| 摘要 |
PURPOSE:To prolong the service life of a tuyere without using large quantity of cooling gas, by varying flow rate of cooling gas according to variation of temp. in an outer tube, in method in which cooling gas is passed through circular flow passage in the outer tube of a concentric double tube tuyere dipped in molten metal bath. CONSTITUTION:At a part of inner surface of the outer tube 2 of the tuyere 1, a linear groove 5 for inserting a rod thermocouple 4 is provided in tube axis direction, the couple 4 is set thereto drawably and insertably (up-and-down movement), and temp. is measured while lowering gradually the couple 4 according to the consumed extent of the tuyere 1. Flow rate of cooling gas passed through circular flow passage in the tube 2 is adjusted due to said temp. By this method, since tuyere temp. variation can be decreased by direct temp. measurment of the tube 2, effective suppression of erosion of tuyere itself and spalling of the vicinity bricks, and tuyere service life can be prolonged remarkably. |
