Spray drying is commonly used in the chemical and food industries and is the preferred drying process for many materials, such as dairy products, foods, pharmaceuticals, polymers, etc. This research focuses on the effect of the nozzle diameter in the spray drying region against velocity distribution. The results from previous studies have shown that CFD can be a useful tool for predicting the pattern of gas flow and particle histories such as temperature, velocity, time of residence and place of effect. The predictions from these model were validated against reported experimental results, and other simulations. From the simulation analysis, the present studies have identified the performance in the spray dryer through with different size of spray nozzle diameter as the parameter. For the nozzle diameter part, the smaller the spray nozzle diameter, the higher the velocity of the droplets with beneficial to the thermal efficiency of drying particles. The statements finding from the simulation of nine different case study with different nozzle diameter found that the higher velocity has been identified in simulation results due to incomplete vaporize droplets. The main impact of this study is to identify the most optimized condition of the spray dryer chamber after the analysis of the results of simulation data. In conclusion, the design on the chamber has many potential ways to be developed and improved. These findings will benefit the designing of spray dryers.
