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Fluidization And Fluidized Beds
Published in Shintaro Furusaki, John Garside, L.S. Fan, The Expanding World of Chemical Engineering, 2019
Other particle properties are also important. The particle density is nearly as important as its size and shape. Many particles, for example those used as industrial catalysts, contain interior pores, and the interior “porosity” or “voidage” (interior void volume divided by total particle volume) is then of direct interest, as is the distribution of pore diameters. Some catalysts are made to have hundreds of square meters of interior surface area per gram of catalyst. In particulate materials (often called powders), the distribution of particle sizes is also of considerable interest since, for example, a powder made of identical particles usually behaves quite differently from one having the same average particle size but a wide distribution of sizes from much smaller to much larger than the average. Hardness, ability to dissipate electrical charges, and surface characteristics are also important in some applications. In addition, interparticle forces are of great importance for fine particulate materials. These forces are usually described as van der Waals forces. An excellent discussion of their origin and importance in the context of fluidized beds has been provided by Visser (1989).
Discrete Element Method Applications in Process Engineering
Published in Mariano Martín Martín, Introduction to Software for Chemical Engineers, 2019
Ali Hassanpour, Massih Pasha, Mohammadreza Alizadeh Behjani
In such systems, common parameters to be analysed are particle mixing and segregation indices (Figure 9.25 (a)), stress distribution (Figure 9.25 (c)), residence time distribution, collisions frequency and motion analysis (Figure 9.25 (b)). Hassanpour et al. [69] analysed the motion of particles in a commercial paddle mixer (Figure 9.26 (a)). The particle behaviour such as velocity pattern as well as quantitative powder dynamics in terms of particle mixing and velocity distribution were analysed under various process conditions (rotational speed, fill level and particle density). They compared the DEM prediction with the experimental measurements based on Positron Emission Particle Tracking (PEPT) [70], where an acceptable agreement was obtained (Figure 9.26 (b)).
Estimating the Storage Capacity of the Vadose Zone
Published in L.G. Wilson, Lorne G. Everett, Stephen J. Cullen, Handbook of Vadose Zone Characterization & Monitoring, 2018
Stephen J. Cullen, Lome G. Everett
The particle density can be accurately measured using the air pycnometer technique (Blake and Hartge, 1986). Often, a particle density of 2.65 g/cm3 is assumed for many soils based on the density of quartz which is commonly prevalent in sandy soils. The particle density of some clays may, however, be less and the density of soils with appreciable amounts of ferromagnesian minerals, iron oxides, or heavy metals may be greater (Hausenbuiller, 1972). Organic-rich soils and subsurface strata may have a particle density less than 2.65 g/cm3. Brady (1984) states that organic matter has a typical particle density in the range of 1.1 to 1.4 g/cm3. Cullen (1981) measured mineral particle densities as low as 2.4 to 2.5 g/cm3 on volcanic ash soils in western Montana. As indicated in the equation above, accurate knowledge of the particle density is critical to calculation of the porosity based on the bulk density. Assumptions of particle density values should be validated by use of correlative data or by representative sampling and testing.
Ecological assessment of pit lakes in Raniganj, India: Application of different indices and multivariate statistics
Published in Water Science, 2023
The bulk density of sediment samples was calculated using a specific gravity bottle with a 50 ml volume that was weighed without the stopper. The bottle was then filled with sediment samples up to the edge of the neck, tapped 20 times, and weighed. By dividing the weight of the sediment samples by the volume of the sediment, the bulk or apparent density was calculated (Baver, 1956). The particle density was calculated using a pycnometer and the Baver technique (1956). As indicated by Jackson, the pH of the sediment was determined using Oakton PCSTestr 35 in a 1:10 sediment-water suspension. A volumetric approach for estimating organic carbon content in sediment samples was used according to Muhr et al. (1965). The Olsen technique was used to estimate available phosphorus in sediment samples (Olsen, Cole, Watanabe, & Dean, 1954), while the Kjeldahl method was used to estimate available nitrogen in sediment samples, as described by Subbiah and Asija (1956).
Effects of drying treatment-induced changes in the physicochemical properties of starch on the textural characteristics of Ginkgo seed crisps
Published in Drying Technology, 2023
Chunju Liu, Yue Li, Yayuan Xu, Zhuqing Dai, Lei Feng, Da-jing Li, Ya-dong Xiao, Wen-qian Pang, Han-ci Ren, Min Zhang
The bulk density is the ratio of mass to volume, and the particle density was measured using the pycnometer method. The samples were dried at 105 °C in an electric blast drying oven for 12 h and then ground into powder using a high-speed grinder. Equation (1) allows calculating the particle density, and Equation (2) was used to determine the porosity of the materials: where ε, ρ, ρ0, W1, W2, W3, and W4, are porosity (%), bulk density (g/cm3), particle density (g/cm3), weight of the pycnometer (g), weight of the pycnometer and xylene (g), weight of the sample and pycnometer (g), and weight of the sample, xylene, and pycnometer (g), respectively.
Feasibility of transforming lightweight aggregate made of pulp and paper mill sludge into insulating concrete
Published in Journal of the Chinese Institute of Engineers, 2020
Table 6 presents the results of particle density tests on samples with different additives and mix proportions at various temperatures and durations. The table exhibits the effects of PPMS proportion on particle density. The content of particle density was inversely proportional to that of PPMS, suggesting that particle density decreased as PPMS increased.During sintering at high temperatures, oxidative decomposition occurs among the combustibles in PPMS (i.e., organic matters), creating pores inside a sample. When pores increase, particle density decreases. Moreover, PPMS has low specific gravity. Therefore, a high PPMS content indicates low particle density. Overall, the particle density of samples with various mix proportions in this study were in the range 0.8–1.2 g/cm3, which was similar to the density of average lightweight aggregate.