关键词: 气液两相流, 分布, 搅拌容器, 混合, 成像

Abstract: The oxygen-enriched bottom-blowing smelting process is taken as research object. In order to measure and compare the local mixing characteristics in the bottom-blowing stirred reactor,the grayscale intensity was obtained based on field images of bubble perturbation. According to the actual size of bottom-blowing copper melting furnace,the test platform for water model of gas blowing was built. By watching high-speed videos of experimental process at different design parameters,the field RGB images of water model above the nozzles were captured and saved. Only the area undisturbed by apparatus was extracted as the study area. Finally,the grayscale intensity average and standard deviation of green component can be obtained. It was found that the green component of bubble RGB images extracted the contour features of actual bubble images more than other grayed images at our experimental conditions. The horizontal profiles of green component present obvious single apex and double peak,corresponding to the operating conditions of single-line nozzle and double-line nozzles,respectively. These results proved the validity of grayscale intensity for characterizing the mixing process. The mean and standard deviation time series of grayscale intensity in study area were calculated. Results showed that most times series follow Gaussian distributions statistically at the dynamic equilibrium stage of the bath. This work provides some academic bases and references on pushing the research about adopting image analysis techniques to investigate flow and mixing in the bottom-blowing stirred reactors.

Key words: gas-liquid flow, distributions, stirred vessel, mixing, imaging