Combined type blast furnace gas pipe network anti-corrosion device and method

Abstract

The invention relates to a combined blast furnace gas pipe network anti-corrosion device and method, and belongs to the technical field of blast furnace gas production devices and methods. According to the technical scheme, the upgraded alkali spraying tower is provided with three spraying gun sets, a first-layer spraying gun (4), a second-layer spraying gun (3) and a third-layer spraying gun (2) are arranged in the upgraded alkali spraying tower in a layered mode from bottom to top, spraying liquid components of the first-layer spraying gun (4) and the second-layer spraying gun (3) are alkali liquid, and spraying liquid components of the third-layer spraying gun (2) are special formula agents; in the blast furnace gas on-line spraying device, a spraying group I (9) and a spraying group II (10) are arranged on the most serious corrosion section of a pipe network. The alkali spraying tower has the beneficial effects that the corrosion degree of pipe network equipment such as an alkali spraying tower body, a gas pipeline, a compensator and a drainer can be effectively reduced, the stability of a gas system is ensured, the service life of a subsequent pipe network and equipment is prolonged, and the power generation efficiency of a unit is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a combined blast furnace gas pipe network anti-corrosion device and method, belonging to the technical field of blast furnace gas production device and method. BACKGROUND

[0002] Blast furnace gas is a by-product in the process of blast furnace smelting, has high recycling and utilization value, is an important medium for TRT power generation, gas boiler, CCPP power generation, and many other processes such as steelmaking and rolling. However, due to the problem of blast furnace material consumption, there are a large amount of chlorides and other acid gases in the blast furnace gas. After the temperature is reduced by TRT expansion work, a large amount of Cl- and S2-, SO32-, SO42- are precipitated from the gas, causing very serious corrosion and blockage problems to the gas pipe network and subsequent production users. Due to the presence of a large amount of acid substances and chlorides in the gas, the substances are gaseous at high temperature and are easily soluble in water. After the temperature of the turbine expansion work gas is reduced, the acid components and chlorides are precipitated from the gas, so that the blast furnace gas containing a large amount of acid substances and chlorides enters the pipe network, causing serious impact on the gas pipe network, auxiliary facilities and subsequent users, especially the section from the TRT unit to the alkali injection tower, the corrosion is quite serious, the lower half of the entire pipeline from the TRT outlet is corroded from 12mm thick steel plate to only 4mm thick, which poses a serious safety hazard. At the same time, the blast furnace gas containing a large amount of chlorides entering the pipe network has a serious impact on the production plant, boiler, gas pressurizing station equipment, power generation equipment, coking coke oven, iron smelting hot blast furnace, etc. Among them, the rotor of the pressurizing machine is damaged by a large amount of salt accumulation in less than a month of operation, and the maintenance cycle of power generation is shortened by nearly 1 / 2. At the same time, due to the acidity of the gas condensate water, serious corrosion occurs to the gas pipeline, pressurizing machine rotor, etc. Due to the accumulation of chloride ions and acid substances, the pipeline, corrugated pipe compensator and gas drainer appear to leak gas, which constitutes a serious accident hazard.

[0003] Although the alkali injection tower bears the function of alkali injection and dechlorination, the high content of acid substances and chlorides in the blast furnace gas causes serious corrosion to the alkali injection tower itself, including the corrosion of the internal filler layer support, spray gun and wreath. In severe cases, the alkali injection tower completely loses its functional type. Once the alkali injection tower is paralyzed, it will aggravate the corrosion of the subsequent pipeline and auxiliary equipment, causing a serious safety hazard and affecting the stable operation of the gas pipe network and subsequent users. At present, it is urgent to solve this problem.

[0004] In summary, the blast furnace gas pipeline anti-corrosion process technology needs to be upgraded and improved. It cannot rely solely on the single function of the alkali injection tower. It is necessary to solve the corrosion problem of the pipeline from the TRT outlet to the alkali injection tower, and more importantly to solve the corrosion problem of the alkali injection tower itself, to enhance the processing capacity of the alkali injection tower itself, to achieve the goal of delaying the corrosion of the pipeline and equipment facilities, and to ensure the long-term stable operation of the blast furnace gas pipe network. SUMMARY

[0005] The purpose of this invention is to provide a combined anti-corrosion device and method for blast furnace gas pipelines. Through a combination of an upgraded caustic soda spraying tower and a blast furnace gas pipeline spraying system, it achieves efficient multi-stage treatment, effectively reducing the corrosion level of the spraying tower body, gas pipelines, compensators, and drainers, ensuring the stability of the gas system. Simultaneously, it solves the problems of burner blockage and corrosion in power generation users, as well as severe corrosion of the valve group before the burner, extending the service life of subsequent pipelines and equipment. Furthermore, it significantly reduces salt accumulation on the coal press and gas turbine blades of subsequent power generation users, extending the blade cleaning cycle and improving the unit's power generation efficiency. This is of great significance for the overall safety of the pipeline network and for the company to further reduce costs and increase efficiency, effectively solving the aforementioned problems existing in the background technology.

[0006] The technical solution of this invention is: a combined blast furnace gas pipeline anti-corrosion device, comprising an upgraded alkali spraying tower and an online blast furnace gas spraying device. The upgraded alkali spraying tower is equipped with three sets of spray guns, namely a first-layer spray gun, a second-layer spray gun, and a third-layer spray gun. The first-layer spray gun, the second-layer spray gun, and the third-layer spray gun are arranged in layers from bottom to top in the upgraded alkali spraying tower. The spray liquid composition of the first-layer spray gun and the second-layer spray gun is alkali solution, and the spray liquid composition of the third-layer spray gun is a special formula agent. The online blast furnace gas spraying device includes a spray group one and a spray group two, which are installed in the section of the pipeline where corrosion is most severe.

[0007] The first, second, and third spray guns are arranged in a petal shape. The spray guns are atomizing spray guns with Hassler alloy spiral nozzles. The flower rings are special flower rings made of 316L stainless steel. The spray ring pipes and flower ring layer support beams are made of Q355-NS type steel. The spray gun water supply hoses are stainless steel hoses lined with polytetrafluoroethylene. The spray water volume of the first and second spray guns is 100t / h and 200t / h, respectively, and the spray water volume of the third spray gun is 20t / h.

[0008] The upgraded alkali spraying tower has a gas dehydration layer above the three sets of spray guns. The gas dehydration layer is filled with stainless steel 316L rosette packing. A packing flushing nozzle is installed above the gas dehydration layer. The packing flushing nozzle is a bowl-shaped spherical nozzle with a star-shaped arrangement.

[0009] The packing material of the gas dehydration layer is made of stainless steel SUS316L and is fixed to the steel beam with stainless steel bolts. The packing is divided into 12 zones by a grid plate and is evenly arranged. The packing is 80mm away from the top grid and the diameter of the grid is 2.5 times.

[0010] A method for corrosion protection of a combined blast furnace gas pipeline network includes the following steps: The specific steps in the second step are as follows: The first step is to prepare the reagents one day before the blast furnace restarts, including the circulating water tank of the upgraded caustic soda injection tower and the dosing tank of the online spray device for blast furnace gas. The upgraded caustic soda injection tower and the online spray device are turned on simultaneously one hour before the blast furnace restarts. The second step involves simultaneously starting the upgraded alkali spraying tower and the online spraying device. The blast furnace gas expands and does work through the TRT power generation, and a large amount of condensate is released after the blast furnace gas is cooled and depressurized. The third step involves the blast furnace gas passing through the TRT and entering the online blast furnace gas spraying device. This device consists of two spraying groups. The gas is first atomized and sprayed through these two groups. A special formulation of reagents comes into contact with the blast furnace gas in a counter-current manner, neutralizing and removing acidic substances from the gas. A protective film is formed on the inner wall of the reagent pipeline, protecting this section of the pipeline from rapid corrosion and reducing the pressure on the alkali spraying tower. The gas is then discharged through drainers along the pipeline. The sprayed water absorbs NH4Cl, HCl, and HF substances from the gas. The dosage of the spraying reagents is automatically controlled by monitoring the pH value of the condensate. The fourth step involves the blast furnace gas being treated by an online spraying device before entering an upgraded alkali spraying tower. Inside the tower, a certain concentration of alkali solution is sprayed from the bottom layer of spray guns, and a special formula agent is sprayed from the top layer of spray guns. The packing flushing nozzles are located above the gas dehydration layer. The blast furnace gas entering from the bottom of the tower is cooled by the three layers of spraying in a counter-current manner, while simultaneously dissolving and removing chlorine- and sulfur-containing substances and other corrosive gases from the gas. Then, it passes through the packing in the gas dehydration layer to remove some of the chlorinated mechanical water. Finally, the gas exits from the top of the upgraded alkali spraying tower. Fifth, the gas exiting the pipeline is dehydrated by a cyclone separator and then connected to the clean gas pipeline network after passing through a U-shaped water seal and an electric butterfly valve. The spray return water flows into the circulating water tank to replenish the industrial fresh water. An online pH meter is installed to regularly perform chemical dosing and drainage replacement. The water pumps, alkali pumps, and valves are controlled by a PLC interlock. Through three layers of spraying, a protective film is gradually formed inside the alkali spraying tower to prevent corrosion.

[0011] In the first step, the reagent is upgraded by mixing liquid alkali and a special corrosion inhibitor for coal gas and water in a certain proportion.

[0012] In the fourth step, the water spraying volume of the first and second spray guns is 100t / h and 200t / h respectively, and the water spraying volume of the third spray gun is 20t / h. The metering pump draws special reagents from the reagent tank, and the soft water pump draws softened water from the soft water pool. After the two are mixed in the pipeline static mixer, they are sent to the third spray gun of the upgraded alkali spraying tower.

[0013] The beneficial effects of this invention are as follows: By combining the upgraded alkali spraying tower and the blast furnace gas pipeline spraying group for efficient multi-stage treatment, the corrosion of the alkali spraying tower body, gas pipeline, compensator, drainer and other pipeline equipment can be effectively reduced, ensuring the stability of the gas system. At the same time, it can also solve the problems of burner blockage and corrosion and severe corrosion of valve groups before the burner for power generation users, extending the service life of subsequent pipelines and equipment. In addition, the salt accumulation on the coal press and gas turbine blades of subsequent users is also greatly reduced, and the blade cleaning cycle is extended, improving the power generation efficiency of the unit. This is of great significance to the overall safety of the pipeline network and the company's further cost reduction and efficiency improvement. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the upgraded alkali spraying tower of the present invention; Figure 2 This is a schematic diagram of the arrangement of the spray layer in the upgraded alkali spraying tower of the present invention; Figure 3 This is a schematic diagram of the overall structure of the present invention; Figure 4 This is a front view of the online spraying device for blast furnace gas of the present invention; Figure 5 This is a side view of the online spraying device for blast furnace gas of the present invention; Figure 6 This is a spray atomization coverage diagram of the online spray device for blast furnace gas of the present invention; In the diagram: 1. Packing flushing nozzle; 2. Three-layer spray gun; 3. Two-layer spray gun; 4. One-layer spray gun; 5. Gas dehydration layer; 6. Gas inlet; 7. Gas outlet; 8. Drainage overflow pipe; 9. Spray group one; 10. Spray group two; 11. Blast furnace; 12. Gravity dust collector; 13. Bag filter dust collector; 14. TRT generator set; 15. Blast furnace gas online spray device; 16. Upgraded alkali spraying tower; 17. Nitrogen atomizing gas source; 18. Gas pipeline; 19. Sampling point; 20. Total outlet DN2400 gate valve; 21. Gravity dust collector gate valve; 22. Purge head; 23. Furnace top vent; 24. Main pipeline. Detailed Implementation

[0015] To make the purpose, technical solutions, and advantages of the invention's embodiments clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only a small part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0016] A combined blast furnace gas pipeline corrosion prevention device includes an upgraded alkali spraying tower 16 and an online blast furnace gas spraying device 15. The upgraded alkali spraying tower 16 is equipped with three sets of spray guns: a first-layer spray gun 4, a second-layer spray gun 3, and a third-layer spray gun 2. The first-layer spray gun 4, the second-layer spray gun 3, and the third-layer spray gun 2 are arranged in layers from bottom to top in the upgraded alkali spraying tower. The spray liquid composition of the first-layer spray gun 4 and the second-layer spray gun 3 is alkali solution, and the spray liquid composition of the third-layer spray gun 2 is a special formula agent. The online blast furnace gas spraying device 15 includes a first spray group 9 and a second spray group 10, which are installed in the section of the pipeline where corrosion is most severe.

[0017] The first-layer spray gun 4, the second-layer spray gun 3, and the third-layer spray gun 2 are arranged in a petal shape. The spray guns are atomizing spray guns, the nozzles are Hasselblad alloy spiral nozzles, the flower rings are special flower rings made of 316L stainless steel, the spray ring pipes and the flower ring layer support beams are made of Q355-NS type steel, and the spray gun water supply hoses are stainless steel hoses lined with polytetrafluoroethylene. The spray water volume of the first-layer spray gun 4 and the second-layer spray gun 3 are 100t / h and 200t / h, respectively, and the spray water volume of the third-layer spray gun 2 is 20t / h.

[0018] The upgraded alkali spraying tower 16 has a gas dehydration layer 5 above the three sets of spray guns. The gas dehydration layer 5 is filled with stainless steel 316L rosette packing. A packing flushing nozzle 1 is installed above the gas dehydration layer 5. The packing flushing nozzle 1 is a bowl-shaped spherical nozzle with a star-shaped arrangement.

[0019] The upper and lower wall meshes of the gas dehydration layer 5 are made of stainless steel SUS316L and are fixed to the steel beam with stainless steel bolts. The packing is divided into 12 zones by a grid plate and evenly arranged. The packing is 80mm away from the top wall mesh and the diameter of the ring is 2.5 times.

[0020] A method for corrosion protection of a combined blast furnace gas pipeline network includes the following steps: The second step, in detail, is as follows: The first step is to prepare the reagents one day before the blast furnace restarts, including the circulating water tank of the upgraded caustic soda injection tower and the dosing tank of the online spray device for blast furnace gas. The upgraded caustic soda injection tower and the online spray device are turned on simultaneously one hour before the blast furnace restarts. The second step involves simultaneously starting the upgraded alkali spraying tower and the online spraying device. The blast furnace gas expands and does work through the TRT power generation, and a large amount of condensate is released after the blast furnace gas is cooled and depressurized. The third step involves the blast furnace gas passing through the TRT and entering the online blast furnace gas spraying device. This device consists of two spraying groups. The gas is first atomized and sprayed through these two groups. A special formulation of reagents comes into contact with the blast furnace gas in a counter-current manner, neutralizing and removing acidic substances from the gas. A protective film is formed on the inner wall of the reagent pipeline, protecting this section of the pipeline from rapid corrosion and reducing the pressure on the alkali spraying tower. The gas is then discharged through drainers along the pipeline. The sprayed water absorbs NH4Cl, HCl, and HF substances from the gas. The dosage of the spraying reagents is automatically controlled by monitoring the pH value of the condensate. The fourth step involves the blast furnace gas being treated by an online spraying device before entering an upgraded alkali spraying tower. Inside the tower, a certain concentration of alkali solution is sprayed from the bottom layer of spray guns, and a special formula agent is sprayed from the top layer of spray guns. The packing flushing nozzles are located above the gas dehydration layer. The blast furnace gas entering from the bottom of the tower is cooled by the three layers of spraying in a counter-current manner, while simultaneously dissolving and removing chlorine- and sulfur-containing substances and other corrosive gases from the gas. Then, it passes through the packing in the gas dehydration layer to remove some of the chlorinated mechanical water. Finally, the gas exits from the top of the upgraded alkali spraying tower. Fifth, the gas exiting the pipeline is dehydrated by a cyclone separator and then connected to the clean gas pipeline network after passing through a U-shaped water seal and an electric butterfly valve. The spray return water flows into the circulating water tank to replenish the industrial fresh water. An online pH meter is installed to regularly perform chemical dosing and drainage replacement. The water pumps, alkali pumps, and valves are controlled by a PLC interlock. Through three layers of spraying, a protective film is gradually formed inside the alkali spraying tower to prevent corrosion.

[0021] In the first step, the reagent is upgraded by mixing liquid alkali and a special corrosion inhibitor for coal gas and water in a certain proportion.

[0022] In the fourth step, the water spraying volume of the first and second spray guns is 100t / h and 200t / h respectively, and the water spraying volume of the third spray gun is 20t / h. The metering pump draws special reagents from the reagent tank, and the soft water pump draws softened water from the soft water pool. After the two are mixed in the pipeline static mixer, they are sent to the third spray gun of the upgraded alkali spraying tower.

[0023] In practical applications, this invention includes an upgraded alkali spraying tower and an online spraying device for blast furnace gas. The online spraying device for blast furnace gas includes a storage tank, a dosing pump, an online pH monitor, an electrical controller, a buffer tank, two spraying groups, a nitrogen supply pipe, etc. It can automatically adjust the dosing according to the pH of the pipeline condensate. The chemical formula will be explained in detail in the next paragraph. This chemical neutralizes acidic substances on the one hand, and forms a protective film inside the pipeline on the other hand. Each spraying group can cover the entire pipeline through nitrogen atomization, and the dosing can be adjusted in real time to protect the pipeline network.

[0024] As the most important piece of equipment for treating blast furnace gas, the upgraded caustic soda spraying tower's functionality is crucial in preventing accelerated corrosion of subsequent pipelines and auxiliary equipment. The upgraded tower includes the tower body, first-layer spray guns, second-layer spray guns, third-layer spray guns, a gas dehydration layer, and auxiliary pump sets. The key to this upgrade lies in the improved atomization area design of the first, second, and third-layer spray guns, and the upgraded materials of the spray guns and the ferrule layer to prevent rapid corrosion that could render the tower ineffective. Specifically, the spray guns and atomizing spiral nozzles are upgraded to Hasselblad alloy, the spray ring pipes and ferrule layer support beams are upgraded to Q355-NS steel, the ferrules are upgraded to 316L steel, and the spray gun water supply hoses are upgraded to stainless steel hoses lined with PTFE. Simultaneously, increased supply pressure improves atomization. The most crucial upgrade lies not in a single NaOH spray formula, but in a unique reagent formula developed through numerous experiments and technical exchanges. This formula, composed of NaOH, water, and a special corrosion inhibitor for the alkali spraying tower (the exact proportions are confidential and can be purchased upon request), neutralizes acidic substances and removes a large amount of chloride ions through the first and second layers of spray guns. Furthermore, the specialized reagent spraying forms a protective film inside the alkali spraying tower, affecting the spray guns, nozzles, rings, and support beams, resisting corrosion from acidic substances and chloride ions on critical internal components. This multi-stage treatment, with different formulas for each layer, ensures the long-term functionality of this key piece of equipment—the upgraded alkali spraying tower—and achieves excellent results.

[0025] The process implementation method of this invention is as follows: After passing through baghouse dust collectors and TRT power generation, blast furnace gas is cooled and depressurized. Upon entering the TRT downstream pipeline, condensate forms in the blast furnace gas. A large amount of acidic substances and chloride salts in the gas precipitate with this condensate, which is the root cause of corrosion. Firstly, an online blast furnace gas spraying device is installed at the TRT outlet pipeline. This device has two spraying groups. The two groups perform atomized spraying, with a specially formulated agent contacting the blast furnace gas in a counter-current manner to neutralize and remove acidic substances. A protective film forms on the inner wall of the agent-treated pipeline, protecting this section of the pipeline from rapid corrosion and reducing the pressure on the alkali spraying tower. The condensate is then discharged through drainers along the pipeline. The sprayed water absorbs substances such as NH4Cl, HCl, and HF from the gas. The spraying is automatically controlled by monitoring the pH value of the condensate. This is the first line of protection in the combined high-efficiency blast furnace gas pipeline anti-corrosion technology device.

[0026] After passing through the blast furnace gas online spraying device, the blast furnace gas enters the second-stage upgraded alkali spraying tower. Industrial water is sprayed from the bottom of the tower through the first and second spray guns, mainly spraying alkali solutions of a certain concentration, with spray rates of 100t / h and 200t / h respectively. The third spray gun mainly sprays special formula reagents, with a spray rate of 20t / h. The metering pump draws special reagents from the reagent tank, and the soft water pump draws softened water from the soft water pool. The two are mixed in the pipeline static mixer and then sent to the third-stage spray gun nozzles of the upgraded alkali spraying tower. The packing flushing nozzle is located above the gas dehydration layer. The blast furnace gas entering from the bottom of the tower is cooled by a three-layer spray system in a counter-current manner. This process simultaneously dissolves and removes chlorine- and sulfur-containing substances, as well as other corrosive gases. The gas then passes through the packing material in the upper gas dehydration layer to remove some of the chloride-containing mechanical water. After exiting from the top of the tower, the gas is dehydrated by a pipe-type cyclone dehydrator and then connected to the clean gas pipeline network via a U-shaped water seal and an electric butterfly valve. The cooled gas temperature is approximately 55°C. The spray return water flows into the gas washing return water tank. After absorbing NH4Cl, HCl, and HF from the gas, the chloride ion concentration in the spray water increases, requiring continuous replenishment of industrial fresh water to the circulating water tank. The average replenishment volume is 23-69 m³. 3 / h. To control the chloride ion concentration in the circulating water system, an online pH meter is installed, and chemical dosing and drainage are performed regularly. The water pumps, alkali pumps, and valves are all controlled by PLC interlocking. Through three-layer spraying, a protective film is gradually formed inside the alkali spraying tower to prevent corrosion.

[0027] This invention combines an upgraded caustic soda spraying tower with an online blast furnace gas spraying device for efficient multi-stage treatment. This effectively reduces corrosion of the spraying tower body, gas pipelines, compensators, and drainers, ensuring the stability of the gas system. Simultaneously, it solves the problems of burner blockage and corrosion, and severe corrosion of the valve group before the burner for power generation users, extending the service life of subsequent pipelines and equipment. Furthermore, it significantly reduces salt accumulation on the coal compressor and gas turbine blades of subsequent power generation users, extending the blade cleaning cycle and improving the unit's power generation efficiency. This is of great significance for the overall safety of the pipeline network and for the company's further cost reduction and efficiency improvement.

Claims

1. A combined blast furnace gas pipe network corrosion protection device, characterized in that: The application relates to a blast furnace gas online spraying device (15) and an upgraded alkali spraying tower (16), wherein the upgraded alkali spraying tower (16) is provided with three groups of spraying guns, namely a first layer of spraying guns (4), a second layer of spraying guns (3) and a third layer of spraying guns (2), the first layer of spraying guns (4), the second layer of spraying guns (3) and the third layer of spraying guns (2) are arranged in layers from bottom to top in the upgraded alkali spraying tower, the spraying liquid of the first layer of spraying guns (4) and the second layer of spraying guns (3) is alkali solution, and the spraying liquid of the third layer of spraying guns (2) is special formula medicament; the blast furnace gas online spraying device (16) comprises spraying group one (9) and spraying group two (10), and the spraying group one (9) and the spraying group two (10) are installed in a section of pipe network where corrosion is most serious.

2. The combined blast furnace gas pipe network corrosion prevention device according to claim 1, characterized in that: The first layer of spraying guns (4), the second layer of spraying guns (3) and the third layer of spraying guns (2) are arranged in petal-shaped structures; the spraying guns are atomizing spraying guns, the nozzles are Hastelloy spiral nozzles, the garlands are special garlands made of stainless steel 316L, the spraying ring pipes and the garland layer support beams are Q355-NS type steel materials, and the spraying gun water supply hoses are stainless steel hoses lined with polytetrafluoroethylene; the spraying water quantity of the first layer of spraying guns (4) and the second layer of spraying guns (3) is 100t / h and 200t / h respectively, and the spraying water quantity of the third layer of spraying guns (2) is 20t / h.

3. The combined blast furnace gas pipe network corrosion prevention device according to claim 1, characterized in that: The upper part of the upgraded alkali spraying tower (16) is provided with a gas dehydration layer (5) above the upper layer of the three groups of spraying guns, and the gas dehydration layer (5) is filled with stainless steel 316L garland fillers; a filler flushing nozzle (1) is installed above the gas dehydration layer (5), the filler flushing nozzle (1) is a bowl-shaped spherical nozzle and is arranged in a star angle structure.

4. The combined blast furnace gas pipe network corrosion prevention device according to claim 3, characterized in that: The upper and lower wall nets of the fillers of the gas dehydration layer (5) are made of stainless steel sus316L and are fixed on steel beams through stainless steel bolts, the fillers are evenly arranged by being separated into 12 areas through lattice plates, and the fillers are kept 80mm away from the top wall net, which is 2.5 times the diameter of the garland.

5. A combined method of corrosion protection of a blast furnace gas pipe network, characterized in that The application further discloses a method for preventing and treating the corrosion of the blast furnace gas pipeline, and the method comprises the following steps: the first step is to prepare medicament one day before blast furnace blast, the second step is to start the upgraded alkali spraying tower and the online spraying device one hour before blast furnace blast, the third step is to make the blast furnace gas pass through the TRT to generate power, the fourth step is to make the blast furnace gas pass through the online spraying device, the fifth step is to make the blast furnace gas pass through the pipeline, and the sixth step is to drain water. The first step, medicament preparation, is performed one day before blast furnace blast, including medicament preparation for the circulating pool of the upgraded alkali spraying tower and the medicament tank of the blast furnace gas online spraying device, and the upgraded alkali spraying tower and the online spraying device are started simultaneously one hour before blast furnace blast; The second step, after the upgraded alkali spraying tower and the online spraying device are started simultaneously, the blast furnace gas passes through the TRT to generate power, and a large amount of condensed water is separated out after the blast furnace gas is cooled and decompressed; The third step, after the blast furnace gas passes through the TRT, the blast furnace gas first enters the blast furnace gas online spraying device, the blast furnace gas online spraying device comprises two spraying groups, the blast furnace gas is atomized and sprayed through the two spraying groups, the special formula medicament and the blast furnace gas are contacted in a countercurrent mode, acidic substances in the blast furnace gas are neutralized and removed, a protective film is formed on the inner wall of the medicament pipeline to protect the pipeline from being corroded too fast, the pressure of the alkali spraying tower is reduced, water is drained through a pipeline drainer along the pipeline, NH4Cl, HCl and HF substances in the blast furnace gas are absorbed by the spraying water, the spraying and medicament adding amount are automatically controlled through monitoring of the PH value of the condensed water, and the corrosion of the pipeline is prevented and treated. Fourth step, the blast furnace gas is treated by the blast furnace gas online spraying device, enters the upgraded type alkali spraying tower, the alkali solution of certain concentration is sprayed from the first layer and the second layer of the spraying gun at the lower part of the tower, the special formula medicament is sprayed from the third layer of the spraying gun; the packing flushing nozzle is arranged at the upper part of the coal gas dehydration layer; the blast furnace gas entering from the lower part of the tower is cooled and dissolved to remove the chlorine and sulfur substances and other corrosive gases in the coal gas in the countercurrent mode, then the mechanical water containing part of the chlorides is removed through the packing of the coal gas dehydration layer, and then the coal gas is discharged from the top of the upgraded type alkali spraying tower; Fifth step, the discharged coal gas is dehydrated by the pipeline type cyclone plate dewaterer, is connected to the clean gas pipe network after passing through the U-shaped water seal and the electric butterfly valve; the spraying backwater flows into the circulating water pool, and the industrial fresh water is supplemented to the circulating water pool; the online PH detector is arranged, the regular dosing and drainage replacement are carried out, and the water pump, the alkali pump and the valve are controlled by the PLC interlocking control; through the three layers of spraying, a protective film is gradually formed in the body of the alkali spraying tower, so that the body corrosion is avoided.

6. A combined method of preventing corrosion in a blast furnace gas pipe network according to claim 1, characterized in that: In the first step, the medicament is upgraded in formula, and the liquid alkali and the special coal gas water corrosion inhibitor are mixed according to a certain proportion.

7. A combined method of preventing corrosion in a blast furnace gas pipe network according to claim 1, characterized in that: In the fourth step, the spraying water quantity of the first layer and the second layer of the spraying gun is 100t / h and 200t / h respectively, and the spraying water quantity of the third layer of the spraying gun is 20t / h; the special medicament is extracted from the medicament tank by the metering pump, the softened water is extracted from the softened water pool by the soft water pump, and after being mixed in the pipeline static mixer, the mixture is sent to the third layer of the spraying gun of the upgraded type alkali spraying tower.

Images