Post-treatment system for high-temperature waste gas of steel mill
By adjusting the flow area and dynamic sampling of the steel plant's high-temperature exhaust gas conveying pipeline, the problem of inaccurate sampling results caused by uneven dust distribution was solved, and dynamic adjustment of electrostatic precipitator parameters and energy consumption reduction were achieved.
Patent Information
- Application Number
- CN202510988391.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2025-09-12
AI Technical Summary
The dust distribution in the high-temperature exhaust gas transmission pipelines of existing steel mills is uneven, resulting in poor reference value of sampling results and affecting the high energy consumption of electrostatic precipitators.
By adjusting the flow area of the conveying pipeline, combining the built-in detection axis parallel detection technology, using a ring sampler and a dust metering module, the uniform distribution and dynamic sampling of dust can be achieved, and the electrostatic precipitator module is used to dynamically adjust the dust removal parameters according to the feedback of the dust metering module.
The consistency of sampling results is improved, the energy consumption of the electrostatic precipitator system is reduced, and more efficient dust treatment is achieved.
Smart Images
Figure CN120618690A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of waste gas treatment, and in particular to a post-treatment system for high-temperature waste gas from a steel plant. Background Art
[0002] The treatment process sequence of high-temperature exhaust gas generated by steel mills is generally: denitrification (SCR / SNCR) → dust removal (electrostatic precipitator / bag filter) → desulfurization. Denitrification takes priority because the denitrification reaction requires a higher temperature (300-400°C). Therefore, it is usually placed before dust removal and desulfurization to ensure the activity of the catalyst. Dust removal equipment (such as electrostatic precipitators or bag filters) is used to remove particulate matter in the flue gas to prevent dust from clogging the nozzles, fillers or catalysts in the desulfurization tower, thereby improving the desulfurization efficiency. Desulfurization comes after: wet desulfurization (such as the limestone-gypsum method) needs to be carried out when the dust content in the flue gas is low to reduce the impact of impurities in the desulfurization slurry on the purity of the gypsum.
[0003] For dust removal of high-temperature flue gas, there are currently methods such as cyclone dust removal, bag dust removal and electrostatic precipitator. Electrostatic precipitator is widely used due to its advantages in efficiency and dust removal rate. In addition, the products obtained from electrostatic precipitator can also be used in new fields such as metal recovery.
[0004] However, electrostatic precipitators have the characteristic of high energy consumption. Therefore, it is expected that the power of electrostatic precipitators can be dynamically adjusted according to the amount of dust. This requires dynamic sampling of the exhaust gas conveying pipeline. The exhaust gas conveying pipeline has the characteristics of fast flow rate (general experience flow rate range is 15-25m / s) and large pipe diameter (DN600-DN800 or even higher). These characteristics make the dust inside the conveying pipeline unevenly distributed, resulting in poor reference value of the collection results. Summary of the Invention
[0005] The present application provides a post-processing system for high-temperature exhaust gas from a steel plant, which achieves representative sample collection by adjusting the flow area. The results obtained by this collection method are more consistent with the actual results, which helps to reduce the energy consumption of the treatment system.
[0006] The above-mentioned purpose of this application is achieved through the following technical solutions: The present application provides a post-treatment system for high-temperature exhaust gas from a steel plant, comprising: transportation pipelines; The detection shaft is arranged inside the conveying pipe, and the axis of the detection shaft is parallel to the axis of the conveying pipe; An inner diameter regulator is provided on the detection shaft and is used to adjust the flow area inside the conveying pipe; An annular sampler is provided on the delivery pipeline and is capable of communicating with the space inside the delivery pipeline; Dust metering module, installed on the ring sampler; The electrostatic precipitator module is connected to the conveying pipeline and electrically connected to the dust metering module. The electrostatic precipitator module dynamically adjusts the dust removal parameters according to the feedback from the dust metering module.
[0007] In a possible implementation of the present application, the inner diameter regulator includes: A sleeve, provided on the detection shaft; The fan blades are evenly distributed on the sleeve, and the first ends of the fan blades are hinged to the sleeve; Slip ring, slidingly connected to the detection shaft; An adjusting rod, both ends of which are hinged to the second end of the fan blade and the slip ring respectively; The first driver is arranged on the outer wall of the conveying pipeline and is connected to the slip ring.
[0008] In a possible implementation of the present application, the first driver includes: The linear expansion joints are symmetrically arranged and are all arranged on the outer wall of the conveying pipe; The crossbar is connected to the slip ring and is slidably connected to the telescopic end of the linear expander.
[0009] In a possible implementation of the present application, the first driver includes: The symmetrically arranged linear expansion joint and passive expansion unit are both arranged on the outer wall of the conveying pipe; The crossbar is connected to the slip ring and is slidably connected to the telescopic end of the linear expander.
[0010] In a possible implementation of the present application, the annular sampler includes: A sampling ring is provided on the delivery pipe, and first sampling channels are provided at intervals in the circumferential direction of the delivery pipe, and the first sampling channels are used to connect the first sampling channel and the sampling ring; A rotating ring is rotatably connected to the delivery pipe, and a second sampling channel is provided on the rotating ring; The second driver is provided on the sampling ring or the first sampling channel and is connected to the rotating ring. The second driver is used to drive the rotating ring to rotate so that the sampling ring and the first sampling channel are in a connected state or a disconnected state.
[0011] In a possible implementation of the present application, a vacuum pump connected to the sampling loop is also included.
[0012] In one possible implementation of the present application, the dust metering module includes: A circulation pump is connected to the sampling loop to form a loop; The dust sensor is arranged on the sampling ring, and the detection end of the dust sensor extends into the interior of the sampling ring.
[0013] In a possible implementation of the present application, a feedback substrate is further included in the sampling ring, and the feedback substrate is used to reflect the light signal emitted by the dust sensor.
[0014] In a possible implementation of the present application, a purge pipe is further included, one end of which extends into the interior of the sampling ring and faces the feedback substrate.
[0015] The beneficial effects of this application are: The post-processing system for high-temperature exhaust gas from a steel mill, provided in this application, concentrates dust inside the conveying pipeline by adjusting the flow area. It then uses negative pressure collection to obtain samples, while simultaneously using active circulation to ensure that the distribution of dust in the sample is as uniform as possible. This collection method yields results that are more consistent with actual results, allowing the electrostatic precipitator module to dynamically adjust its operating parameters while maintaining a constant dust removal rate, thereby reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a structural schematic diagram of a post-treatment system for high-temperature exhaust gas from a steel plant provided in this application.
[0017] Figure 2 This is a schematic diagram of the internal structure of a conveying pipeline provided by this application.
[0018] Figure 3 This is a structural schematic diagram of an inner diameter regulator, an annular sampler and a dust metering module provided in this application.
[0019] Figure 4 This is a structural diagram of a first driver provided in this application.
[0020] Figure 5 It is a structural schematic diagram of another first driver provided in this application.
[0021] Figure 6 This is a schematic diagram of the distribution of the second sampling channel on a rotating ring provided by this application.
[0022] Figure 7 This is a schematic diagram of the relative positions of the first sampling channel and the second sampling channel when the first sampling channel is turned on, provided by the present application.
[0023] Figure 8 This is a schematic diagram of the relative positions of the first sampling channel and the second sampling channel when the first sampling channel is closed, as provided in the present application.
[0024] Figure 9 This is a structural diagram of a dust metering module provided in this application.
[0025] Figure 10This is a connectivity diagram of a circulation pump provided in this application.
[0026] In the figure, 1. conveying pipeline, 2. detection shaft, 3. inner diameter adjuster, 4. annular sampler, 5. dust metering module, 6. electrostatic precipitator module, 11. first sampling channel, 31. sleeve, 32. fan blade, 33. slip ring, 34. adjusting rod, 35. first driver, 351. linear telescope, 252. passive telescopic unit, 353. cross bar, 41. sampling ring, 42. rotating ring, 43. second sampling channel, 44. second driver, 45. vacuum pump, 51. circulating pump, 52. dust sensor, 53. feedback substrate, 54. purge pipeline. DETAILED DESCRIPTION
[0027] The technical solution in this application is further described in detail below with reference to the accompanying drawings.
[0028] This application discloses a post-processing system for high-temperature exhaust gas from a steel plant. In some examples, the post-processing system for high-temperature exhaust gas from a steel plant disclosed in this application includes a conveying pipeline 1, a detection shaft 2, an inner diameter regulator 3, an annular sampler 4, a dust metering module 5, and an electrostatic precipitator module 6. Figure 1 and Figure 2 The detection shaft 2 is fixedly installed inside the conveying pipe 1, and the axis of the detection shaft 2 is required to be parallel to the axis of the conveying pipe 1.
[0029] In some possible implementations, the axis of the detection shaft 2 coincides with the axis of the conveying pipe 1 .
[0030] The inner diameter regulator 3 is installed on the detection shaft 2, and its function is to adjust the flow area inside the conveying pipe 1. The state of the inner diameter regulator 3 can be described here as having an expanded state and a closed state. When the inner diameter regulator 3 is in the closed state, the flow area inside the conveying pipe 1 is the largest. When the inner diameter regulator 3 is in the expanded state, the flow area inside the conveying pipe 1 is the smallest.
[0031] The annular sampler 4 is installed on the conveying pipeline 1. The annular sampler 4 can be connected to the space inside the conveying pipeline 1. The purpose is to sample the gas flowing inside the conveying pipeline 1. The dust metering module 5 is arranged on the annular sampler 4 and is used to detect the sample inside the annular sampler 4. The concentration data obtained by the detection is sent to the electrostatic precipitator module 6.
[0032] The electrostatic precipitator module 6 is connected to the conveying pipeline 1 and electrically connected to the dust metering module 5. During operation, the electrostatic precipitator module 6 dynamically adjusts the dust removal parameters according to the feedback of the dust metering module 5. The feedback of the dust metering module 5 is concentration data. The main working parameters adjusted by the electrostatic precipitator module 6 are discharge voltage and discharge frequency. Of course, if other parameters are involved, they can also be adjusted according to the set program.
[0033] Overall, the post-treatment system for high-temperature exhaust gas from a steel plant provided in this application can obtain low-flow-rate and evenly distributed samples through dynamic sampling of the delivery pipeline (large diameter, high flow rate, uneven distribution), and the size of the space where the sample is located is also small.
[0034] The advantage of the smaller sample space is that the detection light emitted by the dust metering module 5 experiences almost no path loss. It should be understood that the operating principle of the dust metering module 5 is to emit light, detect the returned light, and calculate the dust content in the sample through comparison. When the propagation path of the emitted light is long, some of the returned light may not return. This is because the distribution of scattered light is difficult to control due to the long propagation path.
[0035] High flow rates also have an impact on test results, as follows: The time dependence of scattered light signals. In dynamic light scattering (DLS), flow velocity introduces directional translational motion of particles, which, superimposed on Brownian motion, causes the decay of the intensity autocorrelation function (ACF) to include both diffusion and translational terms. If the flow velocity is too high, the characteristic translational time (inversely proportional to the flow velocity) may be much smaller than the characteristic diffusion time, resulting in an inability to accurately separate the Brownian motion signal during inversion and an underestimation of particle size.
[0036] The spatial angle of the light intensity distribution shifts. Laser diffraction methods (such as Mie scattering) rely on the relationship between scattering angle and particle size. The rapid passage of particles at high flow rates can shorten the effective detection time, resulting in an incomplete light intensity distribution signal. In particular, the sensitivity to forward small-angle scattering decreases, affecting the detection accuracy of large particles.
[0037] Therefore, it is necessary to obtain a product with low flow rate and uniform distribution in a small space. The present application performs sampling by adjusting the flow area and then sampling, so as to obtain a more representative sample.
[0038] For some examples, see Figure 3 The inner diameter adjuster 3 includes a sleeve 31, a fan blade 32, a slip ring 33, an adjusting rod 34 and a first driver 35. The sleeve 31 is fixedly mounted on the detection shaft 2, and the fan blades 32 are evenly distributed on the sleeve 31. The specific connection method is that the first end of the fan blade 32 is hinged to the sleeve 31, and the second end of the fan blade 32 is hinged to the adjusting rod 34.
[0039] The slip ring 33 is slidably connected to the detection shaft 2 and is also hinged to the adjustment rod 34. When the distance between the slip ring 33 and the fan blade 32 changes, the fan blade 32 can swing. The first driver 35 is mounted on the outer wall of the conveying pipe 1 and is connected to the slip ring 33, driving the slip ring 33 to slide back and forth on the detection shaft 2.
[0040] The first driver 35 has the following two structural forms: First, the first driver 35 includes two symmetrically arranged linear expanders 351, such as Figure 4 As shown, the two linear expanders 351 are fixedly mounted on the outer wall of the conveying pipe 1 , and the linear expanders 351 can use a cylinder or a linear expansion module.
[0041] The cross bar 353 is connected to the slip ring 33 and is slidably connected to the telescopic end of the linear expander 351. The axis of the linear expander 351 is not parallel to the axis of the conveying pipe 1. When the telescopic end of the linear expander 351 moves, the cross bar 353 can push the slip ring 33 to slide back and forth on the detection shaft 2.
[0042] The second method is to replace a linear expander 351 in the first structural form of the first driver 35 with a passive expansion unit 252, such as a expansion rod. Figure 5 As shown, the passive telescopic unit 252 may use a telescopic cylinder without a power source.
[0043] See also Figure 3 and Figure 6 The annular sampler 4 includes a sampling ring 41, a rotating ring 42, and a second driver 44. The sampling ring 41 is fixedly mounted on the delivery pipe 1. First sampling channels 11 are spaced apart in the circumferential direction of the delivery pipe 1. The first sampling channels 11 can connect the first sampling channel 11 and the sampling ring 41, and can also achieve multi-point synchronous sampling.
[0044] contrast Figure 7 and Figure 8 The rotating ring 42 is rotatably connected to the conveying pipe 1, and a second sampling channel 43 is provided on the rotating ring 42. The second sampling channels 43 are the same in number and one-to-one correspondence with the first sampling channels 11. When the relative positions of the two change, the first sampling channel 11 and the sampling ring 41 will switch between connection and disconnection.
[0045] The second driver 44 is provided on the sampling ring 41 or the first sampling channel 11 and is connected to the rotating ring 42. The function of the second driver 44 is to drive the rotating ring 42 to rotate. The second driver 44 can use a motor to drive the rotating ring 42 to rotate through a gear rack pair.
[0046] Further, see Figure 3 A vacuum pump 45 is also added, which is connected to the sampling ring 41. The function of the vacuum pump 45 is to evacuate the sampling ring 41 before sampling, so that the interior of the sampling ring 41 is under negative pressure. In this way, during the sampling process, the airflow in the delivery pipe 1 can be actively drawn into the sampling ring 41.
[0047] See also Figure 9 and Figure 10 The dust metering module 5 includes a circulation pump 51 and a dust sensor 52. The circulation pump 51 is connected to the sampling ring 41 to form a loop. Its function is to drive the sample in the sampling ring 41 to be fully mixed. The detection end of the dust sensor 52 extends into the interior of the sampling ring 41 and uses the laser scattering method to detect the sample inside the sampling ring 41.
[0048] Here, for the circulation pump 51, both its input and output ends are required to be connected to the annular sampler 4, and the input and output ends are oriented in opposite directions, in order to drive the gas in the annular sampler 4 to circulate in the same direction.
[0049] Furthermore, a feedback substrate 53 is added inside the sampling ring 41 , and the feedback substrate 53 is used to reflect the optical signal emitted by the dust sensor 52 .
[0050] Furthermore, a purge pipe 54 is added, one end of which extends into the sampling ring 41 and toward the feedback substrate 53 , in order to remove floating dust on the feedback substrate 53 and improve the accuracy of detection.
[0051] The embodiments of this specific implementation method are all preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.
Claims
1. A post-processing system for high-temperature exhaust gas from a steel plant, characterized in that: include: Delivery pipeline (1); A detection shaft (2) is provided inside the conveying pipe (1), and an axis of the detection shaft (2) is parallel to the axis of the conveying pipe (1); An inner diameter regulator (3) is provided on the detection shaft (2), and the inner diameter regulator (3) is used to adjust the flow area inside the conveying pipe (1); An annular sampler (4) is provided on the delivery pipe (1), and the annular sampler (4) is capable of communicating with the space inside the delivery pipe (1); A dust metering module (5) is provided on the annular sampler (4); The electrostatic precipitator module (6) is connected to the conveying pipeline (1) and electrically connected to the dust metering module (5). The electrostatic precipitator module (6) dynamically adjusts the dust removal parameters according to the feedback of the dust metering module (5).
2. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 1, characterized in that: The inner diameter regulator (3) comprises: A sleeve (31) is provided on the detection shaft (2); The fan blades (32) are evenly distributed on the sleeve (31), and the first ends of the fan blades (32) are hinged to the sleeve (31); A slip ring (33) is slidably connected to the detection shaft (2); An adjusting rod (34), both ends of which are hinged to the second end of the fan blade (32) and the slip ring (33); The first driver (35) is provided on the outer wall of the conveying pipe (1), and the first driver (35) is connected to the slip ring (33).
3. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 2, characterized in that: The first driver (35) comprises: The linear expansion joints (351) are symmetrically arranged and are both arranged on the outer wall of the conveying pipe (1); The crossbar (353) is connected to the slip ring (33) and is slidably connected to the telescopic end of the linear telescope (351).
4. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 2, characterized in that: The first driver (35) comprises: The symmetrically arranged linear expansion device (351) and the passive expansion unit (252) are both arranged on the outer wall of the conveying pipe (1); The crossbar (353) is connected to the slip ring (33) and is slidably connected to the telescopic end of the linear telescope (351).
5. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 1, characterized in that: The ring sampler (4) comprises: A sampling ring (41) is provided on the delivery pipe (1), and first sampling channels (11) are provided at intervals in the circumferential direction of the delivery pipe (1), and the first sampling channels (11) are used to connect the first sampling channels (11) and the sampling ring (41); A rotating ring (42) is rotatably connected to the delivery pipe (1), and a second sampling channel (43) is provided on the rotating ring (42); The second driver (44) is provided on the sampling ring (41) or the first sampling channel (11) and is connected to the rotating ring (42). The second driver (44) is used to drive the rotating ring (42) to rotate, so that the sampling ring (41) and the first sampling channel (11) are in a connected state or a disconnected state.
6. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 5, characterized in that: Also included is a vacuum pump (45) connected to the sampling loop (41).
7. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 1, 5 or 6, characterized in that: The dust metering module (5) includes: A circulation pump (51) is connected to the sampling loop (41) to form a loop; The dust sensor (52) is provided on the sampling ring (41), and the detection end of the dust sensor (52) extends into the interior of the sampling ring (41).
8. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 7, characterized in that: It also includes a feedback substrate (53) disposed in the sampling ring (41), and the feedback substrate (53) is used to reflect the light signal emitted by the dust sensor (52).
9. The post-processing system for high-temperature exhaust gas from a steel plant according to claim 8, characterized in that: It also includes a purge pipe (54), one end of which extends into the interior of the sampling ring (41) and faces the feedback substrate (53).