This project belongs to the technical field of environmental protection machinery and equipment design and manufacturing.
Precision steel pipes (used in high temperature, high pressure, corrosion, etc.) must undergo one or more cold rolling and undergo different processes such as acid washing, phosphating, and saponification. Among them, the quality of pickling process technology and equipment directly affects the quality of precision steel pipe finished products and waste emissions. The traditional acid cleaning line has backward technological equipment. The acid cleaning static immersion and manual tank edge operation not only have a very harsh environment, but also have high acid consumption, large waste acid emissions, and unorganized emission of waste acid mist.
Baosteel Engineering relies on the product structure optimization project of Baosteel Precision Steel Pipe Factory and cooperates with Baosteel Precision Steel Pipe Factory to develop an automatic environmentally friendly steel pipe pickling line, which is the first in China. On the premise of meeting the production process and production capacity, in order to achieve the goals of environmental protection, low consumption and low emissions, in-depth research and development has been carried out on various aspects such as process routes, equipment configuration, material applications and energy consumption. The main innovations include: (1) Production automation technology and logistics information technology: Through computer simulation and real-time calculation of the consumption of various media, automatic liquid dispensing and fluid replacement are realized, and automatic control of bar code positioning is realized at 29 stations for acid cleaning. (2) Automatic precise positioning technology for pickling transport vehicles: The vehicle can intelligently realize pipe material lifting, tilting liquid pouring, and accurate material transportation between stations. (3) Cascade and turbulent acid pickling technology: Cascade flow can reduce the consumption of acid and water, and turbulence can improve the quality of steel pipe pickling per unit time. (4) Online slag removal technology and saponification liquid preparation technology: Online slag removal can improve phosphating quality and reduce labor intensity; saponification liquid preparation can achieve quantitative and precise control and reduce phosphating liquid consumption. (5) Acid mist washing absorption and recycling emission technology: Water washing absorption achieves orderly collection and utilization of acid mist, and almost zero emission of waste acid mist.
This project has applied for 8 patents (6 invention patents), identified 4 technical secrets, and published 1 paper.
The automatic steel pipe pickling line developed in this project has been successfully put into operation for more than two years. After operation, various indicators have met or exceeded the design requirements, effectively improving the quality of pickling. This achievement has achieved the following effects through major breakthroughs in the process: (1) Environmentally friendly production: According to the report issued by the Shanghai City Environmental Monitoring Center, the sulfuric acid mist emission concentration has dropped from the national standard of 45mg/m3 standard dry to the actual test results of 0.0405~ 0.136 mg/m3 standard dry; The amount of waste acid has dropped by 49% compared with traditional methods (originally 10700t/year, now 5544t/year); the hourly amount of acid-containing wastewater has dropped from 20t/h to 8t/h. (2) Saving investment: Compared with introducing similar foreign core equipment, it can save 41.42 million yuan in investment per set. (3) Reduce the consumption of raw and auxiliary materials: The consumption of 98% of concentrated sulfuric acid per ton has dropped from 11.5 kg/t to 8.5 kg/t; steam has dropped from the traditional 5 - 8t/h to 3 - 4t/h; Industrial water has dropped from an average of 23t/h to 10t/h. (4) Due to the effective implementation of automation and informatization, the number of personnel has been reduced, and the working environment has been significantly improved, achieving safe and environmentally friendly production.
This project closely follows clean production, energy conservation, reduction of waste emissions, reduction of environmental pollution, reduction of labor intensity, etc., and is of great significance to the upgrading and transformation of old enterprises. Its application principle, technology and equipment can also be extended to automatic environmentally friendly pickling lines for wire rods and plates. It has significant economic and social benefits, and its promotion and application prospects are very broad.