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. In the actual operation

there will be problems of uneven distribution of gas and a serious erosion wear phenomenon in the distributor

and they have influences on the distribution effect and life of the distributors. The study on the jet characteristics of the nozzle was carried out in a two-dimensional bed experimental device. The solid material used in the experiment is FCC catalyst particles. In the experiment

the gas flow velocity through the nozzles ranged from 30 m·s-1 to 70 m·s-1

and the jet angle of the nozzles was in the range of 0°-67.5°. The jet length of the nozzles and the flow field of the bed near the nozzle were recorded by photogrammetry. The results show that the jet length increases with increasing the nozzle gas velocity and the nozzle angle. During the process when jet gas is turned upwards

swirl vortex appears in the upper part between the two branch pipes. The swirl vortex has a great relationship to the gas velocity and the jet angle. The size of the vortex is related to the size of the dilute phase space. Finally

based on the experimental data

a calculation model about the nozzle jet length was established.