Experimental study of induced airflow characteristics during liquid metal pouring process through PIV, thermography, and color schlieren imaging

Abstract

Contaminated airflows are frequently generated during various liquid-metal pouring processes in industrial plants. An in-depth understanding of the induced airflow characteristics is necessary to develop an energy-saving ventilation system. In this study, the airflow characteristics induced by liquid metal pouring were investigated experimentally. The results indicate that the time-averaged velocity distribution of induced airflow at different pouring heights Z/r’ essentially follow Gaussian curves and that the influence range of the dimensionless horizontal velocity of the induced airflow is 0–2.5 at a Z/r’ of 0 to −3 with the maximum pouring flow rate. The angle Ф between the mainstream movement direction and the horizontal plane is approximately 85° based on the streamline variations. In addition, the temperature attenuation of the induced airflow approximately follows an exponential decay, and the dimensionless horizontal influence range of the temperature is almost four times that of the velocity. Moreover, the air mass formation and contaminated airflow generation process are illustrated, and the temperature peak of the induced airflow at the pouring cup outlet is explained in terms of the air mass generation. By combining the air mass position S* and dimensionless air mass diameter D* variations, it is demonstrated that the polluted airflow generation function is similar to a trigonometric function during the pouring period. In summary, the obtained conclusions can assist in the design of high-efficiency ventilation systems and in reducing energy consumption in industrial plants.