Abstract: In the catalytic cracking unit, the bottom of the regenerator is equipped with a pipe grid gas distributor. The gas is distributed into the regenerator bed through the nozzles on the distributor. The pressure signals in the jet area can react well to the flow characteristics of the distributor, which provide a theoretical basis for the structural improvement to reduce wear. The experimental study on the distribution of pressure and pressure fluctuation in jet area was conducted in a two-dimensional bed experimental device. The experimental results showed that the pressure of bed between the branch pipes decreases along the axial height of the bed, decreases with the increase of the jet angle, increases with the increase of the nozzle gas velocity, and the static bed height, bed pressure is determined by the amount of particles above the measuring point, which could judge different operating conditions; When the jet angle is 0 ° and 22.5 °, the pressure fluctuation between branch pipes first increases and then decreases, which corresponds to the law of bubble generating, convergenting and crushing; when the jet angle is 45.0 ° and 67.5 °, the lean phase space is formed by the jet between the two branches, the pressure fluctuation is determined by the turbulence degree of the jet and higher than that of the dense phase, increases with the gas velocity and the height of the static bed, providing a basis for reducing the external wear of branch pipes. The co-work of adjacent nozzle jet impact and particles are the factor to influence the nozzle jet pressure fluctuation. Jet pressure fluctuation at a jet angle of 22.5 ° has a critical gas velocity depending on whether it is impacted by an adjacent jet, providing a basis for the stability of the jet and reducing internal and external erosion wear of gas distributor.

Key words: fluid catalytic cracking, pipe grid gas distributor, pressure distribution, Pressure fluctuation, erosion wear