Abstract: The atomization process is the key control step in catalyst forming by spray drying technology, and the atomization results directly affect the particle size distribution of the final product. Aiming at the problem that it was difficult to measure the intermediate process of the transient atomization process by the experimental method, and it was difficult to simulate the process effectively because of the complexity of the process, the atomization process was divided into two parts: the first stage atomization and the second stage atomization, and the liquid film tearing process of the first-stage atomization was simulated by the volume of fluid (VOF) model, the volume of fluid-deformable component model (VOF-TO-DPM) was used to simulate the secondary atomization, which greatly reduced the computational load. The results showed that when the feeding pressure was over 4 MPa, the primary atomization was sufficient and the droplet size was basically unchanged. The droplet size presented a bimodal distribution, and the smaller droplet size was mainly concentrated in about 40 μm, and the large droplet size was mainly concentrated in 95~100 μm. The higher the feed pressure was, the fuller the primary atomization and the larger the initial velocity of the droplets was, and the more the small droplets were produced by the secondary atomization. The comparison between the simulation results and the test results showed that they were in good agreement, indicating that the simulation results had a good accuracy.

Key words: catalyst forming, spray drying, atomization process, step-by-step simulation