Influence of particles size distribution on the carbon content throughout sinter bed height

2021 ◽  
Vol 77 (11) ◽  
pp. 1136-1141
Author(s):  
V. A. Kobelev ◽  
G. A. Nechkin ◽  
G. E. Isaenko ◽  
V. V. Kirsanov
Keyword(s):  
Carbon Content ◽  
Size Distribution ◽  
Solid Fuel ◽  
Middle Part ◽  
Size Segregation ◽  
Bottom Part ◽  
Fuel Distribution ◽  
Bed Height ◽  
Particles Size Distribution ◽  
Fuel Fraction

By the previous studies it was established that the character of solid fuel distribution throughout the bed height considerably effects the sintering machines productivity and the sinter quality. The purpose of the study was assessment of solid fuel distribution in the agglomerated burden throughout the height of bed at sintering machine. Sinter mix samples were taken from three sections of the bed: 150 mm - top part, 150 mm - middle part and 170 mm - bottom part at the sintering machines of NLMK. After screening the samples, particle size distribution was determined, as well as carbon content throughout the bed height and in the particles of different sizes. It was found that all solid fuel, irrespective of the size, gets balled into sinter mix granules, fine fuel (fraction -0.63 mm) was almost evenly distributed over the granules of different sizes, while coarse fuel (+3 mm) is mainly picked up by large granules. Solid fuel of -3 mm +0.63 mm fraction is mostly balled into 3-5 mm granules. Such nature of solid fuel distribution in the granules of the pelletized mix results in suboptimal distribution of fuel throughout the bed height at sintering machines No. 1, 2, despite satisfactory size segregation of the mix: it changes from low content in the top part to a higher content at the bottom of the bed. At sintering machines No. 3, 4 where there was no size segregation of the mix, fuel distribution throughout the bed height changes from optimal to non-optimal (low content in the top part). To optimize solid fuel distribution throughout the bed height with both good and poor segregation of the mix, it is necessary to reduce the content of 0-0.5 mm particles fraction in coke breeze.

A Novel Turbulent Aggregation Device for Flue Gas

2014 ◽  
Vol 955-959 ◽  
pp. 2425-2429 ◽  
Author(s):  
Yun Fei Li ◽  
Jian Guo Yang ◽  
Yan Yan Wang ◽  
Xiao Guo Wang
Keyword(s):  
Size Distribution ◽  
Flue Gas ◽  
Large Scale ◽  
Balance Model ◽  
Small Scale ◽  
Multiphase Model ◽  
Specific Performance ◽  
Particles Size Distribution ◽  
Scale Turbulence ◽  
Eulerian Multiphase Model

The purpose of this study is to construct a turbulent aggregation device which has specific performance for fine particle aggregation in flue gas. The device consists of two cylindrical pipes and an array of vanes. The pipes extending fully and normal to the gas stream induce large scale turbulence in the form of vortices, while the vanes downstream a certain distance from the pipes induce small one. The process of turbulent aggregation was numerically simulated by coupling the Eulerian multiphase model and population balance model together with a proposed aggregation kernel function taking the size and inertia of particles into account, and based on data of particles’ size distribution measured from the flue of one power plant. The results show that the large scale turbulence generated by pipes favours the aggregation of smaller particles (smaller than 1μm) notably, while the small scale turbulence benefits the aggregation of bigger particles (larger than 1μm) notably and enhances the uniformity of particle size distribution among different particle groups.

scholarly journals Infestation Pattern of Macrosiphum rosae and Tetranychus sp. in Rose Plants (Rosa hybrida) Cultivated in Protected and Open Cultivation in Kathmandu District

2009 ◽  
Vol 23 ◽  
pp. 88-91
Author(s):  
Vinod Kumar Thapa ◽  
Prem Bahadur Budha
Keyword(s):  
Natural History ◽  
Middle Part ◽  
Rosa Hybrida ◽  
Natural History Museum ◽  
Bottom Part ◽  
Aphid Infestation ◽  
History Museum ◽  
Infestation Pattern ◽  
Macrosiphum Rosae

A study was carried out from January to December 2005 in four different sites of Kathmandu district. Infestation pattern of mite and aphid was observed in different canopy levels (top, middle and bottom) of rose plant. Top part of the plant showed highest aphid infestation followed by middle part and bottom part showed little or no infestation. Similar trend was observed in case of mite, with highest distribution in top, middle part and relatively low in bottom part. Macrosiphum rosae and Tetranychus sp. were found to be the dominant pests infesting rose plants in open and protected conditions respectively.Key words: Rose; mites; aphids; infestation; canopy level; KathmanduJournal of Natural History Museum Vol. 23, 2008 Page 88-91

SERS of a-C Thin Film on Ag, Au, Ag0.52-Au0.48 Alloy Nanoparticle Arrays with Normal Particles Size Distribution Formed by Vacuum Thermal Evaporation

2018 ◽  
Vol 386 ◽  
pp. 250-255 ◽  
Author(s):  
Sergey Dubkov ◽  
Alexey Trifonov ◽  
Yuri Shaman ◽  
Evgeny Kitsyuk ◽  
Andrey Savitskiy ◽  
...  
Keyword(s):  
Thin Film ◽  
Particle Size ◽  
Raman Scattering ◽  
Size Distribution ◽  
Thermal Evaporation ◽  
Experimental Studies ◽  
Alloy Nanoparticles ◽  
Nanoparticle Arrays ◽  
Vacuum Thermal Evaporation ◽  
Particles Size Distribution

This paper presents the results of experimental studies of arrays of Ag0.52Au0.48 alloy nanoparticles. Arrays were formed by vacuum-thermal evaporation on an unheated substrate and subsequent low-temperature vacuum annealing. The TEM images of the obtained nanoparticle arrays and corresponding histograms of particle size distribution are shown. The transmission spectra of these arrays showing the displacement of the plasma frequency as a function of the mean particle size are obtained. Spectra of Raman scattering from a thin film of amorphous carbon in presence of AgAu particles are obtained, and a comparative analysis of Raman scattering amplification factors for pure Ag, pure Au and Ag0.52Au0.48 alloy nanoparticles is presented.

Horizontal Pressure Fluctuation in Bubbling Fluidized Bed

2003 ◽  
Author(s):  
Vesa V. Walle´n
Keyword(s):  
Pressure Gradient ◽  
Fluidized Bed ◽  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
Middle Part ◽  
Biomass Combustion ◽  
Bottom Part ◽  
Pressure Transducers ◽  
Bubbling Fluidized Bed ◽  
Horizontal Pressure

Pressure measurements were conducted in a two-dimensional hot atmospheric bubbling fluidized bed reactor in the laboratory of Energy and Process Engineering at Tampere University of Technology. A set of six fast pressure transducers was used to detect the rapid pressure fluctuations inside the bubbling bed of the reactor. These pressure transducers were placed both vertically and horizontally into the reactor. From these measurements it was found that the vertical pressure fluctuation took place at the same time at different levels of the bed. Also the same fluctuation could be seen under the air distributor. The horizontal pressure fluctuation was found to vary both by place and time. At the bottom part of the bed the highest pressure peaks was found at centre of the bed. Most of the time there was a pressure gradient the highest pressure being in the centre of the bed. This gradient creates horizontal flow of gases from middle to the sides. The velocity of this flow varies with the size of the pressure gradient. The opposite effect can be found in the upper part of the bed. The highest pressure was no more in the middle part of the bed. Instead, it was found to be between the centre of the bed and left and right walls. The pressure was low at the walls but also rather low at the middle of the bed. There must be flow towards the walls and to the centre axis. These pressure fluctuations can provide an explanation for the well-known “wandering plume” effect. They can also give a tool to better describe the mixing inside a bubbling fluidized bed. This kind of tool is needed when biomass combustion is modelled in bubbling fluidized bed.

Glutenin macropolymer particles size distribution of six wheat varieties in eastern China

2017 ◽  
Vol 22 (5) ◽  
pp. 455-460 ◽  
Author(s):  
Wenyang Li ◽  
Bingbing Yang ◽  
Qingqin Shao ◽  
Feng Xu ◽  
Suhui Yan
Keyword(s):  
Size Distribution ◽  
Eastern China ◽  
Wheat Varieties ◽  
Particles Size Distribution ◽  
Glutenin Macropolymer

scholarly journals Size-resolved measurements of ice-nucleating particles at six locations in North America and one in Europe

2016 ◽  
Vol 16 (3) ◽  
pp. 1637-1651 ◽  
Author(s):  
R. H. Mason ◽  
M. Si ◽  
C. Chou ◽  
V. E. Irish ◽  
R. Dickie ◽  
...  
Keyword(s):  
North America ◽  
Size Distribution ◽  
Ground Level ◽  
Size Segregation ◽  
Significant Component ◽  
Size Dependent ◽  
Coarse Mode ◽  
Sampling Locations ◽  
Immersion Freezing ◽  
Removal Processes

Abstract. Detailed information on the size of ice-nucleating particles (INPs) may be useful in source identification, modeling their transport in the atmosphere to improve climate predictions, and determining how effectively or ineffectively instrumentation used for quantifying INPs in the atmosphere captures the full INP population. In this study we report immersion-mode INP number concentrations as a function of size at six ground sites in North America and one in Europe using the micro-orifice uniform-deposit impactor droplet freezing technique (MOUDI-DFT), which combines particle size-segregation by inertial impaction and a microscope-based immersion freezing apparatus. The lowest INP number concentrations were observed at Arctic and alpine locations and the highest at suburban and agricultural locations, consistent with previous studies of INP concentrations in similar environments. We found that 91 ± 9, 79 ± 17, and 63 ± 21 % of INPs had an aerodynamic diameter > 1 µm at ice activation temperatures of −15, −20, and −25 °C, respectively, when averaging over all sampling locations. In addition, 62 ± 20, 55 ± 18, and 42 ± 17 % of INPs were in the coarse mode (> 2.5 µm) at ice activation temperatures of −15, −20, and −25 °C, respectively, when averaging over all sampling locations. These results are consistent with six out of the nine studies in the literature that have focused on the size distribution of INPs in the atmosphere. Taken together, these findings strongly suggest that supermicron and coarse-mode aerosol particles are a significant component of the INP population in many different ground-level environments. Further size-resolved studies of INPs as a function of altitude are required since the size distribution of INPs may be different at high altitudes due to size-dependent removal processes of atmospheric particles.

Synthesis of Nickel Silicide/Silicon/Silica Composite Nanostructures by Coevaporation of SiO Powder and Nickel Formate

2011 ◽  
Vol 181-182 ◽  
pp. 599-603 ◽  
Author(s):  
Yang Cao ◽  
Gang Zhou ◽  
Jun Hui He
Keyword(s):  
Electron Microscopy ◽  
Silicon Oxide ◽  
Average Diameter ◽  
Middle Part ◽  
Nickel Silicide ◽  
Polycrystalline Nickel ◽  
Bottom Part ◽  
Nickel Formate ◽  
Silica Composite ◽  
Transmission Electron

Nickel silicide/silicon/silica composite nanostructure, i.e., Ni31Si12/Si/SiO2, was synthesized successfully by a coevaporation method, using nickel formate and SiO powder as the source materials. The structure of product was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscope (HRTEM). The results indicated that the product had a rod morphology, which consisted of three parts with different morphologies and crystallographic structures. The top of the rod was a polycrystalline nickel silicide (Ni31Si12) nanoball with average diameter of 100 nm; the middle part was a single-crystal Si short rod with average diameter of 80 nm; the bottom part was an amorphous silicon oxide nanowire with average diameter of 60 nm. A possible growth mechanism of the composite nanorod was briefly discussed

Sign in / Sign up

Export Citation Format

Share Document