scholarly journals Physical Modelling of Aluminum Refining Process Conducted in Batch Reactor with Rotary Impeller

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 726 ◽  
Author(s):  
Mariola Saternus ◽  
Tomasz Merder
Keyword(s):  
Liquid Metal ◽  
Flow Rate ◽  
Batch Reactor ◽  
Physical Modelling ◽  
Processing Parameters ◽  
Refining Process ◽  
Impeller Speed ◽  
Water Model ◽  
Aluminum Production ◽  
Gas Dispersion

The refining process is one of the essential stages of aluminum production. Its main aim is to remove hydrogen, that causes porosity and weakens the mechanical and physical properties of casting aluminum. The process is mainly conducted by purging inert gas through the liquid metal, using rotary impellers. The geometry of the impellers and the processing parameters, such as flow rate of gas and rotary impeller speed, influence the gas dispersion level, and therefore the efficiency of the process. Improving the process, and optimization of parameters, can be done by physical modelling. In this paper, the research was carried out with the use of a water model of batch reactor, testing three different rotary impellers. Varied methods were used: visualization, which can help to evaluate the level of dispersion of gas bubbles in liquid metal; determination of residence time distribution (RTD) curves, which was obtained by measuring the conductivity of NaCl tracer in the fluid; and indirect studies, completed by measuring the content of dissolved oxygen in water to simulate hydrogen desorption. The research was carried out for different processing parameters, such as flow rate of refining gas (5–25 L·min−1) and rotary impeller speed (3.33–8.33 s−1). The obtained results were presented graphically and discussed in detail.

Physical Model of Aluminium Refining Process in the Batch and Continuous Reactors

2010 ◽  
Vol 654-656 ◽  
pp. 1553-1556 ◽  
Author(s):  
Mariola Saternus ◽  
Jan Botor
Keyword(s):  
Liquid Metal ◽  
Batch Reactor ◽  
Gas Bubbles ◽  
Physical Modelling ◽  
Processing Parameters ◽  
Refining Process ◽  
Continuous Reactor ◽  
Gas Dispersion ◽  
Uniform Dispersion ◽  
Over Dispersion

Both primary and secondary aluminium need to be refined. The most popular methods of aluminium refining is barbotage. This method is based on the introduction of refining gas bubbles into liquid metal. It can be done in batch or continuous reactors. The refining gas can be introduced to the metal by lances, ceramic porous plugs or rotary impellers. The gas bubbles generated in this way are then mixed with the liquid metal and the level of mixing depends on the processing parameters such as the flow rate of refining gas or the impeller speed. Five patterns of the refining gas dispersion in the liquid metal are known: no dispersion, minimal dispersion, intimate dispersion, uniform dispersion and over-dispersion. Physical modelling is the best way to visualize these kinds of dispersion. It also helps to choose the adequate processing parameters. However, it is also important to keep the dynamic and geometrical similarities to the refining process. In the paper the physical modelling of the aluminium refining process is presented. Two reactors: URO-200 batch reactor with a rotary impeller and URC-7000 continuous reactor with ceramic porous plugs were taken into consideration.

The Influence of the Impeller Shape on Hydrogen Removal from Liquid Aluminium - Physical Model

2012 ◽  
Vol 706-709 ◽  
pp. 1515-1520 ◽  
Author(s):  
Mariola Saternus
Keyword(s):  
Liquid Metal ◽  
Physical Modelling ◽  
Processing Parameters ◽  
Oxygen Removal ◽  
Test Stand ◽  
Liquid Aluminium ◽  
Gas Dispersion ◽  
Whole Process ◽  
Different Shapes ◽  
Rotary Speed

Today the barbotage process is commonly used for refining aluminium and its alloys. There are many refining reactors available all over the world. The refining gas can be introduced to the liquid metal by nozzles, ceramic porous plugs and rotary impellers. The last ones become the most popular. The shape of impellers is different and influences the level of gas dispersion in the liquid metal. Physical modelling is quite often used for modelling the aluminium barbotage process. In this way it is possible to observe the phenomena that take place in the whole process. Results obtained from this kind of research can be representative and transformed to real conditions if the test stand is built according to the theory of similarity. The test stand was built for modelling the refining process in the URO-200 reactor. Three different shapes of impellers were tested. The processing parameters like the flow rate of refining gas and the impeller rotary speed changed in the range from 5 to 15 dm3/min and from 0 to 500 rpm respectively. Additionally the research of oxygen removal from water was carried out as an analogy of hydrogen removal from liquid aluminium. The level of oxygen was measured by means of oxygen meter Elmetron CO-401. The obtained results were discussed and graphically presented.

scholarly journals Physical Modeling of the Impeller Construction Impact on the Aluminum Refining Process

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 575
Author(s):  
Mariola Saternus ◽  
Tomasz Merder
Keyword(s):  
Liquid Metal ◽  
Physical Modeling ◽  
Batch Reactor ◽  
Gas Bubbles ◽  
Processing Parameters ◽  
Refining Process ◽  
High Quality ◽  
Optimal Processing ◽  
Industrial Use ◽  
Selection Of

Obtaining high-quality aluminum is associated with the use of an effective method of refining, which is argon-purging, in which gas bubbles are introduced into the liquid metal by means of rotary impellers. Various rotary impellers are used in the industry; however, if a newly designed impeller is constructed, it should be tested prior to industrial use. For this purpose, physical modeling is used, which enables the investigation of the phenomena occurring during refining and the selection of optimal processing parameters without costly research carried out in the industry. The newly designed rotary impeller was tested on the physical model of a URO-200 batch reactor. The flow rate of refining gas was: 10, 15 and 20 dm3·min−1, whereas rotary impeller speed was 300, 400 and 500 rpm. The research consists of a visualization test showing the schemes of the gas bubbles’ dispersion level in the liquid metal and experiments for removing oxygen from water, which is an analogue of removing hydrogen from aluminum.

Numerical and Physical Modelling of Aluminium Refining Process Conducted in URO-200 Reactor

2012 ◽  
Vol 191 ◽  
pp. 3-12
Author(s):  
Mariola Saternus ◽  
Tomasz Merder
Keyword(s):  
Liquid Metal ◽  
Numerical Modelling ◽  
Volume Fraction ◽  
Physical Modelling ◽  
Calculation Model ◽  
Refining Process ◽  
Inert Gas ◽  
Gas Dispersion ◽  
Commercial Program ◽  
Small Bubbles

At present both primary and secondary aluminium needs to be refined before further treatment. This can be done by barbotage process, so blowing small bubbles of inert gas into liquid metal. This way harmful impurities especially hydrogen can be removed. Barbotage is very complex taking into consideration hydrodynamics of this process. Therefore modelling research is carried out to get to know the phenomena that take place during the process better. Two different modelling research can be applied: physical and numerical. Physical modelling gives possibility to determine the level of gas dispersion in the liquid metal. Whereas, numerical modelling shows the velocity field distribution, turbulent intensity and volume fraction of gas. The paper presents results of physical and numerical modelling of the refining process taking place in the bath reactor URO-200. Physical modelling was carried out for three different flow rate of refining gas: 5, 10 and 15 dm3/min and three different rotary impeller speeds: 0, 300, 500 rpm Commercial program in Computational Fluid Dynamics was used for numerical calculation. Model VOF (Volume of Fluid) was applied for modelling the multiphase flow. Obtained results were compared in order to verify the numerical settings and correctness of the choice.

scholarly journals The Influence of Impeller Geometry on the Gas Bubbles Dispersion in Uro-200 Reactor – RTD Curves / Wpływ Rodzaju Wirnika Na Dyspersję Pęcherzyków Gazowych W Reaktorze URO-200 – Krzywe Mieszania

2015 ◽  
Vol 60 (4) ◽  
pp. 2887-2894 ◽  
Author(s):  
M. Saternus ◽  
T. Merder ◽  
J. Pieprzyca
Keyword(s):  
Flow Rate ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Gas Bubbles ◽  
Refining Process ◽  
Inert Gas ◽  
Impeller Speed ◽  
Batch Reactors ◽  
Liquid Aluminium ◽  
Impeller Geometry

URO-200 reactor belongs to batch reactors used in refining process of aluminium and its alloys in polish foundries. The appropriate level of hydrogen removal from liquid aluminium can be obtained when the mixing of inert gas bubbles with liquid metal is uniform. Thus, the important role is played by the following parameters: flow rate of refining gas, geometry of the impeller, rotary impeller speed. The article presents the results of research conducted on physical model of URO-200 reactor. The NaCl tracer was introduced to water (modelling liquid aluminium) and then the conductivity was measured. Basing on the obtained results the Residence Time Distribution (RTD) curves were determined. The measurements were carried out for two different rotary impellers, flow rate equaled 5, 10, 15 and 20 dm3/min and rotary impeller speed from 250 to 400 rpm every 50 rpm.

The Study of Fire-extinguishing Process of Modelled Fire Seats

2021 ◽  
pp. 57-62
Author(s):  
V.N. Bordakov ◽  
Keyword(s):  
Flow Rate ◽  
Experimental Studies ◽  
Physical Modelling ◽  
Specific Flow Rate ◽  
Specific Flow ◽  
Acceptable Error ◽  
Fire Extinguishing ◽  
Fire Zone ◽  
Analysis Of Results ◽  
Fire Extinguishers

Test-fires to determine fire-extinguishers’ efficiency for extinguishing B class fires are conducted by operators equipped with working clothes, which does not comply with the requirements of physical modelling. This is why the ranks of extinguished modelled seats are significantly overestimated. The quantitative results of fire seats’ extinguishing can be comparatively evaluated in accordance with the value of specific flow rate of a fire-extinguishing agent. As it was detected, the specific flow rate of a fire-extinguishing agent does not actually depend on the rank of modelled fire seat when extinguished by an operator wearing thermal-protective clothes. At the same time, it is increasing along with the expansion of the fire zone scale in case the fire is extinguished without special protective clothes. Consequently, to increase the fire-extinguisher’s efficiency data reliability, the certifying tests should be conducted in conditions close to the real application conditions when the first person to firefight is not equipped with such special protective clothes. The experimental studies to determine the specific flow rate of a fire-extinguishing agent used modelled fire seats of various ranks. The analysis of results showed that the fire-extinguishers ensuring generation of drops of prevailing size more than 0,5 mm are required to extinguish the modelled sire seats. The degree of increasing flow rate for the fire-extinguishing agent to eliminate a fire and observation of a safe distance from the flame for an operator are conditioned by the scale of fire zone and affect the specific flow rate of agent required to ensure stable fire-extinguishing. Based on the results of extinguishing the fire seats «34В» or «55В», it is demonstrated that via using a correction factor it is possible, assuming an acceptable error, to evaluate the flow rate of fire-extinguishing agent to extinguish a modelled fire seat of any rank.

scholarly journals Effect of radial impeller size in the presence and absence of baffles on the copper exchange on zeolite NaX

2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Sandra Svilović ◽  
Marija Ćosić ◽  
Anita Bašić
Keyword(s):  
Power Consumption ◽  
Batch Reactor ◽  
Copper Ion ◽  
Impeller Speed ◽  
Zeolite Nax ◽  
Mixing Parameters ◽  
Initial Stage ◽  
Zeolite Particle ◽  
Exchange Kinetics ◽  
Copper Exchange

Effect of hydrodynamics on ion exchange in a batch reactor is still not appropriately studied even though proper mixing parameters may considerably affect the process of solid suspension and its costs. In this work, hydrodynamic conditions generated by straight blade turbine (SBT) impellers on suspension in the batch reactor with and without baffles were investigated. The aim of this work was to analyze influence of impeller diameter and zeolite mass on just suspended impeller speed, (NJS) power consumption, maximum amount of copper exchanged onto zeolite NaX and copper exchange kinetics as well. All experiments were conducted at the same temperature, initial concentration of the copper solution and zeolite particle size. The obtained results showed that just suspended impeller speed decreases as impeller diameter increases in the reactor with and without baffles but this trend is considerably more pronounced in the reactor with baffles. The increase in zeolite mass causes a slight increase of NJS in the both reactor. In the reactor with the baffles this increment became noticeably higher as impeller diameter decrease. Power consumption, at the state of complete zeolite suspension, decreases as impeller diameter increases and its values in the reactor without baffles are considerably lower as well. Kinetics results indicated that the amount of copper ion increases significantly in the initial stage and then gradually until the equilibrium is reached for all hydrodynamics conditions and mass of zeolite examined.

Arrays of Rotating Permanent Magnet Dipoles for Stirring and Pumping of Liquid Metals

2015 ◽  
Vol 15 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Andris Bojarevičs ◽  
Toms Beinerts ◽  
Mārtiņš Sarma ◽  
Yurii Gelfgat
Keyword(s):  
Liquid Metal ◽  
Permanent Magnet ◽  
Large Scale ◽  
Liquid Metals ◽  
Physical Modelling ◽  
Industrial Applications ◽  
Parameter Analysis ◽  
Wide Range ◽  
Metallurgical Furnaces ◽  
Multiple Configurations

AbstractMultiple configurations of synchronously rotating permanent magnet cylinders magnetized across the axes are proposed for liquid metal stirring for homogenization as well as for pumping. Universal analytical model is used for an initial parameter analysis. Then experimental setups were built to perform physical modelling of the industrial applications, e.g. large-scale metallurgical furnaces. Velocity distribution in the liquid metal was measured using different methods: the Ultrasound Doppler anemometry and the potential difference probes. The study shows that the cylindrical permanent magnet setups can achieve up to 10 times higher energy efficiency compared to AC inductors and have potential of wide-range industrial application, e.g. can be used as stirrers for secondary aluminium furnaces with up to 50 cm thick walls.

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