Dynamic behaviors of feed jets and catalyst particles in FCC feed injection zone

The gas-solid dynamic behaviors in FCC feed injection zone are investigated by analyzing the solids holdup fluctuation signals. Four different phases are found during the mixing between jet and particles, i.e., the cluster phase, the denser dispersed particulate phase, the diluter dispersed particulate phase and the gas phase (without particles). The clusters in the feed jets-solids mixing zone are identified by combining wavelet decomposition with sensitivity analysis method. The time fractions of different phases in the upward and downward feed injection schemes are calculated to show the effects of different types of injections. Results show that the time fractions of cluster phase and gas phase are quite high in the feed influence zone of upward injection scheme. While low cluster and gas time fractions as well as high dispersed particulate time fraction are obtained when the injections are downward. (C) 2018 Elsevier Ltd. All rights reserved.