in this paper, combustion of char in the riser of circulating fluidized bed was modeled using aspen plus. since physical and chemical phenomena are involved in the process, the model integrates the two-phase hydrodynamic sub-model with the reaction sub-model derived from the literature. in the proposed model, the fluidized bed is divided into several sections and the behavior of each section wa...

In this study, thermochemical biomass gasification was performed on a bench-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Distillers grains, a non-fermentable byproduct of ethanol production, were used as the biomass feedstock for the gasification. The goal was to investigate the effects of furnace temperature, steam to biomass ratio and equivalence ratio o...

Changes in the physical properties (such as particle density, bulk density of the bed, shrinkage and bed porosity of fresh green peas particulates were compared at 50 o C, during fluidized bed drying and fixed bed drying. Empirical relationships of the following nature were developed for the changes in shrinkage [VR = A + B MR], particle density [ρ p = A + B MR + C exp (-DMR)], and bulk density...

One significant factor in the operation of a fluidized bed combustor is the manner in which coal particles disperse and mix with the bed material upon entering the bed. A thermal tracing technique was used to study the mixing characteristics in a 1/4 scale model of a pressurized bubbling fluidized bed combustor. Particles cooled by liquid nitrogen are injected into the bed in the same way that ...

The production of granules by wet granulation in a fluidized bed was assessed after the construction of a quality index based on a file of attributes (relevant factors). These attributes are combined by a methodology relying on Correspondence Analysis, as a discriminant procedure, using two extreme simulated active vectors representing, respectively, the best and the worst cases for the granule...

Fluidized bed techniques are employed in coal combustion power plants, because they allow for the use of low-quality fuel and result in low pollutant emissions. The most important dynamical difference between fluidized beds and normal combustion chambers, is that the former are characterized by a significant loading of carbon, usually absent in conventional plants. Fluidized beds are remarkably...

conclusions results indicated that annular fluidized bed reactor’s adsorbers are useful techniques for vocs adsorption. comparison of two particle ranges indicates that in all concentrations and all flow rates of the experiments, smaller particle size adsorption are better. in superficial velocity above the minimum fluidization velocity, pressure drop of fluidized beds are less than the pressur...

Natural substrates like sand, soil, leaf litter and snow vary widely in penetration resistance. To search for principles of appendage design in robots and animals that permit high performance on such flowable ground, we developed a ground control technique by which the penetration resistance of a dry granular substrate could be widely and rapidly varied. The approach was embodied in a device co...