جستجوی مقالات مرتبط با کلیدواژه "کوره دوار" در نشریات گروه "مکانیک"

In this study, the computational fluid dynamics (CFD) simulation of an experimental 350 kg cast iron rotary furnace was conducted for the aim of optimizing its fuel consumption and pollutants reduction. The furnace is divided into 3 distinct simulation zones: a) solid charge zone with liquid-solid phase, b) combustion zone with gas phase, and c) solid rotating zone or furnace refractory wall. These three zones are three-dimensionally and transiently modeled in terms of the leading phenomena within each zones and interfaces. The simulation in each region is based on the simultaneous solution of hydrodynamic equations, including vortex dissipation and chemical reaction kinetics equations. The simulation results for the outside wall temperature of the furnace body are in close agreement with the data obtained from experimental units. Furthermore, melting rate, NOx and CO pollutant generation, specific fuel consumption, rotating speed, preheating of combustion air, excess air percentage, and pollutant production were all evaluated in this simulation. Changing the furnace configuration decreases fuel consumption by 5%, which is important in terms of improving fuel consumption and alloy product quality in this furnace.  The results of this study can be used to optimize the industrial rotary furnace operations.

This paper aims at force analysis of rotary kiln elastomers under static, dynamic, and thermal loadings. The main goal is to extract maximum shear and normal forces which should be tolerated by the elastomers in severe operational conditions. The understudy rotary kiln has two supports, each comprises two stations, which is made by Polysius Company and installed in the Neyzar Qom Cement Company. At each station, the elastomers are distributed in two levels with different orientations to handle the constraint forces caused by different applied loadings. In this project, first, the three-dimensional CAD model of the kiln is produced. Then, based on the severe operational conditions which were reported by the manufacturer and the cement company, the force analysis is conducted by means of a commercial finite element software package. In order to validate the accuracy of the results, some of them will be compared with simple engineering calculations as well.

Rotary kilns have some applications in industrial due to high production capacity, uniform and extensive combustion. Rotary kiln performance not easy and despite of technology development, the problems exist in the filed from combustion them. Reasons of some problems are separate design of burner and kiln and inattention to coordination and harmony between them. According to in the present study, flame behavior has been studied under governed condition on the kiln and secondary air flow. In the first step, suitable methods and models are verified on the basis of benchmark problem due to lack of experimental data. Finally, rotary kiln simulation done with realizable k-ε turbulence model, partially stirred reacting flow combustion model and P1 radiation model. The present simulation done in OpenFOAM open source software by using reactingFOAM solver. Also in the present work, ability of applying radiation model has been created with addition source term to energy equation and ability of applying rotation boundary condition has been created with addition source term to momentum equation. According to obtained results, applying of gravity acceleration leading to deviation of flame to the upper wall. The results show that radiation heat transfer is important in the governing condition on the problem. Finally, effect of excess air studied on the temperature distribution that obtained results show temperature of kiln and wall temperature kiln reduced with increasing of excess air percent in the investigation limit.