Sieves particle-size distribution

D-4513 Particle Size Distribution of Catalytic Material by Sieving Particle size distribution of catalyst particles (20 to 420jim) as measured weight of sample passing through calibrated sieves ... 

Screening. A 100-g sample of mica is usually used for this test, plus a rack of six Tyler sieves and a pan. The stack of sieves containing the sample is rotated, and after screening, the mica remaining on each screen is weighed and the percentage retained is calculated. A combination of wet and dry screening may also be used to determine particle size distribution of fine mica (<0.147 mm ( — 100 mesh)). 

Particle-SiZe Distribution. Particle-size specifications for sugar are not usually a part of the legislated standards, but they are of concern to commercial users and suppHers and are often specified in contracts. Grain-size distribution is determined by using a series of sieves, either hand-sieved or machine-sieved (13). 

Particle-Size Distribution This is defined as the relative percentage by weight of grains of each of the different size fractious represented in the sample. It is one of the most important factors in evaluating a screening operation and is best determined by a complete size analysis using testing sieves. 

Particle size distribution (R) Design of separation equipment Toxic hazard Environmental impact Wide range including Microscopy Holography Light scatter Sieving... 

Modeling the pore size in terms of a probability distribution function enables a mathematical description of the pore characteristics. The narrower the pore size distribution, the more likely the absoluteness of retention. The particle-size distribution represented by the rectangular block is the more securely retained, by sieve capture, the narrower the pore-size distribution. 

Two-phase suspension systems produce beaded products with broader particle-size distribution (e.g., 1-50 /rm). The microspherical particles usually need to be classified repeatedly to reduce the particle-size distribution in order to improve the resolution and efficiency in the separation for use in chromatography. The actual classification process depends on the size range involved, the nature of the beaded product, and its intended applications. Relatively large (>50 /rm) and mechanically stable particles can be sieved easily in the dry state, whereas small particles are processed more conveniently in the wet state. For very fine particles (<20 /rm), classification is accomplished by wet sedimentation, countflow setting, countflow centrifugation, or air classification. 

Mechanical analyses determine the particle-size distribution in a soil sample. The distribution of coarse particles is determined by sieving, and particles finer than a 200 or 270-mesh sieve and found by sedimentation. 

The carbon raw material in the form of coke, coal or natural or synthetic graphite is ground and sieved (following calcination at 700-1300°C to control volatiles, if necessary) to give a desired particle size distribution. The distribution depends upon the size of the artifact to be formed and the method of forming. 

Data in Table I reveal that sieved fractions of different particle size distribution lose varying amounts of moisture dining the same drying period at 70° C. The last column in the table shows that the apparent percentage of moisture in the different frac-... 

The particle size distribution of AP was determined and Compared using the Ro-Tap, the Alpine Air Jet Sieve and the Micromerograph. For this purpose six different samples of ground AP were chosen and separated using sieves calibrated with National Bureau of Standards spherical glass beads. The results were plotted... 

The particle-size distribution of two test powders, spherical glass beads and crushed quartz was determined with different types of app (Ref 32), and indicate that the micro-mesh sieve data is in good agreement with those of other methods (Table 6) ... 

Despite shortcomings, the Micromerograph in the early 1960 s was the only instrument generally available for determining particle size distribution of sub-sieve pro pint and pyrotechnic ingredients. 

Particle Size Distribution by Sieve Analysis , MIL-STD-1233 (1962) 22) S.M. Kaye, D.E. 

The most commonly used methods for detn of the particle size distribution of fine AP are the Micromerograph and Turbidometric Methods. For coarser AP samples standard sieves are used (see below under Specifications)... 

Powdered Teflon for use in pyrots is covered by US Mil Spec MIL-P-48296IPA) (1 May 1974), Polytetrafluoroethylene (TFE) . Three classes of material are specified (1,2 3). The requirements are purity, 99.4% min infrared spectrum, peaks consistent with figure shown color, TFE shall be opaque and the color shall range from white to gray moisture, 0.05% max ash, 0.1% max mp, 337° 10°C packing density, Class 1 — 1.18 0.13g/cc, Class 2 - 1.25 0.02g/cc, Class 3- 1.14 0.09g/cc particle size by sieve analysis, Class 1 — 95 15 microns, Class 2 — 237 27 microns, Class 3 — 200 30 microns particle size distribution by sieve analysis, as specified in Table 1... 

Different methods are available for the determination of the particle-size distribution of powdered solids [30]. These are optical microscopy (usually combined with image analysis), sieve analysis, laser light scattering of suspended particles, and electrical zone sensing. 

The narrower the particle size distribution, the higher in theory is the potential theoretical plate number. A rough sieving is achieved by a water flow, air flow, or a vibration method. A common sieving method is Hamiltonian water flow (Figure 3.4). The particle distribution can be controlled within + 1 jum by this method. A slurry of stationary phase material is allowed to float in the cylinder, and a solvent flows from the bottom to the top. The smaller and lighter particles float to the top of the cylinder and the larger and heavier particles sink to the bottom. The required particles are collected at the top of the cylinder. The selection of suspension solvent and control of the temperature are important. 

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