A two-stage high-efficiency low-NOx radiant tube combustion device convenient to replace

Abstract

The application belongs to the field of radiant tube combustion, and particularly relates to a two-stage high-efficiency low-NOx radiant tube combustion device convenient to replace, which comprises a heat exchanger, a burner, a radiant tube, a flange assembly and a mounting plate assembly, the heat exchanger and the burner are connected to two ends of the radiant tube through the flange assembly respectively, the radiant tube is connected to the outside through the mounting plate assembly, the heat exchanger comprises a primary heat exchanger and a secondary heat exchanger, and the primary heat exchanger is provided with a flue gas reflux device at an end far from the secondary heat exchanger, the primary heat exchanger and the secondary heat exchanger are arranged to perform two-stage heat exchange on air, the efficiency of heat exchange is effectively improved, the temperature of flue gas emission is reduced, the flue gas reflux device is integrated, the temperature of the flame zone of the burner is reduced, the generation of NOx is effectively reduced, the flange assembly and the mounting plate assembly are arranged, the convenience of the device is improved, and the replacement process is more convenient.

Description

Technical Field

[0001] This invention belongs to the field of radiant tube combustion, and specifically relates to a two-stage high-efficiency, low-NOx radiant tube combustion device that is easy to replace. Background Technology

[0002] With the energy crisis worsening, the world is exploring new energy sources and making more efficient and economical use of existing energy sources. At the same time, the greenhouse effect necessitates a reduction in emissions of greenhouse gases such as carbon dioxide. Nitrogen oxides (NOx) are toxic substances and a major contributor to acid rain, with industrial production activities being the primary cause of NOx and other pollutants. The high-temperature environment of the thermal power industry is a major source of thermal NOx emissions. With increasing environmental awareness and stricter environmental standards, reducing NOx emissions from the thermal power industry, especially in high-temperature combustion applications, has become a top priority.

[0003] Against this backdrop, some low-NOx radiant tube combustion systems have emerged on the market. For example, a compact two-stage high-efficiency low-NOx radiant tube combustion system (Publication No.: CN220624032U, Publication Date: 2024-03-19) includes a burner, heat exchanger, shell, flue gas recirculation device, gas collection chamber, heat exchange tubes, and radiant tubes. The shell is divided into an air shell and a secondary shell, and the heat exchanger has two types: a primary heat exchanger and a secondary heat exchanger. This combustion system, through a reasonable structural arrangement, can achieve high-efficiency heat exchange, which helps improve energy utilization and reduce fuel consumption. Simultaneously, the integrated flue gas recirculation device can form a recirculation structure, thereby reducing the temperature of the burner flame zone, which helps reduce NOx gas generation and pollutant emissions. However, the radiant tubes, burner, and heat exchanger in this application are fixedly connected by ordinary flanges, making replacement inconvenient. Furthermore, the application does not provide a structural description of how the entire radiant tube combustion system is installed on the furnace body. Summary of the Invention

[0004] To address the technical deficiencies in the background technology, this invention proposes a two-stage, high-efficiency, low-NOx radiant tube combustion device that is easy to replace, based on the aforementioned radiant tube combustion system. This solves the above-mentioned technical problems and meets practical needs. The specific technical solution is as follows: A two-stage high-efficiency, low-NOx radiant tube combustion device that is easy to replace includes a heat exchanger, a burner, a radiant tube, a flange assembly, and a mounting plate assembly. The heat exchanger and the burner are respectively connected to the two ends of the radiant tube through the flange assembly. The radiant tube is connected to the outside through the mounting plate assembly. The end of the heat exchanger away from the radiant tube is connected to the burner through a pipe. The heat exchanger includes a primary heat exchanger and a secondary heat exchanger. The secondary heat exchanger is located outside the primary heat exchanger. The end of the primary heat exchanger away from the secondary heat exchanger is provided with a flue gas recirculation device. The flange assembly includes a first flange and a second flange that mate with each other, a gasket disposed between the first flange and the second flange, and a retaining strip and a threaded ring for fixing the flange assembly. The threaded ring is disposed on the side of the second flange away from the first flange. The retaining strip has a pin portion that passes through the first flange and the second flange, and a fixing portion disposed on the outside of the first flange and the second flange. The end of the retaining strip away from the first flange is connected to the threaded ring by a thread. The mounting plate assembly includes a mounting plate, a clamping block, and a rotating opening and closing component. The clamping block and the rotating opening and closing component are respectively located on the side of the mounting plate away from the flange assembly. The two ends of the rotating opening and closing component along the vertical direction are respectively connected to the clamping block. The rotating opening and closing component is used to control the vertical movement of the clamping block.

[0005] As a further technical solution of the present invention, the heat exchanger further includes an air duct, which is disposed inside the primary heat exchanger. The primary heat exchanger includes a flue gas recirculation device, a bare tube section, and a finned section. The finned section is disposed between the flue gas recirculation device and the bare tube section. One end of the air duct is connected to the flue gas recirculation device, and the other end is provided with a hot air outlet. The flue gas recirculation device is provided with an air nozzle and a flue gas recirculation hole. The air nozzle is disposed at the end of the flue gas recirculation device near the air duct, and the flue gas recirculation holes are arranged in pairs and pass through the flue gas recirculation device.

[0006] As a further technical solution of the present invention, the secondary radiant tube is located outside the bare tube section. The secondary heat exchanger includes, from the outside to the inside, an air shell, a secondary shell, a heat exchange tube, and a flue gas inner tube. A cooling channel is formed between the secondary shell and the air shell. A cold air collection chamber is connected to one end of the heat exchange tube near the fin segment. The cold air collection chamber is connected to the cooling channel. The other end of the heat exchange tube is connected to a hot air collection chamber. The hot air collection chamber is connected to the end of the bare tube section away from the fin segment. The area between the flue gas inner tube and the secondary shell forms the internal area of ​​the secondary heat exchanger. One end of the flue gas inner tube is connected to the internal area of ​​the secondary heat exchanger, and the other end is open.

[0007] As a further technical solution of the present invention, the secondary heat exchanger is provided with a cold air inlet and a flue gas outlet, the cold air inlet is connected to the cooling channel, and the flue gas outlet is connected to the internal area of ​​the secondary heat exchanger.

[0008] As a further technical solution of the present invention, the burner includes a burner shell, a gas inlet and an ignition electrode, the gas inlet and the ignition electrode are respectively disposed in the burner shell, the burner shell has a hot air inlet, and the hot air outlet is connected to the hot air inlet through a pipe.

[0009] As a further technical solution of the present invention, the heat exchanger and the burner are respectively located inside the radiant tube at the ends near the radiant tube, and the heat exchanger and the radiant tube are connected by a set of flange assemblies.

[0010] As a further technical solution of the present invention, the end of the fixing part near the first flange is connected to the pin part, and the inner wall of the other end is connected to the outer wall of the threaded ring by threads. The end of the pin part away from the first flange extends out of the second flange and is connected to the inner wall of the threaded ring by threads. The locking strips are arranged in pairs and symmetrically distributed along the central axis of the first flange.

[0011] As a further technical solution of the present invention, the mounting plate assembly further includes an outer frame, the clamping blocks and the rotating opening and closing components are respectively disposed in the outer frame, the outer frame is fixed to the mounting plate, the clamping blocks are provided in two sets, the rotating opening and closing components are disposed between the two sets of clamping blocks, the two sets of clamping blocks are respectively disposed on the upper and lower sides of the radiant tube and symmetrically distributed along the rotating opening and closing components, the clamping blocks are provided with fixing blocks and connecting plates, the fixing blocks are disposed on the side of the connecting plate away from the rotating opening and closing components, and the outer frame is provided with a slot that matches the fixing blocks.

[0012] As a further technical solution of the present invention, the rotating opening and closing component includes a slider, a rotating plate, a fixed frame, and a knob. The fixed frame is fixed to the outer frame, and the fixed frame has a slider groove in the vertical direction. The rotating plate is slidably connected to the fixed frame. The slider is slidably connected to the groove on the rotating plate through a locking block. The rotating plate can rotate along its own central axis. The slider can move in the slider groove in the vertical direction. There are two sliders. The end of the slider near the locking block is fixedly connected to the connecting plate. The end of the rotating plate near the flange assembly extends out of the mounting plate through a connecting shaft and is connected to the knob.

[0013] As a further technical solution of the present invention, the primary heat exchanger is one of a metal finned heat exchanger, a ceramic heat exchanger, a tube bundle heat exchanger, or a non-circular tube bundle heat exchanger, and the radiant tube is one of a U-shaped radiant tube or a W-shaped radiant tube.

[0014] The beneficial effects of this invention are as follows: This invention utilizes a primary and secondary heat exchanger to perform two-stage heat exchange on the air, effectively improving heat exchange efficiency, maximizing preheated air temperature, increasing combustion efficiency, and reducing flue gas emission temperature. Simultaneously, the invention integrates a flue gas recirculation device to lower the burner flame zone temperature, effectively reducing NOx formation. This device also efficiently utilizes excess heat from the flue gas, contributing to reduced fuel consumption. Furthermore, the inclusion of flange and mounting plate assemblies enhances the device's convenience, simplifying replacement processes.

[0015] The flange assembly of this invention secures two flanges via a helical connection between a retaining strip and a threaded ring. During use, simply rotating the threaded ring causes the retaining strip and threaded ring to hold the two flanges together. Similarly, disassembly is achieved by simply rotating the threaded ring in the opposite direction to loosen the two flanges. This invention uses a flange assembly to connect radiant tubes to burners and radiant tubes to heat exchangers, ensuring not only structural stability and operational efficiency but also simplifying component replacement procedures.

[0016] This invention uses an installation plate assembly fixed to the furnace body. During installation, the installation plate assembly drives the clamping block to move by rotating the opening and closing component. The clamping block clamps and fixes the furnace body to the installation plate, thereby fixing the radiant tube to the furnace body. During disassembly, rotating the opening and closing component can loosen the installation plate assembly, allowing the radiant tube to be easily removed. This simplifies the installation and disassembly process of the radiant tube and facilitates the replacement of the radiant tube. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of a two-stage high-efficiency, low-NOx radiant tube combustion device that is easy to replace.

[0018] Figure 2 This is a structural diagram of a two-stage high-efficiency, low-NOx radiant tube combustion device that is easy to replace.

[0019] Figure 3 This is a structural diagram of a flange assembly for a two-stage high-efficiency, low-NOx radiant tube combustion device that is easy to replace.

[0020] Figure 4 This is a structural diagram of a mounting plate assembly for a two-stage, high-efficiency, low-NOx radiant tube combustion device that is easy to replace.

[0021] Figure 5 This is a diagram showing the internal structure of a mounting plate assembly for a two-stage, high-efficiency, low-NOx radiant tube combustion device that is easy to replace.

[0022] Figure 6 This is a cross-sectional view of a heat exchanger for a two-stage, high-efficiency, low-NOx radiant tube combustion device that is easy to replace.

[0023] Figure 7 This is a schematic diagram of the structure of a two-stage high-efficiency low-NOx radiant tube combustion device with easily replaceable radiant tubes, showing the optional types of radiant tubes.

[0024] Figure 8 This is a schematic diagram of the optional heat exchanger tube types for a two-stage high-efficiency, low-NOx radiant tube combustion device that is easy to replace.

[0025] Figure 9 This is a schematic diagram of the optional type of the first-stage heat exchanger in a two-stage high-efficiency low-NOx radiant tube combustion device that is easy to replace.

[0026] The components include: heat exchanger 1, primary heat exchanger 11, bare tube section 111, finned section 112, secondary heat exchanger 12, air shell 121, secondary shell 122, heat exchange tube 123, flue gas inner tube 124, cold air collection chamber 125, hot air collection chamber 126, cold air inlet 127, flue gas outlet 128, flue gas recirculation device 13, air nozzle 131, flue gas recirculation hole 132, air duct 14, hot air outlet 141, burner 2, and hot air. 21. Gas inlet; 22. Ignition electrode; 23. Radiant tube; 3. Flange assembly; 4. First flange; 41. Second flange; 42. Gasket; 43. Clip; 44. Pin part; 441. Fixing part; 442. Threaded ring; 45. Mounting plate assembly; 5. Mounting plate; 51. Clamping block; 521. Fixing block; 522. Connecting plate; 523. Rotating opening and closing part; 53. Slider; 531. Rotating plate; 532. Fixing frame; 533. Knob; 534. Outer frame; 54. Furnace body; 6. Detailed Implementation

[0027] The following is in conjunction with the appendix Figures 1-9 The embodiments of the present invention will be described in conjunction with related examples. The embodiments of the present invention are not limited to the following examples, and the relevant necessary components of the present invention should be regarded as well-known technology in the field of this art, which can be known and mastered by those skilled in the art.

[0028] This invention provides a two-stage, high-efficiency, low-NOx radiant tube combustion device that is easy to replace, such as... Figure 1 As shown, the invention includes a heat exchanger 1, a burner 2, a radiant tube 3, a flange assembly 4, and a mounting plate assembly 51. The heat exchanger 1 and the burner 2 are connected to both ends of the radiant tube 3 via the flange assembly 4, and the radiant tube 3 is connected to the outside via the mounting plate assembly 51. The end of the heat exchanger 1 furthest from the radiant tube 3 is connected to the burner 2 via a pipe. The heat exchanger 1 includes a primary heat exchanger 11 and a secondary heat exchanger 12. The secondary heat exchanger 12 is located outside the primary heat exchanger 11, and a flue gas recirculation device 13 is provided at the end of the primary heat exchanger 11 furthest from the secondary heat exchanger 12. By setting up a primary heat exchanger 11 and a secondary heat exchanger 12, the invention performs two-stage heat exchange on the air, effectively improving the heat exchange efficiency, maximizing the preheated air temperature, improving combustion efficiency, and reducing the flue gas emission temperature. At the same time, the invention integrates the flue gas recirculation device 13, which reduces the flame zone temperature of the burner 2, effectively reducing NOx formation. The flue gas recirculation device 13 achieves efficient utilization of excess flue gas heat, which helps reduce fuel consumption. Furthermore, by setting up the flange assembly 4 and the mounting plate 51 assembly 5, the present invention improves the convenience of the device and makes the replacement process simpler.

[0029] like Figure 2As shown, the flange assembly 4 includes a first flange 41 and a second flange 42 that mate with each other, a gasket 43 disposed between the first flange 41 and the second flange 42, and a retaining strip 44 and a threaded ring 45 for fixing the flange assembly 4. The threaded ring 45 is disposed on the side of the second flange 42 away from the first flange 41. The retaining strip 44 has a pin portion 441 that passes through the first flange 41 and the second flange 42, and a fixing portion 442 disposed on the outside of the first flange 41 and the second flange 42. The end of the retaining strip 44 away from the first flange 41 is threadedly connected to the threaded ring 45. The flange assembly 4 of the present invention fixes the two flanges by the helical connection between the retaining strip 44 and the threaded ring 45. In use, simply rotate the threaded ring 45, and the retaining strip 44 and the threaded ring 45 will fix the two flanges together. Similarly, in disassembly, simply rotate the threaded ring 45 in the opposite direction to loosen the two flanges. The present invention uses a flange assembly 4 to connect the radiant tube 3 to the burner 2 and the radiant tube 3 to the heat exchanger 1, which not only ensures the stability of the structure and the operating efficiency, but also simplifies the replacement process of the components.

[0030] Mounting plate assembly 51 includes mounting plate 51, clamping block 52, and rotating opening / closing component 53. The clamping block 52 and rotating opening / closing component 53 are respectively located on the side of mounting plate 51 away from flange assembly 4. The two ends of rotating opening / closing component 53 are connected to clamping block 52 in the vertical direction, and the rotating opening / closing component 53 controls the vertical movement of clamping block 52. In this invention, mounting plate assembly 51 is fixed to furnace body 6. During installation, rotating rotating opening / closing component 53 drives clamping block 52 to move, clamping block 52 to secure furnace body 6 to mounting plate 51, thus fixing radiant tube 3 to furnace body 6. During disassembly, rotating rotating opening / closing component 53 releases mounting plate assembly 51, allowing radiant tube 3 to be easily removed, simplifying the installation and disassembly process of radiant tube 3 and facilitating replacement.

[0031] The following are embodiments of the present invention.

[0032] A two-stage, high-efficiency, low-NOx radiant tube combustion device that is easy to replace, such as Figure 1 As shown, the device includes a heat exchanger 1, a burner 2, a radiant tube 3, a flange assembly 4, and a mounting plate assembly 51. The heat exchanger 1 and the burner 2 are respectively connected to the two ends of the radiant tube 3 through the flange assembly 4. The radiant tube 3 is connected to the outside through the mounting plate assembly 51. The end of the heat exchanger 1 away from the radiant tube 3 is connected to the burner 2 through a pipe. The heat exchanger 1 includes a primary heat exchanger 11 and a secondary heat exchanger 12. The secondary heat exchanger 12 is located outside the primary heat exchanger 11. The end of the primary heat exchanger 11 away from the secondary heat exchanger 12 is provided with a flue gas recirculation device 13.

[0033] This invention utilizes a primary heat exchanger 11 and a secondary heat exchanger 12 to perform two-stage heat exchange on the air, effectively improving heat exchange efficiency, maximizing the preheated air temperature, increasing combustion efficiency, and reducing flue gas emission temperature. Simultaneously, the invention integrates a flue gas recirculation device 13 to reduce the flame zone temperature of the burner 2, effectively reducing NOx formation. The flue gas recirculation device 13 efficiently utilizes excess heat from the flue gas, which helps reduce fuel consumption. Furthermore, the invention improves the convenience of the device by incorporating a flange assembly 4 and a mounting plate 51 assembly 5, making the replacement process simpler.

[0034] like Figure 6 As shown, heat exchanger 1 also includes an air duct 14, which is located inside the primary heat exchanger 11. The primary heat exchanger 11 includes a flue gas recirculation device 13, a bare tube section 111, and a finned section 112, with the finned section 112 located between the flue gas recirculation device 13 and the bare tube section 111. Wherein, as... Figure 9 As shown, the primary heat exchanger 11 is one of the following: a metal finned heat exchanger, a ceramic heat exchanger, a tube bundle heat exchanger, or a non-circular tube bundle heat exchanger. One end of the air duct 14 is connected to a flue gas recirculation device 13, and the other end is provided with a hot air outlet 141. The outlet direction of the hot air outlet 141 can be customized according to the actual connection situation on site and is not restricted.

[0035] The flue gas recirculation device 13 is equipped with an air nozzle 131 and a flue gas recirculation hole 132. The air nozzle 131 is located at one end of the flue gas recirculation device 13 near the air duct 14, and the flue gas recirculation holes 132 are arranged in pairs and pass through the flue gas recirculation device 13. Preferably, the air nozzle 131 can be a conical or straight nozzle, and the outlet position of the air nozzle 131 can be located at the center of the axis of the flue gas recirculation hole 132 or at the front or rear edge along the air flow direction. The flue gas recirculation device 13 can achieve a recirculated flue gas to combustion air ratio of up to about 70%.

[0036] like Figure 6As shown, the secondary heat exchanger 12 is located outside the bare tube section 111. The secondary heat exchanger 12 is preferably a compact tubular heat exchanger 1. From the outside to the inside, the secondary heat exchanger 12 includes an air casing 121, a secondary casing 122, a heat exchange tube 123, and a flue gas inner tube 124. A cooling channel is formed between the secondary casing 122 and the air casing 121. A cold air collection chamber 125 is connected to one end of the heat exchange tube 123 near the fin section 112, and the cold air collection chamber 125 communicates with the cooling channel. A hot air collection chamber 126 is connected to the other end of the heat exchange tube 123 away from the fin section 112. The arrangement of the cold air collection chamber 125 and the hot air collection chamber 126 effectively distributes the airflow evenly and stabilizes the air pressure. The area between the flue gas inner tube 124 and the secondary shell 122 forms the internal area of ​​the secondary heat exchanger 12. One end of the flue gas inner tube 124 is connected to the internal area of ​​the secondary heat exchanger 12, and the other end is an opening.

[0037] like Figure 8 As shown, Figure 8 Various types of heat exchange tubes 123 are available, including single-layer or multi-layer arrangements. The heat exchange tubes 123 can be square, round, flat, or irregularly shaped. Furthermore, a flow-around baffle can be optionally arranged between the flue gas inner tube 124 and the heat exchange tubes 123 to adjust the flow of the flue gas. The secondary heat exchanger 12 has a cold air inlet 127 and a flue gas outlet 128. The cold air inlet 127 is connected to the cooling channel, and the flue gas outlet 128 is connected to the internal area of ​​the secondary heat exchanger 12. When the flue gas temperature at the end of the heat exchanger 1 is 950~1000℃, the exhaust gas temperature is in the range of 400~450℃.

[0038] like Figure 1 As shown, the burner 2 includes a burner housing, a gas inlet 22 and an ignition electrode 23. The gas inlet 22 and the ignition electrode 23 are respectively located inside the burner housing. The burner housing has a hot air inlet 21, and the hot air outlet 141 is connected to the hot air inlet 21 through a pipe.

[0039] like Figure 1 As shown, the working principle of the radiant tube 3 combustion device is as follows: External combustion air (cold) enters the secondary heat exchanger 12 through the cold air inlet 127. After entering, it flows through the cooling channel between the air casing 121 and the secondary casing 122 to absorb heat and cool the outer shell of the overall heat exchanger 1, and then enters the cold air collection chamber 125. Air from the cold air collection chamber 125 is distributed to the heat exchange tubes 123 of the secondary heat exchanger 12, where it fully exchanges heat with the external flue gas. After that, it enters the hot air collection chamber 126 to complete the first heat exchange. Air from the hot air collection chamber 126 is distributed into the channel between the primary heat exchanger 11 and the air duct 14, and undergoes a second heat exchange with the external flue gas through the bare tube section 111 and the finned section 112 of the primary heat exchanger 11.

[0040] After passing through the primary heat exchanger 11, the hot air flows through the flue gas return device 13 and converges at the end. Then it flows back and is injected into the air duct 14 from the air nozzle 131. During this process, the flue gas outside the primary heat exchanger 11 is ejected from the flue gas return hole 132 by the air nozzle 131 and mixes with the hot air in the air duct 14. Finally, it flows out from the air outlet through the connecting pipe.

[0041] The direction of the air outlet is adjustable. The hot air here is connected to the hot air inlet 21 on the burner 2 through the pipe (this pipe is equipped according to the actual site conditions) and then enters the burner 2. At the same time, the external gas enters the burner 2 through the gas inlet 22. After mixing at the front end, it is ignited by the ignition electrode 23 to form a flame zone and generate high-temperature flue gas. This flue gas exchanges heat with the outside through the radiant tube 3 and reaches the end inlet of the heat exchanger 1 near the flue gas return device 13 described in the patent.

[0042] During the flue gas flow, as it passes through the flue gas recirculation device 13, a portion is injected by the air nozzle 131 and enters the air duct 14 through the flue gas recirculation hole 132 for mixing. The other portion continues along the outside of the primary heat exchanger 11, exchanging heat with the inner air through the primary heat exchanger 11. After passing through the primary heat exchanger 11, the flue gas enters the secondary heat exchanger 12 through the free end of the flue gas inner tube 124 inside the secondary heat exchanger 12, located on the outside of the heat exchanger 1. It then exchanges heat with the air through the heat exchange tube 123. At this time, the flue gas passes through the flow-around baffle to improve the heat exchange efficiency, and then converges and is discharged from the combustion system through the flue gas outlet 128.

[0043] like Figure 2 As shown, the heat exchanger 1 and the burner 2 are respectively located inside the radiant tube 3 at their ends near the radiant tube 3. The heat exchanger 1 and the radiant tube 3, and the burner 2 and the radiant tube 3, are each connected by a set of flange assemblies 4. Figure 7 As shown, radiation tube 3 is either U-radiation tube 3 or W-radiation tube 3.

[0044] As shown in Figure 3, the flange assembly 4 includes a first flange 41 and a second flange 42 that mate with each other, a gasket 43 disposed between the first flange 41 and the second flange 42, and a retaining strip 44 and a threaded ring 45 for fixing the flange assembly 4. The threaded ring 45 is located on the side of the second flange 42 away from the first flange 41, and the end of the retaining strip 44 away from the first flange 41 is threadedly connected to the threaded ring 45. The gasket 43 is provided to ensure the sealing and safety of the pipe flange connection. In practical applications, it is recommended to select the appropriate type and specification of the flange gasket 43 according to the specific working environment and requirements. The retaining strip 44 is provided with a pin portion 441 that passes through the first flange 41 and the second flange 42, and a fixing portion 442 located on the outside of the first flange 41 and the second flange 42. The fixing portion 442 is connected to the pin portion 441 at one end near the first flange 41, and the inner wall of the other end is connected to the outer wall of the threaded ring 45 by threads. The pin portion 441 extends out of the second flange 42 at one end away from the first flange 41 and is connected to the inner wall of the threaded ring 45 by threads. The retaining strips 44 are arranged in pairs and symmetrically distributed along the central axis of the first flange 41.

[0045] The connection between heat exchanger 1 and radiant tube 3 is as follows: the first flange 41 is fixed to the end of radiant tube 3, and the second flange 42 is fixed to the end of the secondary heat exchanger 12 near radiant tube 3. The pin 441 of the retaining strip 44 is inserted into the hole between the first flange 41 and the second flange, and the fixing part 442 is fixed to the outside of the first flange 41 and the second flange 42. The threaded ring 45 (which should be fitted onto the radiant tube 3 before fixing the first flange 41) is rotated. At this time, the threaded ring 45 is screwed into the fixing part 442 and the pin 441. The cooperation between the threaded ring 45 and the retaining strip 44 ensures that the first flange 41 and the second flange 42 are pressed tightly together, guaranteeing a tight connection between heat exchanger 1 and radiant tube 3 and preventing leakage and loosening.

[0046] When heat exchanger 1 needs to be replaced, simply rotate the threaded ring 45 in the opposite direction to disengage the retaining strip 44 from the threaded ring 45, and the old component can be easily removed. Then, the new component can be installed, and the components can be reconnected via the flange assembly 4. This invention not only ensures the stability and operational efficiency of the equipment structure but also greatly simplifies the component replacement process. During long-term use, it facilitates maintenance and replacement, reducing maintenance costs and improving the overall performance and service life of the equipment.

[0047] Similarly, the connection between burner 2 and radiant tube 3 is the same as the connection between heat exchanger 1 and radiant tube 3, and will not be described in detail here.

[0048] like Figure 2 and Figure 4As shown, the mounting plate 51 assembly 5 includes a mounting plate 51, a clamping block 52, and a rotating opening and closing component 53. The clamping block 52 and the rotating opening and closing component 53 are respectively located on the side of the mounting plate 51 away from the flange assembly 4. The two ends of the rotating opening and closing component 53 along the vertical direction are respectively connected to the clamping block 52. The rotating opening and closing component 53 is used to control the vertical movement of the clamping block 52.

[0049] Mounting plate 51 assembly 5 also includes an outer frame 54, clamping blocks 52 and rotating opening and closing parts 53 are respectively disposed inside the outer frame 54, the outer frame 54 is fixed on the mounting plate 51, the clamping blocks 52 are provided in two sets, the rotating opening and closing parts 53 are disposed between the two sets of clamping blocks 52, the two sets of clamping blocks 52 are respectively disposed on the upper and lower sides of the radiant tube 3 and symmetrically distributed along the rotating opening and closing parts 53, the clamping blocks 52 are provided with fixing blocks 521 and connecting plates 522, the fixing blocks 521 are disposed on the side of the connecting plates 522 away from the rotating opening and closing parts 53, and the outer frame 54 is provided with a groove that matches the fixing blocks 521.

[0050] The rotating opening and closing component 53 includes a slider 531, a rotating plate 532, a fixed frame 533, and a knob 534. The fixed frame 533 is fixed to the outer frame 54. The fixed frame 533 has a groove for the slider 531 in the vertical direction. The rotating plate 532 is slidably connected to the fixed frame 533. The slider 531 is slidably connected to the groove on the rotating plate 532 through a locking block. The rotating plate 532 can rotate along its own central axis. The slider 531 can move in the groove of the slider 531 in the vertical direction. There are two sliders 531. The end of the slider 531 near the locking block 52 is fixedly connected to the connecting plate 522. The end of the rotating plate 532 near the flange assembly 4 extends out of the mounting plate 51 through a connecting shaft and is connected to the knob 534.

[0051] like Figure 5 As shown, the process of installing the radiant tube 3 on the furnace body 6 is as follows: The end of the radiant tube 3 furthest from the flange assembly 4 is inserted into the furnace body 6, and the mounting plate 51 is secured to the outside of the furnace body 6. At this point, the mounting plate 51 is in close contact with the furnace body 6. Preferably, a gasket 43 is placed between the mounting plate 51 and the furnace body 6. Then, by rotating the knob 534, the rotating plate 532 is rotated, causing the two sliders 531 to move the clamping block 52 in opposite directions. The fixing block 521 of the clamping block 52 moves out of the slot in the outer frame 54, securing the mounting plate 51 to the furnace body 6. For disassembly, rotating the knob 534 causes the fixing block 521 to retract into the outer frame 54, allowing the radiant tube 3 to be easily removed from the furnace body 6.

[0052] Furthermore, the fixing blocks 521 on both sides of the connecting plate 522 are connected to the connecting plate 522 by inclined slide rails. When the connecting plate 522 is driven away from each other by the slider 531, the inclined slide rails on the sides of the connecting plate 522 cause the fixing blocks 521 on both sides of the connecting plate 522 to move away from each other. When the connecting plate 522 moves closer to each other, the fixing blocks 521 on both sides of the connecting plate 522 also move closer to each other along the slide rails.

[0053] This invention uses a mounting plate 51 assembly 5 fixed to the furnace body 6. The structural design of the mounting plate 51 assembly 5 makes the installation of the components more stable and also provides convenience for replacement operations. During installation, the mounting plate 51 assembly 5 moves the clamping block 52 by rotating the rotating opening and closing part 53. The clamping block 52 clamps and fixes the furnace body 6 to the mounting plate 51, thereby fixing the radiant tube 3 to the furnace body 6. During disassembly, rotating the rotating opening and closing part 53 can loosen the mounting plate 51 assembly 5, allowing the radiant tube 3 to be easily removed, simplifying the installation and disassembly process of the radiant tube 3 and facilitating the replacement of the present invention.

[0054] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A two-stage high-efficiency low-NOx radiant tube combustion device that is easy to replace, comprising a heat exchanger (1), a burner (2), a radiant tube (3), a flange assembly (4), and a mounting plate assembly (5), characterized in that, The heat exchanger (1) and the burner (2) are respectively connected to the two ends of the radiant tube (3) through the flange assembly (4). The radiant tube (3) is connected to the outside through the mounting plate assembly (5). The end of the heat exchanger (1) away from the radiant tube (3) is connected to the burner (2) through a pipe. The heat exchanger (1) includes a primary heat exchanger (11) and a secondary heat exchanger (12). The secondary heat exchanger (12) is located outside the primary heat exchanger (11). The end of the primary heat exchanger (11) away from the secondary heat exchanger (12) is provided with a flue gas recirculation device (13). The flange assembly (4) includes a first flange (41) and a second flange (42) that mate with each other, a gasket (43) disposed between the first flange (41) and the second flange (42), and a retaining strip (44) and a threaded ring (45) for fixing the flange assembly (4). The threaded ring (45) is disposed on the side of the second flange (42) away from the first flange (41). The retaining strip (44) is provided with a pin portion (441) that penetrates the first flange (41) and the second flange (42) and a fixing portion (442) disposed on the outside of the first flange (41) and the second flange (42). The end of the retaining strip (44) away from the first flange (41) is connected to the threaded ring (45) by threads. The mounting plate assembly (5) includes a mounting plate (51), a clamping block (52), and a rotating opening and closing component (53). The clamping block (52) and the rotating opening and closing component (53) are respectively located on the side of the mounting plate (51) away from the flange assembly (4). The two ends of the rotating opening and closing component (53) in the vertical direction are respectively connected to the clamping block (52). The rotating opening and closing component (53) is used to control the vertical movement of the clamping block (52). The mounting plate assembly (5) also includes an outer frame (54). The clamping block (52) and the rotating opening and closing component (53) are respectively disposed inside the outer frame (54). The outer frame (54) is fixed on the mounting plate (51). There are two sets of clamping blocks (52). The rotating opening and closing component (53) is disposed between the two sets of clamping blocks (52). The two sets of clamping blocks (52) are respectively disposed on the upper and lower sides of the radiant tube (3) and symmetrically distributed along the rotating opening and closing component (53). The clamping block (52) is provided with a fixing block (521) and a connecting plate (522). The fixing block (521) is disposed on the side of the connecting plate (522) away from the rotating opening and closing component (53). The outer frame (54) is provided with a slot that matches the fixing block (521). The rotating opening and closing component (53) includes a slider (531), a rotating plate (532), a fixed frame (533), and a knob (534). The fixed frame (533) is fixed on the outer frame (54). The fixed frame (533) has a slider (531) groove in the vertical direction. The rotating plate (532) is slidably connected to the fixed frame (533). The slider (531) is slidably connected to the groove on the rotating plate (532) through a locking block. The rotating plate (532) can rotate along its own central axis. The slider (531) can move in the slider (531) groove in the vertical direction. There are two sliders (531). The end of the slider (531) near the locking block (52) is fixedly connected to the connecting plate (522). The end of the rotating plate (532) near the flange assembly (4) extends out of the mounting plate (51) through a connecting shaft and is connected to the knob (534). By rotating the knob (534), the rotating plate (532) is driven to rotate, causing the two sliders (531) to drive the clamping block (52) to move in opposite directions. When the fixing block (521) of the clamping block (52) enters the groove of the outer frame (54), the mounting plate (51) and the furnace body (6) are clamped together. When the fixing block (521) of the clamping block (52) retracts into the outer frame (54), the mounting plate (51) and the radiant tube (3) can be removed from the furnace body (6).

2. The easily replaceable two-stage high-efficiency low-NOx radiant tube combustion device according to claim 1, characterized in that, The heat exchanger (1) also includes an air duct (14), which is located inside the primary heat exchanger (11). The primary heat exchanger (11) includes a flue gas recirculation device (13), a bare tube section (111), and a finned section (112). The finned section (112) is located between the flue gas recirculation device (13) and the bare tube section (111). One end of the air duct (14) is connected to the flue gas recirculation device (13), and the other end is provided with a hot air outlet (141). The flue gas recirculation device (13) is provided with an air nozzle (131) and a flue gas recirculation hole (132). The air nozzle (131) is located at the end of the flue gas recirculation device (13) near the air duct (14). The flue gas recirculation holes (132) are arranged in pairs and pass through the flue gas recirculation device (13).

3. The easily replaceable two-stage high-efficiency low-NOx radiant tube combustion device according to claim 2, characterized in that, The radiant tube (3) is located outside the light tube section (111). The secondary heat exchanger (12) includes an air shell (121), a secondary shell (122), a heat exchange tube (123), and a flue gas inner tube (124) from the outside to the inside. A cooling channel is formed between the secondary shell (122) and the air shell (121). The end of the heat exchange tube (123) near the fin section (112) is connected to a cold air collection chamber (125). The cold air collection chamber (125) is connected to the cooling channel. The other end of the heat exchange tube (123) is connected to a hot air collection chamber (126). The hot air collection chamber (126) is connected to the end of the light tube section (111) away from the fin section (112). The area between the flue gas inner tube (124) and the secondary shell (122) forms the internal area of ​​the secondary heat exchanger. One end of the flue gas inner tube (124) is connected to the internal area of ​​the secondary heat exchanger, and the other end is an opening.

4. The easily replaceable two-stage high-efficiency low-NOx radiant tube combustion device according to claim 3, characterized in that, The secondary heat exchanger (12) has a cold air inlet (127) and a flue gas outlet (128). The cold air inlet (127) is connected to the cooling channel, and the flue gas outlet (128) is connected to the internal area of ​​the secondary heat exchanger (12).

5. The easily replaceable two-stage high-efficiency low-NOx radiant tube combustion device according to claim 2, characterized in that, The burner (2) includes a burner shell, a gas inlet (22) and an ignition electrode (23). The gas inlet (22) and the ignition electrode (23) are respectively located inside the burner shell. The burner shell has a hot air inlet (21). The hot air outlet (141) is connected to the hot air inlet (21) through a pipe.

6. The easily replaceable two-stage high-efficiency low-NOx radiant tube combustion device according to claim 1, characterized in that, The heat exchanger (1) and the burner (2) are respectively located inside the radiant tube (3) at the end closest to the radiant tube (3). The heat exchanger (1) and the radiant tube (3) are connected by a set of flange assemblies (4), and the burner (2) and the radiant tube (3) are connected by a set of flange assemblies (4).

7. The easily replaceable two-stage high-efficiency low-NOx radiant tube combustion device according to claim 1, characterized in that, The fixing part (442) is connected to the pin part (441) at one end near the first flange (41), and the inner wall of the other end is connected to the outer wall of the threaded ring (45) by threads. The pin part (441) extends out of the second flange (42) at one end away from the first flange (41) and is connected to the inner wall of the threaded ring (45) by threads. The locking strips (44) are arranged in pairs and symmetrically distributed along the central axis of the first flange (41).

8. The easily replaceable two-stage high-efficiency low-NOx radiant tube combustion device according to claim 1, characterized in that, The primary heat exchanger (11) is one of a metal fin heat exchanger, a ceramic heat exchanger, a tube bundle heat exchanger, or a non-circular tube bundle heat exchanger, and the radiant tube (3) is one of a U-shaped radiant tube or a W-shaped radiant tube.

Images