The Integration Study On Coking Coal Moisture Control And Classification In Vibration Fluidized Bed

China is a big country of coke production, owing an annual output of100million tons. Clenedcoal is used in domestic coke plant as coking coal, which has a high moisture content. A large amount of water comes into the coke oven with clenedcoal, making loss of furnace body, increasing the consumption of gas and generating a large number of coking wastewater, which has a bad influence on the production. Hence the control of coal moisture is needed.Coal moisture control technology has well solved this problem. And the vibration fluidized bed coal moisture control technology has been recently developed as the4th generation of CMC. This technology has both coal moisture and particle classification function, and does well in economic benefits and environmental effects. It’s expected to be energetically popularized. Mechanism study on vibration fluidized bed coal moisture control is rare and limited to the aspects of fluid dynamics. Meanwhile, the concept of grain grading is relatively vague in the actual production. These shortcomings restrict the further perfect of the technology.This article launched the research from two aspects:coal moisture and particle classification. Though analyzing the flow phenomena of the coking coal grain entering the vibration fluidized bed, which are different from in the general fluidized bed. We found out the flow law, and pointed out that in the steady flow state there may be three kinds of classification:large particles vibrated layer, middle particle suspension-vibration coexisting layer, and small particle suspended layer. Though analyzing the drying mechanism, we found out that small particles have a constant rate drying stage, large particles experience a reduction of speed in drying stage and middle particles may owe both these two stages. By measuring the particle size distribution and density distribution of coking coal, according to particle settling velocity, we precisely defined the particle classification model. By measuring the coal moisture content distribution, we verified the deduction of coal particle drying stages. And it indicates that, particle size range:0.6-3.2mm, moisture content over10%, accounting for more than80%of the total quality, is the main part of coking coal. The setting of operating parameters in the drying process of VFB should based on this part. Particle size range:>4.0mm, moisture content below6%, has reached the drying target, should be discharged form the bed immediately.Based on the grading model and the analysis of drying process, this article established corresponding drying model for different drying model of coking coal. Thus we could avoid the problems of a single drying model describing the drying process of coking coal in VFB in the previous research. By establishing differentiated drying models, we could describe the drying process of coking coal particle precisely and offer references to further study of fluidized bed.