Dust removal and denitration equipment and method for cement kiln

Abstract

The invention discloses dust removal and denitration equipment and method for a cement kiln, a dust and nitrate integrated module of the equipment comprises a gas inlet unit, a dust removal unit and a denitration unit, and the gas inlet unit comprises a gas inlet pipeline and a fan-shaped flow guide channel extending from the bottom of the gas inlet pipeline to the two sides; the dust removal unit comprises a rectification channel and a filter bag dust removal structure which are sequentially arranged on the two sides of the denitration unit, an inlet of the rectification channel is connected with the tail end of the flow guide channel, and the dust removal unit is provided with a gas purification cavity and a plurality of dust removal ash hoppers above and below the filter bag dust removal structure respectively; the upper part of the rectifying channel is equidistantly provided with communicating flues for communicating the purified gas cavity and the denitration unit; and the denitration unit is provided with a plurality of SCR catalyst layers in parallel at the position lower than the communicating flue. The dust removal and denitration functions are integrated in one module, the system and the waste heat boiler are combined into a whole, and denitrated flue gas is discharged from the boiler outlet after being subjected to heat exchange through the waste heat boiler, so that the dust removal and denitration efficiency is improved, and the overall energy efficiency of equipment is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cement kiln tail flue gas treatment, and in particular to a cement kiln dust removal and denitrification device and method. Background Art

[0002] Cement kilns produce a large amount of nitrogen oxides (NOx) during the calcination process. These pollutants not only have a serious impact on air quality, but also pose a threat to human health and the ecological environment. In order to meet increasingly stringent environmental regulations, the cement industry urgently needs efficient and economical denitrification technology and equipment.

[0003] Most of the existing cement kiln dust removal and denitrification devices adopt a structure of multiple devices in series, and are generally composed of multiple devices placed side by side. This structure not only requires a larger footprint for the entire device, but also multiple devices in series will increase the flow resistance of the flue gas, thereby affecting the dust removal and denitrification efficiency of the device.

[0004] The existing integrated dust removal and denitrification equipment on the market is prone to uneven flue gas flow during the dust removal and denitrification process, resulting in uneven flue gas distribution, local high or low flow rates, and dust re-suspension. Since the captured smoke dust is not transported in time, the dust is re-suspended and enters the subsequent denitrification unit. At the same time, the dust removal and denitrification process consumes a lot of energy, so improving energy efficiency and reducing operating costs are also important issues. Summary of the invention

[0005] In view of the problems of large space occupation, uneven flue gas distribution, easy dust resuspension, low dust removal efficiency and energy efficiency in the prior art dust removal and denitrification devices, the present application proposes a cement kiln dust removal and denitrification equipment and method to solve the above problems.

[0006] According to the first aspect of the present application, a cement kiln dust removal and denitrification equipment is proposed, including a dust and denitrification integrated module and a waste heat boiler, the dust and denitrification integrated module including an air intake unit, a dust removal unit and a denitrification unit, the air intake unit including an air intake duct and a fan-shaped guide channel extending from the bottom of the air intake duct to both sides; the dust removal unit includes a rectifying channel and a filter bag dust removal structure sequentially arranged on both sides of the denitrification unit, the inlet of the rectifying channel is connected to the end of the guide channel, the dust removal unit is formed with a clean air cavity and a plurality of dust hoppers above and below the filter bag dust removal structure, respectively, and a connecting flue connecting the clean air cavity and the denitrification unit is evenly spaced at the upper part of the rectifying channel; the denitrification unit is provided with a plurality of SCR catalyst layers arranged in parallel below the connecting flue, and an exhaust pipe is extended downward from the bottom of the denitrification unit; the exhaust pipe is directly connected to the boiler inlet of the waste heat boiler.

[0007] By adopting the above technical scheme, the dust removal and denitrification functions are integrated into one module. The fan-shaped guide channel design in the air intake unit helps to evenly divert the flue gas entering the module, ensuring that the subsequent dust removal and denitrification processes can be carried out more effectively. The diverted flue gas enters the dust removal unit through the rectification channel. After entering the dust removal unit, the flue gas penetrates the filter bag dust removal structure for dust removal. The dust-removed flue gas flows upward into the clean air cavity and is further collected to the upper part of the denitrification unit through the connecting flue. The collected flue gas passes downward through the SCR catalyst layer for denitrification. The denitrified flue gas is discharged from the boiler outlet after heat exchange in the waste heat boiler. The flue gas enters the waste heat boiler after dust removal and denitrification, which can improve the heat exchange efficiency and also acts as a boiler protector, which can reduce the wear of the waste heat boiler pipeline.

[0008] Preferably, a plurality of guide plates are evenly arranged at equal intervals in the fan-shaped region of the guide channel.

[0009] By adopting the above-mentioned technical solution, the guide plate can effectively distribute the smoke entering the air intake unit evenly to various areas of the guide channel, avoiding the smoke from being concentrated in a certain place, helping to reduce turbulence and turbulence in the smoke, making the airflow flow more smoothly, and the uniform smoke distribution reduces the impact on local areas of the equipment, reduces the wear and loss of the equipment, and can further extend the service life of the equipment.

[0010] Preferably, a filter bag rectifying grid inclined toward the filter bag dust removal structure is provided at the lower portion of the rectifying channel, and the transverse rectifying plates of the filter bag rectifying grid from top to bottom are equidistantly staggered in the direction close to the denitrification unit, and the vertical spacing is equal.

[0011] By adopting the above technical solution, the inclined design of the filter bag rectifier grid and the equidistant and staggered horizontal rectifier plate arrangement help to evenly distribute the flue gas, ensure that the flue gas entering the filter bag dust removal structure is more uniform, thereby improving the dust removal efficiency. By optimizing the flue gas distribution, the force on the filter bag surface is evenly distributed, and the dust can be captured more effectively, which improves the dust removal efficiency and effect. By further optimizing the flue gas path and reducing the flue gas resistance, the energy consumption of the equipment is reduced and the overall energy efficiency is improved.

[0012] Further preferably, a side wall of the dust removal unit opposite to the rectification channel is provided with a baffle ring below the filter bag dust removal structure.

[0013] By adopting the above technical solution, the uniformity of the flow field around the side wall of the dust removal unit can be improved, smoke concentration at the side wall can be avoided, and a baffle ring can be added near the side wall below the filter bag dust removal structure to disrupt the concentrated airflow and reduce the scouring of the filter bag of the filter bag dust removal structure by the smoke.

[0014] Further preferably, a plurality of evenly distributed rectifying holes are provided on the transverse rectifying plate.

[0015] Through the above technical solution, uniform rectifying holes are opened on the transverse rectifying plate, which can reduce the resistance of the smoke when passing through the rectifying plate, further make the smoke evenly distributed, and can reduce the turbulence generated when the smoke passes through the rectifying plate, making the smoke flow more stable.

[0016] Preferably, the left and right edges of the connecting flue expand evenly from the entrance to the exit, a number of vertically equidistant horizontal cross plates are arranged at the entrance of the connecting flue, and a vertical triangular column diverter is provided at the central axis position of the outlet of the connecting flue.

[0017] By adopting the above technical solution, the connecting flue expanding to the left and right sides can help to avoid the problem of chaotic flue gas distribution due to excessive concentration of high-speed airflow when the flue gas passes through the connecting flue and enters the upper part of the denitrification unit. The horizontal cross plate at the entrance can filter out the upward tendency of the flue gas passing through the connecting flue, and the triangular column diverter at the outlet can divide the flue gas evenly to the left and right, so that the flue gas gathered at the upper part of the denitrification unit is more evenly distributed.

[0018] Further preferably, the denitrification unit is further provided with a drainage device between the interconnecting flues on both sides, the drainage device comprising a central drainage plate and inverted L drainage plates symmetrically arranged on both sides of the central drainage plate, and the position of the inverted L drainage plate corresponds to the position of the horizontal cross plate.

[0019] By adopting the above technical solution, the flue gas entering the denitrification unit through the flue gas connected on both sides is blocked by the central guide plate to avoid collision when the flue gas converges. At the same time, the symmetrically arranged inverted L guide plates correspond to the position of the horizontal cross plates, which can evenly and stably turn the flow direction of the flue gas from the horizontal direction by 90° and then flow vertically downward.

[0020] Preferably, the denitration unit is provided with an SCR rectifying grid above the SCR catalyst layer, and the position of the SCR rectifying grid is lower than the connecting flues on both sides.

[0021] By adopting the above technical solution, an SCR rectifying grid is set at a position below the connected flue on the upper part of the denitrification unit to further adjust the state of the flue gas before denitrification, so that its incident angle, ammonia nitrogen distribution and velocity distribution are uniformly distributed downward through the SCR catalyst layer.

[0022] Preferably, an ash conveying device is further provided below the dust removal hopper, and a terminal end of the ash conveying device extends to below the waste heat boiler.

[0023] By adopting the above technical solution, with the help of the ash conveying device arranged under the dust removal hopper, the smoke separated from the dust removal unit can be promptly transported to the bottom of the waste heat boiler, so as to achieve unified collection of smoke discharged from the dust removal unit and the waste heat boiler. The setting of the ash conveying device simplifies the smoke treatment process, reduces intermediate links, and reduces treatment costs and complexity.

[0024] According to the second aspect of the present application, a cement kiln dust removal and denitrification method is proposed, comprising:

[0025] S1: The flue gas to be treated is input into the dust and saltpeter integrated module through the air intake duct. The flue gas is evenly divided into two streams by the guide channel and the guide plate at the bottom of the air intake duct and enters the rectification channel of the dust removal unit;

[0026] S2: The flue gas passes through the filter bag rectification grid in the rectification channel for rectification. The rectified flue gas evenly penetrates the filter bag dust removal structure for dust removal. After dust removal, the flue gas flows upward into the clean air cavity;

[0027] S3: The flue gas is diverted through the horizontal plate at the entrance of the connected flue and the triangular column diverter at the outlet. The diverted flue gas is collected from the clean gas cavity to the upper part of the denitrification unit;

[0028] S4: The collected flue gas is diverted 90 degrees through the drainage device, and the diverted flue gas evenly and vertically passes through the SCR rectifier grid for rectification before denitrification;

[0029] S5: After rectification, the flue gas evenly penetrates downward through the SCR catalyst layer for denitrification to obtain clean flue gas. The clean flue gas enters the waste heat boiler through the exhaust pipe, and is discharged from the boiler outlet of the waste heat boiler after heat exchange in the waste heat boiler.

[0030] The method uses the design of the guide channel, the guide plate, the rectification channel and the filter bag rectification grid to enable the flue gas to be effectively rectified when entering the dust removal unit, thereby ensuring the uniformity of the flue gas flow rate and flow direction, and improving the dust removal and denitrification efficiency. At the same time, multiple diversion designs (such as when entering the rectification channel and passing through the drainage device) are used to help evenly distribute the flue gas and avoid the concentration of the flue gas in a certain part, thereby improving the dust removal and denitrification effect. Through the rectification effect of the SCR rectification grid, the flue gas can maintain a uniform incident angle, ammonia nitrogen distribution and velocity distribution when entering the SCR catalyst layer, thereby improving the denitrification efficiency of the SCR catalyst layer and ensuring the generation of clean flue gas. The clean flue gas after denitrification is heat exchanged through the waste heat boiler, which not only improves the overall energy efficiency of the equipment, but also helps to recover and utilize waste heat, further reducing energy waste.

[0031] Compared with the prior art, the beneficial effects of this application are:

[0032] The present application mainly solves the problems of large space occupation of dust removal and denitrification devices in the prior art (the existing structural type can be directly arranged on the top of the waste heat boiler and organically combined into a whole), uneven flue gas distribution, easy dust re-suspension, and low dust removal efficiency and energy efficiency. The integrated dust and denitrification module in the present application utilizes the design of guide channels, guide plates, rectification channels and filter bag rectification grids to enable the flue gas to be effectively rectified when entering the dust removal unit, thereby ensuring the uniformity of the flue gas flow rate and direction, and improving the dust removal and denitrification efficiency. At the same time, multiple diversion designs (such as when entering the rectification channel and passing through the drainage device) are utilized to help evenly distribute the flue gas and avoid the concentration of flue gas in a certain part, thereby improving the dust removal and denitrification effects. Through the rectification effect of the SCR rectification grid, the flue gas can maintain a uniform incident angle, ammonia nitrogen distribution and velocity distribution when entering the SCR catalyst layer, thereby improving the denitrification efficiency of the SCR catalyst layer and ensuring the generation of clean flue gas. The clean flue gas after denitrification is heat exchanged through the waste heat boiler, which not only improves the overall energy efficiency of the equipment, but also helps to recover and utilize waste heat, further reducing energy waste. At the same time, the flue gas directly enters the waste heat boiler after dust removal and denitrification, which also acts as a boiler protector and can reduce the wear of the waste heat boiler pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and are used together with the description to explain the principles of the present invention. It will be easy to recognize other embodiments and many expected advantages of the embodiments because they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale with each other. The same reference numerals refer to corresponding similar parts.

[0034] Figure 1 2 is a schematic structural diagram of a cement kiln dust removal and denitrification device according to an embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of the side structure of a cement kiln dust removal and denitrification equipment according to a specific embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of the internal flue gas flow direction of the dust and saltpeter integrated module according to a specific embodiment of the present invention;

[0037] Figure 4 is a schematic structural diagram of a transverse rectifier according to a specific embodiment of the present invention;

[0038] Figure 5 is a schematic diagram of a three-dimensional structure of a connected flue according to a specific embodiment of the present invention;

[0039] Figure 6It is a partial enlarged view of a dust and saltpeter integrated module according to a specific embodiment of the present invention;

[0040] Figure 7 is another partial enlarged view of the dust and saltpeter integrated module according to a specific embodiment of the present invention;

[0041] Figure 8 It is a flow chart of a cement kiln dust removal and denitrification method according to one embodiment of the present application.

[0042] The meaning of the numbers in the figure:

[0043] Dust and saltpeter integrated module 01, air intake unit 02, dust removal unit 03, denitrification unit 04, air intake duct 05, guide channel 06, rectification channel 07, filter bag dust removal structure 08, clean air cavity 09, dust removal ash hopper 10, connecting flue 11, SCR catalyst layer 12, air outlet duct 13, waste heat boiler 14, boiler inlet 15, ash hopper 16, boiler outlet 17, guide plate 18, ash conveying device 19, SCR rectifying grid 20, drainage device 21, filter bag rectifying grid 22, transverse rectifying plate 23, rectification hole 24, horizontal cross plate 25, triangular column diverter 26, central drainage plate 27, inverted L drainage plate 28, baffle ring 29. DETAILED DESCRIPTION

[0044] In the following detailed description, reference is made to the accompanying drawings, which form a part of the detailed description and are shown by illustrative specific embodiments in which the present invention can be put into practice. To this end, directional terms, such as "top", "bottom", "left", "right", "up", "down", etc., are used with reference to the orientation of the figures described. Because the parts of the embodiments can be positioned in several different orientations, directional terms are used for the purpose of illustration and are by no means limiting. It should be understood that other embodiments may be utilized or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description should not be adopted in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0045] According to the first aspect of the present application, a cement kiln dust removal and denitrification device is proposed. Figure 1 FIG. 4 shows a schematic diagram of a cement kiln dust removal and denitrification device according to an embodiment of the present invention. Figure 1As shown, the equipment includes a dust and nitrate integrated module 01 and a waste heat boiler 14, the dust and nitrate integrated module 01 includes an air intake unit 02, a dust removal unit 03 and a denitration unit 04, the air intake unit 02 includes an air intake pipe 05 and a fan-shaped guide channel 06 extending from the bottom of the air intake pipe 05 to both sides; the dust removal unit 03 includes a rectifying channel 07 and a filter bag dust removal structure 08 which are sequentially arranged on both sides of the denitration unit 04, the inlet of the rectifying channel 07 is connected to the end of the guide channel 06, The dust unit 03 is formed with a clean air cavity 09 and a plurality of dust hoppers 10 above and below the filter bag dust removal structure 08, respectively; the upper part of the rectifying channel 07 is provided with connecting flues 11 connecting the clean air cavity 09 and the denitrification unit 04 at equal intervals; the denitrification unit 04 is provided with a plurality of SCR catalyst layers 12 arranged in parallel below the connecting flue 11, and an exhaust pipe 13 extends downward from the bottom of the denitrification unit 04; the exhaust pipe 13 is directly connected to the boiler inlet 15 of the waste heat boiler 14.

[0046] By adopting the above technical solution, the dust removal and denitrification functions are integrated into one module. The fan-shaped guide channel 06 design in the air intake unit 02 helps to evenly divert the flue gas entering the module, ensuring that the subsequent dust removal and denitrification processes can be carried out more effectively. The diverted flue gas enters the dust removal unit 03 through the rectification channel 07. After entering the dust removal unit 03, the flue gas penetrates the filter bag dust removal structure 08 for dust removal. The dust-removed flue gas flows upward into the clean air cavity 09, and is further collected to the upper part of the denitrification unit 04 through the connecting flue 11. The collected flue gas passes downward through the SCR catalyst layer 12 for denitrification. The denitrified flue gas is discharged from the boiler outlet 17 after heat exchange in the waste heat boiler 14. The flue gas enters the waste heat boiler 14 after dust removal and denitrification, which can improve the heat exchange efficiency and also acts as a boiler protector, which can reduce the wear of the waste heat boiler 14 pipeline.

[0047] In a specific embodiment, an ash conveying device 19 is further provided below the dust removal hopper 10 , and a terminal end of the ash conveying device 19 extends to below the ash hopper 16 of the waste heat boiler 14 .

[0048] By adopting the above technical solution, with the help of the ash conveying device 19 arranged under the dust hopper 10, the smoke separated from the dust removal unit 03 is promptly transported to the bottom of the waste heat boiler 14, so that the smoke discharged from the dust removal unit 03 and the waste heat boiler 14 can be uniformly collected, the scattering and flying of smoke during the transportation process is reduced, and the risk of secondary pollution is reduced. The setting of the ash conveying device 19 simplifies the smoke treatment process, reduces the intermediate links, and reduces the treatment cost and complexity.

[0049] Figure 2 FIG. 4 shows a schematic diagram of the side structure of a cement kiln dust removal and denitrification device according to a specific embodiment of the present invention. Figure 1-2As shown, the guide channel 06 is a fan-shaped structure that expands downward, and a number of guide plates 18 are evenly arranged at equal intervals in the fan-shaped area of ​​the guide channel 06.

[0050] By adopting the above-mentioned technical solution, the guide plate 18 can effectively distribute the smoke entering the air intake unit 02 evenly to various areas of the guide channel 06, avoiding the smoke from being concentrated in a certain place, helping to reduce turbulence and turbulence in the smoke, making the airflow flow more smoothly, and the uniform smoke distribution reduces the impact on local areas of the equipment, reduces the wear and loss of the equipment, and can further extend the service life of the equipment.

[0051] Figure 3 FIG. 1 shows a schematic diagram of the internal flue gas flow direction of a dust and saltpeter integrated module according to a specific embodiment of the present invention. Figure 1-3 As shown, a filter bag rectifying grid 22 inclined toward the filter bag dust removal structure 08 is provided at the lower portion of the rectifying channel 07, and each lateral rectifying plate 23 from top to bottom of the filter bag rectifying grid 22 is equidistantly staggered in a direction close to the denitrification unit 04, and the vertical spacing is equal.

[0052] Furthermore, the horizontal distances between the center of the topmost and bottommost transverse rectifying plates 23 of the filter bag rectifying grid 22 and the side walls of the rectifying channel 07 close to the denitrification unit 04 are 1100 mm and 290 mm respectively, and each transverse rectifying plate 23 is inclined toward the direction of the filter bag dust removal structure 08, and the angle between the transverse rectifying plate 23 and the horizontal direction is 45°, the horizontal offset distance between the centers of each transverse rectifying plate 23 is 45 mm, and the vertical spacing is 300 mm.

[0053] By adopting the above-mentioned technical scheme, the inclined design of the filter bag rectifying grid 22 and the equidistant and staggered arrangement of the transverse rectifying plates 23 help to evenly distribute the flue gas, ensuring that the flue gas entering the filter bag dust removal structure 08 is more uniform, thereby improving the dust removal efficiency. By optimizing the flue gas distribution, the filter bag surface of the filter bag dust removal structure 08 is evenly stressed, and dust can be captured more effectively, thereby improving the dust removal efficiency and effect. By further optimizing the flue gas path and reducing the flue gas resistance, the energy consumption of the equipment is reduced and the overall energy efficiency is improved.

[0054] In a specific embodiment, an SCR rectifying grid 20 is disposed above the SCR catalyst layer 12 , and the position of the SCR rectifying grid 20 is lower than the connecting flues 11 on both sides.

[0055] Furthermore, after CFD simulation optimization, the closer the SCR rectifier grid 20 is to the inlet of the SCR catalyst layer 12, the more uniform the airflow above the SCR catalyst layer 12 is. Therefore, the distance between the bottom of the SCR rectifier grid 20 and the bottom of the SCR catalyst layer 12 is set to 2400 mm.

[0056] By adopting the above technical solution, by setting the SCR rectifying grid 20 at the upper part of the denitrification unit 04 below the connected flue 11, the state of the flue gas before denitrification is further adjusted so that its incident angle, ammonia nitrogen distribution and velocity distribution pass through the SCR catalyst layer 12 evenly downward.

[0057] Figure 4 FIG. 4 shows a schematic diagram of the structure of a transverse rectifier according to a specific embodiment of the present invention. Figure 1-4 As shown, a plurality of evenly distributed rectifying holes 24 are formed on the transverse rectifying plate 23 .

[0058] Furthermore, the width of the transverse rectifying plate 23 is 200 mm, the distance between the centers of the rectifying holes 24 is 500 mm, and the diameter of the rectifying holes 24 is 140 mm. Appropriate spacing and diameter help to further reduce the resistance of the flue gas when passing through the transverse rectifying plate 23.

[0059] Through the above technical solution, uniform rectifying holes 24 are opened on the transverse rectifying plate 23, which can reduce the resistance of the smoke when passing through the transverse rectifying plate 23, further make the smoke evenly distributed, and can reduce the turbulence generated when the smoke passes through the transverse rectifying plate 23, making the smoke flow more stable.

[0060] Figure 5 FIG. 1 shows a schematic diagram of a three-dimensional structure of a connected flue according to a specific embodiment of the present invention. Figure 1-5 As shown, the left and right edges of the connecting flue 11 expand uniformly from the entrance to the exit, a number of vertically equidistant horizontal cross plates 25 are arranged at the entrance of the connecting flue 11, and a vertical triangular column diverter 26 is provided at the central axis position of the outlet of the connecting flue 11.

[0061] Furthermore, after CFD simulation, when the horizontal cross plate 25 and the triangular column diverter 26 are not set, not only will a large volume vortex appear in the connected flue 11, but the direction and flow rate of the flue gas outflow are very random and unevenly distributed. After the horizontal cross plate 25 and the triangular column diverter 26 are set, the flue gas will be diverted into dozens of small vortices and evenly distributed.

[0062] Furthermore, the left and right widths of the entrance and exit of the connecting flue 11 are 800mm and 1200mm respectively, the vertical height of the exit is 1800mm, the horizontal cross plates 25 are horizontally arranged at a spacing of 300mm at the entrance, the triangular column diverter 26 is an equilateral triangle with a side length of 200mm in cross section and a triangular prism with a height of 1800mm, and the bottom edge of the entrance of the connecting flue 11 can also be set at an angle from bottom to top, which can further reduce the resistance of the smoke when entering the connecting flue 11 from bottom to top. At the same time, the top of the connecting flue can also be set as a dome structure, which can further reduce the wear of the connecting flue 11.

[0063] By adopting the above technical solution, the connecting flue 11 expanding outward to the left and right sides helps to avoid the problem of chaotic flue gas distribution due to excessive concentration of high-speed airflow when the flue gas passes through the connecting flue 11 and enters the upper part of the denitrification unit 04. The horizontal cross plate 25 at the inlet can filter out the upward tendency of the flue gas in the process of passing through the connecting flue 11, and the triangular column diverter 26 at the outlet can divide the flue gas evenly to the left and right, so that the flue gas collected at the upper part of the denitrification unit 04 is more evenly distributed.

[0064] Figure 6 FIG. 1 shows a partial enlarged view of a dust and saltpeter integrated module according to a specific embodiment of the present invention, as shown in FIG. Figure 1-6 As shown, the denitrification unit 04 is further provided with a drainage device 21 between the connecting flues 11 on both sides. The drainage device 21 includes a central drainage plate 27 and inverted L drainage plates 28 symmetrically arranged on both sides of the central drainage plate 27. The position of the inverted L drainage plate 28 corresponds to the position of the horizontal cross plate 25.

[0065] Furthermore, through CFD simulation, when the drainage device 21 is not provided, the flue gases connecting the flue ducts 11 on both sides will collide when they converge, and the direction of the downward flow after convergence is random and the flow velocity distribution is uneven, which affects the denitrification effect. After the drainage device 21 is provided, the flow velocity of the converged flue gases can be uniform and stable to penetrate the SCR catalyst layer 12 downward.

[0066] Furthermore, the turning point of the inverted L-shaped guide plate 28 is rounded, and the radius of the rounded corner is 200 mm.

[0067] By adopting the above technical solution, the flue gas entering the denitrification unit 04 through the flue ducts 11 connected on both sides is blocked by the central guide plate 27 to avoid collision when the flue gas gathers. At the same time, the symmetrically arranged inverted L guide plates 28 correspond to the position of the horizontal cross plate 25, which can evenly and stably turn the flow direction of the flue gas from the horizontal direction by 90° and then flow vertically downward.

[0068] Figure 7 Another partial enlarged view of the dust and saltpeter integrated module according to a specific embodiment of the present invention is shown. Figure 1-7 As shown, a baffle ring 29 is provided on the side wall of the dust removal unit 03 opposite to the rectifying channel 07 below the filter bag dust removal structure 08 .

[0069] Furthermore, after CFD simulation, after the flue gas passes through the filter bag rectifying grille 22, there will be airflow concentration on the side wall of the dust removal unit 03. A baffle ring 29 is provided to disrupt the concentrated airflow and reduce the scouring of the filter bag of the filter bag dust removal structure 08 by the airflow.

[0070] Furthermore, the angle between the baffle ring 29 and the side wall of the dust removal unit 03 is 60°, and a suitable angle can effectively disrupt the concentrated airflow.

[0071] By adopting the above-mentioned technical solution, the uniformity of the flow field around the side wall of the dust removal unit 03 can be improved, smoke concentration at the side wall can be avoided, and a baffle ring 29 is added near the side wall below the filter bag dust removal structure 08 to disrupt the concentrated airflow and reduce the scouring of the filter bag of the filter bag dust removal structure by the smoke.

[0072] According to the second aspect of the present application, a cement kiln dust removal and denitrification method is proposed. Figure 8 A flow chart of a cement kiln dust removal and denitrification method according to an embodiment of the present application is shown. As shown in the figure, the method includes:

[0073] S1: The flue gas to be treated is input into the dust and saltpeter integrated module through the air intake duct. The flue gas is evenly divided into two streams by the guide channel and the guide plate at the bottom of the air intake duct and enters the rectification channel of the dust removal unit;

[0074] S2: The flue gas passes through the filter bag rectification grid in the rectification channel for rectification. The rectified flue gas evenly penetrates the filter bag dust removal structure for dust removal. After dust removal, the flue gas flows upward into the clean air cavity;

[0075] S3: The flue gas is diverted through the horizontal plate at the entrance of the connected flue and the triangular column diverter at the outlet. The diverted flue gas is collected from the clean gas cavity to the upper part of the denitrification unit;

[0076] S4: The collected flue gas is diverted 90 degrees through the drainage device, and the diverted flue gas evenly and vertically passes through the SCR rectifier grid for rectification before denitrification;

[0077] S5: After rectification, the flue gas evenly penetrates downward through the SCR catalyst layer for denitrification to obtain clean flue gas. The clean flue gas enters the waste heat boiler through the exhaust pipe, and is discharged from the boiler outlet of the waste heat boiler after heat exchange in the waste heat boiler.

[0078] The method uses the design of the guide channel 06, the guide plate 18, the rectification channel 07 and the filter bag rectification grid 22 to effectively rectify the flue gas when it enters the dust removal unit 03, thereby ensuring the uniformity of the flue gas flow rate and flow direction, and improving the dust removal and denitrification efficiency. At the same time, multiple diversion designs (such as when entering the rectification channel 07 and passing through the drainage device 21) are used to help evenly distribute the flue gas and avoid the concentration of the flue gas in a certain part, thereby improving the dust removal and denitrification effect. Through the rectification effect of the SCR rectification grid 20, the flue gas can maintain a uniform incident angle, ammonia nitrogen distribution and velocity distribution when entering the SCR catalyst layer 12, thereby improving the denitrification efficiency of the SCR catalyst layer 12 and ensuring the generation of clean flue gas. The clean flue gas after denitrification is heat exchanged through the waste heat boiler 14, which not only improves the overall energy efficiency of the equipment, but also helps to recover and utilize waste heat, further reducing energy waste.

[0079] The present application mainly solves the problems of large space occupation, uneven flue gas distribution, easy dust resuspension, low dust removal efficiency and energy efficiency in the dust removal and denitrification devices in the prior art. The dust and denitrification integrated module 01 in the present application utilizes the design of the guide channel 06, the guide plate 18, the rectification channel 07 and the filter bag rectification grid 22 to enable the flue gas to be effectively rectified when entering the dust removal unit 03, ensuring the uniformity of the flue gas flow rate and flow direction, and improving the dust removal and denitrification efficiency. At the same time, the use of multiple diversion designs (such as when entering the rectification channel 07 and passing through the drainage device 21) helps to evenly distribute the flue gas and avoid the concentration of the flue gas in a certain part, thereby improving the dust removal and denitrification effect. Through the rectification of the SCR rectification grid 20 The flow effect enables the flue gas to maintain a uniform incident angle, ammonia nitrogen distribution and velocity distribution when entering the SCR catalyst layer 12, thereby improving the denitrification efficiency of the SCR catalyst layer 12 and ensuring the generation of clean flue gas. The clean flue gas after denitrification is heat exchanged through the waste heat boiler 14, which not only improves the overall energy efficiency of the equipment, but also helps to recover and utilize waste heat, further reducing energy waste. At the same time, the flue gas directly enters the waste heat boiler 14 after dust removal and denitrification, which also plays the role of a boiler protector and can reduce the wear of the waste heat boiler 14 pipeline.

[0080] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and changes are within the scope of the claims of the present application and their equivalents, the present application is also intended to cover these modifications and changes. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are recorded in mutually different dependent claims does not indicate that the combination of these measures cannot be used to profit. Any figure mark in the claims should not be considered to limit the scope.

Claims

1. A cement kiln dust removal and denitrification equipment, comprising a dust and denitrification integrated module and a waste heat boiler, characterized in that: The dust and nitrate integrated module includes an air intake unit, a dust removal unit and a denitrification unit. The air intake unit includes an air intake pipe and a fan-shaped guide channel extending from the bottom of the air intake pipe to both sides; the dust removal unit includes a rectifying channel and a filter bag dust removal structure sequentially arranged on both sides of the denitrification unit, the inlet of the rectifying channel is connected to the end of the guide channel, the dust removal unit is respectively formed with a clean air cavity and a plurality of dust hoppers above and below the filter bag dust removal structure, and a connecting flue connecting the clean air cavity and the denitrification unit is evenly spaced at the upper part of the rectifying channel; the denitrification unit is provided with a plurality of SCR catalyst layers arranged in parallel below the connecting flue, and an air outlet pipe extends downward from the bottom of the denitrification unit; the air outlet pipe is directly connected to the boiler inlet of the waste heat boiler.

2. The cement kiln dust removal and denitrification equipment according to claim 1, characterized in that: A plurality of guide plates are evenly arranged at equal intervals in the fan-shaped area of ​​the guide channel.

3. The cement kiln dust removal and denitrification equipment according to claim 1, characterized in that: A filter bag rectifying grid inclined toward the filter bag dust removal structure is arranged at the lower part of the rectifying channel. The transverse rectifying plates of the filter bag rectifying grid from top to bottom are equidistantly staggered in the direction close to the denitrification unit, and the vertical spacing is equal.

4. The cement kiln dust removal and denitrification equipment according to claim 3, characterized in that: A baffle ring is provided on the side wall of the dust removal unit opposite to the rectification channel below the filter bag dust removal structure.

5. The cement kiln dust removal and denitrification equipment according to claim 3, characterized in that: The transverse rectifying plate is provided with a plurality of evenly distributed rectifying holes.

6. The cement kiln dust removal and denitrification equipment according to claim 1, characterized in that: The left and right edges of the connecting flue are uniformly expanded from the entrance to the exit. A plurality of vertically equidistant horizontal cross plates are arranged at the entrance of the connecting flue, and a vertical triangular column diverter is provided at the central axis position of the outlet of the connecting flue.

7. The cement kiln dust removal and denitrification equipment according to claim 6, characterized in that: The denitrification unit is also provided with a drainage device between the interconnecting flues on both sides, and the drainage device includes a central drainage plate and inverted L drainage plates symmetrically arranged on both sides of the central drainage plate, and the position of the inverted L drainage plate corresponds to the position of the horizontal cross plate.

8. The cement kiln dust removal and denitrification equipment according to claim 1, characterized in that: The denitration unit is provided with an SCR rectifying grid above the SCR catalyst layer, and the position of the SCR rectifying grid is lower than the connecting flues on both sides.

9. The cement kiln dust removal and denitrification equipment according to claim 1, characterized in that: An ash conveying device is also arranged below the dust removal hopper, and a terminal end of the ash conveying device extends to below the waste heat boiler.

10. A cement kiln dust removal and denitrification method, using the equipment according to any one of claims 1 to 9, characterized in that: include: S1: The flue gas to be treated is input into the dust and saltpeter integrated module through the air intake duct, and the flue gas is evenly divided into two streams by the guide channel and the guide plate at the bottom of the air intake duct and enters the rectification channel of the dust removal unit; S2: The flue gas passes through the filter bag rectifying grid in the rectifying channel for rectification, and the rectified flue gas evenly penetrates the filter bag dust removal structure for dust removal, and the flue gas flows upward into the clean air cavity after dust removal; S3: The flue gas is diverted through the horizontal plate at the entrance of the flue and the triangular column diverter at the exit, and the diverted flue gas is collected from the clean gas cavity to the upper part of the denitrification unit; S4: The collected flue gas is diverted 90 degrees through the drainage device, and the diverted flue gas evenly and vertically passes through the SCR rectifier grid to be rectified before denitrification; S5: After being rectified, the flue gas uniformly penetrates downward through the SCR catalyst layer for denitration to obtain clean flue gas, and the clean flue gas enters the waste heat boiler through the exhaust pipe, and is discharged from the boiler outlet of the waste heat boiler after heat exchange in the waste heat boiler.

Images