Research on Flow Characteristics of Pulverized Coal in a High Pressure Blow Tank

Abstract

In the present study, the flow characteristics of a top discharge blow tank at high pressure were investigated. Experiments on discharge properties of pulverized coal in dense-phase pneumatic conveying system with a high pressure blow tank were carried out. The influences of fluidizing velocity, pressurizing velocity, transporting differential pressure, sending pressure in the blow tank and pulverized coal diameter on the solid mass flow rate were studied. The experimental results indicated that the ratio of fluidizing velocity to pressurizing velocity was of great importance on the solid mass flow rate and there existed an optimum range. The solid mass flow rate increased as the transporting differential pressure and sending pressure increased. The increase of particle diameter led to the decrease of the solid mass flow rate. A model for determining the solid mass flow rate has been formulated using dimensional analysis. It was found that the calculation results were in good agreement with the experimental data. Finally, a kinetic–frictional model, which treated the kinetic and frictional stresses in an additive manner, was incorporated into the two fluid model based on the kinetic theory of granular flow to simulate the transient behaviors of the high pressure blow tank.