Improvement of Impeller Blade Structure for Gas Injection Refining under Mechanical Stirring  

Improvement of Impeller Blade Structure for Gas Injection Refining under Mechanical Sirring

作　　者：Yan LIU Zi-mu ZHANG Sano MASAMICHI Jun ZHANG Pin SHAO Ting-an ZHANG 

机构地区：[1]Key Laboratory of Ecological Utilization of Multi-metal Intergrown Ores of Ministry of Education,School of Materials and Metallurgy,Northeastern University [2]Nagoya University

出　　处：《Journal of Iron and Steel Research International》2014年第2期135-143,共9页

基　　金：Item Sponsored by National Natural Science Foundation of China(50974035,51074047);National High Technology Research and Development Program(863 Program)of China(2010AA03A405,2012AA062303);Innovation Team Project of Provincial Science and Technology of Liaoning Province of China(LT2010034)

摘　　要：Abstract： The impeller blade structure for gas injection refining under mechanical stirring has been explored by water model experiments. A sloped swept-back blade impeller is＇proposed for the purpose. The central part of the impeller is disk- or plate-shaped, and the blades are fitted to the side of the disk or plate. In addition, a disk is put on the top side of the impeller blades. The impeller can strengthen the radial and downward flow between the blades and weaken the swirl flow in the zone above the impeller. These effects on flow phenomena are favorable for disintegration and wide dispersion of bubbles which are injected from a nozzle attached to the center of the underside of the impeller. In addition, the sloped swept-back impeller requires less power consumption. The impeller shaft should be placed away from the vessel center so as to disperse the injected bubbles widely in the bath under mechanical stirring even with unidi- rectional impeller rotation and without installing baffles. The number of gas holes in the nozzle and the direction of gas injection have a little effect on the bubble disintegration and dispersion in the bath. Highly efficient gas injection refining can be established under the conditions of proper impeller size, larger nozzle immersion depth, larger eccen- tricity and rotation speed of the impeller. The sloped swept back blade impeller can decrease the power consumption and vet improve the bubble disintegration and wide dist^ersion in the bath.Abstract： The impeller blade structure for gas injection refining under mechanical stirring has been explored by water model experiments. A sloped swept-back blade impeller is＇proposed for the purpose. The central part of the impeller is disk- or plate-shaped, and the blades are fitted to the side of the disk or plate. In addition, a disk is put on the top side of the impeller blades. The impeller can strengthen the radial and downward flow between the blades and weaken the swirl flow in the zone above the impeller. These effects on flow phenomena are favorable for disintegration and wide dispersion of bubbles which are injected from a nozzle attached to the center of the underside of the impeller. In addition, the sloped swept-back impeller requires less power consumption. The impeller shaft should be placed away from the vessel center so as to disperse the injected bubbles widely in the bath under mechanical stirring even with unidi- rectional impeller rotation and without installing baffles. The number of gas holes in the nozzle and the direction of gas injection have a little effect on the bubble disintegration and dispersion in the bath. Highly efficient gas injection refining can be established under the conditions of proper impeller size, larger nozzle immersion depth, larger eccen- tricity and rotation speed of the impeller. The sloped swept back blade impeller can decrease the power consumption and vet improve the bubble disintegration and wide dist^ersion in the bath.

关 键 词：gas injection refining cold model eccentric mechanical stirring impeller structure power consump-tion bubble disintegration bubble dispersion 

分 类 号：TF30[冶金工程—冶金机械及自动化]