A lot of metallurgical processes take places in shaft furnaces, where reacting gas carrying powders flows up in packed bed of descending metallurgical materials. Gas + powder two phase flow in fixed packed bed has been investigated by author for many years 1 . At present author undertakes the investigations with moving bed. Physical model with glass bed and glass powders was constructed. The ex...

Capillary rise method is widely used for contact angle determination using Washburn equation. Penetration kinetics of porous media comprised from particles of varying size distribution was investigated. It was found that the penetration kinetics and the validation of Washburn’s theory depend not only on the particle size but also on the pore size distribution. The effect of particle size on con...

This paper presents the numerical investigation of the effects of the general bed characteristics such as superficial gas velocities, bed temperature, bed heights and particle size, on the direct synthesis in a 3D fluidized bed reactor. A 3D model for the gas flow, heat transfer, and mass transfer was coupled to the direct synthesis reaction mechanism verified in the literature. The model was v...

Twenty-eight coupled observations of flow, transport, and bed surface grain size distribution were made in a laboratory flume using a wide range of flows and a sediment with a very poorly sorted, bimodal grain size distribution. These observations permit the transport rates of individual size fractions to be scaled by the proportion of each size immediately available for transport on the bed su...

Bed surface particle size patchiness may play a central role in bedload and morphologic response to changes in sediment supply in gravel-bed rivers. Here we test a 1-D model (from Parker ebook) of bedload transport, surface grain size, and channel profile with two previously published flume studies that documented bed surface response, and specifically patch development, to reduced sediment sup...

Representative bed material samples were taken from the two gauging sites on rivers omi for sieve analysis to obtain the grain size distribution of its bed materials. The analyses of the grain size distribution showed that the bed load accounted for 9% of the total estimated suspended sediment load of 1,703, 548.113 kg/annum in river omi. River omi bed material had a geometric mean particle siz...

Bed surface particle size patchiness may play a central role in bedload and morphologic response to changes in sediment supply in gravel-bed rivers. Here we test a 1-D model (from Parker ebook) of bedload transport, surface grain size, and channel profile with two previously published flume studies that documented bed surface response, and specifically patch development, to reduced sediment sup...

Effects of interstitial air on the motions of a large intruder in a shaken granular bed are studied experimentally as a function of ambient air pressure, particle size of the bed, and the density of the intruder. It is found that the intruder always rises from the granular bed in the absence of air. However, the intruder can acquire both positive and negative buoyancy in the presence of air. Ne...

this study was designed to present and compare iranian hospitals` performance applying ratio analysis technique.this cross-sectional survey was conducted to present an instant image of 139 iranian hospitals` performance status applying ratio analysis as one of the non parametric technical efficiency assessment methods in 2008. data was collected using nine dimensional questionnaires supported b...

Packed bed reactors have many applications in different industries such as chemical, petrochemical, and refinery industries. In this work, the effects of some parameters such as the shape and size of particles, bed size, and bed length on the hydrodynamics of the packed beds containing three spherical, cylindrical, and cubic particles types are investigated using CFD. The effect of the combinat...