Design and analysis on fume exhaust system of blackbody cavity sensor for continuously measuring molten steel temperature

Abstract

Fume exhaust system is the main component of the novel blackbody cavity sensor with a single layer tube, which removes the fume by gas flow along the exhaust pipe to keep the light path clean. However, the gas flow may break the conditions of blackbody cavity and results in the poor measurement accuracy. In this paper, we analyzed the influence of the gas flow on the temperature distribution of the measuring cavity, and then calculated the integrated effective emissivity of the non-isothermal cavity based on Monte-Carlo method, accordingly evaluated the sensor measurement accuracy, finally obtained the maximum allowable flow rate for various length of the exhaust pipe to meet the measurement accuracy. These results will help optimize the novel blackbody cavity sensor design and use it better for measuring the temperature of molten steel.

A Fast Response Sensor for Continuously Measuring Molten Steel Temperature

“…(2) In order to solve the cost problem, a blackbody cavity sensor has been developed, which is currently the most widely applied technology. [8][9][10] In detail, it dipped a measurement tube into molten steel with a certain depth, and then reached thermal equilibrium with molten steel to form an online blackbody cavity approximately. Meanwhile, it generates a stable infrared signal that is received by a probe for representing the temperature.…”

“…Meanwhile, it generates a stable infrared signal that is received by a probe for representing the temperature. To meet the demands of strong thermal shock resistance and corrosion resistance in the destructive environment, both of the above sensors almost use carbon-containing refractories, [5][6][7][8][9][10][11][12] such as Al 2 O 3 -C, MgO-C, and ZrO 2 -C. Al 2 O 3 -C refractory is the optimal practical material, which hasn't the hydration problem of MgO-C refractory and has lower price than ZrO 2 -C refractory.…”