Numerical Analysis Of Gas-solid Flow In The Fluid-bed Dryer For Coking Coal

The moisture content of coking coal was more than 11% which used for metallurgy, and the coke oven consumed lots of heat due to water vaporization, it is an important pretreatment measure to remove water rapidly and effectively. This paper researched the concentration distribution of coking coal, the coking coal velocity distribution and the classification phenomenon of different size particles with CFD software.Numerical simulations are better achieved qualitative description of the particle movement characteristics, quantitative prediction of the flow parameters have a certain bias with the actual.A lower concentration of particles in the central region, the particle concentration of side wall was about 3 times of the middle part,while this value is about 5 times in fluidized bed boiler, particle distribution is more uniform with this new type of air distribution method. At the highest outlet, the particles have a clear classification phenomenon. The concentration of large size particles was lower than the particles with small size. Classification of middle outlet is not obvious, which is similar to the results obtained by DDPM model.When using a three-dimensional numerical model DDPM, the concentration of particles in different cross-sectional height has a clear distinction. Side outlets had a greater influence on the particle concentration distribution, middle region distributed less coking coal particles, while distributed more coking coal particles in the side wall region, even accumulation appeared in the wall.In particle size distribution results, the upper and lower outlet had a better classification than the middle outlet. In the statistical analysis of particle size, obtained a method for determining the minimum fluidization velocity in fluidized bed dryer. Finally, analyze the reason briefly for the different particle size appeared classification in fluidized bed dryer.