Study On The Novel Gas Stream-Screen Calssification Equipment

The thesis firstly introduces the classification theory and evaluation standard. For the specific requirement of classification industry, combined the advantages of classifiers with and without screen, a novel gas stream-screen classifier was designed and studied. This assembled classification conception was first put forward, putting screen into gas stream classification. The machine breaks through the particle diameter lower limit of traditional screen classifier, and eliminates the disadvantage of gas stream classifier in which the product has a few big particles.With this novel classifier, the thesis mainly studies the factors influencing performance of the classifier: barrel structure, material feeding rate and gas velocity. Several geometries were designed and the corresponding experiments were done. If the structure designed isn't reasonable, the classification efficiency maybe decrease, the results indicated that the classification efficiency would be high when cone-shaped inner barrel with diversion blades was installed. Material feeding rate has some influence on the powder dispersion and the efficiency. In some range, material feeding rate has big influence on the efficiency. For a specific screen, there exists optimal gas velocity, so the optimal gas velocity should choose while operating.It was found in the experiments that the new gas stream-screen classifier is suitable for dealing with the powder diameter from 38μm to 106μm.Based on the practice, the novel gas stream-screen classification system which is applied for industry was proposed.