Abstract Accurate modeling of fluidized bed dryers plays a pivotal role in the design and optimization of industrial drying systems. In this work, a comprehensive mathematical model of a fluidized bed dryer is developed, incorporating mass and energy conservation for both gas and solid phases. The heat and mass interaction between solid particles and the gas phase is described utilizing the reaction engineering approach. Instead of assuming perfect back‐mixing, the evolution of gas properties is resolved along the bed height. This allows for the assessment of the impact of the initial mass of wet solid particles in the bed on drying kinetics. The obtained results indicate that the proposed model exhibits better predictive performance compared to previously published studies. Therefore, the model can be considered a useful tool for accurately predicting transport phenomena in fluidized bed drying systems.