Anisotropic shrinkage of cordierite-type glass powder cylindrical compacts

1988 ◽  
Vol 3 (1) ◽  
pp. 122-125 ◽  
Author(s):  
Hans Eckart Exner ◽  
Edward A. Giess
Keyword(s):  
Particle Size ◽  
Particle Shape ◽  
Radial Direction ◽  
Glass Powder ◽  
Sintering Behavior ◽  
Shrinkage Ratio ◽  
Solid Interface ◽  
A Value ◽  
Planar Orientation ◽  
Glass Powders

The pronounced anisotropy of shrinkage in the axial and the radial direction, observed in earlier studies on the sintering behavior of cordierite-type glass powder, is investigated in detail. It is shown that a planar orientation of the pore/solid interface exists that gives rise to an oriented shrinkage in the radial direction. The results show that the axial-to-diametral shrinkage ratio increases from a value of 0.3 to approximately 0.7 with increasing density, and that particle size and particle shape of the glass powders have little influence on shrinkage anisotropy.

Modelling Particle Size Distribution of Residual Fly Ash from Pulverized Biomass Combustion

2021 ◽  
Vol 15 (1) ◽  
pp. 75-82
Author(s):  
Mingzi Xu ◽  
Changdong Sheng
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Simple Model ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Shape ◽  
Great Influence ◽  
Biomass Combustion ◽  
Ash Formation ◽  
Residual Ash

The present work aims to develop a simple model for describing the particle size distribution (PSD) of residual fly ash from pulverized biomass combustion. The residual ash formation was modelled considering the mechanism of fragmentation and coalescence. The influences of particle shape and stochastic fragmentation on model description of the PSD of the fly ash were investigated. The results showed that biomass particle shape has a great influence on the model prediction, and a larger fragmentation number is required for cylindrical particles than that for spherical particles to get the same PSD of fly ash, and the fragment number of the particles increases with the shape factor increasing. For pulverized biomass with a wide size distribution, the model predicted ash PSD considering the stochastic fragmentation is very similar to that assuming uniform fragmentation. It implies that the simple model assuming uniform fragmentation is applicable for predicting fly ash size distribution in practical processes where biomass particles have a wide range of sizes. For the fuel with a narrower initial PSD, the stochastic fragmentation model generally predicts a coarser PSD of the residual ash than assuming uniform fragmentation. It means the stochastic fragmentation is of great influence to be considered for accurate description of ash formation from the fuel with a narrow PSD.

scholarly journals Effects of Particle Size and Cement Replacement of LCD Glass Powder in Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Seong Kyum Kim ◽  
Su Tae Kang ◽  
Jin Kwang Kim ◽  
Il Young Jang
Keyword(s):  
Particle Size ◽  
Glass Powder ◽  
Liquid Crystal Display ◽  
Waste Recycling ◽  
Cement Industry ◽  
Hardened Concrete ◽  
National Scale ◽  
The Sustainable Development ◽  
Technological Level ◽  
And Performance

The high quality liquid crystal display (LCD) processing waste glass (LPWG) generated from the manufacturing process of Korea’s LCD industries, having the world’s highest technological level and production, was finely ground into particles smaller than cement particles (higher fineness than OPC) to verify their applicability and performance as a replacement for cement. For a concrete mix having a W/B ratio of 0.44, cement was replaced with LPWG glass powder (LGP) at ratios of 5, 10, 15, and 20% (LGP12) and 5 and 10% (LGP5) according to the particle size to prepare test cylinder specimens, which were tested with respect to air contents, slump in fresh concrete, and compressive strength and splitting tensile strength of hardened concrete. The microstructure of the concrete specimens was analyzed through Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and a Mercury Intrusion Porosimetry (MIP). Replacement of cement with LGP for cement could effectively decrease the quantity of cement used due to the excellent performance of LGP. It may positively contribute to the sustainable development of the cement industry as well as waste recycling and environment conservation on a national scale.

scholarly journals EFFECTS OF PARTICLE SIZE AND PARTICLE SHAPE IN FLOW SIMULATIONS OF DRY SAND USING DEM

2015 ◽  
Vol 71 (2) ◽  
pp. I_587-I_594
Author(s):  
Shuji MORIGUCHI ◽  
Yuta HIRUMA ◽  
Shinsuke TAKASE ◽  
Kenjiro TERADA
Keyword(s):  
Particle Size ◽  
Particle Shape ◽  
Flow Simulations ◽  
Dry Sand

scholarly journals Optimization of nanostructured/nano sized rice husk ash preparation

2020 ◽  
Vol 17 (3(Suppl.)) ◽  
pp. 0953
Author(s):  
Medhat Mostafa ◽  
Hamdy Salah ◽  
Amro B. Saddek ◽  
Nabila Shehata
Keyword(s):  
Particle Size ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Particle Shape ◽  
Rice Husk Ash ◽  
Loss On Ignition ◽  
Shape Distribution ◽  
Disk Mill ◽  
Grinding Time

The objective of the study is developing a procedure for production and characterization of rice husk ash (RHA). The effects of rice husk (RH) amount, burning/cooling conditions combined with stirring on producing of RHA with amorphous silica, highest SiO2, lowest loss on ignition (LOI), uniform particle shape distribution and nano structured size have been studied. It is concluded that the best amount is 20 g RH in 125 ml evaporating dish Porcelain with burning for 2 h at temperature 700 °C combined with cooling three times during burning to produce RHA with amorphous silica, SiO2 90.78% and LOI 1.73%. On the other hand, cooling and stirring times affect the variation of nano structured size and particle shape distribution. However, no crystalline phases were found in RHA in all cases. Results proved that the Attritor ball mill was more suitable than vibration disk mill for pulverizing nano structured RHA with 50% of particle size (D50) lower than 45 mm and 99 % of particle size (D99) lower than 144 mm to nanosized RHA with D50 lower than 36 nm and D99 lower than 57 nm by grinding time 8.16 min to every 1 g RHA without changes in morphousity of silica.

Prediction of Packing Density of Milled Powder Based on Packing Simulation and Particle Shape Analysis

2007 ◽  
Vol 534-536 ◽  
pp. 1621-1624
Author(s):  
Yuto Amano ◽  
Takashi Itoh ◽  
Hoshiaki Terao ◽  
Naoyuki Kanetake
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Shape Analysis ◽  
Packing Density ◽  
Particle Shape ◽  
Milled Powder ◽  
Spherical Particles ◽  
Nonspherical Particles ◽  
Property Control

For precise property control of sintered products, it is important to know the powder characteristics, especially the packing density of the powder. In a previous work, we developed a packing simulation program that could make a packed bed of spherical particles having particle size distribution. In order to predict the packing density of the actual powder that consisted of nonspherical particles, we combined the packing simulation with a particle shape analysis. We investigated the influence of the particle size distribution of the powder on the packing density by executing the packing simulation based on particle size distributions of the actual milled chromium powders. In addition, the influence of the particle shape of the actual powder on the packing density was quantitatively analyzed. A prediction of the packing density of the milled powder was attempted with an analytical expression between the particle shape of the powder and the packing simulation. The predicted packing densities were in good agreement with the actual data.

NUMERICAL SOLUTIONS OF SMOLUCHOWSKI'S EQUATIONS FOR THE COAGULATION OF UNCHARGED AEROSOLS

1965 ◽  
Vol 43 (8) ◽  
pp. 2312-2318 ◽  
Author(s):  
J. M. Beeckmans
Keyword(s):  
Particle Size ◽  
Numerical Solutions ◽  
Coagulation Factor ◽  
Dispersion Parameter ◽  
Particle Size Range ◽  
Mean Particle Size ◽  
A Value ◽  
Wide Range ◽  
Differential Sedimentation ◽  
Smoluchowski’S Equation

Smoluchowski's equations for the coagulation of uncharged aerosol particles were programmed for solution by electronic computer. Terms representing differential sedimentation, turbulence, and mean aggregate density in solid aerosols were included. The effect of heterogeneity in the particle-size distribution of the aerosols on their rate of coagulation was illustrated by means of a slip-corrected coagulation factor Fc, which assumes a value of unity in all non-turbulent homogeneous aerosols. Curves of Fc vs. σg, the geometrical standard deviation, were calculated for aerosols of various mean particle-size. The effects due to turbulence, and to differential sedimentation, were illustrated in a similar manner. It was also found that the process of coagulation gives rise to a degree of dispersion which is independent of the original dispersion parameter, and depends only slightly on the mean particle-size of the aerosol over a wide range of particle-sizes. In the particle-size range in which differential sedimentation is inappreciable, the relatively constant value of the dispersion parameter implies that heterogeneous aerosols must obey the simplified integrated form of Smoluchowski's equation, which is applicable to homogeneous aerosols. The coagulation constant exceeds that predicted by the simple theory by about 10% for liquid aerosols of 0.1 μ or less.

Effect the Ratio and Particle Size of Glass Powder from Fluorescent Tubes Waste on Electrical Properties of PVA-Glass Composites

2021 ◽  
Vol 19 (10) ◽  
pp. 106-114
Author(s):  
Hani M Hussien
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Dielectric Constant ◽  
Glass Powder ◽  
Dissipation Factor ◽  
Powder Particle Size ◽  
Casting Method ◽  
Glass Composites ◽  
Mixing Ratios ◽  
Solution Casting Method

The polymer composites used in the present study were made of polyvinyl alcohol (PVA) as a matrix and glass powder as a filler. The glass powder was obtained from fluorescent tubes waste. The solution casting method was used to fabricate PVA/glass powder composite. Three groups of samples were prepared. The first was prepared by using PVA with the addition of glass powder (sieved less than 20 μm) in proportions 10, 20, 30, 40, and 50 %. The second: the mixing ratios of PVA and glass powder were 80% and 20%, respectively. The third: The mixing ratios of PVA and glass powder were 60% and 40%, respectively. In Both previous groups, the added glass powder used was sieved with sizes less than 20, 45, 105, and 125 μm. For all samples, the following properties were measured at room temperature: DC electrical conductivity, dielectric constant, electrical conductivity, and dissipation factor. The last three properties were measured with a range of frequencies from 1kHz to 5MHz. DC conductivity increases with increasing of glass powder. It was found that the highest conductivity values are for samples composed of glass powder with a particle size of less than 45 μm for both ratios of glass 20% and 40%. It is also noticed that within most frequencies, the sample with 30% glass has the largest dissipation factor. At 20% filler of glass powder, it is noted that the highest values of the dielectric constant are for samples composed of glass powder with a particle size of less than 45 μm and 125 μm. Below 1 MHz, the effect of glass powder particle size on the AC conductivity is minimal. It is found that the samples containing glass powder (less than 125 μm and 105 μm), have similar and lowest dissipation factor. At 40% filler of glass powder, it is noted that the lowest values of the dielectric constant are for samples composed of glass powder with a particle size little than 105 μm.

Sign in / Sign up

Export Citation Format

Share Document