摘要 |
<p>PROBLEM TO BE SOLVED: To restrain the natural detachment of mud caused by hot blast at the time of shielding a blasting tuyere and to simply execute removal of the mud at the time of opening the shielded hole of the tuyere. SOLUTION: The blasting tuyere 1 in a blast furnace is shielded by using a bottomed annular reverse truncated conical refractory 2 having 3-20 mm thickness, 105-130 deg. angle between the bottom surface and the side surface and >=50 mm height and containing <=40 wt.% Al2 O3 and <=45 wt.% SiO2 , and the mud 3 to stick the bottomed annular reverse truncated conical refractory 2 to the inner surface of the blasting tuyere 1 through the mud. Particularly, since the furnace inner side of the blasting tuyere 1 is formed as a tapered-off truncated conical shape, deeper the insertion of the similar shape bottomed annular reverse truncated conical refractory 2 parallel to the tuyere axial direction, firmer the development of the pressed sticking to the mud filled into the gap between the bottomed annular reverse truncated conical refractory 2 and the blasting tuyere 1. Then, the natural detachment of the mud 3 caused by the hot blast, is restrained, and also, the shielding of the blasting tuyere 1 can be released in a short time.</p> |