Integrated scr reaction device

Abstract

This application relates to the field of flue gas denitrification technology, and in particular to an integrated SCR reactor, which includes a reaction chamber, a catalytic module, a flue gas inlet pipe, a spray assembly, and a mixer. Specifically, the catalytic module is located inside the reaction chamber and is used to catalyze the flue gas containing a reducing agent. The catalytic module divides the inner cavity of the reaction chamber along the width or height direction to form a first chamber and a second chamber. The input end of the catalytic module is connected to the first chamber, and the output end of the catalytic module is connected to the second chamber. A flue gas outlet connected to the second chamber is provided on the outer wall of the reaction chamber. The inlet end of the flue gas inlet pipe is used to connect to an external flue gas outlet pipe, and the outlet end of the flue gas inlet pipe extends through one side of the reaction chamber along its length into the first chamber. The spray assembly is used to spray the reducing agent into the flue gas inlet pipe. The mixer is located inside the flue gas inlet pipe and is used to mix the flue gas and the reducing agent. This application has the effect of improving the integration of the SCR reactor and increasing the treatment efficiency.

Description

Technical Field

[0001] This application relates to the field of flue gas denitrification technology, and in particular to an integrated SCR reactor. Background Technology

[0002] SCR (Selective Catalytic Reduction) flue gas denitrification devices are environmentally friendly devices used for treating ship engine exhaust. Their core principle involves a chemical reaction between a reducing agent (urea solution) and nitrogen oxides (NOx) in the exhaust gas under the action of a catalyst, converting them into harmless nitrogen (N2) and water (H2O), thereby reducing the pollution of ship exhaust gases to the environment. Specifically, a delivery pump pressurizes the urea solution (or ammonia water) in the reducing agent storage tank and sends it to the metering module. After precise flow adjustment, the solution is atomized and sprayed into the exhaust gas pipe by an injector, mixing with the exhaust gas at 250-450℃. The mixed gas then enters the catalytic reactor, where, under the action of a vanadium-titanium-based catalyst, ammonia reacts with nitrogen oxides to produce nitrogen and water vapor.

[0003] However, traditional SCR reactors typically consist of a series of components such as inlet ducts, mixers, reactors, and outlet pipes, resulting in a relatively long overall structure. For many ships under construction and existing older vessels, the lack of sufficient installation space in the initial engine room design makes it difficult, or even impossible, to install or modify an SCR reactor, thus preventing these ships from meeting exhaust emission requirements and restricting their operation. To address this issue, the axial dimensions of individual components are usually shortened, while the height and width are increased during the design of the SCR reactor. However, this design shortens the exhaust gas flow path, causing nitrogen oxides (NOx) and urea solution in the exhaust gas to crystallize and clog the pipes on the inner walls or mixer surface due to insufficient reaction, reducing the overall treatment efficiency of the system.

[0004] Therefore, there is an urgent need for a marine SCR reactor that is compact, has high processing efficiency, and can adapt to limited engine room space. Summary of the Invention

[0005] To improve the integration and processing efficiency of SCR reactors, this application provides an integrated SCR reactor.

[0006] The integrated SCR reactor provided in this application adopts the following technical solution: An integrated SCR reactor includes: reaction chamber; A catalytic module, disposed within the reaction chamber, is used to catalyze a reaction with flue gas containing a reducing agent. The catalytic module divides the inner cavity of the reaction chamber along the width or height direction to form a first chamber and a second chamber. The input end of the catalytic module is connected to the first chamber, and the output end of the catalytic module is connected to the second chamber. A flue gas outlet connected to the second chamber is provided on the outer wall of the reaction chamber. The inlet pipe has an air inlet end for connecting to an external flue gas outlet pipe, and an outlet end for passing through one side of the reaction chamber along the length of the reaction chamber and extending into the first chamber along the length of the reaction chamber. A spray assembly for spraying a reducing agent into the flue gas inlet pipe; A mixer is located inside the flue gas inlet pipe and is used to mix flue gas and reducing agent.

[0007] By adopting the above technical solution, the integration and processing efficiency of the SCR reactor are improved. Specifically, this design makes the flow path of the flue gas in the reaction chamber present a "reversal" shape. That is, the flue gas first needs to flow through most of the length of the inlet pipe, and during this period, the reducing agent is sprayed and mixed before entering the first chamber, and finally it flows back to the catalytic module. Compared with the problem of the long overall structure caused by the linear series connection of the components in the prior art, this application integrates the mixing section (inlet pipe) and the reaction section (catalytic module) in space, realizing the "U-shaped" flow of the flue gas inside the reaction chamber, shortening the overall axial length of the device, improving the integration, and making it suitable for installation space-constrained occasions such as ship engine rooms. At the same time, while shortening the axial dimension, the extended design of the inlet pipe ensures that the flue gas has a sufficiently long flow distance from the reducing agent injection point to the input end of the catalytic module. This solves the problem of insufficient reaction caused by the shortened size in the prior art. A sufficiently long flow path allows the reducing agent and flue gas to be fully mixed under the action of the mixer, improving the mixing uniformity and reducing the problems of crystallization blockage and decreased reaction efficiency caused by uneven mixing, thereby ensuring the efficient progress of subsequent catalytic reactions.

[0008] Optionally, the mixer includes a baffle plate, which is disposed inside the smoke inlet pipe at an angle or perpendicular to the extension direction of the smoke inlet pipe.

[0009] By adopting the above technical solution, the guide plate can obstruct and guide the high-speed flowing flue gas. This forcibly changes the flow state of the flue gas, generating turbulence and eddies behind the guide plate, thereby enhancing the shearing and mixing effect between the flue gas and the reducing agent injected by the spraying assembly, and significantly improving the mixing uniformity of the flue gas and the reducing agent.

[0010] Optionally, two guide plates are provided, which are arranged at an angle, with the tip of the angle facing the air inlet end of the smoke inlet pipe; the width of the guide plate gradually increases from the air inlet end of the smoke inlet pipe to the air outlet end of the smoke inlet pipe.

[0011] By adopting the above technical solution, this structure can "split" the mainstream flue gas from the middle and guide it to both sides, achieving a dual function of diversion and turbulence. Simultaneously, the gradually increasing width of the guide plate along the flow direction causes the separated flue gas to exhibit a stronger tendency to rotate and diffuse. Compared to a single guide plate, this design generates a more complex and intense vortex field, causing the reducing agent to separate and merge on the pipe cross-section, achieving faster and more uniform mixing.

[0012] Optionally, the mixer further includes a baffle plate and a first elastic element; a flow passage is formed through the flow guide plate, and the baffle plate is rotatably connected to the flow guide plate to deflect the flue gas before it passes through the flow passage; the baffle plate can be flipped from one side of the flow guide plate to the other side of the flow guide plate through the flow passage; the first elastic element is used to cause the baffle plate to tend to flip towards the side of the flow guide plate facing the air inlet end of the smoke inlet pipe; when the flue gas velocity in the smoke inlet pipe reaches a preset value, the baffle plate is flipped towards the side of the flow guide plate facing the air outlet end of the smoke inlet pipe.

[0013] By adopting the above technical solution, when the flue gas velocity is low, the mixing of flue gas and reducing agent is difficult. At this time, the thrust generated by the flue gas flow against the baffle plate is insufficient to overcome the elastic force of the first elastic element. In its initial state (located on the side of the guide plate facing the inlet), the baffle plate significantly obstructs the flow of the flue gas, forcing it to pass through the flow holes and generating strong turbulence. This enhances the mixing uniformity of the flue gas and reducing agent at low flow velocities and increases the reaction rate. However, at high flue gas velocities, the flue gas itself has high turbulent kinetic energy and mixes more easily with the reducing agent. At this time, the thrust generated by the flue gas flow against the baffle plate is sufficient to overcome the elastic force of the first elastic element, causing the baffle plate to flip to the side of the guide plate facing the outlet. In this position, the obstruction of the baffle plate to the flue gas flow is greatly reduced, thereby reducing the impact on the flue gas velocity. This allows the flue gas to quickly flow to the catalytic unit for catalytic reaction and then be discharged, improving the efficiency of flue gas treatment. This design intelligently balances the mixing effect and flow resistance, increasing turbulence in the low-speed zone where strong mixing is required, and automatically reducing flow resistance in the high-speed zone where mixing is easy, thereby improving the overall operating efficiency of the device under different operating conditions.

[0014] Optionally, the mixer further includes a scraper and a second elastic element; a groove is provided on the baffle plate, the groove extending from the side of the baffle plate rotatably connected to the guide plate to the side of the baffle plate away from the side rotatably connected to the guide plate; the scraper slides in cooperation with the groove, and the scraper slides against the side of the baffle plate facing the air inlet end of the smoke inlet pipe; the first end of the second elastic element is connected to the scraper, and the second end of the second elastic element extends towards the air outlet end of the smoke inlet pipe, for causing the baffle plate to tend to flip towards the side of the guide plate facing the air outlet end of the smoke inlet pipe; for when the baffle plate flips to the side of the guide plate facing the air outlet end of the smoke inlet pipe, the distance between the second end of the second elastic element and the side of the baffle plate rotatably connected to the guide plate changes from greater than the distance between the second end of the second elastic element and the side of the baffle plate away from the side rotatably connected to the guide plate to less than the distance between the second end of the second elastic element and the side of the baffle plate away from the side rotatably connected to the guide plate.

[0015] By adopting the above technical solution, utilizing the characteristic of the baffle plate flipping under different flow rates, and combining the linkage design of the second elastic element and the scraper, the function of automatically cleaning the baffle plate is realized. Specifically, when the flue gas velocity in the flue reaches a preset value, the baffle plate flips from the side of the guide plate facing the air inlet of the flue to the side of the guide plate facing the air outlet of the flue. This reduces the distance between the end of the chute away from the side of the guide plate that is rotatably connected to the baffle plate and the second end of the second elastic element. Consequently, under the pulling force of the second elastic element, the scraper slides from the end of the chute near the side of the guide plate that is rotatably connected to the baffle plate to the end of the chute away from the side of the guide plate that is rotatably connected to the baffle plate. The sliding process of the scraper removes urea crystals or soot deposits adhering to the side of the baffle plate facing the air inlet of the flue (windward side). This design automatically clears crystal blockages without additional power, ensuring the long-term reliability of the baffle plate flipping function and maintaining the stable operation of the mixer.

[0016] Optionally, the spray assembly includes a spray head; the spray head is disposed inside the smoke inlet pipe, and the inlet of the spray head is connected to an external reducing agent outlet pipe.

[0017] By adopting the above technical solution, the reducing agent output pipe delivers the reducing agent into the spray head, which is responsible for atomizing the liquid reducing agent into fine droplets. Atomization greatly increases the contact surface area between the reducing agent and the high-temperature flue gas, which helps the reducing agent (such as urea solution) to evaporate and decompose rapidly, laying the foundation for its uniform mixing with the flue gas in the flue gas inlet pipe and subsequent efficient catalytic reaction.

[0018] Optionally, the spray assembly further includes a sensor, a control valve, and a controller; the sensor is located at the air inlet end of the flue gas inlet pipe and is used to collect information on the content of nitrogen oxides in the flue gas entering the flue gas inlet pipe; the control valve is located at the inlet of the spray head and is used to control the flow rate at the inlet of the spray head; the controller is electrically connected to the sensor and the control valve and is used to adjust the opening degree of the control valve according to the content information.

[0019] By adopting the above technical solution, precise closed-loop control of the reducing agent injection amount is achieved. Specifically, sensors collect real-time information on the nitrogen oxide content of the flue gas as it enters the flue gas inlet pipe. Based on this real-time data, the controller accurately calculates the theoretical value of the reducing agent required at the current time and adjusts the opening and closing degree of the control valve accordingly. This automatic adjustment mechanism ensures that the amount of reducing agent injected and the amount of nitrogen oxides in the flue gas always maintain the optimal chemical reaction molar ratio. This avoids both the decrease in denitrification efficiency caused by insufficient reducing agent injection and the waste of reducing agent and "ammonia escape" pollution caused by excessive injection, thus achieving the most efficient and economical denitrification treatment under various operating conditions.

[0020] Optionally, the catalytic module includes a mounting box and multiple catalytic corrugated plates; both ends of the mounting box are open, and one end of the mounting box is open to the first chamber, and the other end of the mounting box is open to the second chamber; the multiple catalytic corrugated plates are stacked in a staggered manner in the mounting box, and a reaction channel for flue gas to flow through is formed between adjacent catalytic corrugated plates.

[0021] By adopting the above technical solution, the corrugated plate structure can provide a larger catalyst specific surface area compared with the flat plate, thus improving catalytic efficiency. The reaction channels formed by the staggered stacking force the flue gas to continuously change direction during circulation, forming micro-turbulence on the catalyst surface, disrupting the boundary layer, and greatly enhancing the mass transfer rate of reactants (NOx and reducing agents) in the flue gas to the catalyst surface, thereby significantly improving the catalytic reaction efficiency and denitrification rate.

[0022] Optionally, a jet pipe is arranged around the outer periphery of the input end of the catalytic module. The jet pipe is connected to an external gas source. The jet pipe has multiple jet holes, and the output direction of the multiple jet holes is all towards the middle of the input end of the catalytic module.

[0023] By adopting the above technical solution, when dust and particulate matter carried in the flue gas accumulate at the input end face (windward side) of the catalytic module, an external gas source can be activated to introduce high-pressure gas into the jet pipe. After the gas jet is ejected at high speed, it can effectively purge and remove the dust and impurities accumulated at the input end of the catalytic module, thereby ensuring smooth flue gas flow, reducing system back pressure, and extending the effective service life and maintenance cycle of the catalytic module.

[0024] Optionally, a maintenance port communicating with the second chamber is provided on the side wall of the reaction chamber, and a protective cover for closing the maintenance port is detachably connected to the side wall of the reaction chamber, through which the catalyst module can be taken out from the reaction chamber.

[0025] By adopting the above technical solution, when the catalyst module needs to be repaired or replaced, the operator only needs to open the protective cover to easily pull out or install the catalyst module from the reaction tank through the maintenance port. This design greatly facilitates the daily maintenance, inspection, and replacement of the catalyst module, significantly reducing maintenance difficulty and downtime, and is especially suitable for the confined space of the ship's engine room.

[0026] In summary, this application includes the following beneficial technical effects: 1. Improve the integration and processing efficiency of the SCR reactor. Specifically, this design results in a "reversal" flow path for the flue gas within the reaction chamber. The flue gas first flows through most of the length of the inlet pipe, where it is sprayed and mixed with the reducing agent before entering the first chamber, and finally flows back towards the catalytic module. Compared to the linear series connection of components in the prior art, which leads to a longer overall structure, this application spatially integrates the mixing section (inlet pipe) and the reaction section (catalytic module), achieving a "U-shaped" flow of the flue gas within the reaction chamber. This shortens the overall axial length of the device, improves integration, and makes it suitable for space-constrained applications such as ship engine rooms. Simultaneously, while shortening the axial dimension, the extended design of the inlet pipe ensures a sufficiently long flow distance for the flue gas from the reducing agent injection point to the input end of the catalytic module. This solves the problem of insufficient reaction and short flow paths caused by the shortened dimensions in the prior art. A sufficiently long flow path allows the reducing agent and flue gas to be fully mixed under the action of the mixer, improving the mixing uniformity and reducing the problems of crystallization blockage and reaction efficiency reduction caused by uneven mixing, thereby ensuring the efficient progress of subsequent catalytic reactions; 2. At low flue gas velocities, mixing of flue gas and reducing agent is difficult. At this point, the thrust generated by the flue gas flow against the baffle plate is insufficient to overcome the elastic force of the first elastic element. In its initial state (located on the side of the guide plate facing the inlet), the baffle plate significantly obstructs the flow of flue gas, forcing it through the flow holes and generating strong turbulence. This enhances the mixing uniformity of flue gas and reducing agent at low flow velocities, increasing the reaction rate. However, at high flue gas velocities, the flue gas itself has high turbulent kinetic energy, making it easier to mix with the reducing agent. At this point, the thrust generated by the flue gas flow against the baffle plate is sufficient to overcome the elastic force of the first elastic element, causing the baffle plate to flip to the side of the guide plate facing the outlet. In this position, the obstruction of the baffle plate to the flue gas flow is greatly reduced, thus minimizing its impact on the flue gas velocity. This allows the flue gas to quickly flow to the catalytic unit for catalytic reaction before being discharged, improving the efficiency of flue gas treatment. This design intelligently balances the mixing effect and flow resistance, increasing turbulence in the low-speed zone where strong mixing is required, and automatically reducing flow resistance in the high-speed zone where mixing is easy, thereby improving the overall operating efficiency of the device under different operating conditions. 3. Utilizing the characteristic of the baffle plate flipping under different flow rates, and combined with the linkage design of the second elastic element and the scraper, an automatic baffle plate cleaning function is achieved. Specifically, when the flue gas velocity in the inlet pipe reaches a preset value, the baffle plate flips from the side of the guide plate facing the inlet pipe to the side of the guide plate facing the outlet pipe. This reduces the distance between the end of the slide chute away from the side rotating and connected to the guide plate and the second end of the second elastic element. Consequently, under the pulling force of the second elastic element, the scraper slides from the end of the slide chute closer to the side rotating and connected to the guide plate to the end of the slide chute away from the side rotating and connected to the guide plate. The sliding process of the scraper removes urea crystals or soot deposits adhering to the side of the baffle plate facing the inlet pipe (windward side). This design automatically clears crystal blockages without additional power, ensuring the long-term reliability of the baffle plate flipping function and maintaining the stable operation of the mixer. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application.

[0028] Figure 2 This is a schematic diagram of the internal structure of Embodiment 1 of this application.

[0029] Figure 3 yes Figure 2 A magnified view of part A in the middle.

[0030] Figure 4 This mainly demonstrates the mixer in Embodiment 2 of this application.

[0031] Figure 5 This is a cross-sectional view of the mixer in Embodiment 2 of this application.

[0032] Explanation of reference numerals in the attached drawings: 1. Reaction chamber; 11. First chamber; 12. Second chamber; 13. Flue gas outlet; 14. Maintenance port; 15. Protective cover; 2. Catalytic module; 21. Mounting box; 22. Catalytic corrugated plate; 3. Flue gas inlet pipe; 31. Inlet end; 32. Outlet end; 4. Spray assembly; 41. Spray head; 42. Sensor; 43. Control valve; 5. Mixer; 51. Guide plate; 511. Flow hole; 52. Baffle plate; 521. Slide groove; 53. First elastic element; 54. Scraper; 55. Second elastic element; 6. Jet pipe; 61. Jet hole. Detailed Implementation

[0033] The following combination Figures 1-5 This application will be described in further detail.

[0034] This application discloses an integrated SCR reactor.

[0035] Example 1

[0036] Reference Figure 1 and Figure 2 In this embodiment, the integrated SCR reactor includes a reaction chamber 1, a catalyst module 2, a flue gas inlet pipe 3, a spray assembly 4, a mixer 5, and a jet pipe 6.

[0037] The catalytic module 2 is located inside the reaction chamber 1 and is used to carry out a catalytic reaction with the flue gas containing a reducing agent. The catalytic module 2 divides the inner cavity of the reaction chamber 1 along the width direction to form a first chamber 11 and a second chamber 12. The input end of the catalytic module 2 is connected to the first chamber 11, and the output end of the catalytic module 2 is connected to the second chamber 12. A flue gas outlet 13 connected to the second chamber 12 is opened on the outer wall of the reaction chamber 1.

[0038] The inlet end 31 of the flue gas inlet pipe 3 is used to connect to the external flue gas outlet pipe, and the outlet end 32 of the flue gas inlet pipe 3 passes through one side of the reaction chamber 1 along the length direction of the reaction chamber 1 and extends into the first chamber 11 along the length direction of the reaction chamber 1. The spray assembly 4 is used to spray the reducing agent into the flue gas inlet pipe 3; the mixer 5 is provided in the flue gas inlet pipe 3 and is used to mix the flue gas and the reducing agent.

[0039] Specifically, reaction chamber 1 serves as the outer shell of the entire device, providing installation space and protection for the internal components. Reaction chamber 1 can be made of high-strength and corrosion-resistant metal materials, such as stainless steel and aluminum alloy, to ensure structural stability and corrosion resistance. The shape of reaction chamber 1 can be designed according to the actual installation space, and is generally a cuboid shape.

[0040] The flue gas inlet pipe 3 can be made of metal, which has certain high temperature resistance and corrosion resistance. The length and diameter of the flue gas inlet pipe 3 can be designed according to the actual flue gas flow rate and velocity.

[0041] The length of the inlet pipe 3 extending into the first chamber 11 is equal to 90% of the length of the reaction chamber 1. The length direction of the catalytic module 2 forms a 15° angle with the length direction of the reaction chamber 1, and the tip of the angle points towards the outlet end 32 of the inlet pipe 3.

[0042] In other embodiments, the catalytic module 2 can also divide the inner cavity of the reaction chamber 1 along the height direction of the reaction chamber 1 to form a first chamber 11 and a second chamber 12; the length direction of the catalytic module 2 can also be parallel to the length direction of the reaction chamber 1, or form an angle of less than 15°, greater than 15° and less than 45°; the length of the flue gas pipe 3 extending into the first chamber 11 is equal to the length of the reaction chamber 1 and can also be adjusted according to actual needs, for example, equal to 80% or 70% of the length of the reaction chamber 1.

[0043] By adopting the above technical solution, the integration and processing efficiency of the SCR reactor are improved. Specifically, this design makes the flow path of the flue gas in the reaction chamber 1 present a "reversal" shape. That is, the flue gas first needs to flow through most of the length of the inlet pipe 3, and during this period, the reducing agent is sprayed and mixed before entering the first chamber 11, and finally it flows back to the catalytic module 2. Compared with the problem of the long overall structure caused by the linear series connection of the components in the prior art, this application integrates the mixing section (inlet pipe 3) and the reaction section (catalytic module 2) in space, realizing the "U-shaped" flow of the flue gas inside the reaction chamber 1, shortening the overall axial length of the device, improving the integration, and making it suitable for occasions with limited installation space, such as ship engine rooms. At the same time, while shortening the axial dimension, the extended design of the inlet pipe 3 ensures that the flue gas has a sufficiently long flow distance from the reducing agent injection point to the input end of the catalytic module 2. This solves the problem of insufficient reaction caused by the shortened size in the prior art. The sufficiently long flow path allows the reducing agent and flue gas to be fully mixed under the action of mixer 5, improving the mixing uniformity and reducing the problems of crystallization blockage and reaction efficiency reduction caused by uneven mixing, thereby ensuring the efficient progress of subsequent catalytic reactions.

[0044] Furthermore, the angled arrangement between the catalytic module 2 and the reaction chamber 1 can significantly reduce the direct blowing effect on the input side of the catalytic module 2 when the flue gas flows out through the flue pipe 3 and then turns back, thus reducing the probability of dust and impurities clogging the catalytic module 2.

[0045] Reference Figure 2 and Figure 3In this embodiment, the mixer 5 includes two guide plates 51, both of which are fixedly installed on the inner wall of the smoke inlet pipe 3 at an angle to the extension direction of the smoke inlet pipe 3. The two guide plates 51 are arranged at an angle, with the tip of the angle facing the air inlet end 31 of the smoke inlet pipe 3. The width of the guide plates 51 gradually increases from the air inlet end 31 to the air outlet end 32 of the smoke inlet pipe 3. The two guide plates 51 are arranged symmetrically about the central axis of the smoke inlet pipe 3, rotating 180°. The guide plates 51 can be made of high-temperature resistant and corrosion-resistant metal plates, specifically stainless steel or aluminum alloy plates.

[0046] In other embodiments, the guide plate 51 may also be installed perpendicular to the extension direction of the smoke inlet pipe 3; the shape and number of the guide plate 51 may also be selected as needed, for example, one, three or five; the shape may be fan-shaped, circular or rectangular.

[0047] In this way, the guide vane 51 can obstruct and guide the high-speed flowing flue gas, forcibly changing the flow state of the flue gas to generate turbulence and eddies behind the guide vane 51. This enhances the shearing and mixing effect between the flue gas and the reducing agent injected by the spray assembly 4, significantly improving the mixing uniformity of the flue gas and the reducing agent. Simultaneously, the design of two guide vanes 51 can "split" the flowing flue gas from the middle and guide it to both sides, serving a dual function of diversion and turbulence. Furthermore, the width of the guide vane 51 gradually increases along the flow direction, causing the separated flue gas to generate a stronger tendency to rotate and diffuse. Compared to a single guide vane 51, this design can generate a more complex and intense eddy field, causing the reducing agent to separate and merge on the pipe cross-section, achieving faster and more uniform mixing.

[0048] Reference Figure 1 and Figure 2 In this embodiment, the spray assembly 4 includes a spray head 41, a sensor 42, a control valve 43, and a controller (not shown in the figure).

[0049] The spray head 41 is fixedly installed inside the air inlet end 31 of the smoke inlet pipe 3 and is located on the central axis of the smoke inlet pipe 3. The inlet of the spray head 41 is connected to an external reducing agent outlet pipe, and the spray direction of the spray head 41 is towards the air outlet end 32 of the smoke inlet pipe 3 and parallel to the extension direction of the smoke inlet pipe 3. The spray head 41 can be an atomizing nozzle, which can atomize the liquid reducing agent into fine droplets.

[0050] Sensor 42 is a nitrogen oxide content detection sensor, which can accurately measure the nitrogen oxide content in flue gas. Sensor 42 is fixedly installed on the inner wall of the flue gas inlet pipe 3 and located on the side of the spray head 41 near the air inlet end 31 of the flue gas inlet pipe 3, and is used to collect information on the nitrogen oxide content in the flue gas entering the flue gas inlet pipe 3.

[0051] The control valve 43 can be a solenoid valve. The control valve is located at the inlet of the spray head 41 and is used to control the flow rate of the reducing agent output from the external reducing agent output pipe into the spray head 41.

[0052] The controller can be a microcontroller or other device with data processing and control functions. The controller is electrically connected to the sensor 42 and the control valve 43 and is used to adjust the opening degree of the control valve 43 according to the information on the content of nitrogen oxides in the flue gas entering the flue gas pipe 3 collected by the sensor 42.

[0053] In other embodiments, the spray head 41 can also be a dual-fluid nozzle, with the first inlet of the dual-fluid nozzle connected to an external high-pressure air output pipe and the second inlet of the dual-fluid nozzle connected to an external reducing agent output pipe, so that the atomization degree of the reducing agent can be controlled according to the reaction requirements.

[0054] In this way, the reducing agent output pipe delivers the reducing agent to the inlet of the spray head 41, which then atomizes the liquid reducing agent into fine droplets and sprays them into the flue gas inlet 3. Atomization greatly increases the contact surface area between the reducing agent and the high-temperature flue gas, facilitating the rapid evaporation and decomposition of the reducing agent (such as urea solution), laying the foundation for its uniform mixing with the flue gas within the flue gas inlet 3 and subsequent efficient catalytic reaction. The sensor 42 collects real-time information on the nitrogen oxide content of the flue gas as it enters the flue gas inlet 3. Based on this real-time data, the controller accurately calculates the theoretical value of the reducing agent required and adjusts the opening and closing degree of the control valve 43 accordingly.

[0055] This automatic adjustment mechanism ensures that the amount of reducing agent injected and the amount of nitrogen oxides in the flue gas are always kept at the optimal chemical reaction molar ratio. This avoids both the decrease in denitrification efficiency caused by insufficient injection of reducing agent and the waste of reducing agent and "ammonia escape" pollution caused by excessive injection. As a result, the most efficient and economical denitrification treatment can be achieved under various operating conditions.

[0056] Reference Figure 1 and Figure 2 In this embodiment, the catalytic module 2 includes a mounting box 21 and multiple catalytic corrugated plates 22. The mounting box 21 is specifically a rectangular box with openings at both ends in the width direction, made of stainless steel, which has high strength and good sealing performance. One end of the mounting box 21 is connected to the first chamber 11, and the other end of the mounting box 21 is connected to the second chamber 12.

[0057] Multiple catalytic corrugated plates 22 are stacked and staggered along their height inside the mounting box 21, forming reaction channels between adjacent catalytic corrugated plates 22 for the flow of flue gas. The catalytic corrugated plates 22 can be made of vanadium-titanium-based catalyst material, which has excellent catalytic performance.

[0058] A jet pipe 6 is arranged around the outer periphery of the input end of the catalytic module 2. The jet pipe 6 is connected to an external gas source. Multiple jet holes 61 are opened on the jet pipe 6, and the output direction of the multiple jet holes 61 is all facing the center of the input end of the catalytic module 2. The external gas source can be an air compressor or other equipment that can provide high-pressure gas.

[0059] In this way, the corrugated plate structure can provide a larger catalyst specific surface area compared to the flat plate structure, thereby improving catalytic efficiency. The reaction channels formed by the staggered stacking force the flue gas to constantly change direction during circulation, forming microscopic turbulence on the catalyst surface, disrupting the boundary layer, and enhancing the mass transfer rate of reactants (NOx and reducing agents) in the flue gas to the catalyst surface, thus improving the catalytic reaction efficiency and denitrification rate.

[0060] Furthermore, when dust and particulate matter carried in the flue gas accumulate on the input end face (windward side) of the catalytic module 2, an external gas source can be activated to introduce high-pressure gas into the jet pipe 6. After the gas is ejected at high speed from the jet hole 61, it can effectively purge and remove the dust and impurities accumulated at the input end of the catalytic module 2, preventing them from blocking the reaction channels between the catalytic corrugated plates 22, ensuring smooth flow of flue gas, reducing system back pressure, and extending the effective service life and maintenance cycle of the catalytic module 2.

[0061] Preferably, a maintenance port 14 connecting to the second chamber 12 is provided on the side wall of the reaction chamber 1. A protective cover 15 for closing the maintenance port 14 is also detachably connected to the side wall of the reaction chamber 1 via a flange. The catalyst module 2 can be removed from the reaction chamber 1 through the maintenance port 14. In this way, when it is necessary to inspect or replace the catalyst module 2, the operator only needs to open the protective cover 15 to easily pull out or install the catalyst module 2 from the reaction chamber 1 through the maintenance port 14. This design greatly facilitates the daily maintenance, inspection and replacement of the catalyst module 2, significantly reduces the maintenance difficulty and downtime, and is especially suitable for the confined space of the ship's engine room.

[0062] The implementation principle of Example 1 is as follows: By making the flow path of flue gas in the reaction chamber 1 present a "reversal" shape, that is, the flue gas first needs to flow through most of the length of the inlet pipe 3, and during this period, the reducing agent is sprayed and mixed before entering the first chamber 11, and finally it flows back to the catalytic module 2. Compared with the problem of the overall structure being too long due to the linear series connection of the components in the prior art, this application integrates the mixing section (inlet pipe 3) and the reaction section (catalytic module 2) in space, realizing a "U-shaped" flow of flue gas inside the reaction chamber 1, shortening the overall axial length of the device, improving the integration, and making it suitable for installation space-constrained occasions such as ship engine rooms. At the same time, while shortening the axial dimension, the extended design of the inlet pipe 3 ensures that the flue gas has a sufficiently long flow distance from the reducing agent injection point to the input end of the catalytic module 2. This solves the problem of insufficient reaction and excessively short flow path caused by shortening the size in the prior art. The sufficiently long flow path allows the reducing agent and flue gas to be fully mixed under the action of mixer 5, improving the mixing uniformity and reducing the problems of crystallization blockage and reaction efficiency reduction caused by uneven mixing, thereby ensuring the efficient progress of subsequent catalytic reactions.

[0063] Example 2

[0064] Reference Figure 4 and Figure 5 The difference between this embodiment 2 and embodiment 1 is that the mixer 5 further includes a baffle 52, a first elastic element 53, a scraper 54 and a second elastic element 55.

[0065] The guide plate 51 is rectangular, and two flow holes 511 are formed on both sides of the guide plate 51, extending through its thickness, for the passage of flue gas. The shape of the baffle plate 52 matches the shape of the flow holes 511. The baffle plate 52 is hinged to the guide plate 51 and is used to deflect the flue gas before it passes through the flow holes 511. The baffle plate 52 can be flipped from the side of the guide plate 51 facing the air inlet end 31 of the smoke inlet pipe 3 through the flow holes 511 to the side of the guide plate 51 facing the air outlet end 32 of the smoke inlet pipe 3; the baffle plate 52 can also be flipped from the side of the guide plate 51 facing the air outlet end 32 of the smoke inlet pipe 3 through the flow holes 511 to the side of the guide plate 51 facing the air inlet end 31 of the smoke inlet pipe 3.

[0066] The first elastic element 53 is a high-temperature resistant torsion spring, which is installed at the hinge where the baffle 52 and the guide plate 51 are rotatably connected. It is used to make the baffle 52 tend to rotate so that the guide plate 51 faces the air inlet end 31 of the smoke inlet pipe 3. One end of the first elastic element 53 abuts against the baffle 52, and the other end of the first elastic element 53 abuts against the guide plate 51. The specific installation form is similar to a "torsion spring clip".

[0067] A groove 521 is provided on the side of the baffle plate 52 facing the air inlet end 31 of the smoke inlet pipe 3. The groove 521 extends from the side of the baffle plate 52 that is rotatably connected to the guide plate 51 to the side of the baffle plate 52 that is rotatably connected to the guide plate 51. The extension direction of the groove 521 is perpendicular to the rotation axis of the baffle plate 52.

[0068] The scraper 54 slides along the extension direction of the slide groove 521 via a protruding structure that engages with it. The scraper 54 also slides against the side of the baffle 52 facing the air inlet end 31 of the smoke inlet pipe 3. The width of the scraper 54 matches the width of the baffle 52. The scraper 54 can be made of hard alloy material to ensure high strength and wear resistance.

[0069] The second elastic element 55 is a high-temperature resistant tension spring, used to cause the baffle plate 52 to tend to flip the guide plate 51 toward the outlet end 32 of the smoke inlet pipe 3. The first end of the second elastic element 55 is connected to the scraper 54, and the second end of the second elastic element 55 extends toward the outlet end 32 of the smoke inlet pipe 3 and is connected to the guide plate 51.

[0070] In the initial state, the baffle 52 is located on the side of the guide plate 51 facing the air inlet end 31 of the smoke inlet pipe 3. The elastic force of the first elastic member 53 driving the baffle 52 to flip the side of the guide plate 51 facing the air inlet end 31 of the smoke inlet pipe 3 can completely overcome the elastic force of the second elastic member 55 driving the baffle 52 to flip the side of the guide plate 51 facing the air outlet end 32 of the smoke inlet pipe 3. At this time, the scraper 54 is located at the end of the slide groove 521 near the side of the baffle 52 rotatably connected to the guide plate 51; the distance between the second end of the second elastic member 55 and the side of the baffle 52 rotatably connected to the guide plate 51 is greater than the distance between the second end of the second elastic member 55 and the side of the baffle 52 away from the side rotatably connected to the guide plate 51.

[0071] When the flue gas velocity in the smoke inlet pipe 3 reaches a preset value, the elastic force of the first elastic element 53 driving the baffle 52 to flip the guide plate 51 towards the air inlet end 31 of the smoke inlet pipe 3 cannot overcome the elastic force of the second elastic element 55 driving the baffle 52 to flip the guide plate 51 towards the air outlet end 32 of the smoke inlet pipe 3, plus the force generated by the flue gas flow pushing the baffle 52 to flip the guide plate 51 towards the air inlet end 31 of the smoke inlet pipe 3. The baffle 52 will then flip to the side of the guide plate 51 facing the air outlet end 32 of the smoke inlet pipe 3. At this time, the scraper 54 slides to the end of the slide groove 521 away from the side of the baffle 52 rotatably connected to the guide plate 51; the distance between the second end of the second elastic element 55 and the side of the baffle 52 rotatably connected to the guide plate 51 is less than the distance between the second end of the second elastic element 55 and the side of the baffle 52 away from the side rotatably connected to the guide plate 51.

[0072] The implementation principle of Example 2 is as follows: When the flue gas velocity is low, it is difficult for the flue gas to mix with the reducing agent. At this time, the thrust generated by the flue gas flow against the baffle plate 52 is insufficient to overcome the elastic force of the first elastic element 53. In its initial state (located on the side of the guide plate 51 facing the inlet end 31), the baffle plate 52 creates a large obstruction to the flue gas, forcing the flue gas to pass through the flow hole 511 and generating strong turbulence, thereby enhancing the mixing uniformity of the flue gas and catalyst at low flow rates and increasing the reaction rate. However, when the flue gas velocity is high, the flue gas itself has high turbulent kinetic energy and mixes more easily with the reducing agent. At this time, the thrust generated by the flue gas flow against the baffle plate 52 is sufficient to overcome the elastic force of the first elastic element 53, causing the baffle plate 52 to flip to the side of the guide plate 51 facing the outlet end 32. At this position, the angle between the baffle 52 and the flue gas flow direction is reduced, and the obstruction of the baffle 52 to the flue gas flow is greatly reduced, thereby reducing the impact on the flue gas flow rate, allowing the flue gas to quickly flow to the catalytic unit for catalytic reaction and then be discharged, thus improving the efficiency of flue gas treatment.

[0073] This design intelligently balances the mixing effect and flow resistance, increasing turbulence in the low-speed zone where strong mixing is required, and automatically reducing flow resistance in the high-speed zone where mixing is easy, thereby improving the overall operating efficiency of the device under different operating conditions.

[0074] Meanwhile, by utilizing the characteristic of the baffle 52 to flip under different flow rates, and combined with the linkage design of the second elastic element 55 and the scraper 54, the function of automatically cleaning the baffle 52 is realized. Specifically, when the flue gas velocity in the smoke inlet pipe 3 reaches the preset value, the baffle 52 will flip from the side of the guide plate 51 facing the air inlet end 31 of the smoke inlet pipe 3 to the side of the guide plate 51 facing the air outlet end 32 of the smoke inlet pipe 3. This reduces the distance between the end of the slide groove 521 that is rotatably connected to the guide plate 51 away from the baffle 52 and the second end of the second elastic element 55. As a result, the scraper 54, under the pulling force of the second elastic element 55, slides from the end of the slide groove 521 that is close to the baffle 52 and rotatably connected to the guide plate 51, to the end of the slide groove 521 that is away from the baffle 52 and rotatably connected to the guide plate 51. The sliding process of the scraper 54 removes urea crystals or soot deposits adhering to the side of the baffle 52 facing the air inlet end 31 of the flue pipe 3 (windward side). This design automatically clears crystal blockages without additional power, ensuring the long-term reliability of the baffle 52's flipping function and maintaining the stable operation of the mixer 5.

[0075] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An integrated SCR reactor, characterized in that, include: reaction chamber; A catalytic module, located inside the reaction chamber, is used to carry out a catalytic reaction with flue gas containing a reducing agent; The catalytic module divides the inner cavity of the reaction chamber along the width or height direction to form a first chamber and a second chamber. The input end of the catalytic module is connected to the first chamber, and the output end of the catalytic module is connected to the second chamber. A flue gas outlet connected to the second chamber is provided on the outer wall of the reaction chamber. The inlet pipe has an air inlet end for connecting to an external flue gas outlet pipe, and an outlet end for passing through one side of the reaction chamber along the length of the reaction chamber and extending into the first chamber along the length of the reaction chamber. A spray assembly for spraying a reducing agent into the flue gas inlet pipe; A mixer, located inside the flue gas inlet pipe, is used to mix flue gas and a reducing agent. The mixer includes a guide plate, which is disposed inside the smoke inlet pipe at an angle or perpendicular to the extension direction of the smoke inlet pipe; The mixer further includes a baffle plate and a first elastic element; a flow passage is formed through the flow guide plate, and the baffle plate is rotatably connected to the flow guide plate to deflect the flue gas before it flows through the flow passage; the baffle plate can be flipped from one side of the flow guide plate to the other side of the flow guide plate through the flow passage; the first elastic element is used to cause the baffle plate to tend to flip towards the side of the flow guide plate facing the air inlet end of the smoke inlet pipe; when the flue gas velocity in the smoke inlet pipe reaches a preset value, the baffle plate flips to the side of the flow guide plate facing the air outlet end of the smoke inlet pipe; The mixer further includes a scraper and a second elastic element; a groove is provided on the baffle plate, the groove extending from the side of the baffle plate rotatably connected to the guide plate to the side of the baffle plate away from the side rotatably connected to the guide plate; the scraper slides in cooperation with the groove, and the scraper slides against the side of the baffle plate facing the air inlet end of the smoke inlet pipe; the first end of the second elastic element is connected to the scraper, and the second end of the second elastic element extends towards the air outlet end of the smoke inlet pipe and is connected to the guide plate, the second elastic element causing the baffle plate to tend to flip towards the side of the guide plate facing the air outlet end of the smoke inlet pipe; When the baffle plate flips to the side of the guide plate facing the exhaust end of the smoke inlet pipe, the distance from the second end of the second elastic member to the side of the baffle plate rotatably connected to the guide plate changes from being greater than the distance from the second end of the second elastic member to the side of the baffle plate away from the side rotatably connected to the guide plate, to being less than the distance from the second end of the second elastic member to the side of the baffle plate away from the side rotatably connected to the guide plate.

2. The integrated SCR reactor according to claim 1, characterized in that: The guide plate is provided in two pieces, which are arranged at an angle with the tip of the angle facing the air inlet end of the smoke inlet pipe; the width of the guide plate gradually increases from the air inlet end of the smoke inlet pipe to the air outlet end of the smoke inlet pipe.

3. The integrated SCR reactor according to claim 1, characterized in that: The spray assembly includes a spray head; the spray head is located inside the smoke inlet pipe, and the inlet of the spray head is connected to an external reducing agent outlet pipe.

4. The integrated SCR reactor according to claim 3, characterized in that: The spray assembly also includes a sensor, a control valve, and a controller; the sensor is located at the air inlet end of the flue gas inlet pipe and is used to collect information on the content of nitrogen oxides in the flue gas entering the flue gas inlet pipe; the control valve is located at the inlet of the spray head and is used to control the flow rate at the inlet of the spray head; the controller is electrically connected to the sensor and the control valve and is used to adjust the opening degree of the control valve according to the content information.

5. The integrated SCR reactor according to claim 1, characterized in that: The catalytic module includes a mounting box and multiple catalytic corrugated plates; both ends of the mounting box are open, and one end of the mounting box is open to the first chamber, and the other end of the mounting box is open to the second chamber; the multiple catalytic corrugated plates are stacked in a staggered manner in the mounting box, and a reaction channel for flue gas to flow through is formed between adjacent catalytic corrugated plates.

6. The integrated SCR reactor according to claim 1, characterized in that: A jet pipe is arranged around the outer periphery of the input end of the catalytic module. The jet pipe is connected to an external gas source. Multiple jet holes are opened on the jet pipe, and the output direction of the multiple jet holes is towards the middle of the input end of the catalytic module.

7. The integrated SCR reactor according to claim 1, characterized in that: The side wall of the reaction chamber is provided with a maintenance port that connects to the second chamber. A protective cover for closing the maintenance port is detachably connected to the side wall of the reaction chamber. The catalyst module can be taken out from the reaction chamber through the maintenance port.

Images