We review recent patents on a phosphate rotary dryer, and we present in this paper two-fold. The first aim is the modelling of the phosphate rotary dryer and presentation of the dynamic model which we elaborated for the simulation. So far, no studies to investigate this have been reported. The second aim is to realize tests on the rotary dryer existing in Oued-Zem Complex of drying Khouribga-Morocco. In the present study, an improved numerical heat and mass transfer model has been developed for the rotary dryer used for drying the phosphate. The developed model is obtained on the basis of the equations of heat and mass transfer between the gaseous and solid phases. These equations are simplified by using suitable assumptions. The latter were validated by the tests carried out on the location. In order to better understand the behaviour of the product during drying process and to validate the mathematical model developed, we conducted tests on a rotary dryer installed in Oued-Zem Complex of drying. The purpose of these tests was the determination of phosphate humidity and temperature gas profiles along the dryer. The computer results show that the present model can predict the length of the dryer as well as axial solid and gas temperature distributions with reasonably good accuracy. The model developed is in a dynamic regime and it makes possible to take into account the thermal convective process, the porosity of the product as well as the generation of humidity. The results of the simulation of the model are compared with the experimental data.

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