Discharge characteristics of cohesive fine coal from aerated hopper

This paper presents some experimental results of discharge characteristic of cohesive fine coal from aerated hopper. A plexiglas hopper was used to visualize the flow pattern of the coal discharge. Arch can be easily formed during the gravity discharge. The addition of gas can improve the stability and the flow rate of the discharge. At low gas flow rate, two kinds of flow pattern existed at the same time, mass flow and swirl flow. As the gas flow rate increased up to a high level, gas balanced arch occurred, and the discharge rate decreased sharply. In addition, the effect of aeration pattern and outlet diameter on the coal discharge has been studied. Different aeration position results in different flow pattern and stability. Controlling the gas flow rate can realize maximum discharge rate. During the aerated discharge, the influence of outlet diameter and bulk status is changed with the gas flow rate compared with the gravity discharge. According to this law, a new model has been developed to predict the mass flow rate.