Experimental investigation on the gravity driven discharge of cohesive particles from a silo with two outlets

An experimental study on the gravity driven discharge of cohesive particles from a silo with two outlets was performed. The discharge behaviors under the conditions that a single outlet was open and two outlets were open were investigated by varying the moisture content of the particles and the filling height of the particles in the silo. The results show that the discharge rate of the cohesive particles increases gradually at the beginning, then almost keeps constant, and finally drops obviously. The discharge rate in case of two openings is around 1.1–1.6 times that in case of a single opening. Larger filling height leads to lower discharge rate in case of a single opening but results in higher discharge rate in case of two openings. Furthermore, the avalanche dynamics in case of a single opening was examined, and the mixing behavior of the cohesive particles was evaluated. It is observed that the discharge flow is promoted by the avalanche phenomenon in the silo, generating a general trend that the normalized mass of discharge increases with the filling height at higher moisture contents. In case of a single opening, the transition from mass flow to funnel flow favors the particle mixing, resulting in an increasing mixing index as the moisture content increases. In general, a better performance of mixing can be achieved in case of a single opening compared with in case of two openings. This study provides vital information for fundamental understanding of the gravity driven discharge of cohesive particles from the silo with multiple outlets.