Research On A Novel Spouted Bed Drier With Rotating Draft Tube

For its advantages of higher thermal-efficiency, capability of dealing with heat-sensitive materiel and can be used in many chemical operations, spouted bed has being studied extensively for many years. Up to now, there are many kinds of spouted beds with different structures, but they can't be used wildly in the filed of industry due to their limitations.Spouted bed with draft tube is a good type of spouted bed, it's spouting region and annular region is separated by draft tube to void percolating from each other. It can deal with smaller or larger particles, increase the max height of loading, decrease pressure drop. However spouted bed with draft tube can't still be scaled up to industrial dimension. Thus we dream up a novel structure based on spouted bed with draft tube. The draft tube in the center of new spouted bed is structured of rotating part and fixed part. The rotating draft tube can distribute particles to annular region equably.. This structure can eliminate backtrac king of spouting particles, so it is helpful to scaling up the spouted bed. The thesis is studying the feasibility of this novel structure.Taking wheat as experimental material the hydromechanical characteristic of spouted bed with rotating draft tube was researched in the thesis, and it included the relationship between gas velocity and pressure drop, gas flow rate and wheat mass flow rate, and the circulation of particles. And the curves of their relationship were gotten.A great deal drying experimentations were carried on in the novel spouted bed, including loading experimentations, optimizing experimentations, variable temperature experimentations, intermittent drying experimentations. The best combinations of technical parameters are obtained, drying curves and heat consumption per kg water. And compared the result to preventions researching results. The loading quantity of particles has distinct influence , and the best quantity is 25 kg. In optimizing experimentations, the air temperature and loading quantity are the main factors affecting heat consumption per kg water . Under this spouted bed best technical parameters are: air temperature 90℃, gas flow rate 98m~3/h, loading quantity 25kg.In the fifth chapter of this thesis mathematical model on transfer in this new spouted bed is set up., theoretic value and experimental value is quite close.