Study On Impinging Stream Drying Of Wood Fiber

Impinging stream dryers is a new kind of equipment which is being studied in the world. It takes advantage of the high intensity of turbulence that develops as a result of collision of two or more oppositely directed high velocity gas streams and of the rapid unsteady particle motion in the impingement zone to enhance significantly the heat and mass transfer processes and hence dry wet material in a very short time. It has highly intensive and rapid drying features and maintains high product quality. This advanced class of dryers is fit to dry microbial products, dispersed materials as well as those complicated materials that have high thermo sensitivity, are easy to be condensed and hold high bound water. Therefore, it may be used extensively in process industries.In the present thesis, experimental study on the wood fiber impinging stream drying was performed on vertical-inclined semi-circular combination impinging stream dryer. Experimental study on the influence of air velocity, air temperature, mass loading rates and initial moisture content of materials etc. was made, and then carried out product quality analysis by impinging stream drying. The test results showed that the combined impinging stream drying not only solve the problems of impinging stream drying used for drying high moisture sticky materials, but also can make full use of drying ability of hot air to improve the drying of materials; the influence factors of material decline water percentage is air temperature, the mass loading rates and air velocity; increasing air temperature and chose loading rates properly is the best way to improve the remote water percentage; the combined impinging stream drying can maintains high product quality.In this paper, the single fiber dynamics model is use to describe the flow performance of wood fiber; research on heat and mass-transfer performance of wood fiber impinging stream drying. In the foundation, the hydrodynamics and heat and mass-transfer mathematical model of wood fiber impinging drying was developed according to the hydrodynamics principle between fiber inner part and air current heat and mass-transfer. For prepare to realize wood fiber factory production.