——Liu Shiju talks about the transformation experience of No. 3 hot blast furnace of 2580m³ blast furnace of Chaoyang Iron and Steel Group

Reporter Xia Jason

At 10:56 am on October 17, 2025, the 2580m³ blast furnace No. 3 hot blast oven of Anshan Iron and Steel Group Chaoyang Iron and Steel (hereinafter referred to as Chaoyang Iron and Steel) was successfully ignited, marking the first time that Anshan Iron and Steel Group adopted a hot blast furnace developed by Anshan Iron and Steel Group Engineering Technology Co., Ltd. and Henan Province Yuxing Thermal The Wind Furnace Engineering Technology Co., Ltd. (hereinafter referred to as Anshan Iron and Steel Engineering and Yuxing Engineering) jointly designed and constructed the project to successfully transform Chaoyang Iron and Steel's original internal combustion hot blast stove into a catenary top-fired hot blast stove using online transformation technology in which the original hot blast stove shell and hot air outlet elevation are fixed.

According to Liu Shiju, chairman of Yuxing Company, this renovation project is technically difficult and has high construction requirements. Its successful implementation not only solves practical problems for the owner, but also accumulates valuable experience for similar renovations in the industry!

Frequent problems arise in the original hot blast stove, and renovation is imminent

The 2580m³ blast furnace of the Ansteel Group Chaoyang Iron and Steel Company Ironmaking Plant is equipped with three internal combustion hot blast furnaces. The furnace adopts an apple-shaped fire well structure and a grid burner. The design air temperature is 1250°C and the air supply time is 60 minutes. A plate heat exchanger is used to preheat the coal gas and combustion air to 180°C and 170°C respectively using flue gas and waste gas. The overall design life of the hot blast stove is more than 25 years. It was built in 2008 and put into production in 2010.

After the hot blast stoves were in operation for several years, all three internal-combustion hot blast stoves suffered from inherent structural defects such as structural damage to partition walls and fire pits, falling bricks, peeling off, holes, and cracks to varying degrees. As a result, the air temperature could not be used normally, seriously affecting the company's profits. In particular, the damage to the #2 hot blast furnace was particularly serious, with large-scale partition wall collapse and partition wall hole damage. Since Chaoyang Iron and Steel Company only has one blast furnace and three hot blast furnaces, if a hot blast furnace has serious structural problems, it will directly threaten the company's production safety and corporate efficiency. In order to solve this problem, the company quickly took measures to immediately add a 4# hot blast stove, which formed a 3+1 hot blast stove group configuration, so that the blast furnace and hot blast stove can implement the normal two-burning and two-send working system. The hot blast stove that was suddenly damaged can be overhauled online without affecting production. The additional hot blast stove still uses the internal combustion hot blast stove structure and was completed and put into operation at the end of 2017. The hot blast stove is numbered No. 4 hot blast stove.   

Immediately after the No. 4 hot blast stove was completed and put into operation, all the refractory materials of the internal combustion hot blast stove of the No. 2 hot blast stove were dismantled and scrapped in early 2018. All refractory materials were made according to the original design furnace type and all refractory materials were replaced and laid.

In February 2023, serious damage to the fire well structure inside the partition wall of hot blast stove #1 (formerly #3) occurred. Subsequently, all internal combustion refractories of the hot blast stove #1 were dismantled and scrapped. All refractory materials were made according to the original design furnace type and all refractory materials were replaced and built. After the overhaul, the supply air temperature was about 1150°C.

After the No. 1 (original No. 3) hot blast stove was overhauled and put into operation, the No. 3 (original No. 1) hot blast stove had a short-circuit problem in the partition wall under the grate, which caused the exhaust gas to rise slowly, the gas was not fully burned, the consumption was high, and the heat storage capacity was obviously insufficient, which affected the blast furnace air temperature and output. At the same time, the carbon monoxide content in the exhaust gas seriously exceeded the standard, polluting the environment. In addition, the combustion chamber partition wall, fire well and other structures have sunk, the U-shaped seal of the air pipe has serious cracks, posing safety hazards, and the supply air temperature has dropped sharply. Although an additional hot blast stove was built, the two-burning and one-send mode can be used for normal production when problems arise, but the four internal-combustion hot-blast stoves are really not up to par, and the fire pit partition wall structure is frequently damaged, which affects the air temperature. Under such an embarrassing situation, the company decided to transform the existing internal-combustion hot-blast stove into a top-fired hot blast stove, which is the current mainstream development trend.

Comparing shopping will reveal the truth: the "double immobility" solution stands out

After repeated communication and demonstration with a number of engineering technology companies, all the engineering companies participating in the technical exchange proposed the plan of cutting the internal combustion hot blast stove shell and transforming the internal combustion hot blast stove structure into a small hat top-burning hot blast stove with the same structure. Angang Engineering and Yuxing Company joined forces and relied on several mature large blast furnaces to completely optimize the internal combustion structure technology to replace their inherent structural defects. The hot blast stove shell was used to recycle the old and the hot air outlet price was high. The old (practice has proven that setting the hot air outlet in the middle of the large wall of the regenerator is more reasonable, and the structure is more stable and long-lasting than setting it at the top of the pre-combustion chamber and the cone-top combustion chamber). The technical transformation of the built-in standpipe has been successfully verified by more than 10 years of practice. This transformation technology has been favored by experts from Anshan Iron and Steel Group Chaoyang Iron and Steel Company, and experts have been organized to inspect and demonstrate, making Yuxing Company's top-fired furnace shell recycling scheme stand out! The reporter asked the reason for its success? Liu Shiju believes that the key is that the top-fired transformation of the furnace shell has a relatively large investment saving, and the combustion chamber structure still adopts a catenary vault structure that has reasonable stress and has been used at high wind temperatures for more than 30 years in China and has been used at high wind temperatures for more than 50 years abroad, which is consistent with the original furnace shell structure. In particular, the elevation of the hot air outlet structure remains unchanged. The utilization of this feature will keep the original hot air duct structure and the platform supporting the hot air duct structure unchanged, which will greatly shorten the construction period and greatly save investment. This completely changes the structural instability problem caused by the temperature difference between the upper part of the fire well when the burner is set in the lower part of the fire well when burning, and the temperature difference between the middle and lower parts of the high temperature in reverse operation during air supply. Experts from Yuxing Company implemented internal structural optimization and set the burner in the lower part of the fire well to the top of the catenary. The fire well structure is only used as a hot blast furnace passage, which eliminates the dynamic impact of frequent temperature differences during combustion and air supply on the hot and cold alternation of the fire well and partition structure. A series of material optimization, structural optimization, and thermal expansion and contraction detail optimization of the fire well partition structure are also adopted to ensure the stability and longevity of the fire well passage. In addition, the industry has proposed the disadvantage that the top-fired hot blast furnace burner structure cannot be removed and replaced at any time (Yuxing will have HRK1100℃ water-cooled 100 times thermal shock-resistant brick craft products, and authorizes Russian Kalugin Company to have exclusive sales rights in the CIS region. Kalugin Company designs and uses them in applications including Jingtang 5500m³, Japan JFE5000m³, Russia North 5578m³ and other international and domestic top-fired hot blast stove burner core equipment for blast furnaces above 4000m³. This burner product is also designed and used by Yuxing in Shanxi Tongcai Company 1860m³, Tangshan Ruifeng 1416m³, 2300m³, Donghua 2300m³,The burner structure of more than 700 Yuxing-burning hot blast stoves, including Zongheng 2500m³, Jingye and others, has exerted a stable and long-lasting effect, indicating that as long as the operating procedures meet the design requirements, the burner structure is stable, long-lasting and will not be damaged), and the burner part is set up so that it can be easily replaced and repaired at any time without affecting the vault. Such technological transformation measures have attracted great attention from the Party Committee and Board of Directors of Chaoyang Company. In July 2023, a technical transformation plan was determined to use the hot blast stove shell to recycle the old, the official platform, the hot air outlet elevation to recycle the old, and use the built-in standpipe to replace the air supply duct. Priority was given to the 3# (original 1#) hot blast stove that had been seriously damaged for more than two years after overhaul and resumption of operation. The technical furnace structure was transformed from the original internal combustion type to the Yuxing catenary top-fired hot blast stove. The final project is scheduled to start in June 2025, with a total construction period of 150 days.

After 150 days of intense construction and installation, Chaoyang Iron and Steel Company's 2580m³ blast furnace #3 (formerly #1) internal combustion hot blast stove shell was reused, the hot blast outlet pipe network was reused, and the transformation of the catenary top-fired hot blast stove with built-in fire well was completed on October 10, 2025. The ignition and oven was successfully fired on October 17! For the renovation of this project, Liu Shiju and his team of technical experts believe that the well-known foreign internal combustion hot blast furnace catenary vault structure, Yuxing catenary annular upward spray premixed burner structure, fire well structure, and the connection structure between the fire well and the large wall of the regenerator all adopt the most mature structural technology. The transformed hot blast stove has changed The original burner structure with uneven distribution of the internal combustion flue gas flow field is eliminated, and the flue gas flow field is evenly distributed and highly efficient, so that the CO in the exhaust gas can be reduced to less than 100PPM. This completely solves the inherent structural defects of internal combustion hot blast stoves such as peeling off, holes, and collapse of fire well partition walls, and enables long-term use of stable high air temperatures. Based on the quality of the optimization and transformation, the reasonably designed structural features and rich practical experience, Anshan Iron and Steel Engineering and Yuxing Company confirmed with great confidence that the service life of the optimized and transformed catenary top-fired hot blast furnace can reach more than 20 years.

The technical characteristics, quality and construction period of the hot blast furnace optimized and transformed this time have been highly recognized and praised by Ansteel Group Chaoyang Iron and Steel Plant and Ansteel Engineering Technology Co., Ltd., and Yuxing Company was awarded "Responsible Engineering and Technical Excellence" and "Iron Army Style, Quality Project" respectively. banners, and respectively gave great encouragement to "your company's excellent style of integrity and commitment, excellent technology, and ability to fight tough battles" in letters of commendation. This will encourage Anshan Iron and Steel Engineering and Yuxing Engineering to cooperate more closely and lay a solid foundation for future technological transformation of the industry to create larger and more exemplary projects.

Since the hot blast stove oven was put into operation for nearly half a month, its performance parameters before and after overhaul have been optimized as follows. See the table below for details:

Comparison table of performance parameters before and after overhaul of Chaoyang Iron and Steel No. 3 hot blast furnace

Angang Group Chaoyang Iron and Steel Plant 2580 cubic meter blast furnace internal combustion hot blast furnace shell reuse top combustion type renovation masonry drawing

The picture shows the completed catenary vault and burner renovation of the 2,580 cubic meter blast furnace internal combustion hot blast furnace shell at Chaoyang Iron and Steel Plant of Anshan Iron and Steel Group Co., Ltd.

The picture shows Anshan Iron and Steel Group, Anshan Iron and Steel Design Institute, and Yuxing Company taking a group photo inside the 2,580 cubic meter blast furnace internal combustion hot blast furnace shell reuse and top-fired furnace renovation completed at Chaoyang Iron and Steel Plant of Anshan Iron and Steel Group.

The picture shows the owner, design institute, and Yuxing Company taking a group photo to commemorate the completion acceptance of the 2,580 cubic meter blast furnace internal-combustion hot-blast furnace shell reuse and top-combustion reform at Chaoyang Iron and Steel Plant of Anshan Iron and Steel Group

The picture shows the process of renovating the old top-fired furnace shell of the 2580 cubic meter blast furnace internal combustion hot blast furnace in Chaoyang Iron and Steel Plant of Anshan Iron and Steel Group to build the catenary vault.