A pressure drop model of PCI system was developed for Baosteel No.4 blast furnace based on the additional pressure drop.The empirical expressions of solid phase friction coefficient for horizontal pipe,rising pipe and bends with different radius of curvature were established.The predicted pressure drop was in good agreement with the production data.The model provides not only effective reference for designing blast furnace PCI system but also theoretical support for energy saving on Baosteel No.4 blast furnace system.

The background,innovation highlights,specific work and practical effect of the integration and inno- vation in Baosteel No.4 BF's PCI project.The innovation highlights of the project are as follows:the project's e- quipment scale and design indicators have reached the world top grade;special equipments have been localized;and independent integration of facilities for the project have been realized.All these greatly reduced the investment to the project.In the innovation process,the principles of paying attention to the fundamental research,integrating theory with practice and combining design with production were followed;spot investigation and combining design with pro- duction closely were emphasized;simulating tests in laboratories and on-the-spot industrial tests were focused;tech- nological investment was strengthened;powerful design teams were organized;and decisions were made on the work- ing site so as to facilitate the construction.Practice has proved that integration and innovation of Baosteel's PCI tech- nology for No.4 BF was a great success.

Tests on de-silicon of the 750m 3 blast furnace at Shanghai No.1 Iron Steel Works have been conducted through adding de-silicon agent into the torpedo ladle car and iron runner,a technology called soft feeding process.Factors influencing efficiency of de-silicon and causing temperature drop of hot metal have been analyzed.Test results show that the soft feeding process is effective in de-siliconizing BF iron under current conditions and the silicon content and temperature drop of the desiliconized hot metal can satisfy requirements of de-phosphorization pre-treatment in steel making process.

本文介绍了开关电器弹簧的特点和制造技术.对于如何制造出稳定的和高质量的电器弹簧,文章阐述了应该使用先进的技术、先进的弹簧制造设备、先进的加工工艺等观点,值得同行借鉴.