Biomass water-cooled vibrating grate boiler in-furnace flue gas treatment device and method

Abstract

The present application relates to a biomass water-cooled vibrating grate boiler flue gas treatment device and method, and relates to the technical field of dust removal and purification treatment; it includes a dust remover shell, a high-efficiency ceramic multi-tube dust remover, and a medium-high temperature SCR denitration reactor; the high-efficiency ceramic multi-tube dust remover realizes the replacement and maintenance of ceramic sleeve pipes in a modular way, can realize the quick replacement or maintenance of single ceramic sleeve pipes inside the dust remover shell without stopping the machine, improves the efficiency, and can guarantee the stability of the ceramic sleeve pipes and avoid the violent shaking of the ceramic sleeve pipes during work; secondly, the present application processes the tail flue gas, does not need to reheat the flue gas during the whole process, returns the flue gas after dust removal and denitration to the boiler tail under the high-temperature state, and realizes recycling; not only the clean flue gas can improve the heat energy recovery efficiency, but also can reduce the blockage and wear of the boiler tail heat exchanger, greatly prolongs the continuous operation time of the boiler.

Description

Technical Field

[0001] This invention relates to the field of flue gas denitrification, desulfurization and dust removal and purification technology, and in particular to a device and method for treating flue gas inside a biomass water-cooled vibrating grate boiler. Background Technology

[0002] The flue gas treatment device in a biomass water-cooled vibrating grate boiler integrates multiple technologies to synergistically control pollutant emissions and improve combustion efficiency. With the strengthening of environmental protection across society and the increase in coal market prices, biomass boilers are becoming increasingly popular due to their energy saving, environmental protection, economy, and ease of use.

[0003] A biomass boiler is a boiler that uses biomass fuel as its energy source. Its working principle is similar to that of a traditional coal-fired boiler, but it uses renewable biomass fuels such as sawdust, straw, and rice husks. These fuels generate heat through combustion, and then the heat is transferred to water or steam via a heat exchanger for heating, power generation, or other industrial applications.

[0004] Biomass boilers emit large amounts of harmful substances such as nitrogen oxides, sulfides, and soot during combustion. Therefore, it is necessary to treat the exhaust gas generated by biomass boilers by denitrification, desulfurization, and dust removal to ensure that the exhaust gas meets emission standards.

[0005] For example, Chinese patent CN220758533U discloses a multi-tube ceramic dust collector, relating to the field of dust collector technology. It includes a support frame, a dust collection box, cyclones, and a fixed box. The top of the support frame is fixedly connected to the bottom of the dust collection box. An air inlet is provided on the outer side of the top of the dust collection box, and a set of symmetrical air outlets are also provided on the outer side of the top of the dust collection box. The cyclones are arranged in a rectangular array and are all fixedly connected inside the dust collection box. This invention uses a limiting mechanism, under the action of a return spring, to separate the insert rods from the insertion holes, thereby separating the top plate from the dust collection box. The filter plate can then be removed for cleaning, facilitating quick and easy removal of the filter plate from the dust collection box. The filter plate allows for further filtration of smaller particles in the dust-collecting gas, reducing air pollution from the exhaust gas.

[0006] However, the dust collectors mentioned above still have some shortcomings in actual use:

[0007] 1. First, in the existing technology, the denitrification effect of biomass boilers is not good. Since the SCR reactor is arranged in the flue at the tail end of the biomass boiler, the lack of dust removal can easily lead to severe catalyst wear. In addition, the existing device has poor dust removal effect and still cannot guarantee the service life of the catalyst.

[0008] 2. Secondly, when existing equipment removes dust from the exhaust gas generated by biomass boiler combustion, its wear resistance is poor, which easily leads to wear on the inner wall of the cyclone under the scouring of high-speed dust, requiring frequent replacement. Moreover, the operation steps for replacing and maintaining the cyclone in existing equipment are very complicated.

[0009] 3. Secondly, the existing device adopts an integrated design, which means that if a single tube of the cyclone is damaged, the entire machine must be shut down and disassembled, resulting in low efficiency.

[0010] Therefore, based on the above-stated viewpoints, there is still room for improvement in existing dust collectors. Summary of the Invention

[0011] To address the aforementioned problems, this invention provides an in-furnace flue gas treatment device and method for biomass water-cooled vibrating grate boilers, employing the following technical solution:

[0012] In the first aspect, this application relates to a flue gas treatment device for a biomass water-cooled vibrating grate boiler, including a dust collector shell, an air inlet on one side for the flue gas to enter the furnace, and a dust removal pipe at the air inlet for the flue gas to enter the dust collector shell for dust removal.

[0013] The high-efficiency ceramic multi-tube dust collector is located inside the dust collector shell. It includes two sets of upper and lower steel supports symmetrically arranged in the height direction of the dust collector shell. Several ceramic cyclones are evenly spaced on the steel supports. A smoke distributor is connected to the dust collection pipe. The smoke distributor has several branch round holes connected to the dust collection pipe. A dust hopper is also provided at the bottom of the dust collector shell.

[0014] The medium-high temperature SCR denitrification reactor is used to denitrify the flue gas after dust removal.

[0015] Preferably, a smoke inlet is provided on one side of the cyclone separator, and the branch holes on the smoke distributor are in active contact with the smoke inlet on one side of the cyclone separator;

[0016] The upper end of the cyclone is in contact with the exhaust pipe, and the cyclone has a dust removal chamber that is in contact with the exhaust pipe along the height direction;

[0017] The branch holes of the smoke equalizer are equipped with telescopic pipes, and the end of the telescopic pipe away from the smoke equalizer moves against the smoke inlet of the cyclone.

[0018] The bottom of the exhaust straight pipe is also equipped with a telescopic pipe, and the side of the telescopic pipe at the bottom of the exhaust straight pipe away from the exhaust straight pipe moves to abut against the top of the cyclone.

[0019] Preferably, the dust collector housing is also provided with a control component for controlling the horizontal pulling of several cyclones, the control component including a control frame that is slidably inserted into the side wall of the dust collector housing.

[0020] Preferably, the steel support is composed of three sections: a central support on one side, and side supports that are slidably installed on both sides of the central support. The ends of the two side supports that are away from the central support are slidably set on the inner wall of the dust collector shell. The central support and the side supports are provided with mounting slots, and two sets of symmetrical positioning sliders are slidably installed in the mounting slots. A limiting frame for limiting the cyclone is provided between the two sets of positioning sliders.

[0021] Preferably, the cyclone is composed of segmented ceramic sleeves, with metal clamps between the multiple ceramic sleeves, and elastic sealing rings on both sides of the metal clamps that allow for thermal expansion and facilitate partial replacement.

[0022] Preferably, a first linkage component is also provided between the steel bracket and the control frame. The first linkage component includes three sets of limit frames that are slidably connected to the side bracket and its upper end, each of which is connected to a scissor assembly. A first gear is installed on one side of the three sets of scissor assemblies, and the height of the three sets of first gears on the same side bracket gradually increases along its length.

[0023] The dust collector housing is equipped with a No. 1 linkage rack, which has three sets of rack control slots corresponding to the No. 1 gear at different heights.

[0024] Preferably, the inner side of the limiting frame is provided with an arc-shaped locking groove, and two fan-shaped clamping bars are symmetrically slidably installed in the arc-shaped locking groove. The fan-shaped clamping bars are provided with clamping pouches of gradually increasing size from the outside to the inside along the arc-shaped trajectory of the inner side.

[0025] Two fan-shaped clamping strips are offset on their back sides and have a central rack. Between the two central racks is a central gear that is rotatably mounted on the inner wall of the limiting frame.

[0026] Preferably, a second linkage component is provided on the side support. The second linkage component includes several extended gears installed on the side support. One side of the extended gear is meshed with an opening and closing gear. A control gear is meshed on the opening and closing gear. A central shaft is provided in the middle of the control gear. A linkage gear that meshes with the fan-shaped clamp is also installed on the central shaft. The fan-shaped clamp is provided with a sawtooth structure.

[0027] A second linkage rack is installed on the inner wall of the dust collector housing.

[0028] Preferably, the dust collector housing is also provided with an adjusting component for controlling the angle adjustment of the cyclone. The adjusting component includes several sets of adjusting clips connected to the side wall of the dust collector housing by bearings. Each adjusting clip has a precision sprocket mounted on its back side. A synchronous chain is installed between the precision sprockets. A control sprocket is provided on one side of the synchronous chain to control its rotation. A control knob is provided on the control sprocket.

[0029] Secondly, this application relates to a method for treating flue gas inside a biomass water-cooled vibrating grate boiler, which is as follows:

[0030] S1. Fuel pretreatment: Biomass fuel needs to be crushed to a suitable particle size and the moisture content needs to be controlled;

[0031] S2. Grate Vibration: By adjusting the frequency and amplitude of the vibrating grate, a uniform distribution of the fuel layer is ensured.

[0032] S3, Exhaust Gas Conveying: The exhaust gas generated during combustion is conveyed to the dust collector housing;

[0033] S4. Preliminary treatment of exhaust gas: After the flue gas is transported to the inside of the dust collector shell, it is treated by the high-efficiency ceramic multi-tube dust collector arranged inside, so that the impurities in the flue gas are separated, and the treated flue gas is transported to the medium and high temperature SCR denitrification reactor.

[0034] S5. Secondary treatment of exhaust gas: The separated flue gas is subjected to secondary denitrification treatment through a medium-high temperature SCR denitrification reactor arranged inside the dust collector shell.

[0035] S6. Exhaust gas recirculation: After denitrification, the flue gas is transported to the heating surface at the tail of the boiler to repeatedly recycle the heat in the flue gas.

[0036] S7. Exhaust gas discharge: It is then discharged to the chimney by an induced draft fan.

[0037] In summary, this application includes at least one of the following beneficial technical effects:

[0038] I. In this invention, only a suitable flue gas temperature (320-400℃) needs to be found in the biomass tail flue. The raw flue gas is then led out and passes through a high-efficiency ceramic multi-tube dust collector and a medium-high temperature SCR denitrification reactor. The treated denitrified flue gas is then returned to the vertical flue of the biomass boiler through a connecting flue, flowing through the remaining heating surfaces to prevent heat loss. Sulfur and dust emissions are achieved through an external semi-dry desulfurization and dust removal integrated device, and finally, the clean flue gas is discharged into the atmosphere by an induced draft fan. The entire process does not require reheating of the flue gas. The flue gas, after dust removal and denitrification at high temperature, returns to the boiler tail. The clean flue gas further improves heat recovery efficiency and reduces blockage and wear of the boiler tail heat exchanger, greatly extending the boiler's continuous operating time. It is an ultra-efficient process route that coordinates energy saving, safety, and environmental governance.

[0039] Second, this application achieves the replacement and maintenance of ceramic sleeves through a modular approach. This not only enables the rapid replacement or repair of individual ceramic sleeves inside the dust collector housing without shutting down the machine, thus improving efficiency, but also ensures the stability of the ceramic sleeves and prevents them from shaking violently during operation.

[0040] Third, the high-efficiency ceramic multi-tube dust collector of the present invention can achieve large-scale dust removal of flue gas through matrix-type ceramic sleeves, ensuring the efficiency of impurity separation in flue gas, and the use of ceramic sleeves made of ceramic material can improve the service life of the entire equipment.

[0041] Fourth, the adjusting component of this invention can actively control the ceramic sleeve to make fine adjustments to its angle. The tilted ceramic sleeve causes dust to be thrown against the pipe wall under centrifugal force, and then slides down the tilted pipe wall to the bottom dust collection hopper by gravity, reducing residue on the pipe wall and avoiding blockage caused by dust accumulation. Traditional vertical cyclone pipes require reverse airflow or additional vibration for dust removal, which is energy-intensive and prone to wear. Attached Figure Description

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] Figure 1 This is a schematic diagram of the main structure of the present invention.

[0044] Figure 2 This is a schematic diagram of the dust collector housing of the present invention.

[0045] Figure 3 This is a schematic diagram of the structure of the high-efficiency ceramic multi-tube dust collector inside the dust collector housing of the present invention.

[0046] Figure 4 This is a partial structural schematic diagram of the high-efficiency ceramic multi-tube dust collector of the present invention.

[0047] Figure 5 This is a first-view structural schematic diagram of the steel bracket of the present invention.

[0048] Figure 6 This is a second-view structural schematic diagram of the steel bracket of the present invention.

[0049] Figure 7 This is a schematic diagram of the structure of the ceramic sleeve of the present invention.

[0050] Figure 8 This is a schematic diagram of the structure between the high-efficiency ceramic multi-tube dust collector and the No. 1 linkage component of the present invention.

[0051] Figure 9 This is the present invention. Figure 8 A magnified view of section A in the image.

[0052] Figure 10 This is a schematic diagram of the structure between the first linkage component and the second linkage component of the present invention.

[0053] Figure 11 This is a schematic diagram of the structure of the adjusting component of the present invention.

[0054] Figure 12This is a schematic diagram of the structure between the fan-shaped clamping strip and the clamping pouch of the present invention.

[0055] Figure 13 This is a flowchart of the flue gas treatment method for a biomass water-cooled vibrating grate boiler according to the present invention.

[0056] Explanation of reference numerals in the attached drawings: 1. Dust collector shell; 2. Dust collection duct; 3. High-efficiency ceramic multi-tube dust collector; 30. Steel support; 31. Cyclone separator; 32. Smoke equalizer; 33. Branch hole; 34. Smoke inlet; 35. Exhaust straight pipe; 36. Dust collection chamber; 38. Ash hopper; 8. Medium-high temperature SCR denitrification reactor; 4. Control components; 40. Control frame; 300. Central support; 301. Side support; 302. Mounting slot; 303. Positioning slider; 37. Limiting frame; 310. Ceramic sleeve; 311. Metal clamp; 312. Spring 5. Seal ring; 6. First linkage component; 7. Scissor lift assembly; 8. First gear; 9. First linkage rack; 10. Rack control groove; 11. Fan-shaped clamp; 12. Clamping bag; 13. Centered rack; 14. Centered gear; 15. Second linkage component; 16. Extension gear; 17. Opening and closing gear; 18. Control gear; 19. Centered shaft; 10. Linkage gear; 10. Second linkage rack; 11. Adjusting component; 12. Adjusting clamp; 13. Precision sprocket; 14. Synchronous chain; 15. Control sprocket; 16. Telescopic pipe. Detailed Implementation

[0057] The following combination Figures 1-13 This application will be described in further detail.

[0058] This application discloses an in-furnace flue gas treatment device and method for biomass water-cooled vibrating grate boilers, which is mainly used in the treatment of flue gas at the tail end of biomass boilers.

[0059] First, in the existing technology, the denitrification effect of biomass boilers is not good. Furthermore, since the SCR reactor is arranged in the tail flue of the biomass boiler, the lack of dust removal can easily lead to severe catalyst wear. In addition, the existing devices have poor dust removal effect and still cannot guarantee the service life of the catalyst.

[0060] Secondly, when existing devices remove dust from the exhaust gas generated by biomass boiler combustion, their wear resistance is poor, which easily leads to wear on the inner wall of the cyclone 31 under high-speed dust scouring, requiring frequent replacement. Moreover, the operation steps for replacing and maintaining the cyclone 31 in existing devices are very complicated.

[0061] Secondly, the existing device adopts an integrated design, which means that if a single tube of the Cyclone 31 is damaged, the entire machine needs to be shut down and disassembled, resulting in low efficiency.

[0062] Therefore, this application proposes an in-furnace flue gas treatment device for a biomass water-cooled vibrating grate boiler to solve the above problems.

[0063] This application first provides a brief description of biomass fuels: With increasing emphasis on environmental protection and health across society, and the promotion of energy conservation, environmental protection, and economy, there is a strong push for biomass fuels to replace traditional fuels that are highly polluting and hazardous. Biomass fuels not only reduce costs and are renewable, but also reduce environmental pollution. They are also an important component of building clean energy systems in cities and ensuring the success of new urbanization.

[0064] Biomass fuel requires biomass boilers, which use renewable biomass as fuel. This fuel has a complex composition, containing nitrogen, sulfur, and other elements. Combustion of biomass fuel emits large amounts of harmful substances such as nitrogen oxides, sulfides, and particulate matter, polluting the environment and posing health risks. Therefore, it is essential to denitrify, desulfurize, and remove dust from the exhaust gas produced by biomass boilers. Currently, most regions in China implement the "50355" ultra-low emission standard for biomass boiler exhaust pollutants, which requires NOx concentrations to be ≤50mg / Nm3, SO2 concentrations to be ≤35mg / Nm3, and particulate matter to be ≤5mg / Nm3 (standard conditions, dry basis, 6% O2).

[0065] Currently, the mainstream denitrification technologies in China are SNCR (Selective Non-Catalytic Reduction) and SCR (Selective Catalytic Reduction), but neither of these processes performs well in biomass boilers. With SCR, the high alkali metal content in the flue gas (up to 8% depending on the fuel) causes the SCR catalyst to become poisoned and deactivated quickly. Furthermore, since the SCR reactor is located in the tail flue of the biomass boiler without dust removal, catalyst wear is severe in addition to alkali metal poisoning. With SNCR, the furnace bed temperature is generally low (around 700℃-800℃) due to the unique structure of biomass boilers, while the optimal temperature window for SNCR is 850℃-1050℃. Therefore, the SNCR temperature window is unsuitable, resulting in very low efficiency or even no effect, and ammonia consumption far exceeds the theoretical value, making it uneconomical.

[0066] In view of the current environmental protection process for denitrification, desulfurization and dust removal of flue gas at the tail end of biomass boilers, especially the inability of conventional denitrification technology to adapt to the flue gas treatment of biomass boilers, this application proposes a method for treating flue gas inside a biomass water-cooled vibrating grate boiler.

[0067] First, biomass fuel is fed into a biomass boiler for combustion, converting biomass into heat energy through combustion or gasification. A suitable flue gas temperature (320-400℃) is found in the vertical flue of the biomass boiler for denitrification, desulfurization, and dust removal. The high-temperature flue gas is then drawn out through the flue, and the flue outlet is connected to the inlet of a high-efficiency ceramic multi-tube dust collector 3. After pre-dust removal by the high-efficiency ceramic multi-tube dust collector 3, the dust removal efficiency is high. The outlet of the high-efficiency ceramic multi-tube dust collector 3 is connected to the inlet of a medium-high temperature SCR denitrification reactor 8. The denitrified flue gas is then returned to the residual heat exchanger at the tail end of the boiler. After heat recovery, the flue gas at the boiler tail outlet is approximately 140°C and is connected to the inlet of the CFB semi-dry desulfurization tower. The outlet of the CFB semi-dry desulfurization tower is connected to the inlet of the bag filter, the outlet of the bag filter is connected to the inlet of the induced draft fan, and the outlet of the induced draft fan is connected to the inlet of the chimney. The clean flue gas after denitrification, desulfurization, and dust removal is discharged into the atmosphere through the chimney. At the same time, an SNCR denitrification device is installed at a suitable location in the biomass boiler. Part of this device can improve the denitrification efficiency to some extent, thereby reducing the pressure of SCR denitrification. The other part provides escape ammonia for SCR denitrification.

[0068] It should be noted that the CFB semi-dry desulfurization tower, bag filter, and induced draft fan are existing known structures, and should be referenced. Figure 1 As shown, but without annotation.

[0069] The specific steps for separating impurities from the flue gas produced by biomass fuel combustion are as follows:

[0070] See Figure 2 and Figure 3 As shown, the flue gas treatment device for a biomass water-cooled vibrating grate boiler includes a dust collector shell 1, with an air inlet on one side for supplying flue gas into the furnace, and a dust removal pipe 2 at the air inlet for supplying flue gas into the dust collector shell 1 for dust removal.

[0071] The function of the dust removal pipe 2 is to transport the tail flue gas and ensure that the tail flue gas enters the high-efficiency ceramic multi-tube dust collector 3 inside the dust collector housing 1.

[0072] The high-efficiency ceramic multi-tube dust collector 3 is located inside the dust collector shell 1. It includes two sets of upper and lower steel supports 30 symmetrically arranged in the height direction of the dust collector shell 1. Several ceramic cyclones 31 are evenly spaced on the steel supports 30. A smoke equalizer 32 is connected to the dust collection pipe 2. Several branch round holes 33 connected to the dust collection pipe 2 are provided in the smoke equalizer 32.

[0073] When the tail flue gas enters the dust removal pipe 2, it enters the smoke distributor 32 along the dust removal pipe 2. Then the smoke distributor 32 transports the tail flue gas along the branch round hole 33 to the inside of the cyclone separator 31. The cyclone separator 31 separates the mixture of gas and solid particles into different channels by rotating, thereby achieving separation. The separated impurities enter the ash hopper 38, while the separated tail flue gas enters the next process.

[0074] The high-efficiency ceramic multi-tube dust collector 3's main structural components—cyclone separator 31, flue gas equalizer 32, and exhaust straight pipe 35—are all made of high-alumina ceramic material and fired at high temperatures. The material ratio is reasonable, ensuring it does not deform, crack, or break under high temperature (600℃) and low temperature variations. It features high dust removal efficiency, long service life, and easy maintenance, making it suitable for harsh environments such as biomass boiler flue gas with high humidity and sticky dust. By employing a multi-tube dust collector that removes dust before denitrification, the high dust removal efficiency allows the SCR catalyst to undergo denitrification in a low-dust environment, ensuring high catalyst activity during use, extending catalyst lifespan, and meeting ultra-low nitrogen oxide emission requirements.

[0075] See Figure 4 As shown, a smoke inlet 34 is provided on one side of the cyclone 31, and the branch circular hole 33 on the smoke distributor 32 is in contact with the smoke inlet 34 on one side of the cyclone 31.

[0076] The upper end of the cyclone 31 abuts against the exhaust straight pipe 35, and the cyclone 31 has a dust removal chamber 36 that abuts against the exhaust straight pipe 35 along the height direction.

[0077] A telescopic pipe 39 is provided at the branch circular hole 33 of the smoke equalizer 32. The end of the telescopic pipe 39 away from the smoke equalizer 32 is movably abutting against the smoke inlet 34 of the cyclone separator 31. A telescopic pipe 39 is also provided at the bottom of the exhaust straight pipe 35. The side of the telescopic pipe 39 at the bottom of the exhaust straight pipe 35 away from the exhaust straight pipe 35 is movably abutting against the top of the cyclone separator 31.

[0078] The branch circular hole 33 of the smoke distributor 32 and the smoke inlet 34 on one side of the cyclone separator 31 move and abut against each other. It should be noted that the reason for setting the telescopic pipe 39 at the smoke distributor 32 and the exhaust straight pipe 35 is to ensure that when the angle of the cyclone separator 31 is finely adjusted, the tail smoke can still enter the interior of the cyclone separator 31 through the smoke distributor 32. Similarly, it also ensures that the tail smoke can still enter the next process through the exhaust straight pipe 35, thereby ensuring the sealing between the two and avoiding leakage.

[0079] It should also be noted that the exhaust straight pipe 35 and the branch round hole 33 are equipped with electrically controlled valves, which can automatically control their opening and closing when the equipment is maintained without shutting down.

[0080] See Figure 5 , Figure 6 and Figure 7 The diagram shown is a structural schematic of the steel support 30 in this application. The steel support 30 is composed of three sections. One side is the middle support 300. Side supports 301 are slidably installed on both sides of the middle support 300. The ends of the two side supports 301 away from the middle support 300 are slidably set on the inner wall of the dust collector housing 1. The middle support 300 and the side supports 301 are provided with mounting slots 302. Two sets of symmetrical positioning sliders 303 are slidably installed in the mounting slots 302. A limiting frame 37 for limiting the cyclone separator 31 is provided between the two sets of positioning sliders 303.

[0081] It should be noted that the cyclone 31 is installed in the limiting frame 37 of the side bracket 301 and the middle bracket 300.

[0082] The steel support 30 adopts a three-section structure primarily to facilitate the independent replacement of the ceramic sleeves 310 in the cyclone separator 31. When it is necessary to replace or maintain the three sets of ceramic sleeves 310 on the middle support 300, pull the middle support 300 outwards along the width of the dust collector housing 1 until all three sets of limiting frames 37 on the middle support 300 are exposed. At this point, the three sets of ceramic sleeves 310 on the middle support 300 can be maintained or replaced. Similarly, when it is necessary to maintain or replace the ceramic sleeves 310 on the side support 301, the above operation can be repeated.

[0083] This application achieves the replacement and maintenance of ceramic sleeve 310 through a modular approach. This not only enables the rapid replacement or repair of a single ceramic sleeve 310 inside the dust collector housing 1 without shutting down the machine, thus improving its efficiency, but also ensures the stability of the ceramic sleeve 310 and prevents it from shaking violently during operation.

[0084] See Figure 7 The diagram shown is a structural schematic of the cyclone 31 in this application. The cyclone 31 is composed of segmented ceramic sleeves 310. Metal clamps 311 are provided between the multiple segments of ceramic sleeves 310, and elastic sealing rings 312 are provided on both sides of the metal clamps 311 to allow thermal expansion and facilitate partial replacement.

[0085] The cyclone 31 is a known existing structure, which includes a ceramic sleeve 310, and outside the ceramic sleeve 310, there are also a guide and a dust collection chamber, which are not shown in the figure.

[0086] The main function of the cyclone separator 31 is to separate solid particles from dust-laden gas using centrifugal force. Its working principle is as follows: After entering the cyclone separator 31 through the inlet, the dust-laden gas rotates at high speed inside the outer casing, forming a rotating airflow. During rotation, due to inertia and centrifugal force, solid particles are thrown against the inner wall of the cyclone separator 31 and fall down the wall into the dust collection chamber. The purified gas is then discharged through the exhaust pipe 35.

[0087] The ceramic sleeve 310 is constructed in a multi-segment manner. When treating a large volume of tail gas, a longer ceramic sleeve 310 is required to improve the efficiency of separating impurities. Furthermore, the multi-segment ceramic sleeve 310 facilitates partial replacement. During maintenance, only a portion of the multi-segment ceramic sleeve 310 needs to be replaced, eliminating the need to replace the entire ceramic sleeve 310. This further improves cost control and reduces waste of the ceramic sleeve 310.

[0088] However, it should be noted that the multi-segment ceramic sleeves 310 are connected by metal clamps 311 and elastic sealing rings 312, which can ensure the tightness between the multi-segment ceramic sleeves 310 and prevent impurities from leaking from the gaps between the ceramic sleeves 310 during impurity separation. Furthermore, the ceramic sleeves 310 are connected to the metal clamps 311 by the elastic sealing rings 312, allowing axial thermal expansion.

[0089] The multi-segment ceramic sleeve 310 generally operates in a high-temperature environment, thus allowing for axial thermal expansion and preventing crushing of the contact surfaces between the ceramic sleeves 310, thereby further improving the stability and service life of the ceramic sleeve 310.

[0090] Looking back Figure 3 As shown, the dust collector housing 1 is also provided with a control component 4 for controlling the horizontal pulling of several cyclones 31. The control component 4 includes a control frame 40 that is slidably inserted into the side wall of the dust collector housing 1.

[0091] It should be noted that a control frame 40 is slidably installed on one side of the dust collector housing 1. The control frame 40 is connected to the side support 301 and the middle support 300 by snap-fit. Furthermore, a limit rod is provided on the inner side of the control frame 40 to ensure that the control frame 40 can be pulled along the dust collector housing 1.

[0092] Reference Figure 8 , Figure 9 and Figure 10As shown, specifically, a second linkage component 6 is provided on the side support 301. The second linkage component 6 includes several extension gears 60 correspondingly installed on the side support 301. One side of the extension gear 60 is meshed with an opening and closing gear 61. A control gear 62 is meshed on the opening and closing gear 61. A central shaft 63 is provided in the middle of the control gear 62. A linkage gear 64 that meshes with the fan-shaped clamp 371 is also installed on the central shaft 63. The fan-shaped clamp 371 is provided with a sawtooth structure.

[0093] A second linkage rack 65 is installed on the inner wall of the dust collector housing 1.

[0094] The inner side of the limiting frame 37 is provided with an arc-shaped locking groove, and two fan-shaped clamping strips 371 are symmetrically slidably installed in the arc-shaped locking groove. The fan-shaped clamping strips 371 are provided with clamping pouches 372 with gradually increasing size from the outside to the inside along the arc-shaped trajectory of the inner side.

[0095] It should be noted that the two sector-shaped clamping bars 371 are initially closed to each other, so that the ceramic sleeve 310 in the arc-shaped locking groove of the limiting frame 37 is limited by the sector-shaped clamping bars 371 and the clamping pouch 372 on the sector-shaped clamping bars 371.

[0096] The ceramic sleeve 310 is clamped by the cooperation of the limiting frame 37 and the fan-shaped clamping strip 371, ensuring that the ceramic sleeve 310 can be stably distributed inside the dust collector housing 1. It should be noted that the ceramic sleeve 310 is distributed in an array.

[0097] In specific implementation, when the control frame 40 pulls the side bracket 301 outward, the extension gear 60 on the side bracket 301 engages with the second linkage rack 65. Then the extension gear 60 rotates, and the extension gear 60 controls the opening and closing gear 61 to rotate. The opening and closing gear 61 drives the control gear 62 and the linkage gear 64 coaxial on the central shaft 63 to rotate synchronously. While rotating, the linkage gear 64 controls the two closed fan-shaped clamping bars 371 to retract into the arc-shaped locking groove inside the limit frame 37 until the fan-shaped clamping bars 371 separate from the ceramic sleeve 310. At this time, the fan-shaped rack loses the clamping force on the ceramic sleeve 310, so that the ceramic sleeve 310 is vertically distributed on the side bracket 301.

[0098] When the central support 300 needs to be pulled outward, the fan-shaped rack in the central support 300 will also open automatically along with the movement of the control frame 40. However, it should be noted that the various gears on the central support 300 and the various gears on the side support 301 are only different in position, but their working process and principle are the same.

[0099] Let's look again. Figure 8 , Figure 9 and Figure 10As shown, specifically, a first linkage 5 is also provided between the steel bracket 30 and the control frame 40. The first linkage 5 includes three sets of limit frames 37 that are slidably connected to the side bracket 301 and its upper end, each of which is connected to a scissor assemblies 50. A first gear 51 is installed on one side of the three sets of scissor assemblies 50, and the height of the three sets of first gears 51 on the same side bracket 301 gradually increases along its length.

[0100] The dust collector housing 1 is equipped with a first linkage rack 52, and the first linkage rack 52 is equipped with three sets of rack control slots 53 corresponding to the first gear 51 at different heights.

[0101] After the fan-shaped rack opens, continue to pull the control frame 40. Then, the first gear 51 on the side bracket 301 comes into contact with the first linkage rack 52. The first linkage rack 52 will control the first gear 51 to rotate. While rotating, the first gear 51 drives one side of the scissor assembly 50 to rotate around the hinge point, so that the scissor assembly 50 pushes the limit frame 37 outward until the limit frame 37 protrudes outward from the side bracket 301.

[0102] At this time, the ceramic sleeve 310 installed on the side support 301 not only loses the restriction of external force, but also protrudes outward, making it convenient for operators to maintain and replace it. After the damaged ceramic sleeve 310 is replaced or maintained, the control frame 40 is pushed back into the dust collector housing 1. At this time, the replaced or maintained ceramic sleeve 310 will retract to the middle of the side support 301 along with the limit frame 37, and the fan-shaped clamp 371 will limit it again.

[0103] Reference Figure 11 As shown, the dust collector housing 1 is also provided with an adjusting component 7 for adjusting the angle of the cyclone 31. The adjusting component 7 includes several sets of adjusting clips 70 connected to the side wall of the dust collector housing 1 by bearings. Each adjusting clip 70 has a precision sprocket 71 installed on its back side. A synchronous chain 72 is installed between the precision sprockets 71. A control sprocket 73 is provided on one side of the synchronous chain 72 to control its rotation. A control knob is provided on the control sprocket 73.

[0104] To further ensure the efficiency of the dust collector housing 1 in separating impurities from the tail flue gas, this application also proposes an adjusting component 7. When the ceramic sleeve 310 is in a vertical state, the tail flue gas and the mixed impurities can be separated. The ceramic sleeve 310 is set at an inclination of 15° to 30°, using gravity to assist the dust to slide off and reduce the accumulation of dust on the pipe wall.

[0105] In practice, rotating the control knob causes the control sprocket 73, which is coaxial with it, to rotate. With the cooperation of the synchronous chain 72, the control sprocket 73 drives several precision sprockets 71 to rotate synchronously. After the precision sprockets 71 rotate, they drive the adjusting clamp 70 to rotate. After the adjusting clamp 70 rotates, it can drive the ceramic sleeve 310 to make a slight angle adjustment, so that it is slightly tilted.

[0106] The tilt angle (usually 15° to 30°) causes dust to be thrown against the pipe wall under centrifugal force, and then slide down the tilted pipe wall to the bottom dust collection hopper 38 by gravity, reducing residue on the pipe wall and avoiding blockage caused by dust accumulation. Traditional vertical cyclone pipes require reverse airflow or additional vibration for dust removal, which is energy-intensive and prone to wear.

[0107] The tilt angle alters the airflow swirling path, extending the residence time of dust within the cyclone tube and enhancing centrifugal separation. Simultaneously, it reduces the frictional resistance between the airflow and the tube wall, minimizing pressure loss. Furthermore, the path for dust to fall into the ash hopper 38 is shorter, reducing dust resuspension caused by airflow disturbances.

[0108] Secondly, dust slides along the pipe wall rather than impacts vertically, reducing wear on the 310 ceramic sleeve. The inclined installation combined with the segmented design allows for axial thermal expansion of the ceramic tube, preventing cracking due to thermal stress under high-temperature conditions.

[0109] In addition, when a suitable temperature window of approximately 320℃-400℃ is found in the vertical flue of the biomass boiler, this temperature range is determined by the SCR catalyst. Within this range, the catalyst activity is good; temperatures that are too low or too high will lead to reduced catalyst activity or even deactivation, and the chemical reaction rate will not meet the denitrification requirements. Then, the raw flue gas at approximately 320℃-400℃ is introduced into a high-efficiency ceramic multi-tube dust collector 3. The multi-tube dust collector removes large dust particles, creating favorable conditions for the catalyst and the tail-end heating surface, reducing blockage and wear. It also prevents subsequent SCR catalyst poisoning, failure, and corrosion, extending the service life of the SCR catalyst.

[0110] After dust removal, the low-dust flue gas then enters the medium-high temperature SCR denitrification reactor 8. Inside the reactor, NOx in the flue gas and SNCR escaped ammonia undergo a redox reaction under the action of the SCR catalyst to generate N2 and H2O, thus completing the denitrification process.

[0111] The details are as follows:

[0112] The medium-high temperature SCR denitrification reactor 8 comprises: an SCR reactor body, catalyst, control system, and soot blowing system. SCR denitrification commonly uses vanadium-titanium-based catalysts, which are classified into three types according to their appearance: honeycomb, flat plate, and corrugated plate. These three types of catalysts have similar mineral compositions, all using TiO2 (approximately 80-90%) as the support, V2O5 (approximately 1-2%) as the active material, and WO3 or MoO3 (approximately 3-7%) as auxiliary active materials. They possess similar chemical properties, but their different appearances lead to significant differences in physical properties. Currently, honeycomb catalysts are more commonly used in the market because they have a large specific surface area and require less material to achieve the same denitrification efficiency, making them more economical compared to the other two types.

[0113] Using the methods described above, the NOx concentration in the tail gas of biomass boilers can be stably controlled at ≤50mg / Nm3, SO2 concentration at ≤35mg / Nm3, and particulate matter at ≤5mg / Nm3 (standard conditions, dry basis, 6% O2).

[0114] See Figure 9 and Figure 12 As shown, an arc-shaped locking groove is provided on the inner side of the limiting frame 37. Two fan-shaped clamping strips 371 are symmetrically slidably installed in the arc-shaped locking groove. The fan-shaped clamping strips 371 have clamping pouches 372 with gradually increasing size from the outside to the inside along the arc-shaped trajectory of the inner side.

[0115] Two fan-shaped clamping bars 371 are offset on their back sides and have a central rack 373. A central gear 374 is rotatably mounted on the inner wall of the limiting frame 37 between the two central racks 373.

[0116] It should be noted that the function of the clamping pouch 372 is to clamp the outer wall of the ceramic sleeve 310 to ensure the stability of the clamping of the ceramic sleeve 310, while the centering gear 374 and the centering rack 373 can control the synchronous relative movement of the two fan-shaped clamping bars 371 on the same limiting frame 37.

[0117] See Figure 13 As shown, this application also provides a method for treating flue gas inside a biomass water-cooled vibrating grate boiler, as follows:

[0118] S1. Fuel pretreatment: Biomass fuel needs to be crushed to a suitable particle size and the moisture content needs to be controlled.

[0119] S2. Grate Vibration: By adjusting the frequency and amplitude of the vibrating grate, the fuel layer is ensured to be evenly distributed.

[0120] S3, Exhaust gas conveying: The exhaust gas generated during the combustion process is conveyed to the dust collector housing 1.

[0121] S4. Preliminary treatment of exhaust gas: After the flue gas is transported to the interior of the dust collector shell 1, it is treated by the high-efficiency ceramic multi-tube dust collector 3 arranged inside, so that the impurities in the flue gas are separated, and the treated flue gas is transported to the medium-high temperature SCR denitrification reactor 8. During this process, when it is necessary to replace the ceramic sleeve 310 in the high-efficiency ceramic multi-tube dust collector 3, the individual ceramic sleeve 310 can be maintained and replaced without stopping the machine.

[0122] S5. Secondary treatment of exhaust gas: The separated flue gas is subjected to secondary denitrification treatment through the medium-high temperature SCR denitrification reactor 8 arranged inside the dust collector shell 1.

[0123] S6. Exhaust gas recirculation: After denitrification, the flue gas is transported to the heating surface at the tail of the boiler to repeatedly recycle the heat in the flue gas.

[0124] S7. Exhaust gas discharge: It is then discharged to the chimney by an induced draft fan.

[0125] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A flue gas treatment device for a biomass water-cooled vibrating grate boiler, characterized in that: include, The dust collector housing (1) has an air inlet on one side for the flue gas in the furnace to enter, and a dust removal pipe (2) is provided at the air inlet for the flue gas in the furnace to enter the dust collector housing (1) for dust removal. A high-efficiency ceramic multi-tube dust collector (3) is located inside the dust collector shell (1). It includes two sets of upper and lower steel supports (30) symmetrically arranged in the height direction of the dust collector shell (1). Several ceramic cyclones (31) are evenly spaced on the steel supports (30). A smoke equalizer (32) is connected to the dust collection pipe (2). Several branch round holes (33) connected to the dust collection pipe (2) are provided in the smoke equalizer (32). A dust hopper (38) is also provided at the bottom of the dust collector shell (1). The medium-high temperature SCR denitrification reactor (8) is used to denitrify the flue gas after dust removal; The dust collector housing (1) is also provided with a control component (4) for controlling the horizontal pulling of several cyclones (31). The control component (4) includes a control frame (40) that is slidably inserted into the side wall of the dust collector housing (1). A first linkage component (5) is also provided between the steel bracket (30) and the control frame (40). The first linkage component (5) includes three sets of limit frames (37) that are slidably connected to the side bracket (301) and its upper end, and each set of scissor assemblies (50) is connected to a first gear (51) on one side of the three sets of scissor assemblies (50). The height of the three sets of first gears (51) on the same side bracket (301) gradually increases along its length. The dust collector housing (1) is provided with a No. 1 linkage rack (52), and the No. 1 linkage rack (52) is provided with three sets of rack control slots (53) corresponding to the No. 1 gear (51) at different heights.

2. The flue gas treatment device for a biomass water-cooled vibrating grate boiler according to claim 1, characterized in that: A smoke inlet (34) is provided on one side of the cyclone (31), and the branch round hole (33) on the smoke distributor (32) is in contact with the smoke inlet (34) on one side of the cyclone (31); The upper end of the cyclone (31) abuts against the exhaust pipe (35), and the cyclone (31) has a dust removal chamber (36) that abuts against the exhaust pipe (35) along the height direction. A telescopic pipe (39) is provided at the branch round hole (33) of the smoke equalizer (32). The end of the telescopic pipe (39) away from the smoke equalizer (32) moves against the smoke inlet (34) of the cyclone (31). The bottom of the exhaust straight pipe (35) is also provided with a telescopic pipe (39), and the telescopic pipe (39) at the bottom of the exhaust straight pipe (35) moves to abut against the top of the cyclone (31) on the side away from the exhaust straight pipe (35).

3. The flue gas treatment device for a biomass water-cooled vibrating grate boiler according to claim 1, characterized in that: The steel support (30) is composed of three sections. One side is the middle support (300). Side supports (301) are slidably installed on both sides of the middle support (300). The two side supports (301) are slidably installed on the inner wall of the dust collector housing (1) at the ends away from the middle support (300). The middle support (300) and the side supports (301) are provided with mounting slots (302). Two sets of symmetrical positioning sliders (303) are slidably installed in the mounting slots (302). A limiting frame (37) is provided between the two sets of positioning sliders (303) to limit the movement of the cyclone (31).

4. The flue gas treatment device for a biomass water-cooled vibrating grate boiler according to claim 1, characterized in that: The cyclone (31) is composed of segmented ceramic sleeves (310), with metal clamps (311) between the multiple ceramic sleeves (310), and elastic sealing rings (312) on both sides of the metal clamps (311) that allow for thermal expansion and facilitate local replacement.

5. The flue gas treatment device for a biomass water-cooled vibrating grate boiler according to claim 3, characterized in that: An arc-shaped locking groove is provided on the inner side of the limiting frame (37), and two fan-shaped clamping strips (371) are symmetrically slidably installed in the arc-shaped locking groove. The fan-shaped clamping strips (371) are provided with clamping pouches (372) with gradually increasing size from the outside to the inside along the arc-shaped trajectory of the inner side. Two fan-shaped clamps (371) are offset on the back side and have a central rack (373), and a central gear (374) is provided between the two central racks (373) and is rotatably mounted on the inner wall of the limit frame (37).

6. The flue gas treatment device for a biomass water-cooled vibrating grate boiler according to claim 3, characterized in that: A second linkage component (6) is provided on the side bracket (301). The second linkage component (6) includes several extension gears (60) installed on the side bracket (301). One side of the extension gear (60) is meshed with an opening and closing gear (61). A control gear (62) is meshed on the opening and closing gear (61). A central shaft (63) is provided in the middle of the control gear (62). A linkage gear (64) that meshes with the fan-shaped clamp (371) is also installed on the central shaft (63). The fan-shaped clamp (371) is provided with a sawtooth structure. A second linkage rack (65) is installed on the inner wall of the dust collector housing (1).

7. The flue gas treatment device for a biomass water-cooled vibrating grate boiler according to claim 1, characterized in that: The dust collector housing (1) is also provided with an adjustment component (7) for adjusting the angle of the cyclone (31). The adjustment component (7) includes several sets of adjustment clips (70) connected by bearings on the side wall of the dust collector housing (1). Precision sprockets (71) are installed on the back side of each adjustment clip (70). A synchronous chain (72) is installed between each precision sprocket (71). A control sprocket (73) is provided on one side of the synchronous chain (72) to control its rotation. A control knob is provided on the control sprocket (73).

8. A method for treating flue gas inside a biomass water-cooled vibrating grate boiler, comprising the flue gas treatment device for a biomass water-cooled vibrating grate boiler according to any one of claims 1-7, wherein the method for treating flue gas inside a biomass water-cooled vibrating grate boiler is as follows: S1. Fuel pretreatment: Biomass fuel needs to be crushed to a suitable particle size and the moisture content needs to be controlled; S2. Grate Vibration: By adjusting the frequency and amplitude of the vibrating grate, a uniform distribution of the fuel layer is ensured. S3, exhaust gas conveying: exhaust gas generated during combustion is conveyed to the dust collector shell (1). S4. Preliminary treatment of exhaust gas: After the flue gas is transported to the interior of the dust collector shell (1), it is treated by the high-efficiency ceramic multi-tube dust collector (3) arranged inside it, so that the impurities in the flue gas are separated, and the treated flue gas is transported to the medium and high temperature SCR denitrification reactor (8). S5. Secondary treatment of exhaust gas: The separated flue gas is subjected to secondary denitrification treatment through the medium and high temperature SCR denitrification reactor (8) arranged inside the dust collector shell (1). S6. Exhaust gas recirculation: After denitrification, the flue gas is transported to the heating surface at the tail of the boiler to repeatedly recycle the heat in the flue gas. S7. Exhaust gas discharge: It is then discharged to the chimney by an induced draft fan.

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