Air pre-heater with cleaning function for boiler

Abstract

The utility model discloses a boiler air pre-heater with a cleaning function, which comprises an air pre-heater body, the air pre-heater body comprises a tube box, a smoke tube bundle and a scraper device are arranged in a heat exchange cavity of the tube box, and the scraper device is used for scraping dirt on the outer side wall of each smoke tube in the smoke tube bundle; a smoke inlet pipe and a smoke exhaust pipe are arranged at the two ends of the pipe box respectively, the axis of a smoke inlet of the smoke inlet pipe and the axis of a smoke outlet are arranged in an angle mode, an extending pipe extending in the axial direction is arranged on the side, opposite to the smoke outlet, of the smoke inlet pipe and communicated with the smoke inlet pipe, and a scraping and washing device is arranged in the extending pipe. The scraping and washing device is used for scraping dirt on the inner side wall of each smoke tube in the smoke tube bundle; a valve control assembly is arranged at the joint of the extension pipe and the smoke inlet pipe. According to the smoke tube bundle cleaning device, dirt accumulated on the inner side wall and the outer side wall of each smoke tube in the smoke tube bundle is scraped away in a scraping and washing mode under the condition that disassembly is not needed, and therefore cleaning of the smoke tube bundle is achieved, heat exchange efficiency is improved, cost is reduced, and the service life is greatly prolonged.

Description

Technical Field

[0001] This utility model relates to the field of air preheater technology, and in particular to an air preheater for boilers with a cleaning function. Background Technology

[0002] The air preheater recovers heat from the flue gas discharged from the boiler and transfers it to the air before it enters the boiler, thereby improving the boiler's heat exchange performance and reducing energy consumption. The flue gas discharged from the boiler enters the flue tube bundle directly, while the flue gas introduced enters the heat exchange chamber between the flue tube bundles. As a result, after a long period of use, dirt in the flue gas will accumulate on the inner and outer walls of the flue tubes, thus affecting the heat exchange efficiency.

[0003] To address the aforementioned issues, existing technologies involve directly replacing the air preheater with a new one or disassembling and cleaning it for continued use. However, this process is cumbersome and complex, has a short service life, and is costly, thus failing to meet current market demands.

[0004] Therefore, it is necessary to develop a boiler air preheater with a cleaning function that can remove the dirt accumulated on the inner and outer walls of each flue tube in the flue tube bundle by scraping without disassembly, thereby cleaning the flue tube bundle, improving heat exchange efficiency, reducing costs, and greatly extending service life. Utility Model Content

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

[0006] A boiler air preheater with cleaning function includes an air preheater body, characterized in that the air preheater body includes a tube box, and a flue tube bundle and a scraper device are arranged in the heat exchange chamber of the tube box, the scraper device being used to scrape off the dirt on the outer wall of each flue tube in the flue tube bundle.

[0007] The inlet and outlet ends of the pipe box are respectively provided with an inlet pipe and an outlet pipe. The inlet axis of the inlet pipe is set at an angle to the outlet axis. An axially extended extension pipe is provided on the side of the inlet pipe opposite to the outlet. The extension pipe is connected to the inlet pipe. A scraping device is provided inside the extension pipe. The scraping device is used to scrape off the dirt on the inner wall of each pipe in the pipe bundle.

[0008] A valve control assembly is provided at the connection between the extension pipe and the smoke inlet pipe. The valve control assembly is used to control the opening and closing of the extension pipe and the smoke inlet pipe.

[0009] Preferably, a front cover and a rear cover are respectively provided on the inlet and outlet ends of the tube box, and a heat exchange chamber is formed between the tube box and the front and rear covers.

[0010] The tube box is also provided with a partition that divides the heat exchange chamber into a first heat exchange chamber and a second heat exchange chamber. The upper side of the tube box is provided with an air inlet and an exhaust outlet that communicate with the first heat exchange chamber and the second heat exchange chamber respectively. The lower side of the tube box is provided with a communication port that connects the first heat exchange chamber and the second heat exchange chamber. An air communication cover is provided on the communication port.

[0011] The scraper device can scrape and wash the flue tube bundles located in the first heat exchange chamber and the second heat exchange chamber.

[0012] Preferably, the scraper device includes scrapers disposed opposite to each other in the first heat exchange chamber and the second heat exchange chamber, and the scraper is provided with scraping holes corresponding one-to-one with the flue tube bundle, and the scraping holes are clearance-fitted with the flue tubes in the flue tube bundle;

[0013] The scraper device further includes at least two scraper driving assemblies, which are used to drive the two scrapers symmetrically toward or away from the partition.

[0014] Preferably, the scraper drive assembly includes a first screw and a first driver. The first screw includes a limiting section, which is rotatably connected to the partition. A first threaded section and a second threaded section are respectively provided on both sides of the limiting section. The first threaded section and the second threaded section are respectively located in the first heat exchange chamber and the second heat exchange chamber.

[0015] Both the first and second threaded sections are provided with threads of the same lead but opposite directions of rotation; the first and second threaded sections are respectively threadedly connected to two scrapers; one end of the first screw is rotatably connected to the front end cover, and the other end rotatably passes through the rear end cover and is connected to the drive end of the first driver.

[0016] Preferably, the scraping device includes a plurality of tubes coaxial with and corresponding one-to-one with the flue tubes of the flue tube bundle. One end of each tube is provided with an annular scraper, and the other end is provided with a connecting plate connected to the plurality of tubes. The annular scraper is in clearance fit with the inside of the flue tube.

[0017] The scraping device also includes a tube drive assembly that drives several tubes to approach or move away from the flue tube bundle.

[0018] Preferably, the connecting plate has an air collecting chamber that communicates with the pipe body, the air collecting chamber is connected to an external compressed air source, and the annular scraper has a through hole that communicates with the inside of the pipe body.

[0019] Preferably, the tube drive assembly includes a second screw rotatably connected to the inner wall of the extension tube, and the second screw is threadedly connected to the connecting portion of the connecting plate;

[0020] The tube drive assembly also includes a second driver whose drive end is connected to the second screw, and the second driver is located on the side of the connecting plate away from the tube.

[0021] Preferably, the valve control assembly includes a sealing plate and a third actuator. The sealing plate is disposed at the connection between the extension pipe and the smoke inlet pipe. One end of the sealing plate is provided with two rotating shafts that are rotatably connected to the extension pipe or the smoke inlet pipe. One of the rotating shafts passes through the extension pipe or the smoke inlet pipe and is connected to the external third actuator.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] This invention cleans the flue tube bundle by scraping away the dirt accumulated on the inner and outer walls of each flue tube without disassembly, thereby improving heat exchange efficiency, reducing costs, and greatly extending service life. Attached Figure Description

[0024] Figure 1 This is a top view cross-sectional structural diagram of the present invention;

[0025] Figure 2 This is a schematic diagram of the front cross-sectional structure of this utility model;

[0026] Figure 3 for Figure 1 Enlarged view of a portion of point A in the middle;

[0027] Figure 4 for Figure 1 Enlarged view of a portion of point B in the middle;

[0028] Figure 5 for Figure 1 Enlarged view of a portion of point C in the middle;

[0029] The components include: pipe box 1, flue pipe bundle 2, valve control assembly 3, front end cover 4, rear end cover 5, partition 6, air communication cover 7, scraper 8, scraper drive assembly 9, pipe body 10, annular scraper 11, connecting plate 12, pipe body drive assembly 13, sealing plate 31, third driver 32, first screw 91, first driver 92, exhaust pipe 20, extension pipe 30, inlet pipe 40, through hole 111, gas collection chamber 121, second screw 131, second driver 132, first heat exchange chamber 1a, second heat exchange chamber 2a, air inlet 1b, exhaust port 2b, scraper hole 8a, limiting section 91a, first threaded section 91b, and second threaded section 91c. Detailed Implementation

[0030] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0031] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," "up," "down," "front," "back," and similar expressions used in this document are for illustrative purposes only.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0033] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments:

[0034] like Figure 1-5 As shown, a boiler air preheater with cleaning function includes an air preheater body, the air preheater body includes a tube box 1, the heat exchange chamber of the tube box 1 is provided with a flue tube bundle 2 and a scraper device, the scraper device is used to scrape off the dirt on the outer wall of each flue tube in the flue tube bundle 2.

[0035] The inlet end and outlet end of the pipe box 1 are respectively provided with an inlet pipe 40 and an outlet pipe 20. The inlet axis of the inlet pipe 40 is set at an angle to the outlet axis. An axially extended extension pipe 30 is provided on the side of the inlet pipe 40 opposite to the outlet. The extension pipe 30 is connected to the inlet pipe 40. A scraping device is provided inside the extension pipe 30. The scraping device is used to scrape off the dirt on the inner wall of each pipe in the pipe bundle 2.

[0036] A valve control component 3 is provided at the connection between the extension pipe 30 and the smoke inlet pipe 40. The valve control component 3 is used to control the opening and closing of the extension pipe 30 and the smoke inlet pipe.

[0037] In this embodiment, during normal operation, the valve control component 3 is opened so that the extension pipe 30 is not connected to the flue gas inlet pipe 40. The flue gas generated by the boiler enters the flue gas tube bundle 2 through the flue gas inlet pipe 40 and is discharged from the exhaust pipe 20. During the process, under the action of the FGR pipe and the blower, air and part of the flue gas are introduced into the air preheater, thereby generating a high-temperature mixed gas that is directed to the air before entering the boiler, thereby improving the heat exchange performance of the boiler.

[0038] When cleaning is required, the valve control assembly 3 closes to connect the extension pipe 30 with the flue gas inlet pipe 40. First, the scraper device is activated to scrape the outer wall of each flue gas tube in the flue gas tube bundle 2 back and forth. After completion, the scraping device is activated and extends into each flue gas tube in the flue gas tube bundle 2 to scrape and / or blow clean the inner wall of the flue gas tube until completion. Thus, without disassembly, the dirt accumulated on the inner and outer walls of each flue gas tube in the flue gas tube bundle 2 is removed by scraping, thereby cleaning the flue gas tube bundle 2, improving heat exchange efficiency, reducing costs, and greatly extending service life.

[0039] In this embodiment, when the flue tube bundle 2 is being cleaned, the dirt that has fallen off is discharged from the flue tube by the reverse rotation of the external blower.

[0040] Furthermore, such as Figure 1 , 2 As shown in Figure 5, a front cover 4 and a rear cover 5 are respectively provided on the inlet and outlet ends of the tube box 1, and a heat exchange chamber is formed between the tube box 1, the front cover 4, and the rear cover 5.

[0041] The tube box 1 is also provided with a partition 6 that divides the heat exchange chamber into a first heat exchange chamber 1a and a second heat exchange chamber 2a. The upper side of the tube box 1 is provided with an air inlet 1b and an exhaust outlet 2b that communicate with the first heat exchange chamber 1a and the second heat exchange chamber 2a respectively. The lower side of the tube box 1 is provided with a communication port that connects the first heat exchange chamber 1a and the second heat exchange chamber 2a. An air communication cover 7 is provided on the communication port.

[0042] The scraper device can scrape and wash the flue tube bundle 2 located in the first heat exchange chamber 1a and the second heat exchange chamber 2a.

[0043] Flue gas flow: The flue gas generated in the boiler furnace enters the air preheater through the inlet pipe 40, passes through the flue tube bundle 2, and is discharged through the exhaust pipe 20. Then, part of the flue gas is discharged directly from the chimney, and the other part of the flue gas, under the action of the blower, is mixed with air through the FGR pipe and then enters the first heat exchange chamber 1a and the second heat exchange chamber 2a in sequence to guide the air before entering the boiler, thereby improving the heat exchange performance of the boiler.

[0044] Furthermore, such as Figure 1 , 2As shown in Figure 5, in order to achieve synchronous driving of the two scrapers 8 and improve the scraping efficiency and effect of the outer wall of the flue tube bundle 2, the scraper device includes scrapers 8 disposed opposite to each other in the first heat exchange chamber 1a and the second heat exchange chamber 2a. The scrapers 8 are provided with scraping holes 8a corresponding one-to-one with the flue tube bundle 2, and the scraping holes 8a are fitted with the flue tubes in the flue tube bundle 2 with a gap.

[0045] The scraper device further includes at least two scraper drive assemblies 9, which are used to drive the two scrapers 8 symmetrically to move closer to or further away from the partition 6.

[0046] Furthermore, such as Figure 1 , 2 As shown in Figure 5, the scraper drive assembly 9 includes a first screw 91 and a first driver 92. The first screw 91 includes a limiting section 91a, which is rotatably connected to the partition 6. A first threaded section 91b and a second threaded section 91c are respectively provided on both sides of the limiting section 91a. The first threaded section 91b and the second threaded section 91c are located in the first heat exchange chamber 1a and the second heat exchange chamber 2a, respectively.

[0047] The first threaded section 91b and the second threaded section 91c are both provided with threads of the same lead but opposite direction of rotation; the first threaded section 91b and the second threaded section 91c are respectively threadedly connected to the two scrapers 8; one end of the first screw 91 is rotatably connected to the front end cover 4, and the other end is rotatably connected to the drive end of the first driver 92 after passing through the rear end cover 5.

[0048] In this embodiment, by means of a threaded connection with opposite directions of rotation, the first screw 91 drives the two scrapers 8 to move symmetrically closer to or further away from the partition 6 when it rotates, thereby achieving the scraping and washing of the outer wall of the flue tube bundle 2 of the first heat exchange chamber 1a and the second heat exchange chamber 2a.

[0049] In this embodiment, when the air preheater is working normally, the scraper 8 is placed at one end close to or far from the baffle 6, so as not to affect the heat exchange and flue gas entry and exit effect.

[0050] Furthermore, such as Figure 1 , 2 As shown in Figures 3 and 4, the scraping device includes a plurality of tubes 10 that are coaxial with and correspond one-to-one with the flue tubes of the flue tube bundle 2. One end of each tube 10 near the flue tube bundle 2 is provided with an annular scraper 11, and the other end is provided with a connecting plate 12 that is connected to the plurality of tubes 10. The annular scraper 11 is fitted with the inside of the flue tube with a clearance.

[0051] The scraping device also includes a tube drive assembly 13 that drives several tubes 10 to approach or move away from the flue tube bundle 2.

[0052] In this embodiment, during scraping (with valve control component 3 in the closed state), the tube drive component 13 drives several tubes 10 to move towards the direction of the smoke tube bundle 2, so that the annular scraper 11 enters the smoke tube of the smoke tube bundle 2 after passing through the smoke inlet pipe 40. Then, the annular scraper 11 is driven to move back and forth a set distance inside the smoke tube, thereby scraping away the dirt on the inner wall of the smoke tube. After the scraping is completed, the tubes 10 are reset to the extension pipe 30, and then the valve control component 3 is opened, so that the extension pipe 30 is not connected to the smoke inlet pipe 40, thereby entering the normal working mode.

[0053] Furthermore, such as Figure 1 , 2 As shown in Figures 3 and 4, in order to improve the scraping effect on the inner wall of the flue, compressed air is used to blow the scraped dirt out of the flue while scraping. The connecting plate 12 is provided with an air collection chamber 121 that communicates with the pipe body 10. The air collection chamber 121 is connected to an external compressed air source (not shown in the figure). The annular scraper 11 is provided with a through hole 111 that communicates with the inside of the pipe body 10.

[0054] During operation, the annular scraper 11 enters the flue pipe. While the annular scraper 11 scrapes away dirt, the compressed air source enters several pipes 10 through the air collection chamber 121 and then blows out from one end of the pipe 10 located at the annular scraper 11, thereby achieving scraping and blowing of the inner wall of the flue pipe.

[0055] Furthermore, such as Figure 1 , 2 As shown, in order to drive the tube body 10 to move stably and reliably closer to or away from the smoke tube bundle 2, and to move back and forth inside the smoke tube; the tube body driving assembly 13 includes a second screw 131 rotatably connected to the inner wall of the extension tube 30, and the second screw 131 is threadedly connected to the connecting part of the connecting plate 12.

[0056] The tube drive assembly 13 further includes a second driver 132 whose drive end is connected to the second screw 131. The second driver 132 is located on the side of the connecting plate 12 away from the tube 10.

[0057] Furthermore, such as Figure 1 , 2 As shown, the valve control assembly 3 includes a sealing plate 31 and a third actuator 32. The sealing plate 31 is disposed at the connection between the extension pipe 30 and the smoke inlet pipe 40. One end of the sealing plate 31 is provided with a rotating shaft on both sides, which is rotatably connected to the extension pipe 30 or the smoke inlet pipe 40. One of the rotating shafts passes through the extension pipe 30 or the smoke inlet pipe 40 and is connected to the external third actuator 32.

[0058] In this embodiment, when the valve control component 3 is in the closed state, the sealing plate 31 blocks the smoke inlet of the smoke inlet pipe 40, and the extension pipe 30 is internally connected to the smoke inlet pipe 40. When the valve control component 3 is in the open state, the sealing plate 31 blocks the connection between the extension pipe 30 and the smoke inlet pipe 40, and the smoke inlet of the smoke inlet pipe 40 is connected to the smoke outlet, thus preventing the smoke from entering the extension and affecting the scraping component during operation. This achieves reliable scraping without affecting the flow of smoke during normal operation.

[0059] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this utility model patent.

Claims

1. A boiler air preheater with a cleaning function, comprising an air preheater body, characterized in that, The air preheater body includes a tube box, and the heat exchange chamber of the tube box is provided with a flue tube bundle and a scraper device. The scraper device is used to scrape off the dirt on the outer wall of each flue tube in the flue tube bundle. The inlet and outlet ends of the pipe box are respectively provided with an inlet pipe and an outlet pipe. The inlet axis of the inlet pipe is set at an angle to the outlet axis. An axially extended extension pipe is provided on the side of the inlet pipe opposite to the outlet. The extension pipe is connected to the inlet pipe. A scraping device is provided inside the extension pipe. The scraping device is used to scrape off the dirt on the inner wall of each pipe in the pipe bundle. A valve control assembly is provided at the connection between the extension pipe and the smoke inlet pipe. The valve control assembly is used to control the opening and closing of the extension pipe and the smoke inlet pipe.

2. The air preheater for boilers with a cleaning function according to claim 1, characterized in that, The inlet and outlet ends of the tube box are respectively provided with a front cover and a rear cover, and a heat exchange chamber is formed between the tube box and the front cover and the rear cover. The tube box is also provided with a partition that divides the heat exchange chamber into a first heat exchange chamber and a second heat exchange chamber. The upper side of the tube box is provided with an air inlet and an exhaust outlet that communicate with the first heat exchange chamber and the second heat exchange chamber respectively. The lower side of the tube box is provided with a communication port that connects the first heat exchange chamber and the second heat exchange chamber. An air communication cover is provided on the communication port. The scraper device can scrape and wash the flue tube bundles located in the first heat exchange chamber and the second heat exchange chamber.

3. A boiler air preheater with cleaning function according to claim 2, characterized in that, The scraper device includes scrapers disposed opposite to each other in the first heat exchange chamber and the second heat exchange chamber. The scrapers are provided with scraping holes that correspond one-to-one with the flue tube bundle. The scraping holes are clearance-fitted with the flue tubes in the flue tube bundle. The scraper device further includes at least two scraper driving assemblies, which are used to drive the two scrapers symmetrically toward or away from the partition.

4. A boiler air preheater with cleaning function according to claim 3, characterized in that, The scraper drive assembly includes a first screw and a first driver. The first screw includes a limiting section, which is rotatably connected to a partition. A first threaded section and a second threaded section are respectively provided on both sides of the limiting section. The first threaded section and the second threaded section are located in the first heat exchange chamber and the second heat exchange chamber, respectively. Both the first and second threaded sections are provided with threads of the same lead but opposite directions of rotation; the first and second threaded sections are respectively threadedly connected to two scrapers; one end of the first screw is rotatably connected to the front end cover, and the other end rotatably passes through the rear end cover and is connected to the drive end of the first driver.

5. A boiler air preheater with cleaning function according to claim 1, characterized in that, The scraping device includes a plurality of tubes that are coaxial with and correspond one-to-one with the flue tubes of the flue tube bundle. One end of each tube is provided with an annular scraper, and the other end is provided with a connecting plate that is connected to the plurality of tubes. The annular scraper is fitted with the inside of the flue tube with a clearance. The scraping device also includes a tube drive assembly that drives several tubes to approach or move away from the flue tube bundle.

6. A boiler air preheater with cleaning function according to claim 5, characterized in that, The connecting plate has an air collection chamber that communicates with the pipe body. The air collection chamber is connected to an external compressed air source. The annular scraper has a through hole that communicates with the inside of the pipe body.

7. A boiler air preheater with cleaning function according to claim 5, characterized in that, The tube drive assembly includes a second screw rotatably connected to the inner wall of the extension tube, and the second screw is threadedly connected to the connecting part of the connecting plate. The tube drive assembly also includes a second driver whose drive end is connected to the second screw, and the second driver is located on the side of the connecting plate away from the tube.

8. A boiler air preheater with cleaning function according to claim 1, characterized in that, The valve control assembly includes a sealing plate and a third actuator. The sealing plate is disposed at the connection between the extension pipe and the smoke inlet pipe. One end of the sealing plate is provided with two rotating shafts that are rotatably connected to the extension pipe or the smoke inlet pipe. One of the rotating shafts passes through the extension pipe or the smoke inlet pipe and is connected to the external third actuator.

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