Experimental Study On Flow Characteristics Of Grain Based On Wavelet Analysis

Gas-solid two-phase flow is a flow system forms by the gas phase and solid phase, such as Gas-solid Fluidized Bed, Gas-solid Circulating Fluidized Bed and Pneumatic transmission system etc. The flow characteristics of grain are the base to choose air velocity of fluidized drying bed and pneumatic transmission system, so it is very important to recognize the flow characteristics of grain. In this paper, the pressure fluctuation signal was chose as the main carrier of information to discuss the minimum fluidization velocity and suspending velocity. There are five particles using in the experiment, such as BB bullet, mung bean, lima-bean, soybean and black soybean. The experiment of flow characteristics were done in different filling amount and different diameter of vertical tube. Through detail wavelet energy analysis of minimum fluidization velocity and the wavelet energy analysis of suspending velocity, the conclusions as the follow were obtained: with the increase of the filling amount, the minimum fluidization velocity rises, but the suspending velocity decreases; with the increase of the equivalent diameter or the effective density, the minimum fluidization velocity decreases but suspending velocity rises; in the same bed thickness, the minimum fluidization velocity and suspending velocity decrease while the diameter of vertical pipe increases.