关键词: 提升管, 射流, 进料段, 压降

Abstract: Riser reactor is the core equipment of the catalytic cracking process. In an industrial riser reactor, the feed oil is usually injected by multiple high-speed nozzles to mix and react with catalyst particles. As an important monitoring data, the pressure drop in riser not only reflects the fluidization state but also determines the energy consumption of the process. However, most studies on the pressure drop in riser do not consider the effect of feed injection. The model to predict the pressure drop in the feed injection zone of riser needs to be improved. In this work, the pressure drop in riser under the effect of different types of feed injection is investigated through large-scale cold mold experiments. The dynamic data of both total pressure drop and pressure drop from different sections in riser are collected. Results under the influence of upward injection and downward injection are compared. Besides, the pressure drop characteristics of each section in the riser are analyzed, and the influence of different operating conditions is analyzed. Generally, both the total pressure drop and the pressure drop from each section of riser are larger when the catalysts contact with feed injection by countercurrent way. For both upward and downward jets, the total pressure drop and the pressure drop of each section in riser decrease with the increase of the pre-lift gas velocity, increase wiht the increase of solid flux. When the jet velocity increases, the total pressure drop and the pressure drop of each section in riser do not change significantly when the catalysts contact with feed injection by cocurrent way. On the contrary, for the countercurrent contact situation, the total pressure drop of riser and the pressure drops in the feed mixing and fully developed sections increase significantly. Combined with the traditional riser pressure drop model and dimensional analysis, pressure drop models for the feed mixing and fully developed sections in riser are established, which can be used as a reference for engineering design.

Key words: riser, jet, feed injection zone, pressure drop