the flue gas in the cavity, achieving the purpose of energy conservation.

[0009] As a preferred embodiment of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas of the present utility model, the following is provided: An insulating lining is filled between the inner wall of the flow guide cylinder and the compensator body, protecting the external metal from damage caused by high-temperature radiation, reducing the pressure drop of the isolated nitrogen, and keeping the cavity inside the metal bellows compensator at a slightly positive pressure, which can save the use of nitrogen to the greatest extent and prevent the intrusion of corrosive flue gas.

[0010] As a preferred embodiment of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas of the present utility model, the following is provided: The purging head is located at the central position inside the wave crest of the compensator body, and purging holes are symmetrically arranged on both sides of the purging head to achieve dead-angle-free purging and obtain the best purging effect.

[0011] Beneficial effects:

[0012] 1. By the mutual cooperation among the purging assembly, the flow guide cylinder and the monitoring assembly, the protection performance of the metal bellows compensator is improved;

[0013] 2. By filling the inner cavity of the bellows with nitrogen through the purging assembly, high-temperature sulfur-containing flue gas is isolated throughout the process, solving the problem of the accumulation of high-temperature sulfur-containing flue gas during start-up and shutdown, shortening the replacement cycle of the compensator, reducing the production cost and the losses caused by production stoppage, and having important economic benefits. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0015] Figure 1 It is a schematic diagram of the overall structure of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas.

[0016] Figure 2 It is a partial cross-sectional view of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas.

[0017] Figure 3 It is a partial cross-sectional view of the metal bellows compensator for isolating high-temperature sulfur-containing flue gas from another angle.

[0018] Figure 4 For the metal bellows compensator for isolating high-temperature sulfur-containing flue gas Figure 3 Enlarged view at position A.

[0019] In the figure: 1. Compensator body; 2. Flange; 3. Purge assembly; 31. Air pipe; 32. Connecting pipe; 33. Connecting tube; 34. Purge pipe; 35. Purge head; 36. Flow control valve; 37. Nitrogen heater; 4. Flow guide cylinder; 5. Monitoring assembly; 51. Flue gas sampling pipe; 52. Flue gas analyzer; 6. Heat insulation lining; 7. Purge hole. Detailed implementation manners

[0020] To make the above objects, features and advantages of the present utility model more obvious and understandable, the following detailed description of the specific implementation manners of the present utility model will be given with reference to the accompanying drawings of the specification.

[0021] In the following description, many specific details are set forth to fully understand the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Those skilled in the art can make similar promotions without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0022] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that can be included in at least one implementation manner of the present utility model. The "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0023] Embodiment

[0024] Referring to Figures 1 to 4 , this embodiment provides a metal bellows compensator for isolating high-temperature sulfur-containing flue gas, including a compensator body 1, two flanges 2, a purge assembly 3, a flow guide cylinder 4 and a monitoring assembly 5. The two flanges 2 are symmetrically arranged at the front and rear ends of the compensator body 1 for connecting the metal bellows compensator. The purge assembly 3 is arranged on the compensator body 1 for purging nitrogen of the metal bellows compensator. The flow guide cylinder 4 is arranged on the flange 2 for guiding nitrogen. The monitoring assembly 5 is arranged on the compensator body 1 for monitoring the concentration of SO3 inside the metal bellows compensator.

[0025] The compensator body 1 is integrally cylindrical in structure and serves as the installation foundation of the device. Two flanges 2 are symmetrically installed at the front and rear ends of the compensator body 1. The compensator body 1 can be connected to the conveying pipeline through the two flanges 2. A purging assembly 3 is installed on the compensator body 1. Through the purging assembly 3, nitrogen can be filled into the internal cavity of the entire metal bellows compensator, so as to achieve the purpose of isolating high-temperature sulfur-containing flue gas, thereby improving the protection performance of the metal bellows compensator. Flow guide cylinders 4 are installed on both flanges 2. Through the flow guide cylinders 4, a certain guiding effect can be achieved on the nitrogen entering the metal bellows. And the two flow guide cylinders 4 are staggered from each other, so that a notch is formed at the intersecting part of the two flow guide cylinders 4, facilitating the entry of nitrogen into the internal part of the metal bellows compensator, thus better achieving the effect of isolating high-temperature sulfur-containing flue gas. A monitoring assembly 5 is also installed on the outer surface of the compensator body 1. Through the monitoring assembly 5, the concentration of SO3 inside the metal bellows compensator can be monitored in real time, and at the same time, the dew point temperature of the flue gas can also be monitored.

[0026] Specifically, the purging assembly 3 includes eight gas pipes 31, a connecting pipe 32, a connecting tube 33, a purging pipe 34 and a purging head 35. The eight gas pipes 31 are evenly distributed on the outer wall of the compensator body 1. The connecting pipe 32 is arranged in a ring at the top of the eight gas pipes 31. The bottoms of the eight gas pipes 31 penetrate the inner wall of the compensator body 1. The connecting tube 33 is arranged at the bottom of the gas pipes 31. The purging pipe 34 is arranged on the connecting tube 33. The purging head 35 is arranged on the purging pipe 34.

[0027] The purging assembly 3 is mainly composed of eight gas pipes 31, a connecting pipe 32, a connecting tube 33, a purging pipe 34 and a purging head 35. Eight gas pipes 31 are evenly distributed on the outer wall of the compensator body 1 near the flange 2. A ring-shaped connecting pipe 32 is installed at the top of the eight gas pipes 31. The connecting pipe 32 is interconnected with the eight gas pipes 31, so as to convey external nitrogen into the eight gas pipes 31 through the connecting pipe 32. The bottoms of the eight gas pipes 31 all penetrate the inner wall of the compensator body 1 and extend into the internal cavity of the compensator body 1. Connecting tubes 33 are horizontally installed at the bottoms of the eight gas pipes 31. Purging pipes 34 are vertically installed on the connecting tubes 33. Purging heads 35 are installed on the purging pipes 34. After the external nitrogen enters the connecting pipe 32, it enters the corresponding connecting tubes 33 through the eight gas pipes 31 respectively from the connecting pipe 32, enters the purging pipes 34 through the connecting tubes 33, and finally is blown into the internal cavity of the metal bellows compensator by the purging heads 35 on the purging pipes 34, so as to realize purging nitrogen into the metal bellows compensator, avoid the formation of polythionic acid corrosion, and thus improve the protection performance of the metal bellows compensator.

[0028] Further, the purging assembly 3 further includes a flow control valve 36 and a nitrogen heater 37. The flow control valve 36 is disposed on the connecting pipe 32, and the nitrogen heater 37 is disposed on the flow control valve 36.

[0029] In this embodiment, a flow control valve 36 is installed at the air inlet of the connecting pipe 32. The flow control valve 36 can control the flow rate of nitrogen entering the connecting pipe 32. A nitrogen heater 37 is installed at the air inlet of the flow control valve 36. The nitrogen heater 37 can heat the nitrogen entering the connecting pipe 32, reduce the temperature difference between the inner and outer surfaces of the metal bellows compensator, and thus avoid the condensation of acidic medium on the inner wall of the metal bellows compensator, resulting in corrosion and perforation.

[0030] Specifically, the monitoring assembly 5 includes a flue gas sampling pipe 51 and a flue gas analyzer 52. The flue gas sampling pipe 51 is disposed on the compensator body 1. The bottom of the flue gas sampling pipe 51 extends into the interior of the compensator body 1. The flue gas analyzer 52 is disposed on the top of the flue gas sampling pipe 51. The flue gas analyzer 52 is electrically connected to the flow control valve 36 and the nitrogen heater 37 respectively.

[0031] The monitoring assembly 5 is mainly composed of a flue gas sampling pipe 51 and a flue gas analyzer 52. A flue gas sampling pipe 51 is installed at one end of the outer surface of the compensator body 1 away from the gas pipe 31. The bottom of the flue gas sampling pipe 51 extends into the interior of the compensator body 1 to collect the flue gas inside the metal bellows compensator. A flue gas analyzer 52 is installed on the top of the flue gas sampling pipe 51. The flue gas analyzer 52 can analyze the collected flue gas to monitor the concentration of SO3 in the flue gas and also monitor the dew point temperature of the flue gas. At the same time, the flue gas analyzer 52 is also electrically connected to the flow control valve 36 and the nitrogen heater 37 respectively, so as to control the temperature and purging volume of the nitrogen entering the metal bellows compensator according to the monitoring results of the flue gas in the cavity, so as to achieve the energy-saving effect.

[0032] Further, a heat insulation lining 6 is filled between the guide cylinder 4 and the inner wall of the compensator body 1.

[0033] In this embodiment, by filling a heat insulation lining 6 between the guide cylinder 4 and the inner wall of the compensator body 1, the temperature difference between the inner and outer surfaces of the metal bellows compensator is further reduced, avoiding the condensation of acidic medium on the inner wall of the metal bellows compensator, resulting in corrosion and perforation. At the same time, the heat insulation lining 6 also protects the external metal from being damaged by high-temperature radiation, reduces the pressure drop of the isolated nitrogen, and keeps the cavity in the metal bellows compensator at a slightly positive pressure, which can save the use of nitrogen to the greatest extent and avoid the intrusion of corrosive flue gas.

[0034] Further, the purging head 35 is located at the central position within the wave crest of the compensator body 1, and purging holes 7 are symmetrically formed on both sides of the purging head 35.

[0035] In this embodiment, the purging head 35 is installed at the central position of the peak cavity of the compensator body 1, and purging holes 7 are symmetrically formed on both sides of the purging head 35, so as to achieve dead - angle - free purging inside the metal bellows compensator, thereby achieving the best purging effect.

[0036] During use, external nitrogen is first heated by the nitrogen heater 37, then enters the connecting pipe 32 through the flow control valve 36. Then, the nitrogen entering the connecting pipe 32 enters eight gas pipes 31 respectively, and enters the connecting pipe 33 through the gas pipes 31, enters the purging pipe 34 from the connecting pipe 33, and is then blown into the cavity inside the metal bellows compensator through the purging head 35 on the purging pipe 34. The nitrogen fills the entire cavity, and finally penetrates the heat - insulating lining 6, and enters the flow channel inside the metal bellows compensator through the staggered notches on the flow - guiding cylinder 4, so as to achieve the purpose of purging and isolating high - temperature sulfur - containing flue gas, avoid the accumulation of corrosive gases, and thus improve the protection performance of the metal bellows compensator. During this process, the flue - gas sampling pipe 51 on the compensator body 1 collects the flue gas inside the metal bellows compensator, and analyzes the collected flue gas through the flue - gas analyzer 52 to monitor the concentration of SO3 in the flue gas, and at the same time monitor the dew - point temperature of the flue gas, and transmit the signal to the flow control valve 36 and the nitrogen heater 37, that is, control the temperature and purging volume of the nitrogen entering the inside of the metal bellows compensator through the monitoring results to achieve energy - saving effects.

[0037] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A metal bellows compensator for isolating high-temperature sulfur-containing flue gas, characterized by: The invention comprises a compensator body (1), two flanges (2), a purge assembly (3), a guide tube (4) and a monitoring assembly (5), wherein the two flanges (2) are symmetrically arranged at the front and rear ends of the compensator body (1) for connecting the metal bellows compensator, the purge assembly (3) is arranged on the compensator body (1) for nitrogen purge of the metal bellows compensator, the guide tube (4) is arranged on the flanges (2) for nitrogen diversion, and the monitoring assembly (5) is arranged on the compensator body (1) for monitoring the concentration of SO3 inside the metal bellows compensator.

2. The metal bellows compensator for isolating high-temperature sulfur-containing flue gas according to claim 1, characterized in that: The purge assembly (3) comprises eight air pipes (31), a connecting pipe (32), a connecting pipe (33), a purge pipe (34) and a purge head (35); the eight air pipes (31) are evenly distributed on the outer wall of the compensator body (1); the connecting pipe (32) is arranged around the tops of the eight air pipes (31); the bottoms of the eight air pipes (31) penetrate the inner wall of the compensator body (1); the connecting pipe (33) is arranged at the bottom of the air pipe (31); the purge pipe (34) is arranged on the connecting pipe (33); and the purge head (35) is arranged on the purge pipe (34).

3. The metal bellows compensator for isolating high-temperature sulfur-containing flue gas according to claim 2, characterized in that: The purge assembly (3) further comprises a flow control valve (36) and a nitrogen heater (37); the flow control valve (36) is arranged on the connecting pipe (32); and the nitrogen heater (37) is arranged on the flow control valve (36).

4. The metal bellows compensator for isolating high-temperature sulfur-containing flue gas according to claim 3, characterized in that: The monitoring component (5) comprises a flue gas sampling tube (51) and a flue gas analyzer (52); the flue gas sampling tube (51) is arranged on the compensator body (1); the bottom of the flue gas sampling tube (51) extends to the interior of the compensator body (1); the flue gas analyzer (52) is arranged on the top of the flue gas sampling tube (51); the flue gas analyzer (52) is electrically connected to the flow control valve (36) and the nitrogen heater (37), respectively.

5. The metal bellows compensator for isolating high-temperature sulfur-containing flue gas according to claim 1, characterized in that: A heat insulating lining (6) is filled between the guide tube (4) and the inner wall of the compensator body (1).

6. The metal bellows compensator for isolating high-temperature sulfur-containing flue gas according to claim 2, characterized in that: The purge head (35) is located at the center of the wave crest of the compensator body (1), and purge holes (7) are symmetrically provided on two side surfaces of the purge head (35).

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