scholarly journals Ultrahigh-Temperature Continuous Reactors Based on Electrothermal Fluidized Bed Concept

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Sergiy S. Fedorov ◽  
Upendra Singh Rohatgi ◽  
Igor V. Barsukov ◽  
Mykhailo V. Gubynskyi ◽  
Michelle G. Barsukov ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Electrical Resistance ◽  
Specific Electrical Resistance ◽  
Natural Graphite ◽  
Operating Variable ◽  
The Difference ◽  
Ultrahigh Temperature ◽  
Chaotic Nature ◽  
Functional Prototype ◽  
Dynamics Models

Authors introduce an ultrahigh-temperature (i.e., 2500–3000 °C) continuous fluidized bed furnace, in which the key operating variable is specific electrical resistance of the bed. A correlation has been established to predict the specific electrical resistance for the natural graphite-based precursors. Fluid dynamics models have been validated with the data from a fully functional prototype reactor. Data collected demonstrated that the difference between the calculated and measured values of specific resistance is approximately 25%; due to chaotic nature of electrothermal fluidized bed processes, this discrepancy was deemed acceptable. Optimizations proposed allow producing natural graphite-based end product with the purity level of 99.98 + wt. %C for battery markets.

A method for measuring the residence time distribution of particles in a fluidized bed based on digital image analysis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jiamin Li ◽  
Xiaoping Chen ◽  
Jiliang Ma ◽  
Cai Liang
Keyword(s):  
Image Analysis ◽  
Fluidized Bed ◽  
Residence Time ◽  
Digital Image ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Digital Image Analysis ◽  
Color Space ◽  
The Difference ◽  
Accuracy And Repeatability

AbstractTraditional methods for measuring the residence time distribution (RTD) of particles in a fluidized bed are complex and time-consuming. To this regard, the present work proposes a new measurement method with remarkable efficiency based on digital image analysis. The dyed tracers are recognized in the images of the samples due to the difference of colors from bed materials. The HSV and the well-known RGB color space were employed to distinguish the tracers. By enhancing the Saturation and the Value in HSV and adjusting the gray range of images, the recognition error is effectively reduced. Then the pixels representing the tracers are distinguished, based on which the concentration of the tracers and RTD are measured. The efficiency, accuracy and repeatability of the method were validated by RTD measurements experiments. The method is also fit for distinguishing the target particles from multi-component systems consisting of particles of different colors.

Forecasting Performance of Ceramic Cutting Tool

2017 ◽  
Vol 736 ◽  
pp. 86-90 ◽  
Author(s):  
Vyacheslav Maksarov ◽  
A. Khalimonenko
Keyword(s):  
Electrical Resistance ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Tool Material ◽  
Ceramic Materials ◽  
Specific Electrical Resistance ◽  
Testing Methods ◽  
Microstructural Parameters ◽  
Forecasting Performance ◽  
Nondestructive Testing Methods

The article considers the problems of forecasting the performance of cutting tools equipped with replaceable ceramic cutting bits. It is proposed to forecast the operability of ceramic tools on the ground of dependence between its performance characteristics and the microstructural parameters of the tool material. It is proposed to determine the parameters of ceramic bits microstructure by a nondestructive testing methods based on measuring the specific electrical resistance of ceramic materials. As a result of the study we have undertaken, a relationship was detected between the performance and specific electrical resistance of ceramic cutting tools.

scholarly journals Hydrodynamic analysis of a liquid-solid fluidized bed via cfd-dem simulations, stability analysis, and tomography

2021 ◽  
Author(s):  
Hussein Zbib
Keyword(s):  
Stability Analysis ◽  
Fluidized Bed ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Percentage Error ◽  
Particle Interactions ◽  
Particle Volume ◽  
Computational Fluid Dynamics Cfd ◽  
The Difference ◽  
Dem Model

A coupled computational fluid dynamics (CFD) and discrete element method (DEM) model was developed to analyze the fluid-particle and particle-particle interactions in a 3D liquid-solid fluidized bed (LSFB). The CFD-DEM model was validated using the Electrical Resistance Tomography (ERT) experimental method. ERT was employed to measure the bed-averaged particle volume fraction (BPVF) of 0.002 m glass beads fluidized with water for various particle numbers and flow rates. It was found that simulations employing the combination of the Gidaspow drag model with pressure gradient and virtual mass forces provided the least percentage error between experiments and simulations. It was also found that contact parameters must be calibrated to account for the particles being wet. The difference between simulations and experiments was 4.74%. The CFD-DEM model was also employed alongside stability analysis to investigate the hydrodynamic behavior within the LSFB and the intermediate flow regime for all cases studied.

scholarly journals A Method For Determination Of Specific Electrical Resistance Of Steel And Nano-Coating Sputtered On It

2015 ◽  
Vol 2 ◽  
pp. 118 ◽  
Author(s):  
Andris Martinovs ◽  
Josef Timmerberg ◽  
Konstantins Savkovs ◽  
Aleksandrs Urbahs ◽  
Paul Beckmann
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Permeability ◽  
Electrical Resistance ◽  
Skin Effect ◽  
Specific Electrical Resistance ◽  
Specific Electrical Conductivity ◽  
Relative Magnetic Permeability ◽  
Nano Coating ◽  
Cylindrical Steel

The paper describes methods developed to determine specific electrical conductivity and relative magnetic permeability of cylindrical steel items and nano-coatings deposited on them by sputtering. Research enables development of a new method for determination of thickness of vacuum deposited nano- coating that is based on application of skin effect.

scholarly journals Heat transfer to a moving wire immersed in a gas fluidized bed furnace

2021 ◽  
Author(s):  
Antonio Tannas
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Steel Wire ◽  
Transfer Rates ◽  
New Correlation ◽  
Bed Temperature ◽  
Molten Lead ◽  
The Difference ◽  
Considerable Work ◽  
Work Done

In order to replace hazardous molten lead baths in the heat treatment of carbon steel wire with environmentally friendly fluidized bed furnaces a better understanding is needed of their heat transfer rates. There has been considerable work done in examining heat transfer rates to large cylinders immersed in fluidized beds, and some on wire sized ones as well, but all previous studies have been conducted on static cylinders. In order to gain a deeper understanding of heat transfer rates to a moving wire immersed in a fluidized bed furnace an apparatus has been constructed to move a wire through a fluidized bed. The heat transfer rates were calculated using the difference in inlet and outlet temperatures, wire speed and the bed temperature. As predicted, correlations for static wire were found to under-predict heat transfer rates at higher wire speeds, so a new correlation was developed by modifying an existing one.

Full scale fluidized bed anaerobic reactor for domestic wastewater treatment: performance, sludge production and biofilm

2004 ◽  
Vol 49 (11-12) ◽  
pp. 319-325 ◽  
Author(s):  
N.M. Mendonça ◽  
C.L. Niciura ◽  
E.P. Gianotti ◽  
J.R. Campos
Keyword(s):  
Wastewater Treatment ◽  
Fluidized Bed ◽  
Methanogenic Archaea ◽  
Domestic Wastewater ◽  
Full Scale ◽  
Anaerobic Reactor ◽  
Sulfate Reducing ◽  
Domestic Wastewater Treatment ◽  
The Difference ◽  
Sludge Production

This paper describes the performance, sludge production and biofilm characteristics of a full scale fluidized bed anaerobic reactor (32 m3) for domestic wastewater treatment. The reactor was operated with 10.5 m.h-1 upflow velocity, 3.2 h hydraulic retention time, and recirculation ratio of 0.85 and it presented removal efficiencies of 71 ± 8% of COD and 77 ± 14% of TSS. During the apparent steady-state period, specific sludge production and sludge age in the reactor were (0.116 ± 0.033) kgVSS. kgCOD-1 and (12 ± 5)d, respectively. Biofilm formed in the reactor presented two different patterns: one of them at the beginning of the colonization and the other of mature biofilm. These different colonization patterns are due to bed stratification in the reactor, caused by the difference in local-energy dissipation rates along the reactor's height, and density, shape, etc. of the bioparticles. The biofilm population is formed mainly of syntrophic consortia among sulfate reducing bacteria, methanogenic archaea such as Methanobacterium and Methanosaeta-like cells.

scholarly journals RELATIONSHIP OF ELECTRICAL RESISTANCE OF VAGINAL MUCUS DURING OESTRUS WITH POST-AI PREGNANCY IN COWS

2018 ◽  
Vol 15 (2) ◽  
pp. 113-117 ◽  
Author(s):  
M. Ahmed ◽  
M. K. Chowdhury ◽  
M. M. Rahman ◽  
J. Bhattacharjee ◽  
M. M. U. Bhuiyan
Keyword(s):  
Pregnancy Rate ◽  
Electrical Resistance ◽  
Genital Tract ◽  
Conception Rate ◽  
Heat Detector ◽  
The Mean ◽  
The Difference ◽  
Rectal Palpation ◽  
Relationship Of ◽  
In Pregnancy

Accurate detection of oestrus is a common problem for farmers to do AI timely resulting in conception failure in cows. The objective of the present study was to know the electrical resistance of vaginal mucus (ERVM) during oestrus to determine the best time of AI for improvement of conception in cattle. A total of 28 cows were inseminated with frozen thawed semen after detection of ERVM with Draminski estrus detector at Kendua Upazila Livestock Office under Netrakona district of Bangladesh. Pregnancy was diagnosed by per rectal palpation of genital tract 8-10 weeks after insemination. The mean ERVM in pregnant cows was 208.5 ± 31.2 Ω (163.3 to 263.3 Ω) and the ERVM in non-pregnant cows was 214.4 ± 36.6 Ω (153.3 to 280.0 Ω). Moreover, the pregnancy rate was higher in cows (80.0 to 83.3%) when ERVM during oestrus varied from 150 to 220 Ω than that of 221 to 280 Ω counterpart (36.4%). The difference in pregnancy rates between groups was significant (P<0.05). The present study indicates that Dramniski electrical heat detector may be used for prediction of time for AI in cows of Bangladesh. Up to 220 Ω ERVM during oestrus is better for higher conception rate than that of more than 220 Ω counterparts. Further studies with high number of inseminated cows should be conducted before wide application of this electrical heat detector under field conditions in Bangladesh.

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