a comprehensive mathematical model based on the discrete particle model and computational fluid dynamics was utilized to investigate mixing and segregation of particles in fluidized beds at high pressure. to quantify the extent of mixing in the bed, the lacey mixing index was used. simulations were carried out with different mass fractions of small particles at various pressures ranging from 1 ...

computational fluid dynamics (cfd) is a computational technology that enables researchers to study the dynamics of things that flow. by using cfd, it is possible to build a computational model that represents a system under study. it not only predicts fluid flow behavior, but also the transfer of heat, mass, phase change, chemical reaction, mechanical movement, and stress or deformation of rela...

a linear low density polyethylene (lldpe) production process, including two- fuidized bed reactors in series (fbrs) and other process equipment, was completely simulated by aspen polymer plus software. fluidized bed reactors were considered as continuous stirred tank reactors (cstr consisted of polymer and gas phases). poly-srk and nrtl-rk equations of state were used to describe polymer and no...

microwave assisted fluidized bed drying is a novel drying technique which reduces drying time and yields higher quality products. in this study the effect of this method on color changes of whole and cut hazelnut kernels was investigated. the parameters of color and resulting total color change, chroma, hue angle and browning index were also calculated during drying in three temperatures (40, 5...

canola is known as an important oilseeds crop throughout the world. cultivation and subsequent oil extraction of this crop has gained substatantial development in recent years in iran. many parts of iran (northern provinces) especially golestan and mazandarn are of high relative humidity during harvesting season as well as during storage periods. spoilage and rancidity are problems more encount...

A two-dimensional balance model of populations distributed by property was developed using the ordinates of particle diameter andparticle density. This model makes it possible to calculate the spectrums of granulation changing over time in the fluidized bed duringbatch operation and in addition to calculate the time-dependent size distribution of the product granulate for continuous...

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 mathematical model for the fluidization of polydisperse suspensions is developed. The stationary concentration configurations for a given fluidizing velocity are analyzed and a mixing condition for bed inversion is derived. A central finite difference scheme is applied to the simulation of the fluidization of a bidisperse suspension. The numerical simulations agree with the experimentally rep...

T he concept of chromatography in Expanded Bed Adsorption (EBA) was first proposed in early 90s. The initial advantage of the idea was to be able to directly process particulate containing biological feedstocks for target products, while still maintaining sufficiently high separation efficiency that is usually enjoyed only by the traditional chromatography columns. EBA could potentially replace...