On Design Of Mold LeVel Control System For Continuous Caster

In the modern iron and steel industry,casting equipment has gradually become large-scale,multi-grade,efficient,high-yield and carbon-conscious.With the development of direct hot charging rolling,the demand on casting reliability and quality has been more and more severe.Mould liquid level control is one technology to insure liquid level stable on basis of pre-set height within the casting mold by adjusting casting speed and tundish steel stream pouring area,which is generally adopted.Mould liquid level control is a mostly important technoloy in metallurgical continuous casting system.Level fluctuation of molten metal will result in mould fluxes and impurity involved in molten steel,which will impact on casting blank quality and even lead to steel overflow and bleed-out accidents.Therefor,mold liquid level control has essential effect on improving billet quality,raising placing speed,energy saving and emission reduction as well as consumption reduction.This paper introduces the design and application of BAYI Iron and Steel CO.,LTD(hereinafter called BAYI Company)’s mold liquid level automatic control system according to the production process requirements of BAYI Company’S 150t converters that are equipped with a caster of ten strands.In consideration of output cost and slab quality,the final control approach is established in the design by speed adjustment level on ordinary steel smelting and by stopper control level.In the paper,continuous casting process is analyzed,mathematical model of automatic control is set as well as the caster control is designed and programmed by using traditional PID control approach.Besides,in order to ensure control system accuracy and response speed,liquid level detection system and stopper control mechanism are researched and designed in the paper.According to the practical data,the conclusion is made that level detection system adopts CS13 7 radiographic inspection equipment and stopper control stopper control mechanism adopts high precision servo electric cylinder.After the design is put into the production operation,level control accuracy can be limited within+5mm in most cases,which can satisfy production process requirements.However,the process requirements can not completely be met in some particular cases as a result of level fluctuation because there exist many uncertain disturbance factors which consist of mould level control system’s time-dela,time-variability nonlinear.