Using Flow Properties to Solve Flow Problems with Hard-to-Handle Powders in the Ceramics Industry

2008 ◽  
Vol 591-593 ◽  
pp. 620-627
Author(s):  
Herman Purutyan ◽  
Alfredo del Campo ◽  
Roger A. Barnum
Keyword(s):  
Titanium Dioxide ◽  
Cohesive Strength ◽  
Particle Sizes ◽  
Flow Properties ◽  
Handling System ◽  
Flow Problems ◽  
Fine Powders ◽  
Common Problems ◽  
Ceramic Manufacturing ◽  
Ceramics Industry

Many processes in ceramic manufacturing require handling of fine powders with particle sizes down to sub-micron range. Problems that are often experienced with these powders, such as stoppages and/or surges, can be predicted and prevented by first measuring relevant flow properties of these powders, and then using these properties to design a handling system. In this paper we will review common problems with handling such powders and the relevant flow properties tests, such as permeability, compressibility, cohesive strength and friction, as well as how these properties can be used to prevent and solve problems. Issues related to handling titanium dioxide (TiO2) will be used as an illustration.

Structural and Electrical Properties of Titania Thin Films

2014 ◽  
Vol 925 ◽  
pp. 300-303 ◽  
Author(s):  
Sharipah Nadzirah ◽  
Uda Hashim ◽  
N. Malihah
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Titanium Dioxide ◽  
Current Flow ◽  
Sol Gel ◽  
Particle Sizes ◽  
Structural And Electrical Properties ◽  
Crystallite Sizes ◽  
Average Current ◽  
Flow Through

This research studies the properties of titanium dioxide (TiO2) nanoparticles synthesized by two different stabilizers via sol-gel method. Acetic and hydrochloric acids have been used as stabilizers to form two different TiO2 thin films. 100 μm gap of Al IDEs have been fabricated on each annealed TiO2 films. Finally the samples were physically and electrically characterized. Average crystallite sizes of the nanoparticles are 20 and 25 nm for acetic and hydrochloric acid respectively. The average current flow through the devices was extremely small which are around micro-to-nanoampere. It was found that the electrical conductivity increased significantly when particle sizes decreases.

Effects of Dissolving Agents on Particle Size Reduction of Titanium Dioxide Synthesized by Solution Combustion Technique

2016 ◽  
Vol 690 ◽  
pp. 236-239
Author(s):  
Oratai Jongprateep ◽  
Rachata Puranasamriddhi
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Solution Combustion ◽  
Initial Reagent ◽  
Combustion Technique

High photocatalytic activity of nanoparticulate titanium dioxide has attracted worldwide attention. Synthesis techniques of the nanoparticles, however, often require high energy supply or costly initial reagents. Solution combustion technique is an energy-effective technique capable of synthesizing nanosized titanium powders. This research aimed at utilizing a less expensive initial reagent in synthesis of nanoparticulate titanium dioxide by the solution combustion technique. The research also examined effects of dissolving agents on chemical composition and particle sizes of the synthesized powders. A low-cost initial reagent, titanium dioxide with average particle size of 154 nanometers, was dissolved in sulfuric acid or dispersed in nitric acid prior to the combustion. Experimental results revealed that the pure anatase phase titanium dioxide was successfully obtained in powders prepared from both sulfuric acid and nitric acid. The average particle size of the powder prepared from sulfuric acid was 77 nanometers, while that of the powder prepared from nitric acid was 117 nanometers. The difference in particle sizes was attributed to solubility of the initial reagent in the acid. Complete solution of initial reagent in sulfuric acid was the main factor attributed to finer particle size.

What You Need to Know to Reliably Handle Waste Coal

2003 ◽  
Author(s):  
Roderick J. Hossfeld ◽  
David A. Craig ◽  
Roger A. Barnum
Keyword(s):  
Mass Flow ◽  
Systematic Approach ◽  
Flow Patterns ◽  
Handling System ◽  
Flow Problems ◽  
Energy Facility ◽  
Anthracite Culm ◽  
Funnel Flow ◽  
Major Consideration ◽  
Waste Coal

Many power producers have been designing for, or switching to waste coal. A major consideration when dealing with waste coal is the design of the fuel handling system. Since waste coal is typically finer and more cohesive and therefore harder to handle in silos, bunkers, chutes and feeders, design of the handling system for reliable, non-stagnant flow is essential. This paper describes a systematic approach to designing and retrofitting handling systems to avoid bulk solids flow problems. Potential trouble areas such as coal hoppers, silos, bunkers, and transfer chutes are discussed. Mass flow and funnel flow patterns that develop in silos and bunkers are presented. Funnel flow results in large stagnant regions, which are a major problem for coals that combust easily and are prone to problems such as arching and ratholing. Mass flow patterns, which eliminate the stagnant coal regions, are also explained. Coal properties and bunker designs that result in mass flow and funnel flow are described. Transfer chute design techniques to avoid pluggages, reduce dusting, and minimize chute wear are discussed. The Panther Creek Energy facility in Nesquehoning, Pennsylvania is used as an example where solids flow handling methodologies were used to solve handling problems with anthracite culm. The modifications presented were required for reliable, stagnant-free coal flow, which prevented belt slippage and high belt loading on gravimetric feeders.

Flow properties of fine powders in powder coating

Particuology ◽  
2010 ◽  
Vol 8 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Qing Huang ◽  
Hui Zhang ◽  
Jesse Zhu
Keyword(s):  
Powder Coating ◽  
Flow Properties ◽  
Fine Powders

The Location of Tantalum Atoms in Ni3Al

1988 ◽  
Vol 133 ◽  
Author(s):  
Hui Lin ◽  
David P. Pope
Keyword(s):  
Diffraction Method ◽  
Average Particle ◽  
Grinding Process ◽  
Particle Sizes ◽  
X Ray ◽  
Fine Powders ◽  
Superlattice Peak ◽  
Melt Spun ◽  
Simple Substitution ◽  
Melt Spun Ribbons

ABSTRACTAn X-ray powder diffraction method was used to determine the location of tantalum atoms in Ni3Al. A series of Ni3 (Al,Ta) alloys were produced with tantalum content ranging from 0.1 to 3.0 at%. Fine powders with average particle sizes less than 80 pm were made from melt-spun ribbons by a grinding process. The values of the superlattice peak intensities normalized to the intensity of the (200) fundamental peak agreed with the calculated values assuming that tantalum atoms substitute on aluminum sites, not on nickel sites. Thus it is concluded from our experiments that tantalum atoms substitute for aluminum in Ni3Al, except for Ta contents around 0.2 at% where the data can not be interpreted in terms of a simple substitution scheme.

scholarly journals Effects of particle size on physicochemical and functional properties of superfine black kidney bean (Phaseolus vulgaris L.) powder

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6369 ◽  
Author(s):  
Xianbao Sun ◽  
Yuwei Zhang ◽  
Jing Li ◽  
Nayab Aslam ◽  
Hanju Sun ◽  
...  
Keyword(s):  
Particle Size ◽  
Phaseolus Vulgaris ◽  
Antioxidant Activities ◽  
Food Additives ◽  
Radical Scavenging ◽  
Kidney Bean ◽  
Particle Sizes ◽  
Flow Properties ◽  
Hydration Properties ◽  
Low Cholesterol

Black kidney bean (Phaseolus vulgaris L.) powder (BKBP) with particle sizes of 250–180, 180–125, 125–75, 75–38, and <38 μm was prepared by using coarse and eccentric vibratory milling, respectively. Physicochemical properties, cholesterol adsorption, and antioxidant activities of powders were investigated. Size and scanning electron microscopy analyses showed that particle size of BKBP could be effectively decreased after the superfine grinding treatment, and the specific surface area was increased. Flow properties, hydration properties, thermal stability, and cholesterol adsorption efficiency significantly improved with the reducing of particle size. The superfine powder with sizes of 75–38 or <38 μm exhibited higher antioxidant activity via 2,2-diphenyl-1-picryhydrazyl, hydroxyl radical-scavenging, and ferrous ion-chelating assays. The results indicated that the BKBP with a size of <38 μm could serve as a better potential biological resource for food additives, and could be applied for the development of low-cholesterol products.

Flow properties of homogeneously aerated, expanded emulsion phase of fine powders (quasi-solid emulsion phase viscosity)

2002 ◽  
Vol 122 (2-3) ◽  
pp. 168-176 ◽  
Author(s):  
Hisashi O Kono ◽  
Sridhar Narasimhan ◽  
Larry M Richman ◽  
Takaaki Ohtake
Keyword(s):  
Flow Properties ◽  
Emulsion Phase ◽  
Fine Powders

The location of tantalum atoms in Ni3(Al, Ta)

1990 ◽  
Vol 5 (4) ◽  
pp. 763-768 ◽  
Author(s):  
Hui Lin ◽  
David P. Pope
Keyword(s):  
Long Range ◽  
Diffraction Method ◽  
Range Order ◽  
Average Particle ◽  
Particle Sizes ◽  
Long Range Order ◽  
X Ray ◽  
Fee Structure ◽  
Fine Powders ◽  
Superlattice Peak

An x-ray powder diffraction method was used to determine the location of tantalum atoms in Ni3Al. A series of Ni3(Al, Ta) alloys were produced with tantalum contents ranging from 0.1 to 3.0 at.%. Fine powders with average particle sizes less than 80 μm were made from melt-spun ribbons by a grinding process. The values of the intensity of the (100) superlattice peak normalized to that of the (200) fundamental peak as a function of tantalum content agreed with the calculated values, assuming that tantalum atoms substitute on aluminum sites, not on nickel sites, and also assuming small amounts of anti-site defects exist in the ordered fee structure of Ni3(Al, Ta) alloys. It is concluded from our experiments that tantalum atoms substitute for aluminum in Ni3Al. The long-range order parameters thus calculated of the Ni3(Al, Ta) alloys are generally above 0.84 and below 0.95, except for Ni75Al24.8Ta0.2, at which composition the long-range order parameter is close to unity.

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