Hadeed Saudi Iron & Steel Co
Cold Rolling Lines Automation
Hadeed Saudi Iron & Steel Co. is a large steel company belonging to the SABIC Group, a highly diversified public company based in Riyadh (Saudi Arabia); 70% of SABIC shares is owned by the Saudi government.
Hadeed Saudi Iron & Steel Co., active since the early 80’s, is one of the largest steel companies in the Middle East and produces hot and cold rolled products, galvanized steel products, rebars and wire rod at a plant in Al Jubail (Saudi Arabia).
Between 1997 and 1999 Iso Sistemi, operating as a subcontractor of two world’s leading engineering companies, Voest Alpine and ABB, has developed and performed the commissioning of, the Level 1 Automation System for two Cold Rolling Lines for the Al Jubail plant.
Iso Sistemi was selected as the supplier for its specific expertise in the steel sector and in particular the automation of Cold Rolling Mills.
A picture shows the offices of Sabic, the world’s largest petrochemicals firm by market value, in the Saudi capital Riyadh on January 20, 2009. Sabic said today it has shut some plants temporarily and will restructure some units after fourth-quarter profit plunged 95 percent. AFP PHOTO/STR (Photo credit should read -/AFP/Getty Images)
Project environment and scope
The two lines affected by the project were a Pickling Line (Push-Pull Pickling Line – PPPL) and a Continuous Galvanizing Line (CGL).
A Level 1 automation system has been realized for both lines; this level of automation (also called basic automation), using Programmable Logic Controllers (PLC), activates the set-ups received by the Level 2 or by the operator, and manages plant equipment operations.
The Level 1 of the PPPL includes 4 PLCs implementing the functions of material transportation and chemical section control, in connection with the control systems of the variable speed motors moving the strip (Entry, Process, Exit Drives). Moreover, the PLCs are connected through dedicated serial lines to the machines provided with local automation (Thickness Gauge, Weighing Scale, Oiling machine).
The Level 1 of the CGL includes 7 PLCs implementing the functions of material transportation and chemical section control and one PLC for furnace control. Connections with the equipment, the control systems of the variable speed motors moving the strip and the machines provided with local automation follow the same logic as for the PPPL.
An Ethernet TCP-IP communication backbone (L1 BUS) connects the PLCs among each other and with the video terminals for man-machine interface (HMI) situated in the main control pulpits of the line and in the electric power distribution station. Through suitable interface cards, the Level 1 is connected with the Level 2 Ethernet TCP-IP communication backbone (L2 BUS) and therefore with the Level 2.
The Pickling Line (PPPL)
The line was designed to process low carbon strips, thickness 1.4/6.0 mm, exit width 600/1650 mm DIN 1016. The line includes on the entrance side an unwinding reel, a coil preparation section, a scraper, a thickness gauge, a shear for head cutting and tapering; on the exit side, a rinsing and drying section, a shear, a side trimmer, an oiling section, a winding reel and the weighing scale.
The Continuous Galvanization Line (CGL)
The line can process the same strips as the PPPL, thickness 0.3/2 mm, exit width 800/1400 mm. The process is continuous. The line includes unwinding reel, shear, dry cleaning section, battery of controlled-atmosphere ovens, basin for tape immersion in the bath of molten zinc, air knife for coating thickness adjustment, glossy surface treatment section (crimping), coating thickness gauge, cooling bath and air drying, scraper, final treatment section, control station, a station for oiling (if any), exit shear, recoiler and shear, roll binder, roll weighing on exit.
Role of Iso Sistemi and accrued results
Iso Sistemi participated to the development of the Functional Specifications of all software functions and to the design of the man-machine interface (HMI).
It developed on the PLCs, according to the specifications, all the software functions and tested the developed software using plant simulators implemented to these purposes, prepared the Operator’s Manuals and upon passing the FAT, carried out the training of the system operators and started-up system operations.
After commissioning Iso Sistemi was also requested to provide assistance to plant performance tuning and its specialized technical support for the guarantee and post-guarantee periods.
The project realized all its aims in terms of productivity and product quality.