The heat and mass transfer processes between gas phase and solid wet particles are studied. The corresponding complete set of partial differential equations (PDEs) is solved by a new numerical technique. Some qualitative expectation about the behaviour of the dependent variables enables the definition of the system of discretized equations, which is solved by an original technique. The numerical results obtained are in good agreement with the experimental results that can be found in the literature. The method shows itself to be a robust and powerful tool to deal with the numerical simulation of static dryers or other similar processes.