Abstract: This paper introduces the automatic control system of the acidification disposal line. It focuses on the computer configuration, process characteristics, program functions, and control methods of the control system. This automatic control system is reliable, easy to operate, and highly automated, achieving fully automatic operation. Keywords: acidification disposal; automation control; C80-EPC/HPC [b][align=center]The Automation Control Systems of Acidification Disposal Chen Ge[/align][/b] Abstract: This paper introduces the automation control system applied to the acidification disposal for the metal band surface. Computer components of this control system, technical specialties, program functions, and control methods are all explained. The automation control system is reliable and can auto-control completely. Keywords: acidification disposal; automation control; C80-EPC/HPC Acidification is mainly the treatment of the surface of strip steel. It is one of the most critical steps in the stainless steel manufacturing process, and the effect of acidification directly affects the quality of the finished stainless steel product. One of our company's acidification lines has all its mechanical and electrical equipment imported from abroad, adopts fully automatic control, and its automation level has reached the advanced level in China. 1 System Overview The entire equipment of this processing line is imported from abroad. It mainly consists of an inlet section, a degreasing section, an inlet looper trolley, a heating furnace section, a pickling section, an outlet looper trolley, and an outlet section. The production process flow is shown in Figure 1. This article mainly focuses on the pickling control system, describing its hardware configuration, software functions, and control method characteristics. [align=center] Figure 1 Production Process Flow Diagram[/align] 2 Hardware Configuration 2.1 Composition of the Pickling Section Equipment This pickling equipment is provided by BEUGIN Company of France and consists of the following parts: ① Electrolytic pickling tanks #1, #2, and #3; ② Brushing unit #1; ③ Electrolytic pickling tank #4; ④ Brushing unit #2; ⑤ Electrolytic pickling tanks #5 and #6; ⑥ Pre-cleaning unit; ⑦ Brushing unit #3; ⑧ Final cleaning unit; ⑨ Strip drying unit; ⑩ Electrolyte preparation tank, as well as corresponding motors, encoders, proximity switches, transmitters, valves, filters, etc. 2.2 System Hardware Configuration The control system uses the C80-HPC from ALSTOM, France, specifically a dual-CPU C80-HPC. CPU1 is used for strip steel inlet and outlet control, while CPU2 controls the equipment in the degreasing and pickling sections and collects and processes process data for these sections. The system hardware configuration is shown in Table 1. Table 1 System Hardware Configuration 3 Software Configuration 3.1 C80-PEC/HPC Software Features and Functions The C80-PEC/HPC is a high-performance controller based on the Intel Architecture vxWorks real-time system. It is widely used in metallurgy, petroleum, coal, transportation, and other industries. It is powerful, has a user-friendly programming environment, uses advanced programming languages, and can install VMIC VME boards and PCMCIA/PMC expansion boards. It has the following advantages: (1) Fast response (400 µS for VDM6000); (2) Multiple processors can be installed (up to 4); (3) One processor can handle multiple resources; (4) Multiple loops of all tasks can be handled in one resource; (5) Priority can be automatically defined during program execution; (6) I/O signals can be simulated and modified; (7) System self-diagnosis; (8) Each processor can be connected to Ethernet. 3.2 System Architecture of C80-PEC/HPC The system architecture of C80-PEC/HPC is shown in Figure 2. Its main functions include: · TCP/IP service · Memory management · Resource management · Sycoreg tool · Automatic application startup script · Version management · Watchdog feature [align=center] Figure 2 System architecture of C80-PEC/HPC[/align] 3.3 Network structure of the system The network of this control system adopts a distributed local area network, including: ① Ethernet - to realize communication between HPC and engineering station, remote maintenance station, server, etc.; ② N80 network - to realize information communication between HPC and motor control center, main control console, auxiliary control console, solenoid valve, etc.; ③ CANBUS bus - to realize information communication between HPC and main drive and auxiliary drive systems; 3.4 Control software programming environment ① Engineering station adopts WINDOWS NT4.0 software platform; ② HPC adopts VX-WORKS real-time operating system; ③ HMI workstation adopts WONDERWARE INTOUCH7.1 programming environment; ④ C80-HPC programmable controller adopts P80C programming environment; 3.5 Control Method This system can achieve fully automatic control, manual control at the machine location, and screen display. Operators can also manually intervene during automatic control. 4. Control System Functions Pickling mainly involves treating the surface of strip steel with acids, alkalis, or other solutions. Its effectiveness directly affects the quality of the finished stainless steel product. This pickling system mainly consists of seven steps and has six control functions: 4.1 Steps: ① Pickling: Pickling the surface of the strip steel; ② Brushing: Brushing the surface of the strip steel with hot water; ③ Electrolyte Treatment: Treating the surface of the strip steel with an electrolyte solution; ④ Chemical Treatment: Adding appropriate chemical reagents to further treat the surface of the strip steel; ⑤ Pre-cleaning: Preliminary cleaning of the surface of the strip steel with clean water; ⑥ Final Cleaning: Final cleaning of the surface of the strip steel with hot water; ⑦ Drying: Drying the surface of the strip steel with hot air. 4.2 Control Functions: 4.2.1 Liquid Level and pH Control: Each tank in the pickling section is equipped with an automatic data acquisition unit. Based on the collected actual liquid level and pH value, the unit automatically opens or closes the inlet and outlet valves to adjust the liquid level and pH concentration of the solution within the tank to achieve the set values. 4.2.2 Temperature Control: The solutions (various acids, alkalis, and others) in each tank of the pickling section require a specific temperature. Therefore, the solution in the tank first undergoes a small circulation and is heated by a heater. This section of the program uses PID control to maintain a constant temperature, a simple and reliable method. 4.2.3 Electrolytic Cell Current Control: During electrolysis, the required electrolytic current varies depending on the steel grade and thickness. Therefore, the system can automatically adjust the electrolytic current based on preset settings. 4.2.4 Pickling Process Control: Various acids are pumped from the new acid tank to the corresponding tank, undergo a small circulation heating process, and once the set temperature is reached (i.e., temperature control), a large circulation process begins, pumping the acid into the pickling tank to treat the surface of the strip steel. When the sensor detects that the strip speed on the line is zero, the system immediately discharges the acid from the pickling tank into the main tank to prevent damage to the strip. 4.2.5 Brushing Process Control The brushing unit includes a brushing machine, brush rollers, and an encoder. At the start of brushing, the brush rollers move downwards, and the encoder measures the position of the brush rollers and sends the data to the computer. When the brush contacts the strip, the brush roller stops at this position, brushing the strip surface. The detection unit automatically detects the brushes; if the brushes have been worn down after prolonged use, the brush rollers automatically lift to the brush replacement position, requiring a new brush to be replaced. 4.2.6 Sewage Discharge Control The sewage discharge (sump pump) system is controlled by the liquid level. The sump pump is always running. When the liquid level is within the set range, it is a small circulation, i.e., self-circulation within the sump. When the liquid level is higher than the set value, it is a large circulation, i.e., discharging liquid externally. 5 Conclusion The entire production line successfully completed its trial run on the first attempt and quickly reached full production capacity within a week. All products met quality standards. This automatic control system is reliable, easy to operate, and highly automated, achieving fully automatic operation and meeting the expected results.