A desulfurization system expansion method and a resistance reduction method for air inlet and outlet ports thereof

Abstract

This invention discloses a method for expanding a desulfurization system and a method for reducing the resistance of its inlet and outlet air vents, belonging to the field of environmental protection and energy-saving production technology transformation. The device of this invention includes a desulfurization system comprising a desulfurization tower body and a ventilation unit. The desulfurization tower expansion unit includes a desulfurization tower body with a 3m height increase section added above the original spray layer, and an additional spray layer and a matching slurry circulation pump inside the tower. The ventilation unit includes a relocated kiln tail fan, with the fan inlet and the vertical air duct of the bag dust collector outlet coaxial, and the outlet coaxial with the desulfurization tower inlet. This invention achieves stable ultra-low SO₂ emissions from cement kiln tail flue gas through desulfurization system expansion, with an outlet concentration ≤35mg / Nm³, meeting the environmental performance level A requirements. It can solve the problems of existing desulfurization systems having many bends and large bending angles in the inlet and outlet air ducts, resulting in high system ventilation resistance and high reactive power consumption of the kiln tail fan, which is not conducive to the power consumption and energy consumption control of the production line.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection and energy-saving production technology transformation, and particularly relates to a method for expanding the desulfurization system and a method for reducing the resistance of the inlet and outlet air ducts thereof. Background Art

[0002] At present, a large amount of SO2 pollutants are generated in the flue gas at the kiln tail during the cement production process. Limestone-gypsum wet desulfurization is the mainstream flue gas desulfurization treatment technology in the domestic cement industry. The existing conventional wet desulfurization system for cement kilns is usually designed according to the inlet SO2 concentration ≤ 1500 mg / Nm³, and the designed outlet SO2 concentration ≤ 50 mg / Nm³. However, with the development and advancement of the supporting mines for cement production, the sulfur content in the ore raw materials has been continuously rising. In the actual operation of some production lines, the inlet SO2 concentration of the flue gas at the kiln tail can reach up to 3200 mg / Nm³ at most, and the average concentration is 1900 mg / Nm³, far exceeding the designed treatment capacity of the original desulfurization system and unable to meet the limit value of the outlet SO2 concentration ≤ 35 mg / Nm³ required by the latest ultra-low emission management requirements of the country. At the same time, according to the relevant policies on ultra-low emission transformation of the cement industry in the country and Guizhou Province, the clinker production lines that have completed the full-process ultra-low emission transformation and have achieved an A-level environmental protection performance can produce for 三百三十 days per year, while the unqualified production lines can only produce for 二百七十 days per year. The non-compliance of SO2 emissions will directly limit the legal production duration of the production line, bringing huge economic losses and environmental protection compliance risks to the enterprise.

[0003] In addition, the existing wet desulfurization system for cement kiln tails has a large number of elbows in the inlet and outlet air ducts and large bending angles, resulting in a large ventilation resistance in the system, high reactive power consumption of the kiln tail fan, and being unfavorable for the power consumption and energy consumption control of the production line, which is contrary to the development requirements of energy conservation and carbon reduction in the cement industry; Moreover, for the problem of excessive SO2 in the cement kiln desulfurization system, usually only the desulfurization tower is expanded and reformed alone, such as adding spray layers, replacing circulation pumps, etc. However, such reforms will further increase the ventilation resistance of the system, resulting in a significant increase in the operating load and energy consumption of the kiln tail fan, and presenting the problem of "meeting environmental protection standards but exceeding energy consumption standards". And the separate optimization and reform of the fan air ducts cannot solve the core problem of insufficient treatment capacity of the desulfurization system and cannot achieve the coordinated improvement of environmental protection benefits and energy-saving benefits; Furthermore, the existing reform schemes often have defects such as high reform costs, long investment return periods, and conflicts between reform construction and normal production, and cannot adapt to the actual operation needs of cement production enterprises. Summary of the Invention

[0004] It should be noted that the numbers "三百三十" and "二百七十" in the translation of item [8] should be written in Arabic numerals as "330" and "270" in a formal patent text, but according to your request, the content remains as above. You can adjust it according to actual needs.To address the aforementioned deficiencies in existing technologies, the present invention aims to provide a method for expanding a desulfurization system and a method for reducing the resistance of its inlet and outlet air vents. This method can fundamentally solve the problem of excessive SO2 concentration in cement kiln tail flue gas, which fails to meet national ultra-low emission requirements. Simultaneously, it can reduce system ventilation resistance and fan operating energy consumption, achieving synergistic progress in environmental compliance and energy conservation. Furthermore, it significantly shortens the investment return cycle, helping enterprises complete the entire process of ultra-low emission transformation, achieve an environmental performance rating of A, and comply with national and local industry control policies.

[0005] In a first aspect, the present invention provides a method for expanding a desulfurization system and a method for reducing the resistance of its inlet and outlet air vents, specifically comprising: a desulfurization system, the desulfurization system including a desulfurization tower body and an air ventilation unit; The desulfurization tower body has a 3m high extension section added above the original spray layer, with the extension section having the same diameter as the original desulfurization tower. Inside the extension section, a new spray layer is installed, equipped with a slurry circulation pump. The outlet pipe of the slurry circulation pump is connected to the nozzles of the new spray layer. A new flue is installed at the outlet of the desulfurization tower body, with its inner wall treated for corrosion protection. The original flue of the desulfurization tower is replaced with an expansion joint. The desulfurization tower expansion unit also includes the modification of the original 10kV transformer distribution cabinet of the wet desulfurization system. The ventilation unit includes a kiln tail 1618 system fan, which is moved 19.4m towards the combined storage tank. The inlet of the moved 1618 system fan is coaxially connected to the vertical duct of the bag dust collector outlet, and the outlet of the 1618 system fan is coaxially connected to the desulfurization tower inlet. The original 90° elbow at the fan inlet and the 45° elbow at the outlet are eliminated.

[0006] Preferably, the desulfurization system also includes an upgraded demister, which is installed above the newly added spray layer of the desulfurization tower body.

[0007] Preferably, the desulfurization system also includes a gypsum dewatering system, which includes a newly added gypsum dewatering machine and a gypsum hydrocyclone.

[0008] Preferably, the desulfurization system also includes a modified oxidation duct and a newly added slurry circulation pipeline, wherein the slurry circulation pipeline connects the slurry circulation pump and the newly added spray layer.

[0009] Preferably, the 1618 system fan is a newly replaced tail exhaust fan, and the relocated fan inlet and outlet ducts are straight-connected flues without bends or elbows.

[0010] Preferably, the 1618 system fan is equipped with a modified dust collector connected to the tail exhaust fan flue, and the inner wall of the flue is treated with anti-corrosion.

[0011] The preferred method for expanding the desulfurization system and reducing the resistance at the inlet and outlet air vents includes the following steps: S1 Desulfurization System Expansion and Renovation: Above the existing spray layer of the desulfurization tower, the tower body and flue pipes will be raised by 3m while maintaining the same tower diameter, bringing the total height of the desulfurization tower to 38m. An additional spray layer will be added within the raised section, along with a new slurry circulation pump and corresponding slurry circulation pipes, valves, and instruments. The existing flue expansion joints will be replaced, and the newly added flue at the desulfurization tower outlet will be treated with anti-corrosion measures. The existing 10kV transformer distribution cabinet of the wet desulfurization system will be upgraded. Simultaneously, the demister will be upgraded, the gypsum dehydration system will be renovated, and the oxidation duct will be modified. S2 Inlet and Outlet Resistance Reduction Modification: Move the 1618 kiln tail system fan 19.4m towards the combined storage tank, adjust the fan installation position so that the fan inlet and the vertical air duct of the bag dust collector outlet are on the same axis, and the fan outlet and the desulfurization absorption tower inlet are on the same axis; remove the original 90° elbow at the fan inlet and the 45° elbow at the fan outlet, modify the flue from the dust collector to the tail exhaust fan, and perform anti-corrosion treatment on the modified flue; S3 System Commissioning and Acceptance: After the modification is completed, the desulfurization system and the fan system are jointly commissioned. After the commissioning is qualified, the environmental protection acceptance is completed and the system is put into formal operation.

[0012] Preferably, in step S1, after the desulfurization system is expanded and upgraded, it can handle flue gas with an inlet SO2 concentration of up to 3200 mg / Nm³, ensuring that the SO2 concentration of the flue gas at the outlet of the desulfurization system is stably ≤35 mg / Nm³.

[0013] Preferably, in step S2, after the fan and duct modification is completed, the system ventilation resistance decreases by ≥300Pa, the 1618 fan speed decreases by ≥40rpm, the fan operating current decreases by ≥14A, and the fan operating unit consumption decreases by ≥0.7kwh / t clinker.

[0014] Preferably, the renovation work in steps S1 and S2 is carried out by utilizing the shutdown window of the cement production line, which is the fourth quarter of each year or the first quarter of the following year.

[0015] 1. In this invention, by increasing the height and capacity of the desulfurization tower, adding a spray layer and circulating pump, and upgrading supporting equipment, the processing capacity of the desulfurization system can be greatly improved. It can stably adapt to the extreme high sulfur conditions with an inlet SO2 concentration of up to 3200 mg / Nm³, and achieve the national ultra-low emission requirement of an outlet SO2 concentration of ≤35 mg / Nm³. This helps enterprises complete the ultra-low emission transformation of the entire process, achieve an environmental performance rating of A, enjoy a production policy of 330 days per year, greatly reduce environmental compliance risks, and reduce environmental taxes by about 300,000 yuan per year.

[0016] 2. In this invention, by optimizing the fan relocation and coaxial alignment with the inlet and outlet ducts, the local resistance caused by large-angle bends can be eliminated, resulting in a system resistance reduction of approximately 300 Pa, a fan speed reduction of approximately 40 rpm, a running current reduction of approximately 14 A, and a unit consumption reduction of approximately 0.7 kWh / t. Based on an annual clinker production of 1.9 million tons, this can save approximately 644,000 yuan in electricity costs annually. Furthermore, it can shorten the length of the fan outlet flue, saving approximately 46,000 yuan in flue corrosion protection costs annually. The total direct annual energy-saving benefit is approximately 690,000 yuan.

[0017] 3. In this invention, the expansion of the desulfurization system and the reduction of the resistance of the fan and duct are designed and constructed simultaneously to avoid the industry pain point of increased system resistance and increased fan energy consumption caused by separate expansion. The increase in wind resistance brought about by the expansion is offset by the resistance reduction modification, thus achieving the synergistic promotion of ultra-low emissions and energy saving. After the modification is completed, the stability of the system operation is greatly improved after testing, and there is no problem of secondary energy consumption.

[0018] 4. The total investment of the integrated technical transformation solution of this invention is about RMB 7.58 million, of which the investment in the fan and duct resistance reduction technical transformation part is about RMB 2.5 million. The static investment payback period is only 43 months, which has an excellent return on investment. At the same time, the transformation solution can apply for the central ecological and environmental protection special fund, which can further reduce the investment of enterprises in technical transformation.

[0019] 5. In the process of modification, this invention retains the original desulfurization tower main structure and most of the core equipment, and only makes height increases and supporting optimizations, which can significantly reduce the modification cost and construction period. All construction can be completed during the cement kiln shutdown window. This not only does not affect the normal production and operation of the enterprise, but also adapts to the continuous production characteristics of the cement production line. Attached Figure Description

[0020] The following accompanying drawings will provide a better understanding of the invention by those skilled in the art, and will more clearly demonstrate the advantages of the invention. The drawings described herein are for illustrative purposes only, representing selected embodiments and not all possible implementations, and are not intended to limit the scope of the invention.

[0021] In the attached diagram: Figure 1 A schematic diagram of the modification process according to an embodiment of the present invention is shown.

[0022] Figure 2 A schematic diagram illustrating the effect of desulfurization system expansion and retrofit according to an embodiment of the present invention is shown.

[0023] Figure 3 A schematic diagram illustrating the effect of modifying the ventilation unit of a desulfurization system according to an embodiment of the present invention is shown. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: Please refer to Figures 1 to 3 As shown: The desulfurization system expansion method and its inlet and outlet resistance reduction method in this embodiment include a desulfurization system, which includes a desulfurization tower body and an air circulation unit. The specific structure of the desulfurization system is as follows: Above the existing spray layer of the desulfurization tower, a 3-meter-high tower extension section will be added. The inner diameter of the extension section will be the same as that of the original desulfurization tower, bringing the total height of the desulfurization tower to 38 meters. A new spray layer will be installed inside the extension section, equipped with a slurry circulation pump. The outlet of the slurry circulation pump will be connected to the nozzles of the new spray layer via a newly added slurry circulation pipeline, along with corresponding valves and instruments. The existing circulation pump will be replaced to ensure the stable operation of the slurry circulation system. A new flue will be added to the outlet of the desulfurization tower, with its inner wall made of glass. The system includes glass flake anti-corrosion treatment, replacement of the original flue expansion joints to eliminate potential equipment hazards caused by thermal expansion and contraction; simultaneous upgrades to the existing 10kV transformer distribution cabinet of the wet desulfurization system, with the addition of new cables to meet the power supply needs of the new equipment; upgrading and modifying the demister in the desulfurization tower, installing it above the new spray layer to improve flue gas demisting effect; upgrading the gypsum dewatering system, adding a gypsum dewatering machine and a gypsum hydrocyclone to match the increased slurry processing capacity after the desulfurization expansion; and modifying and optimizing the oxidation duct in the desulfurization tower to ensure the slurry oxidation effect.

[0026] The specific structure of the ventilation unit is as follows: The kiln tail 1618 system fan was moved 19.4m towards the combined storage tank, and the fan's civil engineering foundation was recast. The fan installation position was adjusted so that the inlet of the relocated 1618 system fan and the vertical duct of the bag dust collector outlet were on the same axis, and the fan outlet and the desulfurization absorption tower inlet were on the same axis. The original 90° elbow at the fan inlet and the 45° elbow at the outlet were removed, and the flue from the dust collector to the tail exhaust fan was modified. The modified flue is a straight-connection structure without bends or elbows to minimize ventilation resistance. The inner wall of the modified flue was treated with anti-corrosion coating, and a new tail exhaust fan was installed to match the modified system operating conditions.

[0027] The specific steps of the desulfurization system expansion method and the inlet / outlet resistance reduction method in this embodiment are as follows: Preparations before S1 construction: Complete the special approval and project establishment of the technical transformation plan, complete the procurement and delivery of equipment and materials, complete the design and construction preparation of the civil engineering foundation, and, in conjunction with the production line's production and sales plan, determine to organize construction during the kiln shutdown window in the fourth quarter of 2025, and make preparations for production and material reserves before the kiln shutdown.

[0028] S2 desulfurization system expansion and renovation construction: After the kiln is shut down, the welding and installation of a 3m height increase section of the desulfurization tower body will be completed above the existing spray layer of the existing desulfurization tower. At the same time, the height increase of the flue pipe will be completed, keeping the diameter of the desulfurization tower unchanged. After the renovation, the total height of the desulfurization tower will reach 38m. The installation of the new spray layer and nozzles will be completed in the height increase section of the tower body. The installation of the new slurry circulation pump, slurry circulation pipe, valves and instruments will be completed. At the same time, the old circulation pump will be replaced. The installation and internal anti-corrosion treatment of the new flue at the outlet of the desulfurization tower will be completed, and the expansion joint of the original flue will be replaced. The renovation of the 10kV transformer distribution cabinet and cable laying will be completed. At the same time, the upgrade and renovation of the demister, the installation of the gypsum dewatering machine and gypsum hydrocyclone, and the renovation of the oxidation air duct will be completed.

[0029] S3 ventilation unit drag reduction renovation construction: carried out simultaneously with the desulfurization system renovation. First, the civil engineering foundation of the relocated fan was poured. After the foundation curing met the standards, the 1618 kiln tail system fan was moved 19.4m towards the joint storage and installed and fixed. The installation posture of the fan was adjusted so that the fan inlet and the vertical air duct of the bag dust collector outlet were coaxial, and the fan outlet and the desulfurization absorption tower inlet were coaxial. The original 90° elbow at the fan inlet and the 45° elbow at the outlet were removed. The renovation and installation of the flue from the dust collector to the tail exhaust fan were completed, and the inner wall of the renovated flue was treated with anti-corrosion.

[0030] S4 System Standalone and Linkage Commissioning: After the installation of all equipment and pipelines is completed, standalone tests are first conducted on the slurry circulation pump, blower, gypsum dewatering equipment, etc. After the commissioning is qualified, the linkage cold commissioning of the desulfurization system and the blower system is carried out, followed by hot load commissioning, to verify the SO2 treatment effect of the desulfurization system and the operating parameters of the blower system.

[0031] S5 Environmental Acceptance and Commissioning: After commissioning, the system operates continuously and stably, with the outlet SO2 concentration consistently ≤35mg / Nm³, and the fan operating parameters meet the design requirements. Environmental acceptance and technical renovation project completion acceptance are completed, and the system is officially put into normal production operation.

[0032] After the modification of this embodiment was completed, it was verified through actual operation: The desulfurization system can stably treat flue gas with an inlet SO2 concentration of up to 3200 mg / Nm³ and stably control the outlet SO2 concentration to within 35 mg / Nm³, meeting the national cement industry's ultra-low emission requirements. It helps the production line complete the ultra-low emission transformation of the entire process, achieve the environmental performance level A standard, reduce environmental taxes by about 300,000 yuan per year, and enjoy a 330-day production policy per year, which greatly improves production capacity efficiency. Operating parameters of the fan system: The system resistance decreased by 300Pa, the speed of the 1618 fan decreased by 40rpm, the fan current decreased by 14A, and the fan power consumption decreased by 0.7kwh / t clinker. Based on an annual clinker production of 1.9 million tons, the annual electricity cost is reduced by approximately 644,000 yuan. At the same time, the fan outlet flue is shortened, saving approximately 46,000 yuan in anti-corrosion costs annually. The annual direct energy saving benefit is approximately 690,000 yuan. The total investment for this technical upgrade project is approximately RMB 7.58 million, of which approximately RMB 2.5 million is invested in the technical upgrade of relocating and reducing the resistance of the 1618 fan duct. The static investment payback period is approximately 43 months, and the economic benefits are significant.

[0033] The following points should be noted in this article: 1. The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention; other structures can refer to general designs.

[0034] 2. Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0035] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for expanding the capacity of a desulfurization system and reducing the resistance at the inlet and outlet air vents, characterized in that, Includes a desulfurization system, which includes a desulfurization tower body and an aeration unit; The desulfurization tower body has a 3m high extension section added above the original spray layer, with the extension section having the same diameter as the original desulfurization tower. Inside the extension section, a new spray layer is installed, equipped with a slurry circulation pump. The outlet pipe of the slurry circulation pump is connected to the nozzles of the new spray layer. A new flue is installed at the outlet of the desulfurization tower body, with its inner wall treated for corrosion protection. The original flue of the desulfurization tower is replaced with an expansion joint. The desulfurization tower expansion unit also includes the modification of the original 10kV transformer distribution cabinet of the wet desulfurization system. The ventilation unit includes a kiln tail 1618 system fan, which is moved 19.4m towards the combined storage tank. The inlet of the moved 1618 system fan is coaxially connected to the vertical duct of the bag dust collector outlet, and the outlet of the 1618 system fan is coaxially connected to the desulfurization tower inlet. The original 90° elbow at the fan inlet and the 45° elbow at the outlet are eliminated.

2. The method for expanding the desulfurization system and reducing the resistance at the inlet and outlet air vents according to claim 1, characterized in that, The desulfurization system also includes an upgraded demister, which is installed above the newly added spray layer on the desulfurization tower body.

3. The method for expanding the desulfurization system and reducing the resistance at the inlet and outlet air vents according to claim 1, characterized in that, The desulfurization system also includes a gypsum dewatering system, which includes a newly added gypsum dewatering machine and a gypsum hydrocyclone.

4. The method for expanding the desulfurization system and reducing the resistance at the inlet and outlet air vents according to claim 1, characterized in that, The desulfurization system also includes a modified oxidation duct and a newly added slurry circulation pipeline, which connects the slurry circulation pump to the newly added spray layer.

5. The method for expanding the desulfurization system and reducing the resistance at the inlet and outlet air vents according to claim 1, characterized in that, The 1618 system fan is a newly replaced tail exhaust fan. The relocated fan's inlet and outlet ducts are straight-connected flues without bends or elbows.

6. The method for expanding the desulfurization system and reducing resistance at the inlet and outlet air vents according to claim 1, characterized in that, The modified dust collector is installed in the exhaust fan duct of the 1618 system fan, and the inner wall of the duct is treated with anti-corrosion.

7. A method for expanding a desulfurization system and a method for reducing resistance at the inlet and outlet air vents, characterized in that, The system implementation based on any one of claims 1-6 includes the following steps: S1 Desulfurization System Expansion and Renovation: Above the existing spray layer of the desulfurization tower, the tower body and flue pipes will be raised by 3m while maintaining the same tower diameter, bringing the total height of the desulfurization tower to 38m. An additional spray layer will be added within the raised section, along with a new slurry circulation pump and corresponding slurry circulation pipes, valves, and instruments. The existing flue expansion joints will be replaced, and the newly added flue at the desulfurization tower outlet will be treated with anti-corrosion measures. The existing 10kV transformer distribution cabinet of the wet desulfurization system will be upgraded. Simultaneously, the demister will be upgraded, the gypsum dehydration system will be renovated, and the oxidation duct will be modified. S2 Inlet and Outlet Resistance Reduction Modification: Move the 1618 kiln tail system fan 19.4m towards the combined storage tank, adjust the fan installation position so that the fan inlet and the vertical air duct of the bag dust collector outlet are on the same axis, and the fan outlet and the desulfurization absorption tower inlet are on the same axis; remove the original 90° elbow at the fan inlet and the 45° elbow at the fan outlet, modify the flue from the dust collector to the tail exhaust fan, and perform anti-corrosion treatment on the modified flue; S3 System Commissioning and Acceptance: After the modification is completed, the desulfurization system and the fan system are jointly commissioned. After the commissioning is qualified, the environmental protection acceptance is completed and the system is put into formal operation.

8. The method for expanding the desulfurization system and reducing the resistance at the inlet and outlet air vents according to claim 7, characterized in that, In step S1, after the desulfurization system is expanded and upgraded, it can handle flue gas with an inlet SO2 concentration of up to 3200 mg / Nm³, ensuring that the SO2 concentration of the flue gas at the outlet of the desulfurization system is stably ≤35 mg / Nm³.

9. The method for expanding the desulfurization system and reducing resistance at the inlet and outlet air vents according to claim 7, characterized in that, In step S2, after the fan and duct modification is completed, the system ventilation resistance decreases by ≥300Pa, the speed of the 1618 fan decreases by ≥40rpm, the fan operating current decreases by ≥14A, and the fan operating unit consumption decreases by ≥0.7kwh / t clinker.

10. The method for expanding the desulfurization system and reducing the resistance at the inlet and outlet air vents according to claim 7, characterized in that, The renovation work in steps S1 and S2 is carried out by utilizing the shutdown window of the cement production line, which is the fourth quarter of each year or the first quarter of the following year.

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