refractory, prefers styrror intended to be fitted in veggen in a metallurgical furnace

摘要

An air-cooled refractory guide tube for insertion in the wall of a metallurgical furnace to permit reciprocal movement of an elongated rod-shaped member into and out of the interior of the furnace through a central orifice extending through the tube. The guide tube consists of a metal part and a refractory part, with the metal part including means for directing compressed air through the central orifice of the refractory part and for independently directing air through a series of cooling orifices extending through the ceramic part. Upon the ceramic part being consumed in use, the metal part can be reused. By controlling the rate of flow of cooling air through the ceramic part, its melting rate can be kept equal to that of the furnace wall.