关键词: 顶吹, 扰流型喷枪, 两相流, 混合, 流型

Abstract: This paper focused on the design of tapered tube，converging diverging tube，spiral tube and the four-hole tube for gas-liquid two-phase flow mixing top-blowing experiments. The variations of flow patterns in the pipe of turbulent-spray gun were obtained. The experiment investigated the high-speed photography through the two-phase mixture of gas-liquid in the visualized special nozzle，the adjustment of volume flow in each phase，and visualization of the special flow patterns in different nozzles. The experimental results showed that the following：the flow pattern transition changed regularly with the changes in superficial gas velocity and superficial liquid velocity in all tubes except for the tapered tube；With the great change in section radius in the converging diverging tube，annular-churn flow could be easily produced，and typical bubble flow could also exist；under the influences of the axial velocity，spiral tube could have a high density of bubble flow pattern and annular flow and slug flow for a short period of time，and then form steady annular flow；the design of four-hole pipe was beneficial to two-phase flow of diesel-nitrogen mixture in metallurgical furnaces，the single bubble formed in this type of tube was smaller in diameter，resulting sufficiently scattered diesel fuel，the reduction reaction of slag layer was therefore more efficient with higher，reaction rate of magnetic iron in diesel.

Key words: top-blowing, turbulent-spray gun, two-phase flow, mixing, flow pattern