Particle-size distribution, calculation

Particle size distribution calculations (19,27) have illustrated that modifications in the more standard methods for evaluating the integral dispersion equation are necessary in order to achieve good comparison between measured and calculated results. 

Image analysis Particle size distribution calculation... 

The above discussion illustrates the importance of operator training. If the operator is not well trained there would be various human perception tendencies that can bias the counting and the particle size distribution calculated will be inaccurate due to these issues. Unfortunately, we do not have time to cover all of these concerns in this section but see the reference from Allen for a more complete discussion of operator training for microscopy (9). 

ESP.7 EFFECT OF PARTICLE SIZE DISTRIBUTION Calculate the overall efficiency E of the unit ... 

With regard to the particle size distribution calculations, the results are presented in tabular form. 

Particle size distributions calculated from total mineral content. Organic fraction determined from sample weight loss at 500 °C. 

A transmission electron micrograph of a typical Si02 sample calcined at 500 °C for 4 h is given in Fig. 3 together with its particle size distribution calculated by the collection over 200 points in TEM pictures. This indicates that all Si02 particles are almost spherical in shape. And their sizes seem to be uniform. The mean particle size was estimated to be 1.5 pm in... 

The black graph in Eig. 12.26 shows the particle size distribution at 2 bar atomization pressure, determined with the Spraytec. The particle size distributions, calculated from measured transmission signals with the three inversion methods, are represented as filled data points in different colors. In comparison to the particle size distribution, determined with the Spraytec, those calculated with the inversion algorithm are all shifted toward larger particle sizes, whereby the... 

Fig. 12.26 Particle size distributions calculated with different inversion algorithms from measured (PSD-SE-Sensor, filled data points) and from simulated (unfilled data points) transmission signals of a water spray generated with a Lechler 460.403 and an atomization pressure of p = 2 bar...

Particle Size. The soHds in a fluidized bed are never identical in size and foUow a particle size distribution. An average particle diameter, is generally used for design. It is necessary to give relatively more emphasis to the low end of the particle size distribution (fines), which is done by using the surface mean diameter, to calculate an average particle size ... 

Figure 18 is an entrainment or gas-carryiag capacity chart (25). The operating conditions and particle properties determine the vertical axis the entrainment is read off the dimensionless horizontal axis. For entrainment purposes, the particle density effect is considered through the ratio of the particle density to the density of water. When the entrainable particle-size distribution is smaller than the particle-size distribution of the bed, the entrainment is reduced by the fraction entrainable, ie, the calculated entrainment rate from Figure 18 is multipfled by the weight fraction entrainable. 

Avera.ge Particle Size. Average particle size refers to a statistical diameter, the value of which depends to a certain extent on the method of deterniiaation. The average particle size can be calculated from the particle-size distribution (see Size measurement of particles). 

Deterrnination of the specific surface area can be made by a variety of adsorption measurements or by air-permeability deterrninations. It is customary to calculate average particle size from the values of specific surface by making assumptions regarding particle size distribution and particle shape, ie, assume it is spherical. 

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)). 

For pumoses of calculating size selectivity from cumulative particle size distribution data, Eq. (20-16) can be expressed in incremental form as follows ... 

For solid-liquid systems, settling velocities of the 10, 50. and 90 percent by w eight fractions of particle size distribution must be available from calculations or measurements. 

It calculates one-dimensional heat conduction through walls and structure no solid or liquid ciMiibustion models are available. The energy and mass for burning solids or liquids must be input. It has no agglomeration model nor ability to represent log-normal particle-size distribution. 

Equation 2.101 enables calculation of local average quantities such as moments of the particle size distribution. Baldyaga and Orciuch (2001) review expressions for local instantaneous values of particle velocity and diffusivity of particles, Z)pT, required for its solution and recover the distribution using the method of Pope (1979). 

At the crystallization stage, the rates of generation and growth of particles together with their residence times are all important for the formal accounting of particle numbers in each size range. Use of the mass and population balances facilitates calculation of the particle size distribution and its statistics i.e. mean particle size, etc. 

Turbidimetric methods for particle size analysis (Refs 10, 16 27) are used in conjunction with sedimentation procedures to determine the concn of particles at given distances below the surface at successive time intervals. From these data, and Stokes law, particle size distribution can be calculated... 

Complete recoveries are essential for the calculation of accurate particle size distributions from HDC data. In Small s work (O NaCl was used to increase the ionic strength of the eluant phase, however, quantitative results were not reported for any of the recoveries, especially at high ionic strengths, other than the statement that no latexes of 338 nm or 35T nm diameter were eluted at 0.1T6 M. In our case using SLS only in the mobile... 

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