RH真空室內氣泡行為的研究

趙立華; 郭建龍; 徐佳亮; 張超杰

doi:10.13374/j.issn2095-9389.2018.04.008

RH真空室內氣泡行為的研究

doi: 10.13374/j.issn2095-9389.2018.04.008

1) 北京科技大學冶金與生態工程學院, 北京 100083;
2) 北京科技大學鋼鐵冶金新技術國家重點實驗室, 北京 100083

基金項目:

國家自然科學基金資助項目(51404022)

詳細信息

中圖分類號: TF769.9
計量
- 文章訪問數: 832
- HTML全文瀏覽量: 422
- PDF下載量: 26
- 被引次數: 0
出版歷程
- 收稿日期: 2017-09-07

Complex bubble formation in the vacuum chamber and the up leg of the Rheinsahl-Heraeus

1) School of Metallurgy and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2) State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China

摘要

摘要: Ruhrstahl-Hereaeus (RH)上升管內的氣液兩相流是整個裝置的重要動力源,并對鋼液的流動、混勻及精煉過程有重要影響.上升管及真空室內的氣液兩相流決定了鋼包內鋼液的流動狀態,為了研究真空室及上升管內氣液兩相流,通過1:6的300 t RH的物理模型模擬了RH上升管及真空室內氣泡行為過程,并測量了RH循環流量的變化用于計算上升管內含氣率以及氣泡運動速度最終得到氣泡在真空室內的停留時間,同時記錄了氣泡在真空室內的存在形式.氣泡在真空室的存在形式的主要影響因素為提升氣體流量,研究發現了氣泡從規則獨立的大氣泡經歷聚合長大,碰撞破碎成小氣泡,最后變成小氣泡和不規則大氣泡共存的現象.液面高度達到80 mm之后,氣泡在真空室內的停留時間達到一個平衡值,不再隨真空室液面高度的增加而發生改變.當提升氣體量達3000 L·min^-1,氣泡停留時間減小趨勢弱,對應3000 L·min^-1情況下,真空室內氣泡開始聚合長大.研究認為對于300 t RH的真空室液面高度應為80 mm,提升氣體量應在3500 L·min^-1左右,優化后,脫碳時間由原工藝的21.4 min縮短至現工藝的17.5 min.
- RH精煉 /
- 氣泡行為 /
- 脫碳 /
- 真空室 /
- 含氣率
Abstract: The gas-liquid two-phase flow in the up leg of the Ruhrstahl-Hereaeus (RH) unit is one of the main momentum sources of the whole device, and it affects the flow state of the molten steel in the ladle. A physical model of 300 t RH in 1:6 ratio was set up to simulate the bubble behavior process and to measure the change of the RH circulation flow in the up leg and in the vacuum chamber. The gas-liquid fraction and the movement velocity of bubbles were measured to assess the residence time of the bubbles in the vacuum chamber. In addition, the formation of the bubbles at different values of the RH circulation flow and liquid-level height in the vacuum chamber were recorded by a high-speed camera. One of the main factors influencing the bubble formation is the increase of the lifting gas flow in the vacuum chamber. With the increase of blowing gas, the large independent bubbles undergo multiple collisions, break into small bubbles, and finally small and large irregular-sized bubbles coexist. When the liquid height is>80 mm, the residence time of the bubbles in the vacuum chamber achieves a stable value and cannot be further affected by the increase of the liquid-level height in the vacuum chamber. At a lifting gas flow of 3000 L·min^-1, a weak decreasing trend of the residence time of bubbles is observed, and the bubbles start polymerizing in the vacuum chamber. In conclusion, for the 300 t RH physical model, the liquid height in the vacuum chamber is recommended to be 80 mm, whereas the lifting gas flow should be set at 3500 L·min^-1. After these optimization steps, the decarburization time decreases from 21.4 to 17.5 min.
- Rheinsahl-Heraeus refining /
- bubble behaviors /
- decarburization /
- vacuum chamber /
- gas fraction

HTML全文

參考文獻(14)

[1]	Van Ende M A, Kim Y M, Cho M K, et al. A kinetic model for the ruhrstahl heraeus degassing process. Metall Mater Trans B, 2011, 42(3):477
[2]	Pande M M, Guo M X, Dumarey R, et al. Determination of steel cleanliness in ultra low carbon steel by pulse discrimination analysis-optical emission spectroscopy technique. ISIJ Int, 2011, 51(11):1778
[3]	Geng D Q, Lei H, He J C. Effect of traveling magnetic field on flow, mixing, decarburization and inclusion removal during RH refining process. ISIJ Int, 2012, 52(6):1036
[4]	Yamagauchi K, Kishimoto Y, Sakuraya T, et al. Effect of refining conditions for ultra low carbon steel on decarburization reaction in RH degasser. ISIJ Int, 1992, 32(1):126
[6]	Neves L, de Oliveira H P O, Tavares R P. Evaluation of the effects of gas injection in the vaccum chamber of a RH degasser on melt circulation and decarburization rates. ISIJ Int, 2009, 49(8):1141
[7]	Zhang L F, Li F. Investigation on the fluid flow and mixing phenomena in a Ruhrstahl-Heraeus (RH) steel degasser using physical modeling. JOM, 2014, 66(7):1227
[8]	Bello R A, Robinson C W, Moo-Young M. Gas holdup and overall volumetric oxygen transfer coefficient in airlift contactors. Biotechnol Bioeng, 1985, 27(3):369
[9]	Siegel M H, Merchuk J C. Mass transfer in a rectangular air lift reactor:effect of geometry and gas recirculation. Biotechnol Bioeng, 1988, 32(9):1128
[10]	Kitamura S Y, Aoki H, Miyamoto K I, et al. Development of a novel degassing process consisting with single large immersion snorkel and a bottom bubbling ladle. ISIJ Int, 2000, 40(5):455
[11]	Uemura K, Takahashi M, Koyama S, et al. Production of ultralow carbon steel by RH degasser. Kobe Res Dev Jpn, 1991, 41(4):24
[12]	Takahashi M, Matsumoto H, Saito T. Mechanism of decarburization in RH degasser. ISIJ Int, 1995, 35(12):1452
[13]	Olivieri G, Marzocchella A, van Ommen J R, et al. Local and global hydrodynamics in a two-phase internal loop airlift. Chem Eng Sci, 2007, 62(24):7068
[14]	Sano M, Mori K. Size of bubbles in energetic gas injection into liquid metal. Trans ISIJ, 1980, 20(10):675
[15]	Zhang D Z, Prosperetti A. Averaged questions for inviscid disperse two-phase flow. J Fluid Mech, 1994, 267:185