This paper presents a numerical investigation for laminar forced convection flow of a radiating gas in a rectangular duct with a solid element that makes a backward facing step. The fluid is treated as a gray, absorbing, emitting and scattering medium. The governing differential equations consisting the continuity, momentum and energy are solved numerically by the computational fluid dynamics t...

Nanopowders are applied in a wide range of processes, and their use continues to increase. Fluidization is one of the best techniques available to disperse and process nanoparticles. However, nanoparticles cannot be fluidized individually; they fluidize as very porous agglomerates. Often, it is needed to apply an assisting method, such as vibration or microjets, to obtain proper fluidization. I...

An experimental investigation of hydrodynamics gas-solid flow is carried out by engaging different designs air distributor plates. analysis three plates, i.e., perforated, 45° slotted and novel hybrid plate, revealed the difference in pressure drop minimum fluidization velocities (Umf) for varying input operational variables. Umf found to be lowest perforated highest whereas plate plate. The bu...

effective methodologies for efficient preparation of semicarbazones from aldehydes or ketones via milling and the subsequent regeneration of the parent carbonyls by gaseous nitrogen dioxide are described under solid-solid and gas-solid reaction conditions, respectively. these methods are fast, simple and environmentally benign which do not require the use of any auxiliaries such as catalysts or...

This work presents a computational study of flow behaviour in a bubbling fluidized bed. 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. Different drag models are used and compared. The computational results are validated against experimental results. The experimental data are taken from Hulme (2...

n this work, computational fluid dynamics of the flow behavior in a cold flow of fluidized bed is studied. An improved finite volume based finite element method has been introduced to solve the two-phase gas/solid flow hydrodynamic equations. This method uses a collocated grid, where all variables are located at the nodal points. The fluid dynamic model for gas/solid two-phase flow is based on ...

C ERTAIN attention is paid today to the weaknesses of the classical blast furnace process, and interest is continuously increasing in methods for direct reduction without melting. Several different methods have been developed or suggested in the past, but so far only a few have been adopted for practical use. Another tendency in the iron industry of today is the change-over to concentrates, wit...

Fluidized beds are used in a variety of process industries because they provide uniform temperature distributions, low pressure drops, and high heat/mass rates. Minimum fluidization velocity is an important factor in understanding the hydrodynamic behavior of fluidized beds, and this characteristic may be modified through high frequency (sound) vibrations. The effects caused by sound wave frequ...