scholarly journals Screening the Main Factors Affecting the Wear of the Scraper Conveyor Chute Using the Plackett–Burman Method

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Rui Xia ◽  
Bo Li ◽  
Xuewen Wang ◽  
Zhaojian Yang ◽  
Liping Liu
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Coal Particle ◽  
Normal Load ◽  
Influence Factors ◽  
Optical Microscope ◽  
Operating Conditions ◽  
Wear Loss ◽  
Regression Equations ◽  
Scraper Conveyor

The wear of scraper conveyor chute causes both significant economic and environmental losses by shortening the service life. The life of the chute under coal abrasive wear situations is primarily decided by operating conditions and the materials properties. The comprehensive analysis of the influence factors had not been studied before. In this paper, the Plackett-Burman design (PBD) method was used to screen the main influence factors and a regression equation was developed to predict the wear loss. The steel was tested on a modified pin-on-disk apparatus in which coal abrasive was filled in the disk. The influence factors included water content, gangue content, coal particle size, Hardgrove Grindability-Index (HGI) of the coal, normal load, and scraper chain speed. The results of the investigation suggested that the significance of water content, normal load, and gangue content on wear loss was relatively higher than the HGI of coal, scraper chain speed, and coal particle size. The wear loss increased with the increase of water content, gangue content, normal load, and coal particle size while it decreased as increase in HGI of the coal and scraper chain speed. Based on the significance of the parameters, the regression equations were derived and verified further with a number of test cases. Optical microscope studies revealed the main wear mechanism of the chute was mainly micro-cutting and corrosive wear and accompanied by fatigue fracture.

The relations between soil water retention characteristics, particle size distributions, bulk densities and calcium carbonate contents for Danish soils

2005 ◽  
Vol 36 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Niels Henrik Jensen ◽  
Thomas Balstrøm ◽  
Henrik Breuning-Madsen
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Particle Size Distribution ◽  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Pressure Head ◽  
Pedotransfer Functions ◽  
Regression Equations

A database containing about 800 soil profiles located in a 7-km grid covering Denmark has been used to develop a set of regression equations of soil water content at pressure heads −1, −10, −100 and −1500 kPa versus particle size distribution, organic matter, CaCO3 and bulk density. One purpose was to elaborate equations based on soil parameters available in the Danish Soil Classification's texture database of particle size distribution and organic matter. It was also tested to see if inclusion of bulk density or CaCO3 content (in CaCO3-containing samples) as predictors or grouping in surface and subsurface horizons or textural classes improved the regression equations. Compared to existing Danish equations based on much fewer observations the accuracies of the new equations were better. The equations also predicted the soil water content at the measured pressure heads more accurately than the pedotransfer functions developed in HYPRES (Hydraulic Properties of European Soils). Introducing bulk density as a predictor improved the equation for the pressure head of −1 kPa but not for the lower ones. The grouping of data sets in surface and subsurface horizons or in textural classes did not improve the equations. Based on the equations a set of van Genuchten parameters for soil types in the Danish Soil Classification was elaborated. The prediction of soil water content, especially at pressure head −1 kPa, is more accurate using these van Genuchten parameters than using the pedotransfer functions developed in relation to the HYPRES database from a broad range of European soils.

Study on mechanical and wear characterization of novel Co30Cr4Mo biomedical alloy with added nickel under dry and wet sliding conditions using Taguchi approach

2016 ◽  
Vol 232 (7) ◽  
pp. 535-554 ◽  
Author(s):  
Amit Aherwar ◽  
Amit Singh ◽  
Amar Patnaik
Keyword(s):  
Steady State ◽  
Mechanical Behavior ◽  
Normal Load ◽  
Testing Machine ◽  
Surface Profile ◽  
Operating Conditions ◽  
Wear Loss ◽  
Cross Sectional ◽  
Wear Performance ◽  
Hip Implant

This paper investigates the effect of nickel particulate on mechanical behavior and sliding wear performance of novel Co30Cr4Mo alloy for orthopedic hip implant application with and without an introduction of distilled water (i.e. both dry and wet conditions) medium. The mechanical behavior is examined by the micro-hardness tester and the compression testing machine, while the wear performance is analyzed through a pin-on-disc tribometer where the samples slide against a counter disc made up of hardened alloy steel (EN-31) under different operating conditions at room temperature. Scanning electron microscope, atomic force microscopy, and X-ray diffraction are used to examine the surface morphology, worn surface profile, and cross-sectional microstructure of the fabricated alloy (Co30Cr4Mo) composite. In this study, at the beginning, steady state experimental analysis is carried out to find the volumetric wear loss and friction coefficient by varying the sliding velocity and normal load, respectively. After obtaining the steady state results, the Taguchi design of experiment has been conducted followed by statistical analysis of variance to identify the significant factor setting for obtaining better performance output. From the analysis, it is found that by increasing the nickel wt.%, the hardness and the compression strength of the fabricated alloy composites are increased. Furthermore, the fabricated alloy composite with 1 wt.% Ni shows the better wear resistance under different operating conditions in both dry and wet media. This study will give an idea for hip implant application but not direct replacement of human joints. In future, this study may be extended in more detail for biomedical applications for replacement of either human hip implant or animal implant, respectively.

Numerical Simulation of Coal Gasification in a 1 t/h Two-Stage Entrained Flow Gasifier

2007 ◽  
Author(s):  
Min Du ◽  
Yingli Hao ◽  
Yan Wang
Keyword(s):  
Particle Size ◽  
Coal Particle ◽  
Particle Deposition ◽  
Coal Gasification ◽  
Volatile Component ◽  
Operating Conditions ◽  
Two Stage ◽  
Entrained Flow ◽  
Second Stage ◽  
Entrained Flow Gasifier

Coal gasification has received increasing attention in the past two decades due to the growing demand for clean gaseous fuels. Numerical simulations of the coal gasification process inside a two-stage dry feed entrained flow gasifier were carried out using the commercial CFD solver FLUENT. The predicted main product gas components and carbon conversion were in well agreement with the measured data, which verified the validity of the model. A series of calculations were carried out to investigate the effects of operating parameters on the performance of gasifier, including the coal particle size, coal type and coal feeding ratio between the first and the second stages. The flow field, coal particle deposition on the wall, gas temperature and mole fraction inside of the gasifier were analyzed. And the simulation results indicated that the performance of gasifier is improved with decreasing particle size. The low volatile component fraction or high ash content in coal is not propitious to the gasification performance. And the performance of gasifier of the case with coal distribution with 75% (first stage) vs. 25% (second stage) is better than the case with 50% (first stage) vs. 50% (second stage) and the case with 100% for the first stage. The calculation is helpful for designing the operating conditions of the gasifier.

Mikrokapsul Ekstrak Bawang Tiwai sebagai Pengawet Pangan

2016 ◽  
Vol 9 (1) ◽  
pp. 73-79
Author(s):  
Suroto Hadi Saputra ◽  
Paluphy Eka Yustini
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Rank Test ◽  
Water Particle ◽  
Range Test

Applications bawang tiwaiextractin the form ofpastaI have everdone in thefoodpreservativehaving troubleamong othersinsolubleandmixedwell withthe doughingredientsof food. One alternativeto overcome these problemsismicroencapsulated bawang tiwai extract.In this study, bulb bawangtiwaiextractedwithethanol 98%. Researchusinga completely randomized designfactorial3x2was repeated3times. The firstfactorcomposition ofthe coating materialwith 3 levels, the secondfactorwith 2degreetemperature.  Analysisof variance and dunken multiplerangetestfurthertestat5% confidence levelusing thesoftwareSPSSversion20. Results oftreatment ofthe coating materialcompositionandtemperatureas well as theinteractionsignificantly affected thephenol content, water content, solubilityin water, particle size andconcentration of ethanol. The results of analysisduncanmultiplerank testof showdifferentlevels ofphenol, water content, solubilityin water, particle size andconcentration of ethanol. The results showedthe highest valuein treatment(s1p1) phenolcontent of1.50%, (s2p1) lowwater content15.27%, (s1p1) watersoluble extracthighestlevel of87.45% (s2p1) 216.77smallestparticlesizeand(s2p1) lowethanollevels15, 17ppmABSTRAKAplikasi ekstrak bawang tiwai dalam bentuk pasta yang pernah dilakukan dalam pengawet pangan mengalami kesulitan antara lain tidak mudah larut dan tercampur secara baik dengan bahan adonan pangan. Salah satu alternatif untuk mengatasi permasalahan tersebut adalah mikroenkapsulasi ekstrak bawang tiwai.  Dalam penelitian ini, umbi bawang tiwai diekstrak dengan etanol 98%. Penelitian menggunakan rancangan acak lengkap faktorial 3 x 2 diulang 3 kali. Faktor pertama komposisi bahan penyalut dengan 3 taraf, faktor kedua suhu dengan 2 taraf. Hasil analisis sidik ragam dan uji lanjut dunken multiple range test pada tingkat kepercayaan 5% menggunakan soft ware SPSS versi 20. Analisa parameter pada penelitian ini antara lain kadar fenol, kadar air, kadar sari larut air dan ukuran partikel. Hasil perlakuan komposisi bahan penyalut dan suhu serta interaksi berpengaruh nyata terhadap kadar fenol, kadar air, kelarutan dalam air, ukuran partikel dan kadar etanol. Hasil analisisduncan multiple rank test (DMRT) menunjukkan berbeda nyata terhadap kadar fenol, kadar air, kelarutan dalam air, ukuran partikel dan kadar etanol. Hasil penelitian menunjukkan nilai tertinggi pada perlakuan (s1p1) kadar fenol 1,50 %, (s2p1) kadar air terendah 15,27%, (s1p1) kadar sari larut air tertinggi 87,45%(s2p1) ukuran partikel terkecil 216,77 dan (s2p1) kadar etanol terendah 15, 17 ppm. Kata kunci : bawang tiwa,  mikroenkapsulasi, maltodekstrin, na-kaseinat, pengawet pangan.

The circulating floating bed reactor: effect of particle size distribution of the carrier on ammonia conversion

2000 ◽  
Vol 41 (4-5) ◽  
pp. 393-400 ◽  
Author(s):  
J.M. Garrido-Fernandez ◽  
R. Méndez ◽  
J.M. Lema ◽  
V. Lazarova
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
G Protein ◽  
Biomass Concentration ◽  
Biomass Accumulation ◽  
Ammonia Removal ◽  
Operating Conditions ◽  
Nitrification Rate ◽  
Ammonia Conversion ◽  
Biomass Activity

Three Circulating Floating Bed Reactors (CFBR) R1, R2 and R3 with 20% v/v of a plastic carrier with different size distribution were operated to study the effect of the particles size of the carrier on biomass accumulation and nitrification performance. Operating conditions were similar in the three systems: ammonia concentrations around 50 mg-N–NH4+/ L, ammonia loading rates up to 1.2 kg N–NH4+/m3·d and temperatures between 14 and 27°C. Accumulation of nitrite was observed until day 65th. This w as result both of the inhibition of nitrite oxidation by free ammonia until day 20th and the insignificant accumulation of a biomass with low nitrite oxidising capacity between days 20 and 65th. Ammonia conversion rate and removal efficiency were higher in the reactor with lower particle size, R3 (nitrification rate of 1.1 kg N–NH4+/m3·d and ammonia removal of 97% at 16°C), than in R2 or R1 (nitrification rate of 1.0 kg N–NH4+/m3·d and ammonia removal of 90% at 16°C). The better efficiency in R3 was obtained as a result of the higher specific surface of the biofilm developed. Biomass activity was similar in the three reactors (2.2 and 1.12 g N/g protein · d at 30 and 15°C, respectively). Both the biomass evolution with time and biomass retention in the systems was practically not influenced by the size of particle. Biomass concentration of 1.2 g protein/L was retained in the carrier and up to 20% of the newly produced biomass was retained in the CFBRs.

Investigation of the different particle size dust releases from rigid filter candles during pulse-jet cleaning

2021 ◽  
pp. 095440622110179
Author(s):  
Xin Luan ◽  
Zhongli Ji ◽  
Longfei Liu ◽  
Ruifeng Wang
Keyword(s):  
Particle Size ◽  
Critical Role ◽  
Operating Conditions ◽  
Solid Particles ◽  
Dust Particles ◽  
Cleaning Efficiency ◽  
Term Operation ◽  
Cleaning Performance ◽  
Experimental Apparatus ◽  
Pulse Jet

Rigid filters made of ceramic or metal are widely used to remove solid particles from hot gases at temperature above 260 °C in the petrochemical and coal industries. Pulse-jet cleaning of fine dust from rigid filter candles plays a critical role in the long-term operation of these filters. In this study, an experimental apparatus was fabricated to investigate the behavior of a 2050 mm filter candle, which included monitoring the variation of pressure dynamic characteristics over time and observing the release of dust layers that allowed an analysis of the cleaning performance of ISO 12103-1 test dusts with different particle size distributions. These results showed the release behavior of these dusts could be divided into five stages: radial expansion, axial crack, flaky release, irregular disruption and secondary deposition. The cleaning performance of smaller sized dust particles was less efficient as compared with larger sized dust particles under the same operating conditions primarily because large, flaky-shaped dust aggregates formed during the first three stages were easily broken into smaller, dispersed fragments during irregular disruption that forced more particles back to the filter surface during secondary deposition. Also, a “low-pressure and long-pulse width” cleaning method improved the cleaning efficiency of the A1 ultrafine test dust from 81.4% to 95.9%.

scholarly journals Optical Estimation on Pollution Level of Respirable Dust Based on Infrared Transmitting Behavior in Coalmine Fully Mechanized Working Face

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Wen-Zheng Wang ◽  
Yan-Ming Wang ◽  
Guo-Qing Shi
Keyword(s):  
Coal Particle ◽  
Coal Dust ◽  
Operating Conditions ◽  
Dust Concentration ◽  
Optical Channel ◽  
Pollution Level ◽  
Engineering Practice ◽  
Dust Generation ◽  
Working Face ◽  
Comparison Results

Respirable coal particle generated during underground mining is the main cause for gas-dust explosions and coal workers’ pneumoconiosis (CWP) which needs accurate monitoring especially on its concentration. Focusing on the coal dust pollution in the fully mechanized working face of Huangbaici coalmine, coal particle was sampled for further industrial analysis and FT-IR test to obtain its chemical composition and optical constant. Combined with the simulated spatial distribution of airborne dust, the spectral transmission characteristics of coal dust within wavelengths of 2.5 to 25 μm under different operating conditions were obtained. The simulation results show that the transmittance and aerosol optical depth (AOD) of coal dust are closely linked and obviously influenced by the variation of dust generation source (intensity of dust release, position of coal cutting, and the wetting of the coal seam) and airflow field (wind speed and direction of ventilation). Furthermore, an optical channel of 1260–1280 cm−1(7.937–7.813 μm) which is almost only sensitive to the variation of dust concentration but dull to the diameter change of coal dust was selected to establish the correlation of dust concentration and infrared transmittance. The fitting curve was then applied to retrieve the equivalent dust concentration based on optical information, and the comparison results demonstrate that the estimated pollution level is consistent with field measurement data in engineering practice.

Some Properties and Detection Methods of Paper Sludge

2012 ◽  
Vol 560-561 ◽  
pp. 52-56
Author(s):  
Kai Zhang ◽  
Chao Jun Wu ◽  
Jia Chuan Chen
Keyword(s):  
Water Content ◽  
Organic Material ◽  
Ph Value ◽  
Optical Microscope ◽  
Ash Content ◽  
Detection Methods ◽  
Paper Sludge ◽  
Sludge Treatment ◽  
Material Content ◽  
The Third

Some properties of paper sludge were analyzed, including water content, organic material content, pH value, fiber content, ash content ,C, H, S, N content and metal content of sludge in three sedimentation tanks.Besides,COD,SS, sludge concentration were analyzed and optical microscope photoes of sludge were got.The results showed that water content was high, organic material content was high, pH value of three sludges was alkalescent, metal elements were varied, lots of bacteria in wet sludge. From the first tank to the third one,COD and SS are gradually diminishing The research of sludge’s properties may be helpful to sludge treatment.

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