Chop gate and nozzle

Abstract

A shop gate and a nozzle are suitable for being coupled with the bottom floor of a tundish, said nozzle comprising a hollow tube with an axial bore extending from an inlet opening at a first end of the nozzle to an opposite outlet opening at or adjacent the second, opposite end, and comprising a flange extending substantially normal to the axis of the tube and located between said first and second ends, characterized in that the flange comprises a lower, guiding surface facing towards the second end of the tube, said guiding surface being flat and substantially normal to the tube.

I claim: 
     
         1 - 15 . (canceled) 
     
     
         16 . Chop gate device comprising a frame defining an upper portion, a mid portion, and a lower portion, and further comprising
 (a) a nozzle comprising a hollow tube with an axial bore extending from an inlet opening at a first end of the nozzle to an opposite outlet opening at or adjacent the second, opposite end, and comprising a flange extending substantially normal to the axis of the tube and located between said first and second ends, thus defining a first, inner nozzle portion extending from the flange and the inlet and a second, outer nozzle portion extending from the flange to the outlet, wherein the flange comprises a top, clamping surface facing towards the first, inner nozzle portion, and a lower, guiding surface facing towards the second, outer nozzle portion, said guiding surface being flat and substantially normal to the tube, said nozzle being coupled to the frame such that the first inner portion extends above the frame upper portion, the flange is clamped to the frame mid portion by a clamp, and the second, outer portion extends below the frame lower portion,   (b) a chopper comprising a plate defining a first and second opposite major surfaces separated by the thickness of the plate, and a sharp chopping leading edge, said plate being slidingly mounted in the frame lower portion, such that the first main, sealing surface thereof is parallel to and contacts the flange guiding surface of the nozzle, and such that the chopping leading edge is configured to contact one side of the second, outer portion of the nozzle and is configured to be driven parallel to the flange guiding surface across to the other side of the second outer portion; and   (c) a pusher configured to force the chopping leading edge through the second outer portion of the nozzle and thus sever it off from the nozzle flange and first inner portion, such that the first main surface of the chopping plate seals the bore at the level of the flange guiding surface.   
     
     
         17 . Chop gate device according to  claim 16 , comprising a presser resiliently pressing on the chopper to form a tight and sealing contact between the chopper sealing surface and the flange guiding surface. 
     
     
         18 . Chop gate device according to  claim 16 , comprising a clamp configured to applying a clamping force onto the flange clamping surface and configured to fix in place the nozzle to a receiving surface of the frame. 
     
     
         19 . Chop gate device according to  claim 18 , wherein the clamp comprises three clamping elements, the centroids of said three clamping elements forming the summits of a triangle having two summits on either side of the diameter of the cross section of the axial bore passing by the third summit and wherein the nozzle clamping surface comprises three separate support rims jutting out and distributed around the perimeter of the tube, which centroid form a triangle which summits match the summits of the triangle formed by the clamping elements. 
     
     
         20 . Chop gate device according to  claim 16 , wherein the outer nozzle portion comprises a weakening notch at the interface between the flange guiding surface and the second outer portion, leveled with the leading edge of the chopper. 
     
     
         21 . Chop gate device according to  claim 18 , wherein the flange clamping surface of the nozzle is slanted, reducing the thickness of the flange away from the tube. 
     
     
         22 . Tundish comprising a chop gate device according to  claim 16 , wherein the chop gate device is fixed to the outside of the bottom floor of the tundish, such that the first inner portion of the nozzle protrudes through an opening in the floor of the tundish and is embedded within the refractory layer lining the inner walls of the tundish. 
     
     
         23 . Nozzle suitable for being used in the chop gate device of  claim 16 , said nozzle comprising a hollow tube with an axial bore extending from an inlet opening at a first end of the nozzle to an opposite outlet opening at or adjacent the second, opposite end, and comprising a flange extending substantially normal to the axis of the tube and located between said first and second ends, thus defining a first, inner nozzle portion extending from the flange and the inlet and a second, outer nozzle portion extending from the flange to the outlet, wherein the flange comprises a top, clamping surface facing towards the first, inner nozzle portion, and a lower, guiding surface facing towards the second, outer nozzle portion, said guiding surface being flat and substantially normal to the tube, wherein the outer nozzle portion comprises a weakening notch at the interface between the flange guiding surface and the second outer portion. 
     
     
         24 . Nozzle according to  claim 23 , wherein the flange clamping surface is slanted, reducing the thickness of the flange away from the tube. 
     
     
         25 . Nozzle according to  claim 23 , wherein the second, outer portion forms a shroud nozzle and the outlet is formed by at least one window opening to ambient and being distributed around the peripheral wall of the second outer portion adjacent the second end thereof. 
     
     
         26 . Nozzle according to  claim 23 , wherein the second outer portion forms a pouring nozzle and the outlet opens axially at the second end of said second outer portion. 
     
     
         27 . Nozzle according to  claim 23 , wherein the weakening notch extends around substantially the whole perimeter of the outer nozzle portion. 
     
     
         28 . Nozzle according to  claim 23 , wherein the nozzle clamping surface comprises three separate support rims jutting out and distributed around the perimeter of the tube, the centroids of said three support rims forming the summits of a triangle having two summits on either side of the diameter of the cross section of the axial bore passing by the third summit. 
     
     
         29 . Nozzle according to  claim 23 , wherein the flange is partly clad with a metal casing with the exception of the guiding surface. 
     
     
         30 . Nozzle according to  claim 28 , wherein the three separate support rims are part of the metal casing. 
     
     
         31 . Chop gate device of  claim 21 , wherein the slanting angle is comprised between 30 and 60° with respect to horizontal. 
     
     
         32 . Chop gate device of  claim 21 , wherein the clamping means apply a clamping force substantially normal to the slanting clamping surface of the flange. 
     
     
         33 . Nozzle according to  claim 24 , wherein the slanting angle is comprised between 30 and 60° with respect to horizontal. 
     
     
         34 . Nozzle according to  claim 25 , wherein the outlet comprises pairs of opposed windows.