Ultra-low smoke emission device for large boiler

Abstract

The invention relates to the technical field of boiler equipment, in particular to an ultra-low smoke emission device for a large boiler. The boiler is installed on the support, a desulfurization tower used for flue gas desulfurization is further arranged on the support, and a denitration furnace, an oxidation absorption chamber and a pair of dust removal chambers are sequentially communicated between the boiler and the desulfurization tower from left to right; the proportioning assembly is arranged on the bracket and is used for fusing and proportioning the urea solution; the spraying assembly is arranged on the denitration furnace and used for spraying the urea solution. According to the invention, a denitration mode combining SNCR and a low-temperature oxidation denitration process is adopted, and a plurality of links such as denitration, dust removal and desulfurization are integrated, so that flue gas emission can reach an ultra-low emission standard, the overall adaptability and cost effectiveness of the device are remarkably improved, and moreover, the device is suitable for industrial production. According to the invention, by using the atomizing ejector in rotary spraying operation in the denitration process, not only is the denitration efficiency improved, but also an efficient and economical solution is provided for the field of environmental protection.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler equipment, and in particular to an ultra-low emission device for flue gas from a large boiler. Background Art

[0002] As a key energy conversion facility, large boilers are widely used in thermal power plants, ships, locomotives and various industrial and mining enterprises. Their core function is to convert the chemical energy in the fuel into thermal energy to produce high-temperature water or steam. However, with the improvement of global awareness of environmental protection and the advancement of sustainable development goals, the flue gas emissions of large boilers have received more and more attention because the flue gas emissions of boilers involve the release of various pollutants such as carbon monoxide and other pollutants.

[0003] To meet this challenge, the international community has formulated a series of strict emission standards, requiring relevant units using boilers to take efficient emission reduction measures, especially for coal-fired power plants and large industrial boilers. In practice, the technical path to achieve ultra-low flue gas emissions mainly includes denitrification (removing nitrogen oxides), dust removal (reducing particulate matter emissions) and desulfurization (reducing sulfur dioxide emissions). Among them, selective catalytic reduction (SCR) technology is a commonly used denitrification method. Although the effect is significant, it also faces the problems of high catalyst cost and limited application range.

[0004] Therefore, in order to ensure that emissions meet ultra-low standards and achieve standardization and stability of emission management, it is necessary to continuously optimize the existing treatment processes and technical solutions, which makes it particularly important to urgently develop a large-scale boiler flue gas ultra-low emission device. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides an ultra-low emission device for large-scale boiler flue gas to ensure that the emissions meet the ultra-low standards and achieve standardization and stability of emission management.

[0006] Technical solution: A large boiler flue gas ultra-low emission device is provided, including:

[0007] Bracket;

[0008] The boiler is installed on a bracket, and a fuel adding port and a waste discharge port are respectively provided on the left and lower sides of the boiler, and a desulfurization tower for flue gas desulfurization is also provided on the bracket. A denitrification furnace, an oxidation absorption chamber and a pair of dust removal chambers are connected from left to right between the boiler and the desulfurization tower. The denitrification furnace is in an inverted concave shape, and an arranged induced draft fan is installed in the middle of the denitrification furnace, and the left and right sides of the denitrification furnace are separated by the induced draft fan;

[0009] A proportioning component is arranged on the bracket and is used for fusing and proportioning the urea solution;

[0010] An injection assembly is arranged on the denitrification furnace for injecting urea solution. The injection assembly includes a delivery pump fixedly installed on the side wall of the denitrification furnace. The delivery pump and the proportioning assembly are connected by a connecting pipe. The water outlet of the delivery pump is also connected to a shunt pipe. Straight pipes are symmetrically connected to the left side of the denitrification furnace. The top ends of the two straight pipes are rotatably connected to the adjacent ends of the shunt pipes, and the bottom ends of the straight pipes are connected to an atomizing injector for atomizing the spray solution. An electric gear set is arranged between the two straight pipes on the denitrification furnace. A transmission gear meshing with the gear of the electric gear set is also arranged on the two straight pipes, so that the atomizing injector can rotate and spray. Nozzles for spraying low-temperature oxidation denitrifiers are symmetrically arranged on the right side of the denitrification furnace for oxidation and denitrification treatment of flue gas.

[0011] Preferably, the proportioning component includes a mounting frame fixedly mounted on a bracket, the oxidation absorption chamber passes through the middle of the mounting frame, and blending cylinders for blending urea solution are symmetrically arranged on the mounting frame. The blending cylinders are connected to adjacent connecting pipes, and a stirring assembly for stirring the solution is arranged in the blending cylinders. A feed frame is connected between the top ends of the two blending cylinders, and an electromagnetic valve is arranged between the feed port of the feed frame and the corresponding blending cylinder.

[0012] Preferably, the stirring assembly comprises motors respectively mounted on the top of the two blending cylinders, the output ends of the motors pass through the corresponding blending cylinders, and the output ends of the motors are connected to stirrers for stirring the solution via couplings.

[0013] Preferably, it also includes an electric pressing roller, a circulation frame and a screening frame. The screening frame for screening urea granules is symmetrically and inclinedly arranged in the feed frame, and the middle connection between the two screening frames is convex so that the two screening frames are tilted apart to both sides. A circulation frame is connected to the material port on both sides of the feed frame, and a pair of electric pressing rollers for crushing urea granules are rotatably arranged in the circulation frame.

[0014] Preferably, it also includes an outer shell, a scraper frame, a contact rod and a trapezoidal block. The outer shell is provided on each injection branch pipe of the atomizing injector. A scraper frame that is in contact with the nozzle of the atomizing injector is slidably provided on the outer shell. A contact rod is provided at the bottom end of the scraper frame. The left and right side walls of the denitrification furnace are respectively provided with a group of trapezoidal blocks consistent with the straight pipe layout, and the trapezoidal blocks are in contact and cooperation with the adjacent contact rods.

[0015] Preferably, the trapezoidal block is double-sidedly stepped to accommodate the rotary contact operation of the contact rod.

[0016] Preferably, a dust removal assembly for removing flue gas particles is provided in the dust removal chamber, and the dust removal assembly includes electric push rods fixedly installed on one side of the two dust removal chambers, the telescopic ends of the electric push rods are arranged upward, and movable frames are slidably penetrated in the two dust removal chambers, and the top of the movable frame is connected to the telescopic end of the electric push rod on the same side, and a partition is provided in the dust removal chamber, and a shaping frame connected to the bottom end of the movable frame on the same side is slidably provided on the partition of the dust removal chamber, and a dust filter bag for filtering particulate matter is sleeved on the shaping frame, and the upper end of the dust filter bag is connected to the partition of the dust removal chamber, and a cross bar is also provided at the bottom of the shaping frame, and a buckle plate for passing through the corresponding cross bar is provided at the bottom of the dust filter bag.

[0017] Preferably, it also includes an electric threaded rod, a guide rod and a fitting frame. The electric threaded rod is rotatably arranged between the denitrification furnace and the lower side of one of its dust removal chambers. The guide rods are symmetrically connected between the denitrification furnace and the lower sides of the two dust removal chambers. The electric threaded rod and the guide rod are both located in the oxidation absorption chamber. A fitting frame matching the oxidation absorption chamber is slidably arranged between the two guide rods, and the fitting frame and the electric threaded rod form a threaded fit to slide and move in the oxidation absorption chamber for cleaning the sediment.

[0018] The present invention overcomes the shortcomings of the prior art and can achieve the following beneficial effects:

[0019] 1. The present invention adopts a denitrification method that combines SNCR (selective non-catalytic reduction) with a low-temperature oxidation denitrification process. By integrating multiple links such as denitrification, dust removal and desulfurization, it can comprehensively and effectively treat various pollutants in the flue gas, thereby ensuring that the flue gas emissions can meet the ultra-low emission standards. This significantly improves the overall adaptability and cost-effectiveness of the device. Furthermore, by using a rotary spraying atomizer in the denitrification process, it not only improves the denitrification efficiency, but also ensures the stable operation of the denitrification treatment, simplifies the process flow, and provides an efficient and economical solution for the environmental protection field.

[0020] 2. The present invention realizes the integrated operation of dissolving, screening, mixing and crushing of urea solution by setting up the proportioning components, and uses the delivery pump to accurately deliver the treated solution to the atomizing injector, thereby ensuring the uniform distribution and efficient application of the solution. This not only significantly improves the preparation efficiency of urea solution, but also greatly improves the automation level and operation reliability of the device.

[0021] 3. The present invention uses the contact mechanism of the contact rod and the trapezoidal block to enable the scraping frame to fit the nozzle of the atomizing injector to scrape off the deposits, thereby ensuring the stability of the operation of the atomizing injector and maintaining the overall operating order of the device.

[0022] 4. The present invention drives the movable frame and the forming frame to move up and down through the electric push rod, thereby synchronously driving the dust filter bag to fold, so that the flue gas particles and impurities intercepted and attached by the dust filter bag are forced to fall off due to the folding deformation, thereby effectively removing the accumulated impurities on the dust filter bag, which not only provides convenience for the cleaning and maintenance of the dust filter bag, but also ensures that the subsequent dust removal work is more efficient and rapid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0024] Figure 2 It is a three-dimensional structural cross-sectional view of the internal components of the boiler, denitration furnace, oxidation absorption chamber, dust removal chamber and desulfurization tower of the present invention.

[0025] Figure 3 It is a three-dimensional structural cross-sectional view of some parts of the proportioning component and the injection component of the present invention.

[0026] Figure 4 It is a three-dimensional structural cross-sectional view of the components such as the blending cylinder, the motor and the agitator of the present invention.

[0027] Figure 5 It is a schematic diagram of the three-dimensional structure of part A of the present invention.

[0028] Figure 6 For the present invention Figure 5 Schematic diagram of the three-dimensional structure after the A part is enlarged.

[0029] Figure 7 It is a three-dimensional structural cross-sectional view of the components such as the atomizing injector, the housing and the scraping frame of the present invention.

[0030] Figure 8 It is a three-dimensional structural schematic diagram of the oxidation absorption chamber, dust removal chamber and dust removal assembly of the present invention.

[0031] Fig. 9 It is a three-dimensional structural cross-sectional view of some parts of the dust removal assembly of the present invention.

[0032] Fig.10 It is a three-dimensional structural cross-sectional view of the various components of the dust removal assembly of the present invention.

[0033] Fig.11 It is a schematic diagram of the three-dimensional structure of the electric threaded rod, the guide rod and the fitting frame of the present invention.

[0034] The marks in the drawings provided by the present invention are: 1. bracket, 2. boiler, 3. denitrification furnace, 31. induced draft fan, 32. oxidation absorption chamber, 4. dust removal chamber, 5. desulfurization tower, 6. proportioning component, 61. mounting frame, 62. blending cylinder, 63. motor, 64. agitator, 65. feed frame, 651. solenoid valve, 66. electric pressure roller, 661. circulation frame, 67. screening frame, 7. injection component, 71. conveying Pump, 72, shunt pipe, 73, straight pipe, 74, atomizing injector, 741, housing, 742, scraping frame, 743, contact rod, 744, trapezoidal block, 75, electric gear set, 76, transmission gear, 77, nozzle, 8, dust removal assembly, 81, electric push rod, 82, moving frame, 83, shaping frame, 831, buckle plate, 84, dust filter bag, 9, electric threaded rod, 91, guide rod, 92, fitting frame. DETAILED DESCRIPTION

[0035] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0036] In addition, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. It should be noted that the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] Embodiment: A large boiler flue gas ultra-low emission device, such as Figure 1-Figure 4 As shown, including:

[0038] The bracket 1, as the supporting structure of the whole device, carries the boiler 2 and other related equipment;

[0039] The boiler 2 is fixedly installed on the top left side of the support 1 and is the main equipment for generating heat energy. A fuel adding port is designed on the left side of the boiler 2, and a waste discharge port is opened at the bottom of the right side of the boiler 2. The lower side of the boiler 2 is sloped from left to right, so that the waste can slide out freely. A desulfurization tower 5 for flue gas desulfurization is also arranged on the support 1. The desulfurization process of the desulfurization tower 5 adopts the magnesium oxide method, thereby reducing and removing sulfur dioxide emissions in the flue gas. A denitrification furnace 3, an oxidation absorption chamber 32 and a pair of dust removal chambers 4 are connected from left to right between the boiler 2 and the desulfurization tower 5. The bottom of the dust removal chamber 4 is provided with a useful At the discharge port where impurities are discharged, the dust removal chamber 4 is provided to filter out particulate matter from the flue gas, thereby reducing the emission of particulate matter and impurities; the denitrification furnace 3 is the main place for removing nitrogen oxides from the flue gas, and by combining with the oxidation absorption chamber 32, the SNCR+low-temperature oxidation denitrification process is used to denitrify the flue gas, and the denitrification furnace 3 is in an inverted concave shape, and an arranged induced draft fan 31 is fixedly installed in the middle of the denitrification furnace 3, and the left and right sides of the denitrification furnace 3 are separated by the induced draft fan 31, and the induced draft fan 31 can guide the flue gas into the oxidation absorption chamber 32 for oxidation denitrification, thereby helping to improve the denitrification efficiency;

[0040] A proportioning component 6 is arranged on the support 1 and is used for fusing and proportioning the urea solution;

[0041] The injection assembly 7 is arranged on the denitration furnace 3 for injecting urea solution. The injection assembly 7 includes a delivery pump 71 fixedly installed on the right side wall of the denitration furnace 3. The delivery pump 71 is connected to the proportioning assembly 6 by a connecting pipe. The water outlet of the delivery pump 71 is also connected to a shunt pipe 72. The shunt pipe 72 has two branch pipes. A straight pipe 73 is connected to the left side of the denitration furnace 3 in a symmetrical rotation. The top ends of the two straight pipes 73 are respectively connected to the adjacent ends of the shunt pipe 72. Here, the rotation operation between the straight pipe 73 and the shunt pipe 72 is carried out in a rotational coordination under the premise of ensuring the sealing of the two. The bottom end of the straight pipe 73 is connected to a nozzle for atomizing and spraying the solution. The denitrification furnace 3 is provided with an electric gear set 75 located between the two straight tubes 73, and the electric gear set 75 is composed of a motor and a driving gear. The motor of the electric gear set 75 is fixedly connected to the top of the denitrification furnace 3, so as to stably drive the driving gear to realize rotation operation. The upper sides of the two straight tubes 73 are respectively provided with a transmission gear 76 meshing with the driving gear of the electric gear set 75, thereby driving the corresponding straight tube 73 to rotate, so that the connected atomizing injector 74 can be rotated and sprayed, and a nozzle 77 for spraying a low-temperature oxidation denitrification agent is symmetrically arranged on the right side of the denitrification furnace 3 for oxidation denitrification treatment of the flue gas.

[0042] In a specific embodiment, the urea solution is sprayed into the left furnace of the denitrification furnace 3 by the atomizing injector 74, so that the ammonia generated by pyrolysis undergoes an oxidation-reduction reaction with the NOx in the flue gas, and the main components generated are N2 and H2O. The left furnace of the denitrification furnace 3 is used as an SNCR reactor, and the SNCR denitrification can achieve a denitrification efficiency of up to 70%;

[0043] Then, a low-temperature oxidation denitrification agent is sprayed into the right furnace of the denitrification furnace 3 through the nozzle 77, and then the flue gas is guided to the oxidation absorption chamber 32 through the induced draft fan 31, so that the flue gas reacts in the oxidation absorption chamber 32 to carry out oxidation denitrification, and the remaining NOx in the flue gas is treated, and most of the NO insoluble in water in the flue gas is oxidized into high-valent nitrogen oxides such as NO2 and N2O3 that are easily soluble in water, and then further absorption and purification are carried out by subsequent desulfurization. The low-temperature oxidation denitrification process can achieve a denitrification efficiency of more than 60%.

[0044] Therefore, combined with the above, the advantages of selective non-catalytic reduction technology (SNCR) + low-temperature oxidation denitrification process are summarized:

[0045] 1. Through the efficient rotary atomization spraying operation of the atomizing injector 74 and the efficient combined denitrification treatment, the denitrification efficiency can reach 70%;

[0046] 2. Simple process;

[0047] 3. No catalyst, lower cost and correspondingly reduced operating expenses;

[0048] 4. It occupies a small area and has good adaptability to usage scenarios.

[0049] like Figure 1-Figure 4 As shown, the proportioning component 6 includes a mounting frame 61 fixedly mounted on the bracket 1, and the oxidation absorption chamber 32 passes through the middle of the mounting frame 61. A blending cylinder 62 for blending the urea solution is symmetrically arranged front and back on the top of the mounting frame 61. The blending cylinder 62 is connected to the adjacent connecting pipe, and a stirring assembly for stirring the solution is arranged in the blending cylinder 62. A feeding frame 65 is connected between the top ends of the two blending cylinders 62, and a solenoid valve 651 is arranged between the feed port of the feeding frame 65 and the corresponding blending cylinder 62, and a solenoid valve 651 is also arranged at the connection between the connecting pipe and the corresponding blending cylinder 62, so that the discharge timing of the solution is controlled. From then on, urea solution is added to the inside of the blending cylinder 62 through the feeding frame 65, and the stirring assembly is combined to make the solution more uniform, thereby ensuring the use effect of subsequent denitrification treatment.

[0050] like Figure 3 and Figure 4As shown, the stirring assembly includes motors 63 respectively fixedly mounted on the top of two blending cylinders 62, the output end of the motor 63 passes through the corresponding blending cylinder 62, and the output end of the motor 63 is connected to an agitator 64 for stirring the solution through a coupling, and the stirring shaft and blades of the agitator 64 are made of 304 material, which can effectively handle the mixing between urea and the solution.

[0051] like Figure 3 and Figure 4 As shown, it also includes an electric pressure roller 66, a circulation frame 661 and a screening frame 67. The screening frames 67 for screening urea particles are symmetrically arranged in a tilted manner in the feed frame 65, and the fitting parts in the middle of the two screening frames 67 are connected in a convex manner, so that the two screening frames 67 are separately tilted to the left and right sides respectively. A circulation frame 661 is connected to the material port on the left and right sides of the feed frame 65 respectively, and a pair of electric pressure rollers 66 for crushing urea particles are rotatably arranged in the circulation frame 661. The electric pressure rollers 66 are symmetrically arranged at intervals in the upper and lower parts, and can crush the urea agglomerates that have not been screened and circulated, and then the circulation frame 661 guides the flow to the blending cylinder 62, thereby improving the fluidity and integrity of the urea solution.

[0052] like Figure 4-Figure 7 As shown, it also includes a shell 741, a scraper frame 742, a contact rod 743 and a trapezoidal block 744. Each atomizing injector 74 has four injection branches. Each injection branch of the atomizing injector 74 is provided with a shell 741. A scraper frame 742 is slidably provided on the shell 741 to be attached to the nozzle of the atomizing injector 74. The scraper frame 742 has ring bodies arranged at uniform intervals. The number and layout of the ring bodies are adapted to the nozzles of the corresponding injection branches, so that the scraper frame 742 is slidably attached to scrape the surface of each nozzle, thereby effectively preventing clogging by deposits. A contact rod 743 is provided at the bottom end of the scraping frame 742, and a group of trapezoidal blocks 744 with the same layout as the straight tube 73 are provided on the left and right side walls of the denitrification furnace 3. The trapezoidal blocks 744 are double-sided ladders to adapt to the rotating contact operation of the contact rod 743. After the trapezoidal blocks 744 contact the contact rod 743, they will push the scraping frame 742 to slide toward the center of the circle, and then the scraping frame 742 will slide outward due to its own rotation operation, and then through the contact trapezoidal blocks 744 and repeated contact push, the nozzle surface is scraped back and forth, thereby achieving effective scraping treatment of the deposits.

[0053] like Figure 1 , Figure 2 , Figure 8-Figure 10As shown, a dust removal assembly 8 for removing flue gas particles is provided in the dust removal chamber 4. The dust removal assembly 8 includes electric push rods 81 fixedly installed on opposite sides of the two dust removal chambers 4, respectively. The telescopic ends of the electric push rods 81 are arranged upward, and movable racks 82 are slidably penetrated in the two dust removal chambers 4. The top of the movable rack 82 is connected to the telescopic end of the electric push rod 81 on the same side. A partition is provided at the upper side of the dust removal chamber 4 to divide the dust removal chamber 4 into two upper and lower compartments. A shaping frame 83 connected to the bottom end of the movable rack 82 on the same side is slidably provided on the partition of the dust removal chamber 4. The shaping frame 83 is hollow in design, and a dust filter bag 84 for filtering particles is sleeved on the shaping frame 83. The upper end of the dust filter bag 84 is connected to the partition of the dust removal chamber 4, and a cross bar is provided at the bottom of the shaping frame 83. The bottom of the dust filter bag 84 is provided with a buckle plate 831 for passing through the corresponding cross bar, so that the upper and lower positions of the dust filter bag 84 are fixed, and then the electric push rod 81 is used to drive the moving frame 82 and the shaping frame 83 to move up and down, so that the buckle plate 831 can drive the dust filter bag 84 to fold in accordance with the movement, so that the impurities and particulate matter attached to the dust filter bag 84 can be shaken off, and the fallen impurities are immediately discharged through the discharge port below the dust removal chamber 4, thereby avoiding the accumulation of impurities on the dust filter bag 84, so as to ensure the stable operation of the subsequent particulate matter filtration of the dust filter bag 84.

[0054] like Figure 8 and Fig.11 As shown, it also includes an electric threaded rod 9, a guide rod 91 and a fitting frame 92. The electric threaded rod 9 is rotatably arranged between the denitrification furnace 3 and the lower position of the dust removal chamber 4 on the front side. The guide rod 91 is symmetrically connected front and back between the denitrification furnace 3 and the lower positions of the two dust removal chambers 4. The electric threaded rod 9 and the guide rod 91 are both located in the oxidation absorption chamber 32. A fitting frame 92 that matches the oxidation absorption chamber 32 is slidably arranged between the two guide rods 91, and the fitting frame 92 and the electric threaded rod 9 form a threaded fit, so that they can slide back and forth in the left and right directions in the oxidation absorption chamber 32 for cleaning the sediment.

[0055] During the combustion process of the boiler 2, fuel is added to the boiler 2 through the feeding port, and the burned fertilizer will be discharged from the lower slope of the boiler 2 through the discharge port. Then, the smoke generated by the combustion of the fuel will meander inside the boiler 2, and then rise and flow to the right, so that the smoke flows into the denitrification furnace 3, and then the urea solution is added to the feed frame 65, and the solenoid valve 651 is opened. Then, the dissolved urea will follow the solution through the sieve filter and then enter the blending cylinder 62 on both sides, while the undissolved granular urea agglomerates will be blocked by the sieve frame 67 and slide down between the electric pressing rollers 66 on this side along the inclination trend of the sieve frame 67, and the agglomerates will be crushed by the upper and lower electric pressing rollers 66, and then the crushed urea will be circulated. The frame 661 falls into the blending cylinder 62, and the motor 63 drives the stirrer 64 to further stir the urea solution in the blending cylinder 62, and then starts the delivery pump 71 and the solenoid valve 651 at the connecting pipe. The solution is delivered to the shunt pipe 72 through the delivery pump 71, and then flows into the two straight pipes 73, and is atomized and sprayed through the atomizing injector 74, so that the urea solution is sprayed into the denitrification furnace 3. At the same time, the electric gear set 75 drives the gear to rotate and mesh with the transmission gears 76 on both sides, thereby driving the straight pipe 73 and the atomizing injector 74 to rotate and perform rotational spraying, so that the denitrification furnace 3 is used as an SNCR reactor, thereby performing corresponding chemical reaction treatment. Here, due to the rotation of the atomizing injector 74, the contact rod 743 will rotate during the rotation. During the process, it comes into contact with the adjacent trapezoidal block 744. After being squeezed by the trapezoidal block 744, the contact rod 743 is pushed and drives the corresponding scraper frame 742 to move a certain distance on the shell 741 to scrape the nozzle surface on the adjacent injection branch pipe, thereby achieving the effect of removing accumulated impurities. Subsequently, the flue gas that undergoes chemical reaction will be blown into the right side of the denitrification furnace 3 by the induced draft fan 31, and then sprayed with low-temperature oxidation denitrification agent by the nozzle 77, and then reacted. Then the treated flue gas enters the oxidation absorption chamber 32 to denitrify and purify the flue gas, and at the same time, it also performs a first-step absorption and purification for the subsequent desulfurization. Due to the chemical reaction, the generated precipitate will accumulate on the inner wall of the oxidation absorption chamber 32. That is, the electric threaded rod 9 is started, thereby driving the fitting frame 92 to slide between the guide rods 91, and then fit the wall of the oxidation absorption chamber 32 to scrape off impurities, and then the flue gas will enter the dust removal chamber 4, and the impurities and particulate matter in the flue gas will be intercepted by the dust filter bag 84 in the dust removal chamber 4, so that the dust filter bag 84 is attached with impurities and particulate matter in the flue gas. In order to avoid the clogging of the dust filter bag 84, the electric push rod 81 can be started to drive the moving frame 82 and the shaping frame 83 to move up and down. Since the upper and lower positions of the dust filter bag 84 are fixed by the partition buckle plate 831 respectively, when the shaping frame 83 moves in coordination, the dust filter bag 84 will be pulled to fold in accordance with the movement, so that the impurities and particulate matter attached to the dust filter bag 84 can be shaken off.The fallen impurities will be discharged through the discharge port below the dust removal chamber 4, and then the flue gas after dust filtration will enter the desulfurization tower 5 for desulfurization treatment of the flue gas. From then on, the flue gas treatment is completed and the flue gas can meet the emission standards through layer-by-layer treatment.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A large boiler flue gas ultra-low emission device, comprising: Bracket (1); A boiler (2) is mounted on a support (1), and a fuel adding port and a waste material discharging port are respectively provided on the left side and the lower side of the boiler (2), and a desulfurization tower (5) for flue gas desulfurization is also provided on the support (1). A denitration furnace (3), an oxidation absorption chamber (32) and a pair of dust removal chambers (4) are sequentially connected between the boiler (2) and the desulfurization tower (5) from left to right, wherein the denitration furnace (3) is in an inverted concave shape, and an arranged induced draft fan (31) is installed in the middle of the denitration furnace (3), and the left and right sides of the denitration furnace (3) are separated by the induced draft fan (31); It is characterized by further comprising: a proportioning component (6) arranged on the support (1) for fusing and proportioning the urea solution; The injection assembly (7) is arranged on the denitration furnace (3) for injecting urea solution. The injection assembly (7) includes a delivery pump (71) fixedly mounted on the side wall of the denitration furnace (3). The delivery pump (71) and the proportioning assembly (6) are connected by a connecting pipe. The water outlet of the delivery pump (71) is also connected to a shunt pipe (72). A straight pipe (73) is symmetrically rotated and connected to the left side of the denitration furnace (3). The top ends of the two straight pipes (73) are rotatably connected to the adjacent ends of the shunt pipe (72). The straight pipes (73) ) is connected to the bottom end thereof with an atomizing injector (74) for atomizing and spraying a solution; the denitrification furnace (3) is provided with an electric gear set (75) located between the two straight tubes (73), and the two straight tubes (73) are also provided with a transmission gear (76) meshing with the gear of the electric gear set (75) so that the atomizing injector (74) can rotate and spray, and a nozzle (77) for spraying a low-temperature oxidation denitrification agent is symmetrically provided on the right side of the denitrification furnace (3) for oxidation denitrification treatment of flue gas.

2. A large boiler flue gas ultra-low emission device according to claim 1, characterized in that: The proportioning assembly (6) comprises a mounting frame (61) fixedly mounted on a support (1); the oxidation absorption chamber (32) passes through the middle of the mounting frame (61); a blending cylinder (62) for blending a urea solution is symmetrically arranged on the mounting frame (61); the blending cylinder (62) is connected to an adjacent connecting pipe; a stirring assembly for blending the solution is arranged inside the blending cylinder (62); a feed frame (65) is connected between the top ends of the two blending cylinders (62); and a solenoid valve (651) is arranged between the feed port of the feed frame (65) and the corresponding blending cylinder (62).

3. A large boiler flue gas ultra-low emission device according to claim 2, characterized in that: The stirring assembly comprises motors (63) respectively mounted on the top of two blending cylinders (62), the output ends of the motors (63) pass through the corresponding blending cylinders (62), and the output ends of the motors (63) are connected to stirrers (64) for stirring the solution via couplings.

4. A large boiler flue gas ultra-low emission device according to claim 3, characterized in that: The invention also comprises an electric pressing roller (66), a circulation frame (661) and a screening frame (67). The screening frame (67) for screening urea granules is symmetrically and tiltedly arranged in the feeding frame (65), and the middle connecting part of the two screening frames (67) is convex so that the two screening frames (67) are separated and tilted toward two sides. A circulation frame (661) is connected between the two sides of the feeding frame (65) and the material port respectively, and a pair of electric pressing rollers (66) for crushing urea granules are rotatably arranged in the circulation frame (661).

5. A large boiler flue gas ultra-low emission device according to claim 4, characterized in that: It also includes a shell (741), a scraper frame (742), a contact rod (743) and a trapezoidal block (744). The shell (741) is arranged on each injection branch pipe of the atomizing injector (74). A scraper frame (742) that is in contact with the nozzle of the atomizing injector (74) is slidably arranged on the shell (741). A contact rod (743) is arranged at the bottom end of the scraper frame (742). A group of trapezoidal blocks (744) that are consistent with the layout of the straight pipe (73) are arranged on the left and right side walls of the denitrification furnace (3). The trapezoidal blocks (744) are in contact with the adjacent contact rods (743).

6. A large boiler flue gas ultra-low emission device according to claim 5, characterized in that: The trapezoidal block (744) is double-sided and is used to adapt to the rotational contact operation of the contact rod (743).

7. A large boiler flue gas ultra-low emission device according to claim 6, characterized in that: A dust removal assembly (8) for removing flue gas particles is arranged in the dust removal chamber (4). The dust removal assembly (8) comprises electric push rods (81) respectively fixedly mounted on one side of two dust removal chambers (4). The telescopic end of the electric push rod (81) is arranged upward, and a movable frame (82) is slidably inserted in both dust removal chambers (4). The top of the movable frame (82) is connected to the telescopic end of the electric push rod (81) on the same side. A partition is arranged in the dust removal chamber (4). A shaping frame (83) connected to the bottom end of the movable frame (82) on the same side is slidably arranged on the partition of the dust removal chamber (4). A dust filter bag (84) for filtering particles is sleeved on the shaping frame (83). The upper end of the dust filter bag (84) is connected to the partition of the dust removal chamber (4). A cross bar is arranged at the bottom of the shaping frame (83). A buckle plate (831) for inserting on the corresponding cross bar is arranged at the bottom of the dust filter bag (84).

8. The ultra-low emission device for large boiler flue gas according to claim 7, characterized in that: It also includes an electric threaded rod (9), a guide rod (91) and a fitting frame (92). The electric threaded rod (9) is rotatably arranged between the denitration furnace (3) and the lower side of one of its dust removal chambers (4). The guide rod (91) is symmetrically connected between the denitration furnace (3) and the lower sides of the two dust removal chambers (4). The electric threaded rod (9) and the guide rod (91) are both located in the oxidation absorption chamber (32). A fitting frame (92) that matches the oxidation absorption chamber (32) is slidably arranged between the two guide rods (91), and the fitting frame (92) and the electric threaded rod (9) form a threaded fit so as to slide and move in the oxidation absorption chamber (32) for cleaning sediment.

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