scholarly journals Mathematical Models for the Novel Cathode Convexes in a Reduction Cell

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Z. He ◽  
T. Xia ◽  
W. Xiong ◽  
Q. Shen ◽  
B. Li

A less magnitude of liquid aluminum deformation is required to shorten the anode-cathode distance so as to lower the electric energy consumption of the aluminum reduction cell. A mathematical model aimed to describe the electrolyte/aluminum two-phase flow in reduction cells, based on the computational fluid dynamics method, was developed to study the impacts of the cathode convexes on the electrolyte/aluminum interface deformation. The results showed that the magnitude of the two-phase interface deformation was reduced for about 17.2% with the novel cathode convexes; while at the same time, the washout of the melt on the ledge was also enhanced.

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 110 ◽  
Author(s):  
Fuqiang Wang ◽  
Qinsong Zhang ◽  
Wei Liu ◽  
Youjian Yang ◽  
Zhaowen Wang

Many researchers have investigated the impact factors of the bath–metal flow in an aluminum reduction cell using the simulation method. However, only a few have coupled their models with transient electromagnetic force, which makes the model closer to realistic conditions. In this work, coupling with the transient electromagnetic force, a three dimensional bath–metal two-phase quasi-steady flow model for a full 500 kA cell was built, and the model was validated with the metal velocity and the bath–metal interface deformation measurement in industrial cells. The impacts of local cathode electrical cut-off (LCEC) on the melt flow field were simulated according to six industrial cases. We found that the LCEC has little impact on the general pattern of the melt flow field, but the local metal velocity and the interface deformation would be changed to a certain extent. LCEC at positions A2A3 and A10A11 (as introduced in the full text) could suppress the interface hump at the central downstream area of the cell, with the anode cathode distance (ACD) increased by 3% and 7.5%, respectively. LCEC at positions A18A19 and A22A23 would deteriorate the interface hump condition, with the ACD decreased by 4% and 3%, respectively. The solution given in this paper is to cut the cathode flexes partially at abnormal positions to stabilize the melt flow field.


2012 ◽  
Vol 535-537 ◽  
pp. 2044-2048
Author(s):  
Shu Ping Wang ◽  
Ya Jing Song

The power spectrum method of frequency domain is presented in this paper for analyzing the four states of aluminum reduction cell (that is the normal condition, the liquid aluminum fluctuation, the abnormally low polar distance or drop of an anode and the anodic long bud), the characteristics of frequency domain under circumstances of function and malfunction and pointing out that groove resistance simulation analysis provide reliable basis for fault detection of aluminum reduction cell.


Author(s):  
Naijun Zhou ◽  
Yuqing Xue ◽  
John J J Chen ◽  
Mark.P. Taylor

In the production process of aluminium reduction cells, the anode bubble laden layer has several important influences on the performance of the aluminium reduction cells. Especially for a "drained cathode cell", without the agitating of movement of the melted metal, the bath flow field could be more important. In this paper, the electrolyte two-phase flow fields were studied by using numerically simulation method based on a two-phase turbulence model combining the k - ? model and the Discrete Random Walk model. The results show that: the motion of the bubbles mostly exists within a thin layer under the anode, which results in inducing local electrolyte to flow around the anode in various circulation flows; the flow field in the anode-cathode space can be divided into three regions with different characters; the results also show the Driving action of bubbles is closely related to the current density, inclination of anode and the anode-cathode distance. In general, the increasing in the current density increases the electrolyte velocity and the turbulent kinetic energy. The decrease in ACD significantly enhances the uniformity of the electrolyte flow field in the anode-cathode space. The increase in anode inclination angle increases the velocity of the electrolyte in the anode-cathode space, which would be beneficial to improving the diffusion and dissolution of the alumina and reducing the resistance between the anode and cathode.


2012 ◽  
Vol 7 (3) ◽  
pp. 23-32 ◽  
Author(s):  
Miloslav Bagoňa ◽  
Dušan Katunský ◽  
Martin Lopušniak ◽  
Marián Vertaľ

JOM ◽  
2014 ◽  
Vol 66 (7) ◽  
pp. 1202-1209 ◽  
Author(s):  
Liu Yan ◽  
Li Yudong ◽  
Zhang Ting’an ◽  
Feng Naixiang

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 851
Author(s):  
Heng Ma ◽  
Huiyun Tian ◽  
Juncheng Xin ◽  
Zhongyu Cui

Electrochemical H charging, hydrogen permeation, and hydrogen-induced cracking (HIC) behavior of 690 MPa grade steel substrate and different heat-treatment states (annealed, quenched, normalized, tempered) are investigated by cyclic voltammetry (CV), hydrogen permeation, electrochemical H charging, and slow strain rate tensile test (SSRT). The results show that hydrogen diffuses through the steel with the highest rate in base metal and the lowest rate in annealed steel. The hydrogen-induced cracks in base metal show obvious step shape with tiny cracks near the main crack. The cracks of annealed steel are mainly distributed along pearlite. The crack propagation of quenched steel is mainly transgranular, while the hydrogen-induced crack propagation of tempered steel is along the prior austenite grain boundary. HIC sensitivity of base metal is the lowest due to its fine homogeneous grain structure, small hydrogen diffusion coefficient, and small hydrogen diffusion rate. There are many hydrogen traps in annealed steel, such as the two-phase interface which provides accommodation sites for H atoms and increases the HIC susceptibility.


2021 ◽  
Vol 13 (8) ◽  
pp. 4180
Author(s):  
Andrzej Czerepicki ◽  
Tomasz Krukowicz ◽  
Anna Górka ◽  
Jarosław Szustek

The article presents an analysis of priority solutions for trams at a selected sequence of intersections in Warsaw (Poland). An analysis of the literature has shown the topicality of this issue. A computer simulation model of a coordinated sequence of intersections was constructed. Three test scenarios were designed: the existing control system, the new coordinated fixed-time control system, and the adaptive control system with active priority. In the simulation process, detailed travel characteristics of trams and other traffic participants in a selected section were obtained for the three varying scenarios. Electric energy consumption for traction needs and pollutant emissions was then estimated for each of the variants. It was concluded that for the analyzed configuration, implementation of the adaptive priority will result in a reduction of tram time losses by up to 25%, a reduction in energy consumption by up to 23%, and a reduction in the emission of pollutants from individual vehicles by up to 3% in relation to the original variant. The conducted research may be the basis for a comprehensive method of assessing the effectiveness of applying the adaptative priority when designing new tramway lines and modernizing the existing ones.


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