The Process Mechanism Analysis And Control Method Research Of Steel-Making Bottom Blowing Argon

The bottom blowing argon technology is an important technology in LF refining furnace for the secondary refining.It has great significance to enhance the quality of steel. At present,the workers operate bottom blowing argon equipment to manipulate the flow of argon gas through their experience in our country.This increases ratio of lapsus and decreases work efficiency.The laggard monitor,control and management mechanism can't meet the request of the vield and development of science and technology.Today. precision,convenience,and real time control become the developing trend of bottom blowing argon control,along with the progress of intelligent control.Combining with the actual production status,the paper has analvzed the forming process of the refining bottom of the orifice argon blowing bubbles,and found on the flow of argon gas impacted the bubble formation mechanism.In view of the fact that bubble buoyancy do work on liquid steel,establishing the mixing model of bottom argon blowing. it can be found that the stirring effect of bottom blowing argon can be measured by the scale that the flux insufflated.Adopting water-modeling method,the molten steel fluid and mixing characteristics under the different operating modes in bottom blowing argon process of LF refining furnace were investigated.It may be concluded that under the condition of bottom blowing argon,mixing time shorten with argon flux increasing,but the system has a critical argon flux,when bevond the value,it start to appear that the molten steel surface fiercely,fluctuates and slag is entrapped.Recommendations in a blender for the purpose of blowing refining stage should be used double porous plug bricks 180°symmetrical lavout,every road argon flux in the best control at 200L/min,can achieve good mixing effects and less entrapped slag phenomenon.Through the theoretical analysis and experiment to regulating valve,the result has amended its hysteretic loop characteristic between the incoming signal and the displacement,reaching a basis for the fast and steady control.Further,by the process that researching and analyzing the plant,finally deducing a mechanism model.And then working out its parameter by the experiment and validating its correctness again. Afterward.adopting traditional PID method,pole assignment method based on U model and the method that the former be used in conjunction with the latter to control the plant. their respective control effect can be found by the simulation and analvsis.At last,it be proved that the method joined together is the best. Moreover,this system has a good human-machine interface,including the main pictures,real-time curve:history curve,journaling figure,as well as part of the alarm.It can execute dynamic management of supervisory parameter,create report forms automatically,run at random,and it can he rectified and expanded easily.Computer simulation studies and practical applications prove that the system realizes real-time monitor and survey and dynamic management,and it improves the level of monitor and control of bottom blowing argon.