Numerical Simulation of Fluid Field and Temperature Field Within the Rotary Vane Dryer
|Course||Mechanical Manufacturing and Automation|
|Keywords||Rotary Vane Dryer drying with convection fluid field temperature field Two-phase flow|
The Rotary Vane Dryer can be regarded of a combination of Heated Transport Dryer and stirred Dryer. Pneumatic drying that used in the Rotary Vane Dryer is one method of drying with convection. It is fit for drying high humidity level and high viscosity materials. The research of dryer is a complicated work, which involve multidisciplinary and multi-field. We introduce the principle of work of the Rotary Vane Dryer. We also summarize the theory of drying and heat transfer and hydromechanics. According to the characteristic of the Rotary Vane Dryer, it is an important work to choose a right mathematical model.This dissertation analyzes the fluid field and temperature field of the Rotary Vane Dryer with the computation fluid mechanics software FLUENT. To analyze the single-phase gas, it is feasible to choose the k-εturbulence model. It provides the exact date basis for optimizing the dryer structure. This dissertation simulates the fluid field and temperature field in the dryer with different height of the grid plate. Through study of the numerical simulation, we can see that the lower of the grid plate, the easier to form backset. The backset can prolong the dwell time of the materiel, which is beneficial for the drying quality. But if the grid plates are too low, there are not more improvements for the structure. There should be a best position for the grid plate between its original position and the agitating tank.This dissertation researches the Rotary Vane Dryer in drying sludge. This research reveals the fluid field, temperature field, pressure filed and the distribution of the sludge with the Two-phase flow Models and Species Transport Models. In this dissertation, it is a conception to include the factor of evaporation. For the low humidity sludge, it is high volume fraction in the circumfluence field of the foreside and rearward of the dryer. The drying velocity is high in the foreside of the dryer, and the temperature decreases rapidly. It matches up to the practical situation.Additionally to obtain the distribution of different material, this dissertation chooses the Modeling Discrete Phase. There are two kinds of particles in the analysis, one’s diameter is 0.01mm, and the other’s diameter is 0.1mm. In this section it is feasible to get the distribution of the particles. Through the study of the simulation, we can see that the most of small particles stay in the upside of the dryer and shipped out through air outlet to the gas cyclone separator, while the big particles usually distribute in the agitating tank and shipped out through material outlet.This dissertation provides a proper method for the research of the Rotary Vane Dryer. It proves that the method is right though comparing with the practical process. The result of simulate provides the basis for reorganization and the selection of operating parameter.