This work reports on the recent advances in the continuum approach to dusty gas flow modeling through isotropic porous structures. This approach has received considerable attention over the last half century due to the need to develop dusty gas flow models capable of describing natural and industrial transport phenomena, including subsurface transport of dissolved or suspended particulates, des...

fast pyrolysis is an attractive technology for biomass conversion, from which bio-oil is the preferred product with a great potential for use in industry and transport. corn wastes (cob and stover) and eucalyptus wood are widely being produced throughout the world. in this study, fast pyrolysis of these two materials were examined under the temperature of 500 °c; career gas flow rate of 660 l h...

Thermal creep flow (TCF) is a flow of gas driven by a temperature gradient along a solid boundary. Here, TCF is demonstrated experimentally in a dusty plasma. Stripes on a glass box are heated by laser beam absorption, leading to both TCF and a thermophoretic force. The design of the experiment allows isolating the effect of TCF. A stirring motion of the dust particle suspension is observed. By...

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...

A Large Eddy Simulation approach for Eulerian-Eulerian dispersed two-phase flow is presented. It is shown that not only a Sub-Grid Scales term modeling the unresolved field in the mesoscopic momentum transport equation of the dispersed phase, but also a stress term modeling the Random-Uncorrelated Motion is needed. Simulations of a non-homogeneous particle laden turbulent gas flow allow to comp...

In this paper, a double-cyclone is used as a gas-solid separator in the fluid bed-drying process to prepare dry HDPE powder from a wet feed of 56000 kg/hr. The quality of dry HDPE depends mainly on particles behavior and flow pattern in the dryer which affect the double-cyclones as an effective equipment in this process. Controlling of the inlet carrier gas causes excellent flow pattern, desire...

While built on a sound physical foundation, isentropic, one-dimensional models generally used to analyze the dynamics of dilute two-phase (feed-powder particles suspended in a carrier gas) flow during the cold-gas dynamic-spray process, require the use of numerical procedures to obtain solutions for the governing equations. Numerical solutions, unfortunately, do not enable an easy establishment...

The local solid flow structure of gas-solid bubbling fluidized bed was investigated to identify and characterize the particle clusters. Extensive mathematical calculations were carried out using the energy-minimization multi-scale (EMMS) approach for evaluating cluster properties including the velocity, the size and the void fraction of clusters in the dense phase of the bed. The results showed...

A detailed numerical study was conducted on the dynamics and thermal response of inert, spherical particles in strained, laminar, premixed hydrogen/air flames. The modeling included the solution of the steady conservation equations for both the gas and particle phases along and around the stagnation streamline of an opposed-jet configuration, and the use of detailed descriptions of chemical kin...

This work presents a computational study of flow behaviour in a bubbling fluidized bed polymerization reactor. The model is developed by using the commercial CFD code Fluent 6.3. The model is based on an Eulerian description of the gas and the particle phase. The effect of distributor shape on fluidization is analyzed using the inbuilt Gidaspow and Syamlal-O’brien Drag Model. The computational ...