Investigation on distribution of particles in inlet region of an FCC external catalyst cooler with different inlet structures

Abstract

An external catalyst cooler has been widely used in fluid catalytic cracking, its stability and heat transfer performance are affected by non-uniform distribution of particles in inlet region. Therefore, particles distribution of inlet region is investigated. Most particles flow rapidly to the opposite region to the inlet in the parabolic form in the original structure. Two new inlet structures are designed, which are made of a decelerator and a rectifier plate. For inlet structure 1, particles velocity is decreased obviously by the decelerator and they are divided into two parabolic streams. For inlet structure 2, particles flow into the bed in the form of three parabolic streams due to the groove above the rectifier plate. Particles distributions are improved at Gs = 120–750 kg/(m2·s) in two new inlet structures, while the structure 2 has superior effect. The empirical correlations predicting the uniformity of particles distribution in three inlet structures are obtained.