Numerical study of wall normal stress and discharging characteristics for gravity blending silo

In this work, the wall normal stress and the discharging characteristics of the granular material of gravity blending silo were numerically studied. The simulation accuracy of wall stress distribution and the granular discharge capability were separately verified by experiment. The over pressure and loss pressure phenomena during discharging, the redistribution of the wall normal stress of silo with internal blending pipe, and the influence of blending opening parameters on the performance of the discharge were examined. The results showed that: (1) the maximum over pressure values of transient pressure peak and stable wall normal stress during discharging were not more than 5 times and 2 times of the static pressure values, respectively. The inner blending pipes could dramatically reduce the over pressure. (2) The inner blending pipes could also disorganize wall stress and produce pressure screening effect. The mean values of dimensionless pressure for the four simulated blending pipe locations were all approximately 0.65. (3) The closer the opening of the blending pipe to the granular surface, the larger the discharging mean mass flow rate. (4) The vibration blending pipe could gently improve the granular flow capability. The controlled amplitude conditions had a better impact on the flow capability than the vibration frequency.

Graphical abstract