The Spiral Flow Mechanism Of Drying System And Numerical Simulation

This article has elaborated the elementary theory of the solid-gas two phase flows, introduced the theoretical model of the solid-gas two phase flows simulation, its theoretical model has three kinds mainly at present: the continuum medium model, the discrete particle model and the pseudo particle model. In this foundation, it carries on the further elaboration to pneumatic conveying theory. In fact pneumatic conveying is the question of the solid-gas two phase flows; its numerical simulation method of the research is similar to the solid-gas two phase flows numerical simulation method. In this foundation some main parameters of pneumatic conveying have also been defined and calculated in the article.According to the object of physical working environment (heat, flow field), considering the solid-gas two phase flows theory and the pneumatic conveying theory, this article ascertained the primary influencing factor and established the mathematical model and the control equation. Basing on establishing the screw type dry system in the three dimensional entity models, applying the analysis software to carry on the numerical simulation to the screw type dry system, obtains the flow field temperature, the speed, the pressure and the material distribution in the system and so on. It provides certain theory basis for this system design. The paper also changes variously pneumatic conveying variable parameter, like the high temperature gas initial temperature, the initial velocity and the ratio of solid volume fraction and gas volume fraction, via comparing with the simulate result of each different parameter variable, to analyze how the variable parameters affects the dry result and the entire flow field movement situation, finally through the comparison and the overall evaluation, selects the most superior parameters.This topic, to carry on the screw type dry system multi-physical field coupling numerical simulation can basically and really reflect the material entire treating processes using this system. This article fundamental research method and the numerical simulation and computation method is correct and reliable. Obviously the numerical simulation technology which carries on the computation and analysis to flowing and the heat transfer process in the project question is one extremely economical effective method, also saves the manpower and physicalresource. This research results have provided the theory basis for this product further development design, simultaneously the method has provided means for the solid-gas two-phase flows research, but also has built the foundation for the practical application and the promotion in this project domain.