Abstract: 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.

Abstract: A system for measuring the temperature of the walls of a metallurgical furnace employs a temperature measuring rod mounted for reciprocal movement in an aperture in the furnace wall from an extended position projecting into the interior of the furnace to a withdrawn position. Cyclic reciprocating movement is imparted to the rod by an actuating mechanism, mounted on the furnace wall and including a double acting fluid motor and a servomechanism. The actuating device includes an articulated mounting mechanism permitting the device to be positioned by pivotal movement about two mutually perpendicular axes whereby alignment difficulties on rebuilding the furnace wall are eliminated. Means are also provided for quickly disconnecting the servomechanism to facilitate manual positioning of the measuring rod.