In July 2017, the 2200m3 blast furnace hot air pipeline of ESSAR Steel Company of India was completed by the overall changeover method. The air temperature was increased from 1050°C to 1200°C before the transformation. The current hot air pipeline is stable and provides users with the overall operation. Significant impairment gains and benefits.

Before the renovation, the old hot air pipeline accidents frequently occurred, including the breakage of the tie rods, the compensator burning, the three-mouth grouting, and the multiple lining of the pipeline lining. For many years, it relied mainly on water-cooling and the carbonization of the steel structure was serious. According to the conventional method, the construction period of the old pipeline replacement and renovation project needs at least 60 days to 90 days. In order to achieve the goal of derogation and efficiency improvement, the project adopts the technical scheme of replacing the hot air duct as a whole, that is, prefabricating the new hot air duct on the temporary platform in advance, and removing the old pipeline and the new hot air duct during the blast furnace off-air (the masonry has been completed). The whole is moved and positioned for installation. The new hot air duct has an outer diameter of 3840mm and a total length of about 70m (including 3 hot air branch pipes).

The new hot air duct focuses on improving the rigidity and stability of the hot air duct. The main technical measures include: replacing the round rod with a beam pull rod, adding a spring support to the hot air branch, and providing an axial compensator. The new hot air duct is improved. The lining design standard replaces the old hot air duct lining RDL-75 refractory brick with low creep material DRL-150 refractory brick. Kalukin is responsible for the engineering design and masonry supervision.

This project is the first time in the world to replace the large and medium sized blast furnace hot air pipelines, which minimizes the loss of blast furnace production and has important demonstration significance in the maintenance of hot air ducts.