Method of controlling sliding nozzle device and plate used therefor

Abstract

A method of controlling a sliding nozzle device 10 and a plate 13 used therefor, even if operational conditions are changed, automatically optimizing sliding conditions of the device 10 , increasing a life of the plate 13 , and reducing a corrosion rate and a stroke length of the plate 13 . When the device 10 is controlled, if an average cumulative sliding rate of the plate 13 is outside a control range, a sliding rate of the plate 13 is changed within a preset range, thereby automatically optimizing the sliding conditions of the device 10 even with an operational condition change. Also, 3% to 20% of average sliding rate can reduce the corrosion rate of the plate 13 and drastically increase the life of the plate 13.

1 . A method of controlling a sliding nozzle device in order to control a flow of molten steel discharged from a ladle to a tundish in continuous casting, the method comprising:
 measuring a weight of molten steel in the tundish,   calculating a deviation between the measured value and a reference value of the weight of molten steel, and   outputting control signals at a predetermined cycle, the control signals controlling a sliding distance of a plate, based on the deviation and/or a change rate in the weight of molten steel in the tundish, wherein   an average cumulative sliding rate (%/minute) of the plate is calculated, and   if the average cumulative sliding rate (%/minute) of the plate is out of a preset control range, a sliding rate of the plate is changed within a predetermined setting range.   
     
     
         2 . The method of  claim 1 , wherein the control range for the average cumulative sliding rate of the plate is between 0.5%/minute and 18%/minute. 
     
     
         3 . The method of  claim 1 , wherein the predetermined setting range for the sliding rate of the plate is between 3% and 20%. 
     
     
         4 . A method of controlling a sliding nozzle device used with a ladle, wherein an average sliding rate of a plate included in the sliding nozzle device is between 3% and 20%. 
     
     
         5 . The method of  claim 4 , wherein the number of slides of the plate is between 10 times and 60 times per 60 minutes. 
     
     
         6 . The method of  claim 1 , wherein a stroke length of the plate is 1.5 times or more but less than 2 times a bore diameter of the nozzle provided in the plate. 
     
     
         7 . A plate used in the method of  claim 1 , having the stroke length of 1.5 times or more but less than 2 times the bore diameter of the nozzle. 
     
     
         8 . The method of  claim 4 , wherein a stroke length of the plate is 1.5 times or more but less than 2 times a bore diameter of the nozzle provided in the plate. 
     
     
         9 . A plate used in the method of  claim 4 , having the stroke length of 1.5 times or more but less than 2 times the bore diameter of the nozzle.