Study Of Dense Phase Pneumatic Conveying Mechanism & Application Study Adjustable Throat Area Laval Nozzle

Pneumatic conveying is a transportation technology using compressed energy of air to transport bulk solids particle. In recent years, pneumatic conveying is widely used in chemical, cement, power energy, food, medicament industries etc and becoming more and more important in industry application. This thesis is focused on research of bulk solids particle movement characteristic and airflow control in pneumatic conveying. Also a novel adjustable throat area Laval nozzle is designed, theory analysis and experimental contrast are made. The result shows it is overwhelming advantage to use adjustable Laval nozzle rather than fixing Laval nozzle.The basic theoretic is briefly discussed in the paper. It included the basic concept, basic parameters, analysis of force on solid particle, flow form and study method of pneumatic conveying and model of pneumatic conveying.One important thing is the following: the particle acceleration in accelerative region and the ratio between particle velocity and air velocity is discussed. Then particle movement equation is given in turbulence region and ALLEN region and provides the numerical simulation picture of single particle and group of particles which are also in turbulence region and ALLEN region. Finally, the drag force formula about dilute phase conveying is provided.The other important is about airflow control; the thesis introduced several methods about airflow control and discussed the advantage and disadvantage of different airflow control ways. Adjustable throat area Laval nozzle is studying and developing in this paper, and provide the basic theory and advantage. So author shows the adjustable throat area Laval nozzle is more adapt to airflow control in pneumatic conveying and reduce the power energy consumption, also adjustable throat area Laval nozzle numerical simulation is given and consider the influence of shock waves on...