Simulation of the solid phase distribution and non-stationary heating of the reactive mass in the conversion apparatus

2020 ◽  
Author(s):  
A. S. Lavrov ◽  
A. P. Khomyakov ◽  
S. V. Mordanov
Keyword(s):  
Phase Distribution ◽  
Solid Phase ◽  
Stationary Heating

scholarly journals Influence of Sodium Sulfate Addition on Iron Grain Growth during Carbothermic Roasting of Red Mud Samples with Different Basicity

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1571
Author(s):  
Pavel Grudinsky ◽  
Dmitry Zinoveev ◽  
Denis Pankratov ◽  
Artem Semenov ◽  
Maria Panova ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Grain Growth ◽  
Red Mud ◽  
Sodium Sulfate ◽  
Phase Distribution ◽  
Solid Phase ◽  
Alumina Production ◽  
Metallic Particles ◽  
Iron Phase ◽  
High Alkalinity

Red mud is an iron-containing waste of alumina production with high alkalinity. A promising approach for its recycling is solid-phase carbothermic roasting in the presence of special additives followed by magnetic separation. The crucial factor of the separation of the obtained iron metallic particles from gangue is sufficiently large iron grains. This study focuses on the influence of Na2SO4 addition on iron grain growth during carbothermic roasting of two red mud samples with different (CaO + MgO)/(SiO2 + Al2O3) ratio of 0.46 and 1.21, respectively. Iron phase distribution in the red mud and roasted samples were investigated in detail by Mössbauer spectroscopy method. Based on thermodynamic calculations and results of multifactorial experiments, the optimal conditions for the roasting of the red mud samples with (CaO + MgO)/(SiO2 + Al2O3) ratio of 0.46 and 1.21 were duration of 180 min with the addition of 13.65% Na2SO4 at 1150 °C and 1350 °C followed by magnetic separation that led to 97% and 83.91% of iron recovery, as well as 51.6% and 83.7% of iron grade, respectively. The mechanism of sodium sulfate effect on iron grain growth was proposed. The results pointed out that Na2SO4 addition is unfavorable for the red mud carbothermic roasting compared with other alkaline sulfur-free additives.

Application of Support Vector Machine Modeling on Phase Distribution in the Riser of an LSCFB Reactor

2014 ◽  
Vol 12 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Shaikh A. Razzak ◽  
Muhammad I. Hossain ◽  
Syed M. Rahman ◽  
Mohammad M. Hossain
Keyword(s):  
Support Vector Machine ◽  
Circulating Fluidized Bed ◽  
Phase Distribution ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Absolute Error ◽  
Pilot Scale ◽  
Support Vector ◽  
Cross Sectional ◽  
Machine Modeling

Abstract Support vector machine (SVM) modeling approach is applied to predict the solids holdups distribution of a liquid–solid circulating fluidized bed (LSCFB) riser. The SVM model is developed/trained using experimental data collected from a pilot-scale LSCFB reactor. Two different size glass bead particles (500 μm (GB-500) and 1,290 μm (GB-1290)) are used as solid phase, and water is used as liquid phase. The trained model successfully predicted the experimental solids holdups of the LSCFB riser under different operating parameters. It is observed that the model predicted cross-sectional average of solids holdups in the axial directions and radial flow structure are well agreement with the experimental values. The goodness of the model prediction is verified by using different statistical performance indicators. For the both sizes of particles, the mean absolute error is found to be less than 5%. The correlation coefficients (0.998 for GB-500 and 0.994 for GB-1290) also show favorable indications of the suitability of SVM approach in predicting the solids holdup of the LSCFB system.

Bending theory for laminated composite cantilever beams with multiple embedded shape memory alloy layers

2019 ◽  
Vol 30 (10) ◽  
pp. 1549-1568 ◽  
Author(s):  
Nguyen Van Viet ◽  
Wael Zaki ◽  
Rehan Umer
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Numerical Solutions ◽  
Phase Distribution ◽  
Solid Phase ◽  
Axial Stress ◽  
Laminated Composite ◽  
Beam Theory ◽  
Cantilever Beams ◽  
Element Analysis

In this article, a new analytical model is proposed for laminated composite cantilever beams consisting of multiple alternating superelastic shape memory alloy and elastic layers. The model is based on the Zaki–Moumni model for shape memory alloys combined with Timoshenko’s beam theory. The Zaki–Moumni model accounts for solid phase transformation as well as detwinning and reorientation of martensite under multiaxial thermomechanical loading conditions. Mathematical formulas are first derived to characterize the evolution of the solid phase structure within the beam with a prescribed load at the tip during loading and unloading. Analytical moment–curvature and shear force–shear strain relations are then obtained following the strength of materials approach. The present work is the first to fully develop the nonlinear expressions of the axial stress in terms of the distance from the neutral plane and to allow the description of the phase distribution in both the longitudinal and the transverse directions in the beam as the load evolves. The proposed model is validated against finite element analysis and high-accuracy numerical solutions. The influence of temperature and the number of shape memory alloy layers on the superelastic behavior of the laminate is also investigated.

scholarly journals Investigation of the Primary Phase Segregation during the Filling of an Industrial Mold with Semi-Solid A357 Aluminum

2008 ◽  
Vol 141-143 ◽  
pp. 635-640 ◽  
Author(s):  
Frédéric Pineau ◽  
Geneviève Simard
Keyword(s):  
Phase Distribution ◽  
Solid Phase ◽  
Numerical Models ◽  
Phase Segregation ◽  
Homogeneous Distribution ◽  
Phase Interaction ◽  
Two Phase ◽  
Cast Part ◽  
Α Phase ◽  
Semi Solid

Casting metal alloys in the semi-solid state is now becoming a well established manufacturing technique. But, the success of this technology necessitates a good understanding of the feedstock material behaviour. To obtain high quality components with semi-solid metal processing, a homogeneous distribution of phases must be maintained in the material during the die filling stage. Many parameters affect the process such as temperature, time and stress history, which influence the shape, size and connectivity of the particles that make up the slurry. The subsequent phase interaction mechanisms are quite complex and have direct effects on the flow and final micro-structure distribution of the cast part and thus, without any doubt, on its mechanical properties. Two-phase numerical models have been developed to account for the liquid-solid phase separation e.g. [1,2]. Several two-phase models have been elaborated on the basis of soil mechanics and consider that the phase interaction term is mainly due to the flow through a porous medium. Because of the difficulties of making direct measurements in an extremely hostile environment, there has been very little work done to validate these models. In order to fill this gap, a better understanding of the phase distribution and phase segregation mechanisms during the filling step is required. In this work, the post-solidification primary α-phase distribution inside an industrial semi-solid cast part has thus been investigated. A thorough metallographic analysis has been performed using an upright microscope coupled to a Clemex image-analysis software. The results were then processed to produce a map of the final α-phase distribution. Many different grain scales have been observed in the solidified part and their distributions seem to be closely associated to the velocity field. Contacts between moving particles seem to play an important role in the phase distribution and show many similarities to granular materials. This latter aspect should be considered in the development of new constitutive models for semi-solid slurries.

scholarly journals Vertical distribution of brine and volume structure thin one year ice Amur bay on base NMR and MRT dates

2019 ◽  
Vol 59 (5) ◽  
pp. 859-869
Author(s):  
N. A. Mel’nichenko ◽  
A. V. Tyuveev ◽  
A. Yu. Lazaryuk ◽  
V. E. Savchenko ◽  
E. V. Kustova
Keyword(s):  
Sea Ice ◽  
Snow Cover ◽  
Air Temperature ◽  
Phase Distribution ◽  
Solid Phase ◽  
Empirical Relation ◽  
Amur Bay ◽  
Spatial Phase ◽  
Arctic Ice ◽  
One Year

It was studying distribution of liquid and solid phases in pores one year sea ice on Amur Bay with using NMR and MRT methods in period 20132016. According to findings predominant factor in ice structure formation is snow cover. The patterns of brine content and solid phase distribution are considered in interdependence with air temperature and corresponding ice layer temperatures in compliance with preceding weather conditions. Differences in vertical profiles for temperature and salinity for winter and spring periods was marked. The main features of spatial phase dictribution in thin ice in comparision Arctic ice are presented. Just snow cover effects on ice parameters was demonstrated using data 20132016. The relationship of interlayings number in ice with its thickness, air temperature, and snow cover thickness is discussed. The main features of spatial phase dictribution in thin ice in comparision Arctic ice are presented. The empirical relation for calculations thin sea ice thickness was suggested.

New Formulation of Tertiary Amines for Thermally Stable and Cost-Effective Chemical Additive: Synthesis Procedure and Displacement Tests for High-Temperature Tertiary Recovery in Steam Applications

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Randy Agra Pratama ◽  
Tayfun Babadagli
Keyword(s):  
Heavy Oil ◽  
Phase Distribution ◽  
Solid Phase ◽  
Steam Injection ◽  
Tertiary Amines ◽  
Residual Oil ◽  
Chemical Additive ◽  
Reversible Chemical Reaction ◽  
Tertiary Recovery ◽  
Phase Surface

Summary A newly formulated chemical additive from a group of amines has been tested and applied to in-situheavy oil thermal recovery. Switchable-hydrophilicity chemical additives were successfully synthesized from N,N-dimethylcyclohexylamine in the form of homogeneous and hydrophilic solution. Fundamentally, tertiary amines comprise functional groups of hydrophilic and hydrophobic components. These unique features enable this chemical additive to wet both water and heavy oil, yielding potential interfacial tension (IFT) improvement. Furthermore, the reversible chemical reaction of this chemical additive yields both positive and negative ions. An ion pair formed due to the adsorption of cations—[C8H17NH+]—on the surface of heavy oil, whereas the anions—[HCO3−]—promoted solid-phase surface charge modification, therefore, resulting in the repulsive forces between heavy oil and the rock surface—substantially improving water-wetness and restoring an irreversible wettability alteration due to the phase change phenomenon during steam injection. In this research, two types of heavy oil acquired from a field in western Alberta encompassing the viscosity of 5,616  and 46,140 cp at 25°C was utilized in each experiment. All experiments were performed and measured at high-pressure, high-temperature (HPHT) steam conditions up to 200 psi and 200°C. We perceived that favorable IFT reduction was achieved, and irreversible wettability could be restored after combining switchable-hydrophilicity tertiary amines (SHTA) with steam as a result of the solid-phase surface charge modification to be more negatively charged. Phase distribution/residual oil in the porous media developed after steam injection was able to be favorably recovered, indicating that capillary forces could be reduced. Consequently, more than 80% of the residual oil could be recuperated post-SHTA injection, presenting favorable oil recovery performance. In addition to this promising evidence, SHTA could be potentially recovered by switching its reversible chemical reaction to be in hydrophobic form, hence, promoting this chemical additive to be both reusable and more economically effective. Comprehensive studies and analyses on interfacial properties, phase distribution in porous media, and recovery performance exhibit essential points of view in further evaluating the potential of SHTA for tertiary recovery improvement. Valuable substantiations and findings provided by our research present useful information and recommendations for fields with steam injection applications.

Sign in / Sign up

Export Citation Format

Share Document