Judgment and disposal method for dry quenching waste heat boiler after pipe explosion

Abstract

According to the method, all phenomena of boiler tube explosion are taken as end factors, and different parts corresponding to the tube explosion phenomenon and parameter fluctuation are sorted, so that the tube explosion area and part are quickly judged; boiler tube explosion is divided into a high-temperature area and a low-temperature area, tube explosion at different positions is treated through different methods, and pertinence and operability are better achieved. Compared with a traditional method, the treatment method has the advantages that about 4 hours are reduced, the influence on furnace body refractory materials is reduced, and the boiler treatment time is shortened. After leakage of the dry quenching boiler of the Taiji iron making plant occurs, the method is adopted for many times, and the influence on production caused by cooling of the dry quenching system can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the field of metallurgical coking, and particularly to a method for judging and disposing of a dry quenching coke waste heat boiler after tube burst. Background Art

[0002] The dry quenching coke boiler plays a role in recovering energy, generating steam and cooling the circulating gas in the dry quenching coke process. Under the action of the circulating fan, the circulating gas exchanges heat with the coke in the dry quenching furnace. The temperature of the circulating gas is heated to 880 - 960 °C. After primary dust removal, it enters the dry quenching coke boiler, exchanges heat with the hot water in the boiler, and the temperature drops to 160 - 180 °C. After secondary dust removal and a heat pipe heat exchanger, it enters the dry quenching furnace for recycling. The deaerated boiler feed water is heated by the economizer and enters the steam drum. The saturated water in the steam drum passes through the downcomer, forced circulation pump, and riser to exchange heat with the circulating gas in the evaporator to generate saturated steam and return to the steam drum. The saturated steam passes through the primary superheater and secondary superheater to convert the saturated steam into superheated steam. The desuperheater controls the temperature of the superheated steam at 540 °C and sends it to the steam turbine through the steam pipe.

[0003] Flue gas system flow of the boiler body: The circulating gas that has absorbed the sensible heat of the red coke comes out of the dry quenching coke cooling chamber, removes coarse coke powder through the primary dust collector, enters from the boiler inlet, and flows vertically downward through the secondary superheater, primary superheater, plain tube evaporator, finned tube evaporator, and economizer in sequence, and finally is led out from the bottom of the boiler.

[0004] Steam-water system flow of the boiler body: The boiler feed water is pressurized by a multi-stage centrifugal pump and supplied to the boiler. The demineralized and deaerated pure water is preheated by the economizer and then enters the steam drum. The boiler water in the steam drum is divided into a forced circulation part and a natural circulation part. The steam-water mixture generated by the two parts is separated in the steam drum. The saturated steam is led out from the upper part of the boiler, heated up by the primary superheater, enters the desuperheater for spraying water to cool down, and then enters the secondary superheater to continue heating up. The steam led out from the secondary superheater is the main steam supplied externally.

[0005] After the boiler tube bursts, the water and steam in the boiler will leak into the circulating gas, react with the red coke to produce a water-gas reaction, resulting in a sharp increase in the content of hydrogen (H2) and carbon monoxide (CO) in the circulating gas. If the concentration of these combustible gases exceeds the standard and is not treated in time, it may trigger a serious explosion accident. The impact force generated by the tube burst and the leaked high-temperature steam may cause damage to surrounding equipment, such as the rupture of expansion joints and the detachment of the cold ash hopper. After a tube burst accident occurs, the dry quenching coke system usually needs to be shut down urgently for inspection and repair, resulting in production interruption and affecting the normal production of coke and subsequent processes. The tube burst accident will not only cause equipment damage, but also require a large amount of time and funds for repair and replacement of pipe fittings, and at the same time cause economic losses due to production suspension.

[0006] Abnormal phenomena after the explosion of the coke dry quenching boiler. The conventional judgment is mainly based on the following 8 abnormal phenomena: 1) The content of H2 in the circulating gas suddenly increases sharply. 2) The steam generation of the boiler decreases significantly or the feed water of the boiler increases significantly, and the feed water is significantly greater than the steam generation. 3) There is obvious steam emerging from the outlet of the pressure regulating and discharging valve of the pre-storage chamber. 4) There is obvious water accumulation at the bottom of the boiler and the bottom of the circulating fan. 5) There is water stain on the ash discharging valve of the secondary dust collector or wet ash is discharged. 6) The resistance in other circulation systems becomes significantly larger, the differential pressure at each point in the system changes significantly, and the circulating air volume decreases significantly. 7) The pressure in the pre-storage chamber of the coke dry quenching furnace fluctuates greatly. 8) There is peeling or discoloration on the outer wall of the boiler.

[0007] The above judgment method has strong guidance for judging the abnormal phenomena after the explosion of the coke dry quenching boiler. However, in actual production, the phenomena presented by the explosion of different parts are quite different, and the severity of the explosion is different, so the failure phenomena are also different.

[0008] By inventing a rapid disposal method, the judgment time of the boiler explosion can be effectively shortened, the accuracy of the judgment result can be improved, the adverse impact caused by the accident can be minimized, the failure disposal time can be shortened, the loss of coke production can be reduced, and the steam recovery amount can be increased. Summary of the Invention

[0009] The purpose of the present invention is to provide a judgment and disposal method for the explosion of the coke dry quenching waste heat boiler in view of the above problems.

[0010] The object of the present invention is achieved as follows: A method for determining tube rupture in a coke dry quenching waste heat boiler, including: High-temperature section tube rupture: Tube rupture phenomenon: The content of H2 in the circulating gas increases sharply, and the concentration of H2 in the circulating gas cannot be controlled by the method of normally introducing air for combustion. Determination basis: The content of combustible component H2 in the circulating gas rises above 3% and there is no downward trend in adjusting the H2 content by increasing the air intake; Tube rupture phenomenon: Steam emerges from the outlet of the pressure regulating and discharging pipe of the pre-storage section. Determination basis: 1) White steam is detected at the inspection hole of the inlet flue of the coke dry quenching furnace and the inspection hole of the outlet flue of the circulating fan; 2) Steam emerges or water drips at the air intake valve; 3) Steam emerges at the expansion joint of the fan outlet; 4) Water drips at the flange of the valve on the pressure regulating pipeline of the pre-storage chamber; Tube rupture phenomenon: Water stains or wet ash are discharged at the secondary dust removal grid ash discharge valve. Determination basis: A large amount of water flows out from the flange area of the water-cooled casing of the primary dust removal, and the ash discharged from the primary and secondary dust removal is damp; Tube rupture phenomenon: The pressure in the pre-storage section of the coke dry quenching furnace fluctuates significantly. Determination basis: 1) The pressure in the pre-storage chamber is above 100 Pa when the desulfurization door is fully open; 2) The opening of the desulfurization door changes, and the increase compared to the previous opening is ≥ 10%; Tube rupture phenomenon: The resistance in the gas circulation system increases significantly, the pressure difference at each point in the system changes, and the circulating air volume decreases. Determination basis: 1) The pressure at the boiler inlet rises by more than 0.2 KPa compared to the normal pressure, i.e., -0.8—-1.0 KPa; 2) The abnormal sound ultrasonic detection device installed inside the boiler system issues a prompt alarm; Low-temperature section tube rupture: Tube rupture phenomenon: The steam generation capacity of the boiler decreases by 20 - 40 t / h or the boiler feed water flow rate is 20 - 40 t / h greater than the steam generation capacity. Determination basis: The feed water volume and evaporation volume do not match, that is, under normal circumstances, the feed water volume is 5 - 10 t / h greater than the evaporation volume, and the mismatch means the feed water volume is 20 - 40 t / h greater than the evaporation volume; Tube rupture phenomenon: There is water accumulation at the bottom of the boiler and the bottom of the circulating fan. Determination basis: 1) Water drips or flows out from the drain hole at the bottom of the boiler; 2) The temperature at the boiler outlet drops by more than 10 °C.

[0011] A method for disposing tube rupture in a coke dry quenching waste heat boiler, including: (1) For the failure of water leakage in the low-temperature section, it is disposed as follows: 1) Confirm the leakage of the low-pressure economizer, stop coke charging and gradually reduce it, i.e., reduce it by 5 ± 1% each time, and reduce the rotational speed of the circulating fan to 15% - 20%, i.e., 225 - 300 r / min; 2) Adjust the pre-storage chamber discharge valve to 100%, and adjust the air intake valve to 0%; 3) Open the nitrogen supplement valves before and after the fan and confirm the nitrogen supplement volume of 1500 - 2000 m 3 / h; 4) Reduce the rotational speed of the circulating fan at a speed of 50 - 70 rad / min until it stops, close the desulfurization valve, switch the nitrogen supplement before and after the fan to bottom-blowing nitrogen, and confirm the nitrogen flow rate of 2000 - 3000 m 3 / h. 5) Open the emergency relief valve at the top of the primary dedusting once to carry out leak plugging treatment for the economizer. 6) After the boiler system fault handling is completed and the conditions for starting the circulation fan are met, that is, after all the above-mentioned faults are handled, close the emergency relief valve and start the circulation fan at a speed of 75 - 100 r / min. Switch the bottom-blown nitrogen to nitrogen supplementation before and after the fan, and control the nitrogen supplementation amount at 1500 - 2000 m 3 / h, and start the temperature-raising operation of the coke dry quenching furnace. 7) Use T6 as the main managed temperature for temperature raising. When T6 is lower than 650 °C, carry out the temperature-raising operation at a rate of 25 °C - 30 °C / h. During temperature raising, the temperature-raising speed can be controlled by adjusting the speed of the circulation fan and the amount of coke discharge. 8) When the T6 temperature reaches above 650 °C, resume normal production.

[0012] (2) The treatment of the high-temperature section tube burst is carried out according to the following method: 1) Immediately stop charging coke and reduce the speed of the circulation fan to 75 - 100 r / min at 80 - 100 rad / min and stop the operation of the circulation fan. If necessary, press the emergency stop button of the circulation fan. 2) Adjust the pre-storage chamber relief valve to 100%, and confirm that the pressure in the pre-storage chamber ≤ 100 Pa. If the pressure cannot meet the requirement, manually open the emergency relief valve at the center. 3) Manually open the bottom-blown nitrogen at the center and control the nitrogen flow rate at 2000 - 3000 m 3 / h. 4) After the energy in the circulation system is released, close the emergency relief valve and start the circulation fan to cool down the boiler. 5) During the cooling process, the speed of the circulation fan can be increased to 600 - 800 r / min, but it must be ensured that there is no steam in the circulating gas. If there is still steam in the circulating gas system, maintain the speed of the circulation fan at 225 - 300 r / min to cool down to 200 - 300 °C. 6) When the conditions for leak plugging are met, that is, the hydrogen content in the circulating gas is 0 - 3% and the boiler inlet temperature is 200 - 300 °C, stop the operation of the circulation fan, open the emergency relief valve to cooperate with the boiler maintenance operation, and switch the nitrogen supplementation from nitrogen supplementation before and after the fan to bottom-blown nitrogen, and control the nitrogen supplementation amount at 2000 - 3000 m 3 / h. 7) Confirm that the dust accumulation in the secondary dedusting is emptied to prevent coking powder adhesion or freezing blockage. 8) After the boiler system fault handling is completed and the conditions for starting the circulation fan are met, that is, all the above-mentioned faults are handled, close the emergency relief valve and start the circulation fan at a speed of 50 - 75 r / min. Switch the bottom-blown nitrogen to nitrogen supplementation before and after the fan, and control the nitrogen supplementation amount at 1500 - 2000 m 3 / h, and start the warm air drying and temperature-raising operation of the coke dry quenching furnace. 9) After confirming that there is no steam coming out from the air guide part, prepare to charge red coke for temperature raising. Before charging coke, measure the O2 content in the coke dry quenching furnace < 4%. 10) Manually operate the hoist to charge the first 3 furnaces of red coke, and slowly charge them into the coke dry quenching furnace in 6 - 8 times for each furnace. 11) Use T6 as the main managed temperature for temperature raising. When T6 is lower than 650 °C, carry out the temperature-raising operation at a rate of 20 ± 2 °C / h. During temperature raising, the temperature-raising speed can be controlled by adjusting the speed of the circulation fan and the amount of coke discharge. 12) When the T6 temperature reaches above 650 °C, resume normal production.

[0013] The beneficial effects of the present invention are as follows: During the long-term use of the coke dry quenching boiler, since it is located in the central position of the coke dry quenching circulating gas passage, it is thinned due to long-term wear by coke powder in the circulating gas and is prone to perforation, resulting in water vapor leakage of the boiler and causing a tube explosion accident. In addition, the sudden change of the T6 temperature has a greater impact on the thermal expansion performance of the boiler equipment. In 2024, the economizer of the boiler leaked 4 times in total, and the ceiling tubes of the boiler exploded 2 times in total. Using this system diagram for determination and adopting corresponding disposal methods according to different parts accelerated the entire process of treatment.

[0014] This method saves an average of 4 hours each time compared with the traditional treatment method. Calculated according to the output of 100 t / h for each coke dry quenching furnace and the steam output of 70 t / h for the boiler, at 2000 yuan per ton of metallurgical coke and 10 yuan per gigajoule of steam, the average output increase per treatment can be 100 t / h * 4 * 2000 + 70 t / h * 4 * 3.46 * 10 = 809,600 yuan compared with before. Description of the Drawings

[0015] The present invention will be further described below with reference to the drawings.

[0016] Figure 1 It is a flowchart of the determination method of the present invention. Detailed Embodiments

[0017] Taking the boiler tube explosion as the total event, the present invention finds all the factors (intermediate events) leading to the failure according to the system principle, then finds all the factors for the occurrence of the intermediate events, and then based on all the phenomena caused after the customs declaration, traces back to the part where the tube explosion occurs, and establishes the logical relationship between the tube explosion failure, the intermediate events and the final phenomena, so as to quickly determine the tube explosion part. The tube explosion part is divided into a high-temperature section and a low-temperature section, and different disposal methods are formulated respectively, greatly shortening the fault disposal time.

[0018] 1. Scheme concept: Due to many problems existing in the conventional determination and methods, in order to achieve targeted and rapid determination and disposal after the boiler tube explosion, the tube explosion part of the boiler is divided into a high-temperature section and a low-temperature section, and the specific explosion part is determined according to the specific phenomena and the fluctuation of process parameters generated after the tube explosion in different parts. According to the tube explosion part, corresponding disposal methods and process parameter adjustments are taken to achieve the purpose of accurate determination and rapid treatment.

[0019] 2. Specific scheme: 1) Determination of boiler tube explosion: All the phenomena of the boiler tube explosion are listed as the most terminal variables, and through the intermediate events, the tube explosion part is deduced backward to form, such as Figure 1 , when 2 or more than 2 of the listed pre-judgment criteria appear simultaneously, it can be determined that the boiler tube has exploded and the specific part can be judged, and the corresponding disposal method is implemented.

[0020] 2) Disposal method for tube burst in the low-temperature section: The failure of water leakage in the low-pressure section has not a very severe impact on the coke dry quenching furnace. Dispose it according to the following methods: a. Confirm the water leakage of the low-pressure economizer, stop charging coke and gradually reduce the rotational speed of the circulation fan to 15%-20% (300 r / min). b. Adjust the pre-storage chamber relief valve to 100% and the air inlet valve to 0%. c. Open the nitrogen make-up valves before and after the fan and confirm that the nitrogen make-up volume ≥ 1500 m 3 / h. d. Reduce the rotational speed of the circulation fan at a speed of 50-70 rad / min until it stops. Close the desulfurization valve, switch the nitrogen make-up before and after the fan to bottom-blowing nitrogen, and confirm that the nitrogen flow rate ≥ 2000 m 3 / h. e. Open the emergency relief valve at the top of the primary deduster and conduct leak stoppage treatment on the economizer. f. After the boiler system failure is disposed of and the conditions for starting the circulation fan are met, close the emergency relief valve, start the circulation fan at 300 r / min or 5% rotational speed, switch the bottom-blowing nitrogen to nitrogen make-up before and after the fan, control the nitrogen make-up volume ≥ 1500 m 3 / h, and start the temperature-rising operation of the coke dry quenching furnace. g. Use T6 as the main managed temperature for temperature rise. When T6 is lower than 650 °C, conduct the temperature-rising operation at 25 °C - 30 °C / h. The temperature rise rate can be controlled by adjusting the rotational speed of the circulation fan and the coke discharge volume. h. When the T6 temperature reaches above 650 °C, resume normal production.

[0021] 2) Disposal method for tube burst in the high-temperature section: When the high-pressure section of the boiler has a tube burst, it has a greater impact on the coke dry quenching furnace system. Dispose it according to the following methods: a. Immediately stop charging coke and reduce the rotational speed of the circulation fan to 5% (300 r / min) at 80-100 rad / min and stop the operation of the circulation fan. When necessary, press the emergency stop button of the circulation fan (the fan speed reduction process takes about 20 minutes. When the boiler tube burst is serious and the fan needs to be stopped immediately, press the emergency stop button). b. Adjust the pre-storage chamber relief valve to 100% and confirm that the pressure in the pre-storage chamber ≤ 100 Pa. If the pressure cannot meet the requirement, manually open the emergency relief valve centrally. c. Manually open the bottom-blowing nitrogen centrally and control the nitrogen flow rate ≥ 2000 m 3 / h. d. After the energy in the circulation system is released, close the emergency relief valve and start the circulation fan to cool down the boiler. e. During the cooling process, the rotational speed of the circulation fan can be appropriately increased to 600 r / min or 45%, but it must be ensured that there is no steam in the circulating gas (it can be confirmed at the air inlet guide or the exhaust valve of the fan outlet flue). If there is still a large amount of steam in the circulating gas system, maintain the rotational speed of the circulation fan at 300 r / min or 20% for cooling. f. After the leak stoppage conditions are met, stop the operation of the circulation fan, open the emergency relief valve to cooperate with the boiler maintenance work. Switch the nitrogen make-up from nitrogen make-up before and after the fan to bottom-blowing nitrogen, and control the nitrogen make-up volume at ≥ 2000 m 3 / h. Confirm that the ash accumulation in the secondary dust removal is emptied to prevent coking powder adhesion or freezing and blocking, which may affect the ash discharge after restoration. h. After the boiler system failure is handled and the circulating fan startup conditions are met, close the emergency relief valve and start the circulating fan at 300 r / min or 5% of the rated speed. Switch the bottom-blown nitrogen to nitrogen supplementation before and after the fan, and control the nitrogen supplementation amount at 1500 m 3 / h, and start the warm air drying and temperature increase operation of the coke dry quenching furnace. i. After confirming that there is no steam emitting from parts such as the empty guide, prepare to charge red coke for temperature increase. Measure the O2 content in the coke dry quenching furnace to be less than 4% before charging coke. j. Manually operate the hoist to charge the first three furnaces of red coke, and slowly charge the coke dry quenching furnace in 8 times for each furnace. k. Use T6 as the main temperature management during temperature increase. When T6 is lower than 650 °C, carry out the temperature increase operation at a rate of 20 °C / h. The temperature increase rate can be controlled by adjusting the speed of the circulating fan and the amount of coke discharge. l. When the T6 temperature reaches above 650 °C, resume normal production.

[0022] This method has been used in 4 sets of coke dry quenching units in the Ironmaking Plant of Taiyuan Iron and Steel Group. In 2024, there were 6 boiler leakage incidents. By using this method, the accuracy rate of determining the leakage location was 100%, and the cooling treatment time for each time was controlled within 8 hours, achieving good results.

[0023] The above are only specific embodiments of the present invention, but the structural features within the scope of protection of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the field of the present invention are covered by the patent scope of the present invention.

Claims

1. A determination method after the bursting of a dry quenching coke waste heat boiler, characterized in that: Including: High-temperature section tube burst: Tube burst phenomenon: The content of H2 in the circulating gas rises sharply, and the concentration of H2 in the circulating gas cannot be controlled by the method of burning by normally introducing air. Judgment basis: The content of combustible component H2 in the circulating gas rises above 3%, and there is no downward trend in adjusting the H2 content by increasing the air introduction amount; Tube burst phenomenon: Steam emerges from the outlet of the pressure regulating and discharging pipe of the pre-storage section. Judgment basis: 1) White steam emerges from the inspection holes of the inlet flue of the dry quenching furnace and the inspection holes of the outlet flue of the circulating fan; 2) Steam emerges or drips at the air introduction valve; 3) Steam emerges at the expansion joint of the fan outlet; 4) Water drips at the flange of the valve on the pressure regulating pipeline of the pre-storage chamber. Tube burst phenomenon: There is water stain or wet ash discharged at the secondary dust removal grid ash discharge valve. Judgment basis: A large amount of water flows out from the flange area of the water-cooled casing of the primary dust removal, and there is damp ash in the ash discharge of the primary and secondary dust removal. Tube burst phenomenon: The pressure of the pre-storage section of the dry quenching furnace fluctuates greatly. Judgment basis: 1) When the desulfurization door is fully open, the pressure of the pre-storage chamber is above 100 Pa; 2) The opening of the desulfurization door changes, and the increase compared with the previous opening is ≥10%. Tube burst phenomenon: The resistance in the gas circulation system becomes significantly larger, the pressure difference at each point in the system changes, and the circulating air volume decreases. Judgment basis: 1) The pressure at the boiler inlet rises by more than 0.2 KPa compared with the normal pressure, that is, -0.8—-1.0 KPa; 2) The abnormal sound ultrasonic detection device installed inside the boiler system issues a prompt alarm. Low-temperature section tube burst: Tube burst phenomenon: The steam generation amount of the boiler decreases by 20-40 t / h or the boiler feed water flow rate is greater than the steam generation amount by 20-40 t / h. Judgment basis: The feed water volume and evaporation volume do not match, that is, under normal circumstances, the feed water volume is 5-10 t / h larger than the evaporation volume, and the mismatch means that the feed water volume is 20-40 t / h larger than the evaporation volume. Tube burst phenomenon: There is water accumulation at the bottom of the boiler and the bottom of the circulating fan. Judgment basis: 1) Water drips or flows out from the drain hole at the bottom of the boiler; 2) The temperature at the boiler outlet drops by more than 10 °C.

2. A method for disposing of a dry quenching waste heat boiler after a tube explosion, characterized in that: Including: (1) For the fault of water leakage in the low-temperature section, handle it according to the following method: 1) Confirm the water leakage of the low-pressure economizer, stop coke charging and gradually reduce (reduce by 5±1% each time), and reduce the rotational speed of the circulating fan to 15%-20%, that is, 225-300 r / min. 2) Adjust the pre-storage chamber relief valve to 100%, and adjust the air introduction valve to 0%. 3) Open the nitrogen makeup valves before and after the fan and confirm that the nitrogen makeup volume is 1500 - 2000 m 3 / h. 4) Reduce the speed of the circulating fan at a rate of 50 - 70 rad / min until it stops. Close the desulfurization valve, switch the nitrogen supplementation before and after the fan to bottom-blowing nitrogen, and confirm that the nitrogen flow rate is 2000 - 3000 m 3 / h. 5) Open the emergency relief valve at the top of the primary dust removal for leak plugging treatment of the economizer. 6) After the boiler system failure is disposed of and the circulating fan startup conditions are met, that is, after all the above-mentioned failures are handled, close the emergency relief valve, start the circulating fan at a speed of 75 - 100 r / min, switch the bottom-blown nitrogen to nitrogen supplementation before and after the fan, and control the nitrogen supplementation amount at 1500 - 2000 m 3 / h, and start the temperature-raising operation of the coke dry quenching furnace. 7) Raise the temperature with T6 as the main temperature management. When T6 is lower than 650 °C, carry out the temperature-raising operation at a rate of 25 °C - 30 °C / h. When raising the temperature, the temperature-raising speed can be controlled by adjusting the rotational speed of the circulating fan and the coke discharging amount. 8) When the T6 temperature reaches above 650 °C, resume normal production. (2) For the tube burst in the high-temperature section, handle it according to the following method: 1) Immediately stop coke charging and reduce the rotational speed of the circulating fan to 75-100 r / min at 80-100 rad / min and stop the operation of the circulating fan. If necessary, press the emergency stop button of the circulating fan. 2) Adjust the pre-storage chamber relief valve to 100%, confirm that the pressure of the pre-storage chamber ≤100 Pa. If the pressure cannot meet the requirement, manually open the emergency relief valve centrally. 3) Manually open the bottom blowing nitrogen in the center and control the nitrogen flow rate to be 2000 - 3000 m 3 / h, 4) After the energy in the circulating system is released completely, close the emergency relief valve and start the circulating fan to cool down the boiler. 5) During the cooling process, the rotational speed of the circulating fan can be increased to 600 - 800 r / min, but it must be ensured that there is no steam in the circulating gas. If there is still steam in the circulating gas system, maintain the rotational speed of the circulating fan at 225 - 300 r / min to cool down to 200 - 300 °C. 6) When the conditions for plugging are met, that is, the hydrogen content in the circulating gas is 0-3% and the boiler inlet temperature is 200-300 °C, stop the operation of the circulating fan, open the emergency relief valve to cooperate with the boiler maintenance work, switch the nitrogen supply from the front and back of the fan to bottom-blowing nitrogen, and control the nitrogen supply volume at 2000-3000 m 3 / h, 7) Confirm that the dust accumulation in the secondary dust collector is emptied to prevent coking powder adhesion or freezing blockage. 8) After the boiler system failure is handled and the circulating fan startup conditions are met, that is, all the above-mentioned failures are handled, close the emergency relief valve, start the circulating fan at a speed of 50 - 75 r / min, switch the bottom-blown nitrogen to nitrogen supplementation before and after the fan, control the nitrogen supplementation amount at 1500 - 2000 m 3 / h, and start the warm air drying and temperature rising operation of the coke dry quenching furnace. 9) After confirming that there is no steam coming out from the air guide part, prepare to load the red coke for heating up. Before loading the coke, measure the O2 content in the dry quenching furnace to be less than 4%. 10) Manually operate the hoist to load the red coke for the first 3 furnaces, and slowly load it into the dry quenching furnace in 6 - 8 times for each furnace. 11) Use T6 as the main temperature control during the heating-up process. When T6 is lower than 650 °C, carry out the heating-up operation at a rate of 20 ± 2 °C / h. During the heating-up process, the heating-up speed can be controlled by adjusting the rotational speed of the circulating fan and the amount of coke discharged. 12) When the T6 temperature reaches above 650 °C, resume normal production.

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