The core equipment of the 300㎡ sintering machine flue gas desulfurization and denitrification project at Wuhan Iron and Steel Group's Kun Steel New Area has been topped out.

At the construction site of Wuhan Iron and Steel Group's Kun Steel New District, with the hoisting instruction issued by the company chairman Gu Yongmao, the last section of the desulfurization tower slowly rose from the ground. The Wuhan Iron and Steel Group Kun Steel New District project, undertaken by Yunnan JianTou Second Installation Engineering Company, 300 ㎡ The core device of the sintering machine flue gas desulfurization and denitrification technical transformation project, the desulfurization tower, 2018 year 11 month 7 successfully capped on the morning of day   Gu Yongmao, chairman of the board of directors, and Pu Guangyue, chairman of Yunnan Tianlang Energy Conservation and Environmental Protection Group Co., Ltd., led their respective management teams to the construction site to witness this moment.

Kun Steel New District 300 ㎡ The sintering machine flue gas desulfurization and denitrification technical transformation project officially started on 2018 year 4 month 28 day. The company undertakes the desulfurization tower, super-clean tower, flue and bracket installation project of the first phase of the project, and the electromechanical equipment and pipeline installation project of the second phase. The total project cost is 2425 yuan.

During the implementation of this project, the employees of the project department worked together to overcome difficulties and bravely break through and innovate in technology and processes.

First, a composite plate structure of carbon steel plate with attached duplex stainless steel plate was used for the first time. 2205 In this project, duplex stainless steel 2205 is used as the corrosion-resistant layer, and the carbon steel layer is used as the structural strength support layer. This composite plate is used for the desulfurization tower and the super-clean washing tower, which is the first in the country.

2205 Abbreviated as duplex stainless steel, its composition characteristics are ultra-low carbon and nitrogen-containing. , Its typical composition is 22%Cr+5%Ni+0.17%N ，2205 Further increasing the nitrogen content , enhances the resistance to stress corrosion and pitting corrosion in acidic media with high chloride ion concentration. Duplex stainless steel 2205 also has good weldability, and the sensitivity to cold cracking and hot cracking during welding is relatively small. Usually, no preheating is required before welding, and no heat treatment is required after welding. The welded joint has good comprehensive performance.

The project uses Q235B+2205 composite plate. Since there is no current national welding standard to refer to, the project department refers to Q235 and duplex stainless steel plate 2205 welding process and welding materials to conduct welding tests, and finally determine the welding process and conduct welding process evaluation. According to the welding process evaluation, the corresponding welding process instruction manual is prepared, and the construction method is formed.

Second, in view of the small hoisting construction site and the large weight and volume of the hoisting objects, the optimal hoisting method was formulated to ensure the safe hoisting of the desulfurization tower. The total height of the desulfurization tower body is 80m , located on 9.5m concrete foundation, the distance of the desulfurization tower from the ground is 89.5m . It is divided into five sections from bottom to top. 0-16.025m The material is composite plate Q235B+2205, The thickness is 21+3mm , the inner diameter is 16m；16.025-18.025m The material is carbon Q235B , the thickness is 20mm;18.025-29.025m is a concentric eccentric cylinder, and the inner diameter from bottom to top is 16m-8m , the material is carbon steel Q235B, The thickness is 16mm；29.025-64.025m The material is carbon steel Q235B, The thickness is 14mm , the inner diameter is 8m；64.025-80m The material is stainless steel 316L , the thickness is 10mm , the inner diameter is 8m . 730t , a total of 27 hoisting.

After comparing the schemes, the positive installation method plus attached tooling platform instead of the positive installation method plus scaffolding technology was adopted. Choose 350t a truck crane for the main hoisting, 75t crawler crane for assembly. The 5 hoisting, which is the sixth plate, has the largest hoisting weight, 57.0 t , hoisting height 21.55m , cylinder diameter 16m , crane allowable hoisting weight 60.5t . The highest hoisting point of the desulfurization tower is the 27 hoisting, with a height of 89.5m , and a hoisting weight of 9.035t , crane allowable hoisting weight 11t . The crane load rate is controlled within 95% .

Through the implementation of this project, the technology of hoisting large and ultra-high components using the scaffolding-free positive installation method in a narrow space has been mastered.

After the capping ceremony, Gu Yongmao, chairman of the board of directors, expressed his sincere gratitude to Tianlang Energy Conservation and Environmental Protection Group for their support and trust in our work. The company attaches great importance to the progress and quality of the project and ensures that a satisfactory answer will be delivered. Pu Guangyue, chairman of Yunnan Tianlang Energy Conservation and Environmental Protection Group, also stated that Yunnan JianTou An Er Si is a reliable partner, and both sides will continue to strengthen cooperation, work together in unity, and make progress together.

[Liang Tao Yin Xingxian]