Papers by Keyword: Cyclone

Abstract: Cenospheres are valuable material contained inside the fly ash. Its low weight, low density, and high strength made it very versatile and can be used in various fields. The way of separating the cenosphere from the fly ash consists of two categories, wet and dry separation. For wet separation, it involves submerging the fly ash inside a mixture made either by pure acetone, pure water, or a mixture of water and acetone with different mixing ratios before stirring the mixture. The cenospheres, floating on top of the mix due to low density, can be collected and dried. The dry separation technique involves putting the fly ash into a cyclone separator at a constant velocity. The fly ash will then move into the bottom of the cyclone. Particles can also be separated by diameter sizes by sieving. By manipulating various parameters, cenosphere yield may differ. This paper is written to help gain more understanding on cenosphere properties and its separation method.

Abstract: Drying is a simultaneous process of heat and mass transfer and dimensional changes. In recent years, cyclones have been used as a modern drying technology. In this sense, this research proposes a numerical study to describe drying of sugarcane bagasse, using the cyclone as dryer. Herein, it was adopted the Eulerian-Lagrangian model in steady state. The Reynolds stress model was considered to describe turbulence of the gas phase, while a transient lumped model was used to describe heat and mass transfer on the particulate phase (sugarcane bagasse). Particles were considered with irregular shape, composed of a binary mixture (solid part and water). The solution of the proposed model was obtained using the commercial software Ansys CFX 12. Results of the moisture content, temperature, dimension variation, and paths of particles, as well as velocity, pressure, and temperature distributions of the gas phase inside the cyclone are presented and analyzed. It has been found that the obtained components for axial and tangential velocity inside the cyclone are in good agreement with experimental data available in the literature, and that the drying kinetics, heating, dimensional variations, and residence time of particles are affected by the velocity of the gas phase, velocity of the particles, and the flow direction of gas and particles at the entrance of the feed duct.

Abstract: Countercurrent cyclones have been quite widely applied in various industries [1-12]. In this paper, on the example of classical construction of countercurrent cyclone considers the impact of the conical nozzle on the exhaust pipe to the gas-dynamic picture and efficiency dedusting.

Abstract: Cyclone and cold front are the important weather systems causing storm floods in Dahuofang reservoir. Through analyzing the precipitation daily distribution and flood processes affected by cyclone and cold front weather systems, the influence of different weather systems on reservoir flood control has been summarized. The study results show that flood processes caused by compound weather systems are the most serious threat to reservoir flood control, while flood processes caused by single cold front system have the least risk to reservoir flood safety and the flood threat caused by single cyclone is intermediate.

Abstract: In order to investigate the characteristics of C1 cyclone in a 5000t/d cement production system, the gas flow velocity, pressure and raw particles movement trajectory in this cyclone was simulated on the basis of Fluent 6.3. The RNG k-ε turbulence model and the stochastic trajectory model were proposed. The results indicate that the gas flow velocity and pressure distribute symmetrically, the raw meal particles revolve along with the whirling flow and can be separated more efficiently from the gas in this cyclone.

Abstract: This work presents a 3D computation of fluid-structure interaction in a cyclone separator. The finite volume method was used to simulate the flow field in the cyclone separator. The fluid-structure interaction was conducted by transferring the computational pressure distribution to the corresponding surface of the cyclone shell. The stress and deformation distribution in the cyclone shell was computed by the finite element method. Results obtained show that the maximum equivalent stress and deformation is linearly increases with the increases of the inlet gas velocity.

Abstract: Large eddy simulation to describe the turbulent flow of airflow field was used to calculate the unsteady turbulent flow characteristics in the cyclone. It funded that the tangential velocity in the cyclone profile behaved like rankine vortex, with the downward semi-free vortex of the outer layer and the upward forced vortex. With the increasing import gas velocity, the swirling strength of the center increased which reduced collection efficiency by clouding the dust particles in the ash bucket to the center airflow.

Abstract: In order to achieve the purpose of pre-dusting device efficiency, low resistance, energy-saving after dense phase Semi-dry flue gas desulfurization system. In this paper, computer numerical simulation as the main research method, use single factor and orthogonal method, simulation study of the various factors that affect the performance of the octagon separator, get the law of different factors for separator performance. And designing a separator structure model, use this model as a sintering plant dense phase pre-dusting device after the semi-dry flue gas desulfurization system, get the separation efficiency of 37.6% , obtain the desired effect of better engineering.

Abstract: A new approach to the gamma-ray densitometry tomography(GDT) technique was proposed for measurement of gas-solid flow in cyclone, where the time average concentration field can be simplified to continuous function and symmetry system, based on only one bunch of through the regional center’s ray and another distance the center d position’s ray data, through the measurement of body. So it realized faster data acquisition and image reconstruction, and possessed both the continuous function model’s high gradient of radial concentration distribution and highly accuracy. Due to the collected data were severely diminished, the method sharply reduced the cost of image scans mobile system. The numerical simulation proved the accuracy of that algorithm base on gamma-ray computed tomography method for gas-solid time average concentration field in cyclone

Abstract: The cyclone plays an important role in the downhole oil-water separator during artificial lift for high water cut oil well, the processes of oil-water separation is completing in the cyclone. The oil-water cyclone separator was designed based on the oil and water density contrast and the cyclone separation theory; the laboratory experiment of cyclone separator was carried out and the relationship of the cyclone oil cut of apex and split ratio, oil-water separation efficiency and the velocity , the pressure loss of the cyclone and the velocity were also studied. When the reinjectivity is within 70% of the produced volume, cyclone separator has good water-oil separation ability, split ratio increased with the increase of the vecolity, when the flow vecolity reached 0.25m/s, the split ratio over 30%. But with the increase of the velocity, the increased rate of the split ratio is reduced. The relationship of the flow rate and cyclone intrinsic pressure loss is nonlinear exponential curve.