Design Of Control System Based On PLC For Bright Annealing Furnace

With the rapid development of steel industry, stainless steel requires different types of polishing to create brightness of the material, which requires special process. It is common knowledge that steel oxidizes in the atmosphere, leaving the surface with a layer of oxidation, which is usually removed by pickling after anneal, sometimes polishing and grinding. The acid used in pickling is one of the major causes of environmental pollution. How to reduce or remove these polluting-processes has been urged by demands of environmental protection. To obtain shiny stainless steel, bright annealing is indispensable, which brings up the question of how to find out a better way to set the stainless steel strip to the appropriate annealing temperature, and controlling the heat and cooling rate to afterward as needed. Maintaining a precise temperature throughout the timeline of the annealing process is the key to the performance and mechanical properties of the strip, including the quality of good flatness and brightness of the surface. Therefore, the improvement of control system for bright annealing furnace is important and meaningful.This thesis is based on the design and debugging of the control system of bright annealing furnace in a steel plant. The practical work is summarized, refined, and combined with the actual situation of the project. Following works has been done. First, through the analysis of the configuration and function of the main equipment of bright annealing furnace designed the reasonable control solutions under the basic principles of industrial design planning. At the same time, it introduces the temperature control, and the strategies of the double cross limit and flow compensation, and provided the theory evidences of the follow-up control function. Secondly, detailed description of the hardware configuration of the control system has been made and the network architecture and the main equipment of the automation system are introduced. Through the analysis of the subsystem of the PLC control system, the programming of PLC and WinCC configuration software are completed. Thirdly, debug results are obtained through the collection of real-time process data. Finally, the control system of the project is summarized and the significance of the control mode and the research results are discussed.