Pulse swing salt air system for enhanced soot cleaning

Abstract

The application provides a pulse swing type salinization wind system for strengthening ash removal, and relates to the technical field of waste heat boilers. The application comprises a waste heat boiler and a settling chamber. A smoke baffle and a heat exchange tube screen are arranged in the waste heat boiler. A whole salinization wind nozzle is arranged at the smoke inlet of the waste heat boiler. A first local salinization nozzle is arranged outside the heat exchange tube screen. A second local salinization nozzle is arranged outside the smoke baffle. The application further comprises a gas mixing chamber. The gas mixing chamber is connected with a blower at the inlet side and is connected with the smoke outlet of the settling chamber. The outlet side of the gas mixing chamber is connected with the whole salinization wind nozzle, the first local salinization nozzle and the second local salinization nozzle. The local salinization nozzle comprises three stages of salinization softening, pulse ash removal and maintenance anti-sticking. The application solves the problem of low-temperature corrosion, reduces the cost of heating equipment and energy input, and utilizes resources nearby.

Description

Technical Field

[0001] This invention relates to the field of waste heat boiler technology, and in particular to a pulse swing-type salinization air system for enhanced ash removal. Background Technology

[0002] Currently, waste heat boilers suffer from the common problem of coking and blockage, which is complex and dangerous to handle. During pyrometallurgical processes such as copper and nickel production, the flue gas inside the boiler contains a large amount of metal oxides such as Cu₂O, PbO, and ZnO, as well as sulfides such as Cu₂S. These oxides have a low melting temperature of approximately 500-800℃ and easily form hard slag on the boiler's heating surfaces. Through continuous technological improvements, a solution has been developed: introducing ambient temperature salinization air into the waste heat boiler. During boiler operation, oxygen-rich air is blown into the boiler using a blower. The metal oxides carried in the flue gas react with oxygen and sulfur dioxide to generate sulfates with higher melting points, such as CuSO₄ and PbSO₄. These sulfates have a loose structure and are easy to remove, thus alleviating the problem of flue gas adhesion within the waste heat boiler.

[0003] Currently, there are two main installation positions for the salinization air nozzles in waste heat boilers: three on each side of the flue gas inlet (top and bottom), and three on the upper front wall of the flue gas inlet. Normal temperature salinization air is typically injected, although a small number are heated by a heater before being introduced. Generally, the salinization air is positioned near the flue gas inlet of the waste heat boiler, which reduces direct impact from the flue gas inlet to the top, minimizing corrosion and damage to the boiler roof. However, the salinization air concentration is low near the main coking areas—baffles and radiant tube screens—and the introduced salinization air is easily dispersed by the mainstream flue gas, resulting in a mediocre salinization effect. Furthermore, the low-temperature salinization air can cause low-temperature corrosion near the inlet. Using additional energy to heat the air before introducing it into the boiler increases energy consumption and equipment costs, only alleviating the low-temperature corrosion problem at the inlet. Given the current complex composition of copper concentrate raw materials, with increased impurities such as lead, zinc, and arsenic, and a higher sulfur-copper ratio, the salinization effect is not significant, and this method does not improve the salinization efficiency. Summary of the Invention

[0004] To address the problem of low-temperature corrosion at the inlet of current waste heat boiler salinization air systems, this invention adjusts the temperature and medium of the salinization air. Instead of using heaters or heat exchangers to heat the salinization air, the flue gas from the waste heat boiler is settled in a settling chamber. A pipe can be connected to the flue gas outlet of the settling chamber and integrated into the salinization air pipe. This allows the flue gas at the settling chamber outlet (approximately 320-360°C) to be directly mixed with the salinization air, ensuring that the temperature of the mixed salinization air blown into the waste heat boiler is within the range of 200-250°C. This solves the problem of low-temperature corrosion, reduces the cost of heating equipment and energy input, and utilizes resources locally.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A pulse-oscillating salinization air system for enhanced slag removal includes a waste heat boiler and a settling chamber. The waste heat boiler is equipped with a flue gas baffle and a heat exchange tube panel. An integral salinization air nozzle is installed at the flue gas inlet of the waste heat boiler. A first local salinization nozzle is installed on the outside of the heat exchange tube panel, and a second local salinization nozzle is installed on the outside of the flue gas baffle. The system also includes a mixing chamber. A blower is connected to the inlet side of the mixing chamber, and it is also connected to the flue gas outlet of the settling chamber. The outlet side of the mixing chamber is connected to the integral salinization air nozzle, the first local salinization nozzle, and the second local salinization nozzle. The local salinization nozzles include three stages: salinization softening, pulse cleaning, and curing / anti-sticking. In the salinization softening stage, only the local salinization nozzle is controlled to oscillate up and down. In the pulse cleaning stage, the oscillation mechanism of the local salinization nozzle is kept running, and the pressure and frequency of the pulse valve are adjusted according to the slag thickness. In the curing / anti-sticking stage, the salinization air flow rate of the local salinization nozzle is reduced while the oscillation mechanism remains running.

[0007] Preferably, a micro powder metering device is added to the front end of the salinization air inlet of the mixing chamber, and the micro powder is used to fill the gaps in the smoke and dust as the salinization air flows.

[0008] Preferably, the micro powder is a desulfurization byproduct with a particle size of 50-200 mesh.

[0009] Preferably, the amount of micro powder added is 0.5% to 2% of the volume of the salinization air.

[0010] Preferably, a first temperature sensor is provided on the inlet side of the mixing chamber and a second temperature sensor is provided on the outlet side of the mixing chamber. The amount of gas supplied to the blower and the flue gas outlet of the settling chamber is adjusted according to the values ​​of the two temperature sensors, thereby regulating the temperature of the mixed saltification air blown into the waste heat boiler.

[0011] Preferably, the first temperature sensor is electrically connected to the first local salinization nozzle and the second local salinization nozzle. When the first temperature sensor detects that the temperature exceeds a set threshold, the pulse intensity of the first local salinization nozzle and the second local salinization nozzle is increased.

[0012] Preferably, during the salting and softening stage, mixed salting air at 200-250°C is blown in and continuously blown for 30-60 seconds.

[0013] Preferably, the pulse purging stage lasts for 10-20 seconds; wherein, when the slag thickness is >5mm, the pulse pressure is 0.5-0.6MPa and the frequency is 20-30 times / minute; when the slag thickness is 2-5mm, the pulse pressure is 0.4-0.5MPa and the frequency is 10-20 times / minute; when the slag thickness is <2mm, the pulse pressure is 0.3-0.4MPa and the frequency is 5-10 times / minute.

[0014] Preferably, during the curing and anti-sticking stage, the salinization airflow of the local salinization nozzle is reduced to 50%-60% of the normal flow rate, and the blowing continues for 20-30 seconds.

[0015] The beneficial effects of this invention are as follows:

[0016] Compared with existing technologies, this invention provides a salinization air system that combines overall salinization and local salinization to optimize the dust removal effect. The local salinization adopts a three-stage sequential linkage purging of salinization softening, pulse dust removal, and curing and anti-sticking, which further enhances the dust removal effect and ultimately improves the overall salinization effect. At the same time, the salinization air is heated by nearby waste heat resources, which reduces the problem of low-temperature corrosion and improves the utilization efficiency of waste heat resources. Attached Figure Description

[0017] Figure 1 Schematic diagram of a pulse-oscillating salinization air system for enhanced dust removal.

[0018] Figure 2 Schematic diagram of the locations of the nozzle groups for overall and partial salinization in the waste heat boiler.

[0019] Figure 3 Schematic diagram of the mixing chamber for salinization air and secondary flue gas

[0020] Figure 4 Schematic diagram of the flow direction of hot and cold media in the mixing chamber

[0021] In the diagram: 1. Waste heat boiler; 2. Settling chamber; 3. Flue gas damper; 4. Heat exchanger tube panel; 5. Integrated salinization air nozzle; 6. Settling chamber flue gas outlet; 7. Exhaust fan; 8. Blower; 9. Flue gas flow regulating valve; 10. Salinization air flow regulating valve; 11. Mixing chamber; 12. Second temperature sensor; 13. First flow meter; 14. First pulse valve; 15. Second pulse valve; 16. Second flow regulating valve; 17. First distribution manifold; 18. Second distribution manifold; 19. 20. First flow regulating valve; 21. Third flow meter; 22. Second local salinization nozzle; 23. First local salinization nozzle; 24. First temperature sensor; 25. Micro powder quantitative dosing device; 1101. Mixing chamber; 1102. Mixing chamber; 1103. Salinization air inlet; 1104. Secondary flue gas inlet; 1105. Mixed salinization air outlet; 1106. Vent hole; 1107. Fan central shaft; 1108. First mixing fan; 1109. Second mixing fan. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] To address the issue of ineffective salting with salting air, this invention addresses the problem from three main aspects: First, it retains the three salting air nozzles above the flue gas inlet of the waste heat boiler, blowing in mixed salting air. Simultaneously, it adds a set of salting air nozzles at the front of the flue gas baffle and the heat exchange tube panel for targeted localized salting. Two nozzles are installed, one at the top and one at the bottom, using a swing-up blowing method to increase the area and uniformity of the salting air blowing. Second, the overall salting above the flue gas inlet uses a conventional blowing method, while targeted localized salting uses a pulse-type blowing method, focusing on areas with severe coking for enhanced pulse-type cleaning. Finally, the overall salting nozzle group of the waste heat boiler, the targeted salting nozzle group in front of the flue gas baffle, and the targeted salting group in front of the radiant tube panel are controlled independently in stages. The heat exchange effect is assessed based on temperature monitoring points at different locations on the inner wall of the waste heat boiler, thereby increasing or decreasing the amount of salting air blown in and the pulse intensity.

[0024] 1. Directly introduce secondary air drawn from the tail end of the waste heat boiler to increase the temperature of the salinization air and solve the problem of low-temperature corrosion at the inlet. At the same time, introduce a certain amount of desulfurization by-products, such as calcium sulfate and calcium sulfite, to promote the rapid adhesion and reaction of metal oxides / sulfides in the flue gas, solving the problem of slow sulfate formation under low sulfur-copper ratio conditions. Meanwhile, the calcium sulfate powder can fill the gaps in the flue dust, reduce the density of slag, and further improve the ash removal effect.

[0025] 2. Add localized key sulphation nozzles to the baffles and heat exchange tube panels with severe coking. The two sets of key sulphation nozzles are designed to swing up and down to increase the sulphation air purging area and purging uniformity. Combined with the overall sulphation nozzles, the sulfation effect is enhanced.

[0026] 3. The overall salting nozzle adopts the normal blowing method, while the local key salting nozzle adopts the pulse purging nozzle. It adopts a three-stage sequential linkage purging mode of salting softening - pulse cleaning - curing and anti-sticking to enhance the sulfation reaction and coking effect.

[0027] The three sets of salting nozzles are controlled independently in stages. Temperature sensors and ash monitoring sensors are installed inside the waste heat boiler. The salting air volume, secondary flue gas supply and pulse intensity are adjusted according to changes in temperature and coking thickness.

[0028] See attached document Figure 1 -Appendix Figure 4 A pulse-oscillating salinization air system and method for enhanced dust removal.

[0029] 1. After the high-temperature flue gas is discharged from the waste heat boiler 1, it will immediately pass through the settling chamber 2 to settle the flue gas dust. The flue gas with a temperature of about 320-360℃ is drawn out from the flue gas outlet 6 of the settling chamber by the induced draft fan 7 and connected to a pipe. A first temperature sensor 23 is provided to monitor the temperature of the flue gas at the outlet of the settling chamber in real time. The drawn-out flue gas is directly mixed with the salinization air in the mixing chamber 11. A second temperature sensor 12 is located at the rear end of the mixing chamber 11 to monitor the temperature of the mixed salinization air blown into the waste heat boiler. The opening of the flue gas flow regulating valve 9 and the salinization air flow regulating valve 10 can be adjusted according to the values ​​of the two temperature sensors to adjust the amount of the two gases introduced, thereby adjusting the temperature of the mixed salinization air blown into the waste heat boiler.

[0030] 2. A micro powder quantitative addition device 24 is added to the front end of the salting air inlet 1103 of the mixing chamber 11 to add desulfurization byproducts such as calcium sulfate and calcium sulfite with a particle size of 50-200 mesh. The addition amount is 0.5%-2% of the salting air volume. The micro powder can serve as the crystal nucleus for the sulfation reaction, promoting the rapid adhesion and reaction of metal oxides / sulfides in the flue gas, solving the problem of slow sulfate formation under low sulfur-copper ratio conditions. At the same time, the calcium sulfate micro powder can fill the gaps in the flue dust, reduce the density of slag, and further improve the dust removal effect.

[0031] It should be noted that the initial purpose of using salt-oxidizing air to react the flue gas inside the waste heat boiler with oxygen to generate salts was based on the idea that sulfates have a loose structure that makes them easier to clean. The addition of micro powder is intended to provide reaction nuclei to further increase the rate of the salt-oxidizing reaction. At the same time, filling the gaps in the unreacted flue gas can also increase the flue gas's looseness, reduce its adhesion, and make it easier to clean.

[0032] The reason for choosing calcium sulfate and calcium sulfite micropowder instead of other desulfurization byproducts / nucleation materials is that the crystal lattice structure of calcium sulfate and calcium sulfite is similar to that of the sulfates CuSO4, PbSO4, and ZnSO4 generated in copper metallurgical flue gas. They can serve as the core for heterogeneous nucleation, allowing metal ions, SO2, and O2 in the flue gas to quickly adhere to the surface of the micropowder and undergo sulfation reaction. This solves the problem of "slow homogeneous nucleation and low sulfate generation efficiency" under low sulfur-copper ratio conditions, and directly enhances the sulfation effect.

[0033] Both are common byproducts of pyrometallurgical desulfurization systems, readily available locally at low cost, requiring no additional procurement. Furthermore, they are chemically stable, not decomposing or reacting with other substances in the boiler at the mixed salinization air temperature of 200-250℃, and do not produce corrosive gases such as HCl or HF, nor introduce new impurities that could cause secondary slagging in the boiler. Calcium sulfate, with a density of 2.96 g / cm³, is of moderate density and can flow stably with the salinization air, without settling or clogging in the mixing chamber or pipes. It is compatible with the original patented salinization air pipe flow rate and nozzle purging design, requiring no additional system modifications.

[0034] The selection of micronized powder particle size range (50-200 mesh) requires balancing the catalytic effect of crystal nucleus specific surface area, flue gas suspension and flow field following, and nozzle flowability and anti-clogging. If the particle size is too small and the mass is too light, after being blown into the boiler by the salting air, it will be quickly carried to the boiler outlet by the high-temperature mainstream flue gas and will not be able to stay in the severely coking baffle and tube screen areas, thus losing the crystal nucleus catalytic effect and easily agglomerating together. If the particle size is too large, the specific surface area will be greatly reduced, the crystal nucleus catalytic effect will drop sharply, and the purpose of promoting the sulfation reaction cannot be achieved.

[0035] The dosage is controlled at 0.5%–2% of the volume of the salinization air because insufficient dosage will have no catalytic effect, while excessive dosage will increase the system load and affect boiler heat exchange. In the flue gas of metallurgical waste heat boilers, the mass concentration of metal oxides / sulfides is about 500–2000 mg / m³. According to theoretical calculations, at least 0.5% by volume of micro powder needs to be added per cubic meter of salinization air to provide sufficient crystal nucleation sites.

[0036] 3. After being mixed in the mixing chamber 11, the salinization air is supplied to three sets of salinization air nozzles through pipelines: the overall salinization nozzle 5, the first pulse nozzle for local salinization 21, and the second pulse nozzle for local salinization 22. Each set of salinization air nozzles is equipped with a flow meter and a flow regulating valve / pulse regulating valve to control the salinization air flow of the three sets of salinization air nozzles respectively.

[0037] 4. For example Figure 1 Two sets of local salinization nozzles 21 and 22 are respectively installed on the side walls of the waste heat boiler, in front of the flue gas baffle 3 and the heat exchange tube screen 4. Each set includes two salinization air nozzles that can swing up and down. The swing angle of the swing nozzles is set by a fixed program to ensure the uniformity of salinization air purging. The two sets of local salinization nozzles adopt pulse purging. The front end of the pulse nozzle is equipped with distribution manifolds 17 and 18 to ensure the pressure of each nozzle is balanced.

[0038] 5. The PLC controller implements a three-stage sequential purging process—saltification softening, pulse cleaning, and curing to prevent sticking—for localized salinization pulse nozzles, and adaptively adjusts the purging parameters and cycle period according to the slag thickness.

[0039] (1) Salting and softening stage: Close the pulse valve of the local salting nozzle, only open the up and down swing mechanism, blow 200-250℃ mixed salting air into the slag area at normal flow rate, and continue to blow for 30-60s, so that the metal oxide and sulfide slag and salting air undergo sulfation reaction to form a loose sulfate layer.

[0040] (2) Pulse cleaning stage: Keep the local salinization nozzle swing mechanism running, adjust the pressure and frequency of the pulse valve according to the slag thickness, and pulse purge the softened sulfate layer for 10-20s; when the slag thickness is >5mm, the pulse pressure is 0.5-0.6MPa and the frequency is 20-30 times / minute; when the slag thickness is 2-5mm, the pulse pressure is 0.4-0.5MPa and the frequency is 10-20 times / minute; when the slag thickness is <2mm, the pulse pressure is 0.3-0.4MPa and the frequency is 5-10 times / minute.

[0041] (3) Curing and anti-sticking stage: Close the pulse valve, reduce the salting air flow of the local salting nozzle to 50%-60% of the normal flow, keep the swing mechanism running, and continue purging for 20-30s to form a sulfate protective film on the heated surface. This sequential linkage purging is a cyclic operation. The PLC controller adjusts the cycle period according to the real-time slag thickness data of the ash monitoring sensor. When the slag thickness is ≥5mm, the total cycle period of the three stages is 90s / cycle; when the slag thickness is <2mm, the total cycle period of the three stages is 300s / cycle.

[0042] In a mixed salinization air environment at 200-250℃, the gas-phase sulfation reaction of metal oxides such as Cu2O and PbO in the flue gas with O2 and SO2 completes the softening process from hard slag to a loose sulfate layer. This requires an effective contact reaction time of at least 30 seconds; 60 seconds is the upper limit because the reaction tends to saturate after this time, and continued purging would waste salinization air energy. It also prevents the salinization air in the slag-forming area from being dispersed by the mainstream flue gas, ensuring the effectiveness of the reaction. After salinization and softening, the binding force of the sulfate slag is significantly reduced. Under the impact of pulsed airflow, most of the loose slag can be peeled off in 10 seconds; 20 seconds is the upper limit to prevent prolonged pulsed purging from causing erosion damage to boiler baffles, tube panels, and other heating surfaces, while also avoiding disturbance of the mainstream flue gas flow field by the pulsed airflow, which would affect the normal heat exchange of the boiler.

[0043] If a strong, pulsed airflow is used from the outset, it will affect the reaction time and effectiveness of the salinization reaction. Reducing the salinization airflow to 50%-60% allows a gentle purging airflow to form a uniform, thin sulfate film on the heated surface. 20 seconds is the minimum effective time for film formation, while 30 seconds ensures the film's density. This duration prevents the film from becoming too thick due to prolonged purging, which could affect boiler heat exchange. Simultaneously, it effectively prevents direct contact between flue gas and the heated surface, reducing the slagging rate. The circulation cycle can be adjusted according to actual conditions.

[0044] It should be noted that: First, the salinization air is circulated for a period of time to allow the metal oxides to react. Then, the generated loose sulfate slag is removed by pulsed airflow. However, it is important to avoid using pulsed airflow for a long time, as this will affect the salinization reaction effect and the stability of the boiler's internal operating conditions. Secondly, after the pulsed airflow is used for cleaning, the salinization air is continued to circulate to prevent the accumulation of hard coking material on the surface of the boiler's internal baffles and heat exchange tubes. This prevents coking from forming. When the loose coking material accumulates to a certain thickness, pulse purging is performed again. This cycle is repeated to optimize the internal coking situation and enhance the ash removal effect.

[0045] 6. A set of three integral salting nozzles 5 are installed on the front wall above the flue gas inlet of the waste heat boiler for integral salting of the waste heat boiler, and are equipped with a mixing salting air flow regulating valve 19 and a flow meter 20.

[0046] 7. For example Figure 3 Blower 8 blows ambient temperature salinization air into the mixing chamber 1101 through salinization air inlet 1103, while induced draft fan 7 introduces low-temperature secondary flue gas into the mixing chamber 1101 through secondary flue gas inlet 1104. The two high and low temperature media initially mix in the mixing chamber 1101 and simultaneously enter the mixing chamber 1102 through vents 1106 evenly distributed on the surface of the mixing chamber 1102. After turbulent mixing by the first and second mixing fans 1108 and 1109, they are discharged through the mixed salinization air outlet 1105. The mixing chamber 1101 and the mixed salinization air outlet 1105 are not interconnected. The flow direction of the high and low temperature media within the mixing chamber is shown in [details omitted]. Figure 4 .

[0047] 8. The existing waste heat boiler is equipped with a temperature sensor. The salinization air control parameters can be adjusted based on the temperature values ​​of the existing temperature sensor inside the waste heat boiler, in conjunction with the value of the first temperature sensor 23. When the value of the first temperature sensor 23 is too high, it indicates that the coking in the internal heat exchange section is already quite thick, reducing the heat exchange efficiency of the flue gas. Without adjustment measures, the value of the second temperature sensor 12 will naturally be too high. At this time, the opening of the flue gas flow regulating valve 9 should be reduced to decrease the amount of secondary flue gas introduced. Considering the dew point limitation of sulfuric acid dioxide, the temperature of the mixed salinization air should be appropriately reduced. At the same time, the opening of the first flow regulating valve 19 should be increased to increase the overall amount of salinization air blown in, which will play a certain role in convective heat exchange. Simultaneously, the pulse intensity of the first and second pulse regulating valves 13 and 16 should be increased to strengthen the pulse salinization air purging of severely coked areas.

[0048] 9. The system also includes a PLC controller and an ash monitoring sensor. The ash monitoring sensor is aimed at the slagging area of ​​the flue gas baffle and heat exchange tube screen. The PLC controller integrates the detection data of the ash monitoring sensor and the internal temperature sensor of the waste heat boiler, and forms a linkage control with the swing mechanism of the three sets of salting air nozzles, pulse valves, and flow regulating valves.

[0049] The key points of this invention are as follows:

[0050] 1. It is proposed to add a certain amount of desulfurization byproducts, such as calcium sulfate and calcium sulfite, to the salt-treated air to promote the rapid adhesion and reaction of metal oxides / sulfides in the flue gas, thereby solving the problem of slow sulfate formation under low sulfur-copper ratio conditions. At the same time, the calcium sulfate powder can fill the gaps in the flue gas dust, reduce the density of slag, and further improve the dust removal effect.

[0051] 2. A comprehensive salinization air system combining overall and local salinization was proposed, which increases the probability and area of ​​contact between salinization air and flue gas particles, prolongs the time of salinization reaction, comprehensively improves the probability of salinization reaction and enhances the salinization effect.

[0052] 3. For areas prone to coking, the salinization air nozzle adopts a pulse + up-and-down swing nozzle to enhance the dust removal effect. The PLC controller implements a three-stage sequential purging of local salinization: salinization softening - pulse dust removal - curing and anti-sticking. The purging parameters and cycle are adaptively adjusted according to the thickness of the slag.

[0053] 4. Utilize the waste heat from secondary flue gas nearby to directly mix and heat ambient temperature salinization air, reducing low-temperature corrosion while utilizing waste heat resources.

[0054] The effects of this invention are as follows:

[0055] To address the issues of ineffective salting and low-temperature corrosion in current waste heat boiler salting air systems, this invention provides a salting air system that combines overall and localized salting. Micro-powder is incorporated into the salting air to enhance sulfation and flue gas bulkiness, thus optimizing ash removal. Localized salting employs a three-stage sequential purging process: salting softening, pulse cleaning, and curing / anti-sticking, further strengthening the ash removal effect and ultimately improving the overall salting effect. Simultaneously, waste heat resources are utilized to heat the salting air, reducing low-temperature corrosion and increasing the efficiency of waste heat resource utilization.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pulse-swing type salinization air system for enhanced ash removal, comprising a waste heat boiler (1) and a settling chamber (2), wherein the waste heat boiler (1) is provided with a flue gas baffle (3) and a heat exchange tube panel (4), characterized in that: The waste heat boiler (1) is provided with an integral salting air nozzle (5) at the flue gas inlet, a first partial salting nozzle (22) is provided on the outside of the heat exchange tube panel (4), and a second partial salting nozzle (21) is provided on the outside of the flue gas baffle (3); it also includes a mixing chamber (11), the inlet side of which is connected to a blower (8) and connected to the flue gas outlet (6) of the settling chamber; the outlet side of the mixing chamber (11) is connected to the integral salting air nozzle (5), the first partial salting nozzle (22) and the second partial salting nozzle (21); The localized salinization nozzle includes three stages: salinization and softening, pulse cleaning, and curing and anti-sticking. In the salinization and softening stage, only the localized salinization nozzle is controlled to swing up and down. In the pulse cleaning stage, while keeping the localized salinization nozzle swinging mechanism running, the pressure and frequency of the localized salinization nozzle pulse are adjusted according to the slag thickness. In the curing and anti-sticking stage, the salinization airflow of the localized salinization nozzle is reduced while keeping the swinging mechanism running.

2. The pulse-oscillating salinization air system for enhanced dust removal according to claim 1, characterized in that, A micro powder quantitative dosing device (24) is added to the front end of the salting air inlet (1103) of the mixing chamber (11). The micro powder is used to fill the gaps in the smoke and dust as the salting air flows.

3. The pulse-oscillating salinization air system for enhanced dust removal according to claim 2, characterized in that, The powder is a desulfurization byproduct with a particle size of 50-200 mesh.

4. The pulse-oscillating salinization air system for enhanced dust removal according to claim 2, characterized in that, The amount of micro powder added is 0.5%–2% of the volume of the salinization air.

5. The pulse-oscillating salinization air system for enhanced dust removal according to claim 1, characterized in that, A first temperature sensor (23) is provided on the inlet side of the mixing chamber (11), and a second temperature sensor (12) is provided on the outlet side of the mixing chamber (11). The amount of gas supplied to the blower (8) and the flue gas outlet (6) of the settling chamber is adjusted according to the values ​​of the two temperature sensors, thereby adjusting the temperature of the mixed saltification air blown into the waste heat boiler.

6. The pulse-oscillating salinization air system for enhanced dust removal according to claim 5, characterized in that, The first temperature sensor (23) is electrically connected to the first local salting nozzle (22) and the second local salting nozzle (21). When the first temperature sensor (23) detects that the temperature exceeds the set threshold, the pulse intensity of the first local salting nozzle (22) and the second local salting nozzle (21) is increased.

7. The pulse-oscillating salinization air system for enhanced dust removal according to claim 1, characterized in that, During the salting and softening stage, blow in mixed salting air at 200-250℃ and continue blowing for 30-60 seconds.

8. The pulse-oscillating salinization air system for enhanced dust removal according to claim 1, characterized in that, During the pulse cleaning stage, the pulse purging lasts for 10-20 seconds. Specifically, when the slag thickness is >5mm, the pulse pressure is 0.5-0.6MPa and the frequency is 20-30 times / minute; when the slag thickness is 2-5mm, the pulse pressure is 0.4-0.5MPa and the frequency is 10-20 times / minute; and when the slag thickness is <2mm, the pulse pressure is 0.3-0.4MPa and the frequency is 5-10 times / minute.

9. A pulse-oscillating salinization air system for enhanced dust removal according to claim 1, characterized in that, During the maintenance and anti-sticking stage, reduce the salinization airflow of the local salinization nozzle to 50%-60% of the normal flow rate and continue purging for 20-30 seconds.

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