Discussion on automatic control system of cold rolling pickling unit
Abstract.：Cold-rolled steel is a kind of production raw materials widely used at present, and its product production quality and production efficiency have been widely concerned and highly valued by all walks of life. Pickling units are used to clean the iron oxide on the surface of cold-rolled steel, and the optimization of its performance is an important basis for ensuring the quality of cold-rolled steel products.This paper mainly describes the basic content of cold rolling pickling unit，In order to ensure the smooth progress of all production activities, the automatic control system is analyzed comprehensively，Lay the foundation for the realization of sustainable development goals of the industry。
1、Basic overview of cold rolling pickling unit
In the process of steel production, in order to improve the production quality and production efficiency of steel products, pickling process is very necessary. Pickling unit is an important equipment for pickling steel, and the automatic control system of the unit mainly includes digital transmission, sensor instrumentation and a separate HMI system. When controlling its operations, most of the standard 4-level control strategies are adopted to ensure the smooth implementation of various operations and lay the foundation for the improvement of the overall benefit of the enterprise.
2、Analysis of automatic control system of cold rolling pickling unit
At this stage, the steel pickling work has been highly concerned by various enterprises, different forms of pickling units in the practical application of operating costs and operating efficiency are not the same, with the continuous development of science and technology and wide application, cold rolling pickling unit automation control system is widely used in the manufacturing process of enterprises, its use standard is divided into 4 levels of control, The field level is 0, the basic automation level is 1, the process automation control level is 2, and the production execution control level is 3. The control system includes a separate HMI system with sensor instrumentation and digital drives, while the main control functions of the basic automation level include entry control, strip tension, strip speed, strip tracking process and exit control.
2.1 An overview of entry segment control
As an important part of the basic automatic control system, the work quality and efficiency of the inlet section control have an important impact on the industrial development, and its work content is mainly the sequence control of the main steel coil transportation, pickling inlet and the inlet looping control. Among them, the pickling inlet sequence control includes steel coil from pre-uncoiling position to uncoiling machine, lead automatic threading to waiting position and guide plate, lead automatic cutting, tail automatic cutting, tail automatic dumping to welding machine, strip welding and other contents; The inlet looper control mainly refers to the prediction and setting of empty sleeve and maximum sleeve according to relevant data in the pickling process, so as to ensure the scientific, rational and effective of each operation link to the greatest extent.
2.2 Overview of strip tension control
In pickling unit, strip tension control is divided into rated tension control, temporary stop tension control and strip tension control. Among them, the main purpose of rated tension control is to enhance the safety and reliability of the transportation process, and the tension pre-set value is transmitted to the uncoiler transmission system through the HMI system. The temporary parking tension is automatically given by the control system after the delay when the unit stops temporarily, and its tension value is about 30% of the rated tension. The wearing tension should generally be controlled to 30% of the rated tension.
2.3 Overview of strip speed control
In the pickling unit, the strip speed control is mainly to control the speed of the inlet section, the process section and the export section, and the scientific, rational and effective control has an important impact on the production quality and production efficiency of various operations of the enterprise to a certain extent. In addition, in order to ensure the smooth implementation of various operations, the speed of the entrance section should be set before the completion of the strip welding work.
2.4 An overview of strip tracking control
In the basic automatic control system, strip tracking control mainly includes looping control and coil tracking. The main function of looper control in strip tracking is to monitor the looper position and calculate the predetermined value of the looper position according to the speed and acceleration of the strip at the entrance and exit. Tracking steel coils includes processing data such as coil number, width, thickness, elongation, etc.
2.5 Overview of technical control in process section
The technical control of the process section is mainly the control of the disc shear. In order to ensure that the scrap shear has a certain traction speed, the speed of the disc shear unit should be less than the speed of the scrap shear.
3、peroration
With the continuous acceleration of urbanization and industrialization in recent years, the demand for cold-rolled steel is also rising, in order to fundamentally improve the production quality and production efficiency of steel plates, pickling treatment is very necessary. As an important equipment of pickling process, the automatic control level of pickling unit has been highly valued by all sectors of society. Practice has proved that only by ensuring the scientific and reasonable operation of each control system of the unit can we ensure the smooth implementation of the pickling process and lay the foundation for the further development of the enterprise.
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