scholarly journals DEM Investigation of the Influence of Particulate Properties and Operating Conditions on the Mixing Process in Rotary Drums: Part 2—Process Validation and Experimental Study

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 184 ◽  
Author(s):  
Jakub Hlosta ◽  
Lucie Jezerská ◽  
Jiří Rozbroj ◽  
David Žurovec ◽  
Jan Nečas ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Spherical Particles ◽  
Industrial Processes ◽  
Homogeneity Index ◽  
Mixing Process ◽  
Process Validation ◽  
Relative Standard ◽  
Rotary Drum ◽  
Mixture Homogeneity ◽  
Filling Capacity

The process of homogenization of particulates is an indispensable part of many industrial processes, and, therefore, it is necessary to pay a special attention to this area and develop it. This paper deals with a complex study of homogenization of particulate matters in a rotary drum in terms of shape, size, and density of particles. In addition, the influence of operating parameters, such as drum filling capacity, rotational speed, and drum filling pattern are also investigated. Studies of reproducibility of discrete element method simulations, effects of rotary drum sizes or effects of drum volumetric filling to the mixture homogeneity index were also carried out. In general, the least satisfactory values of the homogeneity index resulted from the mixing of particles with different densities. The dominating factor of homogenization was the drum filling-up degree. The course of the homogeneity index in 140, 280, and 420 mm drums was very similar and after five revolutions of the drum, identical values of the homogeneity index were achieved for all the drum diameters. The optimal drum filling-up degree is at 40–50% for the spherical particles and 30–40% for the sharp-edged particles. The repeatability of simulations showed the maximum relative standard deviation of the homogeneity index at 0.6% from ten simulation repetitions with the same parametric conditions.

scholarly journals Systematic Experimental Investigation of Segregation Direction and Layer Inversion in Binary Liquid-Fluidized Bed

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 177
Author(s):  
Alberto Di Renzo ◽  
Giacomo Rito ◽  
Francesco P. Di Maio
Keyword(s):  
Experimental Investigation ◽  
Operating Conditions ◽  
Industrial Processes ◽  
Process Unit ◽  
Separation Processes ◽  
Solids Concentration ◽  
Expansion Range ◽  
Surface Expansion ◽  
Density Ratios ◽  
Inversion Phenomenon

Multi-component liquid-fluidized beds are encountered in a variety of industrial processes. Often, segregation severely affects the performance of the process unit. Unfortunately, size-driven and density-driven separation processes may occur with a complex interplay, showing prevailing mechanisms that change with the operating conditions. For example, when the solids exhibit contrasting differences in size and density, even the direction of segregation can turn out hard to predict, giving rise for some systems to the so-called “layer inversion phenomenon”. A systematic experimental investigation is presented on 14 different binary beds composed of glass beads and ABS spheres with different size and density ratios and different bed composition. The analysis allows assessing the reliability of a model for predicting the segregation direction of fluidized binary beds (the Particle Segregation Model, PSM). By measurements of the solids’ concentration at the surface, expansion/segregation properties and the inversion voidage are compared with the PSM predictions, offering a direct means of model validation. Both the segregation direction throughout the expansion range and the value of the inversion voidage are compared. Extensive qualitative agreement is obtained for 12 out of 14 fluidized mixtures. Quantitatively, the average discrepancy between predicted and measured inversion voidage is below 5%, with a maximum of 17%.

scholarly journals Reliability of the Determinations of Polychlorinated Contaminants (Biphenyls, Dioxins, Furans)

1996 ◽  
Vol 79 (3) ◽  
pp. 589-621 ◽  
Author(s):  
William Horwitz ◽  
Richard Albert
Keyword(s):  
Performance Studies ◽  
Detection System ◽  
Operating Conditions ◽  
Mass Spectrometers ◽  
Common Reference ◽  
Ring Compounds ◽  
Interlaboratory Variability ◽  
Dioxins And Furans ◽  
Relative Standard ◽  
Good Laboratory

Abstract Precision performance parameters from results of 34 interlaboratory performance studies of polychlorinated aromatic ring compounds (biphenyls, dioxins, and furans) (PCCs) have been recalculated by using the International Union of Pure and Applied Chemistry-1987 harmonized protocol. Most studies of 1052 test samples, 56 analytes, 19 matrixes, and 2 types of detectors (electron capture and mass spectrometers) provide among-laborato- ries relative standard deviations (RSDRs), that are considerably better than those predicted from the Horwitz equation at fractional concentrations of 10−6 down to 10−15. The explanation suggested is that supplying common reference calibration solutions, as was done in many of these studies, does not reflect realistic operating conditions. Furthermore, the ability to repeat, discuss, and reassess aberrant reported values results in underestimating the true RSDR. The commonly reported problems of preparation of standard calibrating solutions, instability of the detection system, and failure to follow quality control instructions and good laboratory practices may be important sources of interlaboratory variability in PCC determinations

scholarly journals Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 2: Two-Phase Ejectors

Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 16 ◽  
Author(s):  
Zine Aidoun ◽  
Khaled Ameur ◽  
Mehdi Falsafioon ◽  
Messaoud Badache
Keyword(s):  
Heat Pumps ◽  
Operating Conditions ◽  
Industrial Processes ◽  
Experimental Investigations ◽  
Mixing Enhancement ◽  
Data Generation ◽  
Two Phase ◽  
Wide Range ◽  
Potential Applications ◽  
And Performance

Two-phase ejectors play a major role as refrigerant expansion devices in vapor compression systems and can find potential applications in many other industrial processes. As a result, they have become a focus of attention for the last few decades from the scientific community, not only for the expansion work recovery in a wide range of refrigeration and heat pump cycles but also in industrial processes as entrainment and mixing enhancement agents. This review provides relevant findings and trends, characterizing the design, operation and performance of the two-phase ejector as a component. Effects of geometry, operating conditions and the main developments in terms of theoretical and experimental approaches, rating methods and applications are discussed in detail. Ejector expansion refrigeration cycles (EERC) as well as the related theoretical and experimental research are reported. New and other relevant cycle combinations proposed in the recent literature are organized under theoretical and experimental headings by refrigerant types and/or by chronology whenever appropriate and systematically commented. This review brings out the fact that theoretical ejector and cycle studies outnumber experimental investigations and data generation. More emerging numerical studies of two-phase ejectors are a positive step, which has to be further supported by more validation work.

scholarly journals Student’s-t Mixture Regression-Based Robust Soft Sensor Development for Multimode Industrial Processes

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3968 ◽  
Author(s):  
Jingbo Wang ◽  
Weiming Shao ◽  
Zhihuan Song
Keyword(s):  
Learning Algorithm ◽  
Real Life ◽  
Industrial Process ◽  
Soft Sensor ◽  
Operating Conditions ◽  
Industrial Processes ◽  
Computationally Efficient ◽  
Mixture Regression ◽  
Student’S T ◽  
T Distribution

Because of multiple manufacturing phases or operating conditions, a great many industrial processes work with multiple modes. In addition, it is inevitable that some measurements of industrial variables obtained through hardware sensors are incorrectly observed, recorded or imported into databases, resulting in the dataset available for statistic analysis being contaminated by outliers. Unfortunately, these outliers are difficult to recognize and remove completely. These process characteristics and dataset imperfections impose challenges on developing high-accuracy soft sensors. To resolve this problem, the Student’s-t mixture regression (SMR) is proposed to develop a robust soft sensor for multimode industrial processes. In the SMR, for each mixing component, the Student’s-t distribution is used instead of the Gaussian distribution to model secondary variables, and the functional relationship between secondary and primary variables is explicitly considered. Based on the model structure of the SMR, a computationally efficient parameter-learning algorithm is also developed for SMR. Results conducted on two cases including a numerical example and a real-life industrial process demonstrate the effectiveness and feasibility of the proposed approach.

scholarly journals Hybrid Optimization Methodology (Exergy/Pinch) and Application on a Simple Process

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3324 ◽  
Author(s):  
Bou Malham ◽  
Zoughaib ◽  
Tinoco ◽  
Schuhler
Keyword(s):  
Process Design ◽  
Exergy Analysis ◽  
Operating Conditions ◽  
Hybrid Optimization ◽  
Industrial Processes ◽  
Pinch Analysis ◽  
Optimal Operating ◽  
And Topology ◽  
Optimization Methodology

In the light of the alarming impending energy scene, energy efficiency and exergy efficiency are unmistakably gathering momentum. Among efficient process design methodologies, literature suggests pinch analysis and exergy analysis as two powerful thermodynamic methods, each showing certain drawbacks, however. In this perspective, this article puts forward a methodology that couples pinch and exergy analysis in a way to surpass their individual limitations in the aim of generating optimal operating conditions and topology for industrial processes. Using new optimizing exergy‐based criteria, exergy analysis is used not only to assess the exergy but also to guide the potential improvements in industrial processes structure and operating conditions. And while pinch analysis considers only heat integration to satisfy existent needs, the proposed methodology allows including other forms of recoverable exergy and explores new synergy pathways through conversion systems. A simple case study is proposed to demonstrate the applicability and efficiency of the proposed method.

Numerical Simulation of Turbulent Mixing for Dislocated Blades in a Stirred Tank

2011 ◽  
Vol 354-355 ◽  
pp. 559-563
Author(s):  
Lei Shi ◽  
Shen Jie Zhou ◽  
Feng Ling Yang ◽  
Fan Jin Hu
Keyword(s):  
Numerical Simulation ◽  
Turbulent Mixing ◽  
Stirred Tank ◽  
Industrial Processes ◽  
Mixing Efficiency ◽  
Mixing Process ◽  
Flow Number ◽  
Stirred Tanks ◽  
Calculation Results ◽  
Better Than

Mixing efficiency is an important parameter in the design of many industrial processes in stirred tanks. In this study, CFD technology was used to simulate the mixing process inside the stirred tank with dislocated blades and standard turbine. Calculations were performed to study the effects of agitator speed and the configuration of impellers on mixing efficiency. The results showed that the flow field in the stirred tank with the dislocated blades is better than the standard turbine, and the flow number of the dislocated blades had been improved while the power number had been reduced. According to calculation results of Wr, we found the mixing efficiency of the dislocated blades had been improved about 4 times than that of standard turbine.

Suppression of Selective Volatilization in a Method for the Spectrographic Analysis of Lanthanum

1966 ◽  
Vol 20 (2) ◽  
pp. 107-112 ◽  
Author(s):  
A. B. Whitehead ◽  
B. C. Piper ◽  
H. H. Heady
Keyword(s):  
Standard Deviation ◽  
Rare Earths ◽  
Analytical Method ◽  
Operating Conditions ◽  
Spectrographic Analysis ◽  
Metal Sample ◽  
Relative Standard ◽  
Arc Current ◽  
Impurity Elements ◽  
Dc Arc

The effects of electrode type, arc current, and the Stallwood Jet on selective distillation of impurities other than rare earths in La2O3 are evaluated. Selective volatilization is reduced by use of a 20-A dc arc with a ⅛-in.-diam electrode. An analytical method incorporating these operating conditions is presented for 19 impurity elements in La2O3 prepared from the lanthanum metal sample. The overall precision is about ±14% relative standard deviation over the concentration range of 30 to 1000 parts per million.

Low-Temperature Electrothermal Vaporization of 8-Hydroxyquinolinate Complex for Determination of Trace Vanadium by ICP-AES

1996 ◽  
Vol 50 (6) ◽  
pp. 785-789 ◽  
Author(s):  
Shiquan Tao ◽  
Takahiro Kumamaru
Keyword(s):  
Low Temperature ◽  
Operating Conditions ◽  
Sample Introduction ◽  
Sample Solution ◽  
Heating Process ◽  
Electrothermal Vaporization ◽  
Foreign Ions ◽  
Relative Standard ◽  
Certified Values

A trace amount of vanadium was vaporized as 8-hydroxyquinolinate complex by using a low-temperature tungsten boat furnace for sample introduction in ICP-AES. Experimental results suggest that vanadium was vaporized as vanadium(III) 8-hydroxyquinolinate complex. Vanadium(V) and vanadium(IV) were reduced in the heating process before vaporization. The operating conditions were optimized, and the effects of foreign ions were investigated. The existence of tin(II) ion in sample solution was found to enhance the emission intensity of vanadium, improve the precision of the proposed method, and also suppress the interferences from other foreign ions. The detection limit in the presence of 5 μg tin(II) was determined to be 4 pg, and in the absence of tin(II), 7 pg, of vanadium. Sub-μg L−1 levels of vanadium in sample solution could be determined by the proposed method. The precisions in relative standard deviation (% RSD) for 100 pg of vanadium under the same conditions described above were 1.9% and 4.1%, respectively. The contents of vanadium in some standard steel and rock samples determined by the proposed method were in good agreement with their certified values.

scholarly journals Mechanical and thermal segregation of milli-beads during contact heating in a rotary drum. DEM modeling and simulation.

2018 ◽  
Author(s):  
Aline Mesnier ◽  
Maroua Rouabah ◽  
C. Cogné ◽  
Roman Peczalski ◽  
Séverine Vessot-Crastes ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Standard Deviation ◽  
Operating Conditions ◽  
Contact Heat ◽  
Segregation Index ◽  
Dem Simulation ◽  
Contact Heating ◽  
Particulate Solid ◽  
Rotary Drum ◽  
Horizontal Drum

The flow mechanics and heat transfer phenomena within a bed of milli-metric size spherical beads rotated and heated by contact in a horizontal drum were simulated by means of commercial discrete element software EDEM. Mono-dispersed and bi-dispersed beds (two particle sizes or two particle densities) were considered. The mechanical segregation index (standard deviation of local bed compositions) and the thermal segregation index (standard deviation of beads temperatures) were calculated for the different types of bed and same operating conditions. The thermal segregation was found to be enhanced by mechanical segregation and was much stronger for bi-dispersed beds than for monodispersed one.   Keywords: rotating drum; particulate solid; segregation; contact heat transfer; DEM simulation. 

Sign in / Sign up

Export Citation Format

Share Document