Upper nozzle/plate integral unit and method of splitting the same

Abstract

Disclosed is an upper nozzle/plate integral unit comprising an upper nozzle and an upper plate integrated together, which is capable of being easily split into the upper nozzle and the upper plate after use, while adequately maintaining a thickness of a joint between the upper nozzle and the upper plate during use. A metal casing 4 is bent inwardly along an outer peripheral surface of a lower end portion of an alumina carbon-based refractory body of the upper nozzle 1 to form a metal member. The metal member formed by bending the metal casing 4 inwardly has a length of 15 mm. A gap between the metal casing and the refractory body is filled with mortar having a thickness of about 0.5 mm. A recess 11 of the lower end portion of the upper nozzle 1 is fitted onto a raised portion 21 of the upper plate 2 through mortar, and the metal casing 4 of the upper nozzle 1 is in contact with a metal casing of the upper plate 2 . A peripheral edge of the metal casing of the upper plate 2 is fixedly joined to the metal casing 4 of the upper nozzle 1 through a plurality of welded portions 6.

1 . An upper nozzle/plate integral unit capable of being split into an upper nozzle and an upper plate and detached from a molten metal vessel, after use, wherein:
 said upper nozzle is in contact with said upper plate through a joint material, in such a manner that respective nozzle holes of said upper nozzle and said upper plate are aligned with each other;   said upper nozzle has a metal member provided on a lower end portion thereof; and   said upper plate has a metal sheet provided on an upper surface thereof,   wherein said metal member of said upper nozzle is weldingly joined to said metal sheet of said upper plate at two or more positions, in such a manner that a weld leg is set in the range of 2 to 5 mm, and a total weld length is set in the range of 5 to 60 mm.   
   
   
       2 . The upper nozzle/plate integral unit as defined in  claim 1 , wherein a product (W) of said weld leg (S [mm]) and said total weld length (L 2  [mm]) is set in the range of 25 to 300. 
   
   
       3 . The upper nozzle/plate integral unit as defined in  claim 1  or  2 , which is installed in a detachable-type sliding nozzle assembly. 
   
   
       4 . A method of splitting the upper nozzle/plate integral unit as defined in  claim 3 , comprising:
 interposing a hydraulic ram cylinder between the detachable-type sliding nozzle assembly and the molten metal vessel; and   moving said hydraulic ram cylinder in such a manner that said detachable-type sliding nozzle assembly is detached from said molten metal vessel while splitting said upper nozzle/plate integral unit into said upper nozzle and said upper plate.   
   
   
       5 . A method of splitting the upper nozzle/plate integral unit as defined in  claim 1  or  2 , comprising:
 providing a retaining metal frame formed with a concave portion having a crowbar insertion groove; and   inserting a crowbar into said crowbar insertion groove, and moving said crowbar to scoop out said upper plate, so as to split said upper nozzle/plate integral unit into said upper nozzle and said upper plate.