scholarly journals Optimization of hydrocyclon for phosphatic rock separation using CFD

Author(s):  
Felipe Orlando Da Costa ◽  
Felipe Leonardo Barcelos Mateus ◽  
Irineu Petri Júnior

Hydrocyclones are equipment for the separation of solid-liquid and liquid-liquid mixtures through the centrifugal flow. The phosphate rock is an essential raw material to the industry of phosphate fertilizers. The mineral needs to be concentrated in its processing, and this can be done through hydrocyclones, considering its robustness and low operation costs. This work aimed to use the computational fluid dynamics to study different multiphase models to represent the hydrocyclones, as well as modifications to its geometry to increase its efficiency. Three multiphase models were studied in order to analyze their efficiency in simulating the separation through hydrocyclones: Eulerian-Lagrangian, Eulerian-Eulerian, and Mixture Model. In order to optimize the separation process and reduce operating costs, 11 modifications were proposed in the geometry of HC11, called B1, B2, B3, C1, C2, C3, D1, D2, E1, E2 and E3. The first 8 proposals involved changes in the vortex finder and the last 3 proposals added a wall in the air core formation region. Geometry and mesh were generated in the GAMBIT® software and the simulation was made in the FLUENT® 19.2 software. In order to compare the multiphase models, the individual and overall efficiency were used along with the experimental results. The Mixture model had the smallest relative error and was used for the subsequent simulations. The parameters evaluated to measure the optimization of HC11 were the pressure drop (?P), the liquid ratio (RL) and the overall efficiency (?). The results obtained for each of the proposals were compared with the value found in the HC11 simulations to evaluate the possible optimization. With that, it was possible to verify that modifications B2, B3, and D1 improved all the parameters evaluated, optimizing the separation process and reducing energy costs involved in the operation.

Author(s):  
Gabriele Di Giacomo ◽  
Pietro Romano

AbstractWine fractionation is an old practice widely applied for many reasons, including the production of food-grade alcohol and spirits, alcohol-reduced wines and beverages, functional products, and aromas. The purpose is the need to satisfy different lifestyles and legal constraints. The raw material, usually called industrial wine, includes wine overproduction and wine not used as such: mainly table wine, the fermented juice of unsold table grapes, and quality wine. Three technologies are currently in use: Vacuum distillation, Reverse osmosis in dialyzing mode, and the Spinning cone column. The process developed in this work results from the integration of a multistage reverse osmosis section operating in dialyzing mode, with the Atmospheric distillation of the permeate stream; the two most applied technologies for fractionating liquid mixtures. This process allows the fractionation of the wine into four products (the vegetation water, the azeotropic Ethanol, a concentrated aqueous solution of the solid extract, and a concentrated alcoholic solution of volatile aroma compounds) while preserving sensorial, nutritional and functional properties of the individual compounds. Then, the proper recombination of these products gives rise to a wide variety of wine-based products to meet the specifications of each market segment. The process is environmentally friendly and, in comparison with the competitors, is less energy-intensive, other than resilient and flexible regarding the production potentiality.


2019 ◽  
Vol 24 ◽  
pp. 25-36
Author(s):  
H. Luma Fernandes Magalhães ◽  
E. Morais Cabral ◽  
T.E. da Silva Freitas ◽  
V.A. Agra Brandão ◽  
A.G. Barbosa de Lima ◽  
...  

Hydrocyclones are equipment that offer various advantages and have been the subject of studying for many researches related to separation processes of gas-solid, solid-liquid, and liquid-liquid mixtures. The purpose of this work is to study the oil-water separation process in a hydrocyclone by Computational Fluid Dynamics (CFD). Results of the pressure, velocity and volume fraction fields inside the device are presented and analyzed. It was possible to conclude that the proposed mathematical model was able to predict separation performance and the three-dimensional behavior of the phases flow analyzed (water/oil) in the hydrocyclone.


Mediaevistik ◽  
2018 ◽  
Vol 31 (1) ◽  
pp. 366-366
Author(s):  
Albrecht Classen

Eddic poetry constitutes one of the most important genres in Old Norse or Scandinavian literature and has been studied since the earliest time of modern-day philology. The progress we have made in that field is impressive, considering the many excellent editions and translations, not to mention the countless critical studies in monographs and articles. Nevertheless, there is always a great need to revisit, to summarize, to review, and to digest the knowledge gained so far. The present handbook intends to address all those goals and does so, to spell it out right away, exceedingly well. But in contrast to traditional concepts, the individual contributions constitute fully developed critical article, each with a specialized topic elucidating it as comprehensively as possible, and concluding with a section of notes. Those are kept very brief, but the volume rounds it all off with an inclusive, comprehensive bibliography. And there is also a very useful index at the end. At the beginning, we find, following the table of contents, a list of the contributors, unfortunately without emails, a list of translations and abbreviations of the titles of Eddic poems in the Codex Regius and then elsewhere, and a very insightful and pleasant introduction by Carolyne Larrington. She briefly introduces the genre and then summarizes the essential points made by the individual authors. The entire volume is based on the Eddic Network established by the three editors in 2012, and on two workshops held at St. John’s College, Oxford in 2013 and 2014.


2018 ◽  
Vol 69 (8) ◽  
pp. 2306-2310
Author(s):  
Aureliana Caraiane ◽  
Razvan Leata ◽  
Veronica Toba ◽  
Doina Vesa ◽  
Luana Andreea Macovei ◽  
...  

The progress made in dentistry during the latest decades is due, conceptually, to the new, systemic vision of man, which has also taken place in this field of medicine. In this context, the link between organic and psychic is indestructible. Thus illness is understood as a drama in which the somatic process has a psychic value, and the mental one has a body value. It is known that the morphological and functional integrity of the dental system, health and vigorousness, gives the individual a state of well-being that affects his somatic and psychic health, as any disturbance at this level entails repercussions in psychological and social behavior. Such a disruption is the total edification that seriously alters not only the dental system but the whole organism, putting various biological and psychosocial problems to the practitioner. The total expression represents not only a physical disability but also a psychological one. A special importance in studying psychological changes at total edentulous presents the psychological aspects of senile involution. This is not only a theoretical but also a practical importance due to the increase in the number of elderly people. Through the researches of the present paper we intend to present the reality of the psychological manifestations in the total edentation, which is objectified on different methods of psychodiagnosis in the first part, in order for the second part to be addressed to problems of prosthetic psychotherapy.The study comprises a group of 43 patients, of whom 24 were men and 19 women with total uni or bimaxilar edentation. Total edentation can be and is responsible for somatopsychic alterations, along with other pathogens, general, local, social, which sometimes can take a dramatic form, converting, where the area is also favorable, a pure somatic disease, for those who are not in psychopathy or even psychosis, although these latter cases are extremely rare and especially in youngsters, which would disrupt not only the person�s behavior as an individual, but also their status, function and social integrity. The treatment of dental and psychological complex is mandatory for any patient, but especially for the elderly, where recovery is more difficult, with disease-specific disorders adding to those of senescence.


Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 178
Author(s):  
Souhail Maazioui ◽  
Abderrahim Maazouz ◽  
Fayssal Benkhaldoun ◽  
Driss Ouazar ◽  
Khalid Lamnawar

Phosphate ore slurry is a suspension of insoluble particles of phosphate rock, the primary raw material for fertilizer and phosphoric acid, in a continuous phase of water. This suspension has a non-Newtonian flow behavior and exhibits yield stress as the shear rate tends toward zero. The suspended particles in the present study were assumed to be noncolloidal. Various grades and phosphate ore concentrations were chosen for this rheological investigation. We created some experimental protocols to determine the main characteristics of these complex fluids and established relevant rheological models with a view to simulate the numerical flow in a cylindrical pipeline. Rheograms of these slurries were obtained using a rotational rheometer and were accurately modeled with commonly used yield-pseudoplastic models. The results show that the concentration of solids in a solid–liquid mixture could be increased while maintaining a desired apparent viscosity. Finally, the design equations for the laminar pipe flow of yield pseudoplastics were investigated to highlight the role of rheological studies in this context.


Clean Energy ◽  
2020 ◽  
Author(s):  
Md Arman Arefin ◽  
Mohammad Towhidul Islam ◽  
Mohammad Zunaed ◽  
Khodadad Mostakim

Abstract Almost 80–90% of energy is wasted as heat (provides no value) in a photovoltaic (PV) panel. An integrated photovoltaic–thermal (PVT) system can utilize this energy and produce electricity simultaneously. In this research, through energy and exergy analysis, a novel design and methodology of a PVT system are studied and validated. Unlike the common methods, here the collector is located outside the PV panel and connected with pipes. Water passes over the top of the panel and then is forced to the collector by a pump. The effects of different water-mass flow rates on the PV panel and collector, individual and overall efficiency, mass loss, exergetic efficiency are examined experimentally. Results show that the overall efficiency of the system is around five times higher than the individual PV-panel efficiency. The forced circulation of water dropped the panel temperature and increased the panel efficiency by 0.8–1% and exergy by 0.6–1%, where the overall energy efficiency was ~81%.


2018 ◽  
Vol 882 ◽  
pp. 215-220
Author(s):  
Matthias Koppmann ◽  
Raphael Lechner ◽  
Tom Goßner ◽  
Markus Brautsch

Process cooling and air conditioning are becoming increasingly important in the industry. Refrigeration is still mostly accomplished with compression chillers, although alternative technologies are available on the market that can be more efficient for specific applications. Within the scope of the project “EffiCool” a technology toolbox is currently being developed, which is intended to assist industrials users in selecting energy efficient and eco-friendly cooling solutions. In order to assess different refrigeration options a consistent methodology was developed. The refrigeration technologies are assessed regarding their efficiency, CO2-emissions and primary energy consumption. For CCHP systems an exergetic allocation method was implemented. Two scenarios with A) a compression chiller and B) an absorption chiller coupled to a natural gas CHP system were calculated exemplarily, showing a greater overall efficiency for the CCHP system, although the individual COP of the chiller is considerably lower.


1986 ◽  
Vol 80 (7) ◽  
pp. 849-854
Author(s):  
E. Pell ◽  
L. E. Arend ◽  
G. T. Timberlake

Patients with age-related visual loss suffer reduced ability to recognize faces and other scenes in photographs and on television. Recently, progress has been made in image enhancement, using controlled distortion of digitally stored images that increases their usefulness in particular applications. Described are two approaches to image enhancement for the visually impaired. In one approach, the visual losses that characterize individual patients and disease classes are described using detailed measurements of visual degradation transfer functions, which are profiles of loss of image information at various spatial scales. The particular distortion used for image enhancement is then adjusted to the impairment of the individual patient or disease class. A second approach takes advantage of the resemblance between the visual losses of many patients and the degradation of picture information in other applications due to external limitations (e.g., fog and haze) on photography. Several enhancement algorithms have been found useful with such images and may also improve picture recognition by the visually impaired.


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