Experimental study on the hung-up regime of a hopper- standpipe system for a Geldart-D powder

The hung-up regime of a hopper-standpipe system with and without a gas-splitting setup is studied experimentally for a Geldart-D powder with respect to the effects of the diameter of the orifice, the stagnant height in the hopper. the angle of the hopper, the length and diameter of the standpipe, and the splitting-fraction of the gas in the system with gas-splitting. The incipient condition, where the discharge rate of particles from the orifice is zero and the ultimate condition, where upward spouting occurs in the hung-up regime with interstitial gas flowing upward, are given. A method for predicting the total pressure drop of the hung-up regime in these systems is also presented. (C) 2002 Elsevier Science B.V. All rights reserved.