Views: 19 Author: Site Editor Publish Time: 2021-05-14 Origin: Site
Designed by our company, the 130tLF steelmaking project of the environmental relocation product upgrade project of HBIS Group Shijiazhuang Iron and Steel Co., Ltd. has been successfully put into operation on January 12, 2021 after 6 months of hard work by all the project team.
HBIS Shijiazhuang Iron and Steel Co., Ltd. Environmental Relocation Product Upgrade Project Constructs three 130t rotating electrode double-station LF furnaces for the secondary refining treatment of two 130t scrap preheating electric arc furnaces.
The following technical improvement measures were taken during the design process of this project.
1) Adopt a water-cooled compensator that can be replaced online.
The traditional water-cooled compensator is connected in place. If one of the compensators is damaged and needs to be replaced, the transformer must be moved backward, and all compensators must be removed before replacement. The workload is huge and the replacement time is long, and other compensations are easy to cause. Damage to the seal of the device. Aiming at the shortcomings of the existing technology, our institute has designed a water-cooled compensator that can realize any single-line replacement. This water-cooled compensator has a double-flange structure, that is, when the transformer is not moved, only the compensator The flanges connected to the transformer terminals and the water-cooled copper tube at both ends are loosened, and the rubber tube part of the middle joint body can be removed. This design is reliable in connection, easy to replace, improves work efficiency, and reduces maintenance costs.
2) Adopt a new type of water-cooled sealed furnace cover.
The design of the furnace cover adds a skirt structure and considers sufficient height. In order to prevent cold air from entering the ladle from the skirt structure and affecting the atmosphere in the furnace, a special flue gas channel was added in the design of the furnace cover. The section of the flue gas channel gradually increases from the circumference to the exhaust hole, forming a negative effect in the channel. Pressure, so that the cold air entering from the skirt can be directly sucked into this channel and discharged from the exhaust hole to ensure the maintenance of the reducing atmosphere in the bag.
3) Use a low-impedance high-current system.
By increasing the cross-sectional area of the copper pipe out of the wall, using a low-reactance conductive cross arm, and selecting reasonable ladle furnace transformer parameters, the design of the short network system is optimized, the three-phase impedance imbalance is reduced, and the heating capacity is calculated Best (with better operating power factor) and good regulator performance, which can reduce the ladle refractory index and prolong the life of the slag line refractory.
4) Advanced argon blowing control system
One of the main functions of the ladle refining furnace is argon blowing and stirring, also called argon blowing operation. The refining effect of the LF furnace is also significantly different when the mixing intensity is different. In order to ensure the effective and smooth progress of argon blowing and stirring during the entire refining process, we adopt an advanced argon blowing control system. The core control components adopt the current mainstream foreign brands. The flow measurement and control unit are integrated. The flow adjustment is linear and continuously adjustable, and the technology is advanced. It is mature, the flow rate is measured by mass flow rate, the argon flow rate is automatically set and adjusted, and the pressure feedback automatic strong blowing bypass branch is provided to prevent air-tightness and ensure the smooth progress of the three-in-one process of steelmaking, refining and continuous casting. The pressure detection accuracy of the ladle bottom blowing gas control system is ≥±0.2%FS, and the flow detection and control accuracy is ≤±3NL/min. The adjustment range of each point is 15~1000NL/min, and the control accuracy is ±3NL/min. The compressive strength of the whole system is ≥2.5MPa.
Since the project was put into production, it has been operating normally and has excellent indicators. As an intermediate link between electric furnaces and continuous casting equipment, it plays a very important role in coordinating the production cycle of smelting and continuous casting machines and realizing multiple ladle continuous casting.
5) Automatic temperature measurement and sampling device
The automatic temperature measurement and sampling device uses an ABB six-axis robot to complete temperature measurement, oxygen determination and sampling. The six-axis robot has a flexible movement posture, which can perfectly adapt to the complex and small working space on site. After the robot is equipped with non-standard customized temperature measurement / oxygen determination, and sampling guns, it can cooperate with the automatic storage warehouse to complete temperature measurement, oxygen determination and sampling; at the same time, it is equipped with thermal insulation clothing to ensure reliable operation in high temperature environments.