Research And Application Of Tension Control In Continuous Annealing Furnace

Continuous annealing is application for an annealing processing line in BaoSteel, it request that the strip complete the heat treatment process from heating up to cooling down in a high speed, that need the strip run stably to maintain the continuity and high-quality. Strip tension is an important processing control parameter; the tension stabilization is a major factor for the continuous annealing and process line running stably and favorably and strip quality’s eligibility continuously. During the process of actual production, there are some nubble on the roll’s surface of heating furnace, it marked the strip’s surface, affected the strip’s quality.Based on the installed equipment, we analyze the reason thoroughly from the view of strip tension control, consider there is some limitation in the strip tension control method, it result in opposite friction between the strip and the furnace roll, the material of the strip adhere to the roll’s surface, then nubble engendered.Based on the traditional strip tension feed-back control, research and analyze the control idea and strategy of high function tension control system, then research the dependency of furnace roll in same tension control section, we set up the mathematic model of tension control by the furnace roll in a row, from the view of motor load stability, found the strategy to resolve the problem of tension fluency in a furnace section. We add the load reference ratio of furnace roll motor to the conventional strip tension feed-back control as a new control gene that is used to compensate the strip stretch between different roll in the same tension section for the heating in the furnace. We adopt the neural network control method to optimize the load reference parameter of the different motor, found out the optimized parameter group that is capable to use in the strip of no matter what kind and thickness, then came true through HITACHI’s R600 series PLC, achieved the goal of strip tension’s stabilization, solved the opposite friction problem between the strip and the furnace roll, abated the nubble engendered on the surface of furnace roll effectively, fulfill for the strip quality’s need of processing line.