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.

-Ce travail porte sur l'élaboration d'un modèle mathématique, unidimensionnel en régime permanent, pour la simulation des fours rotatifs de séchage du phosphate. L'objectif du modèle est de prédire la température et l'humidité des gaz et du produit le long du tube sécheur, ainsi que la température des parois, interne et externe, dudit tube. Le modèle estélaboréà partir des bilans thermiques et massiques appliquésà des tranches fines du four en tenant compte d'hypothèses appropriées. Des essais ontété réalisés sur un four rotatif du Complexe de Séchage d'Oued-Zem (COZ) situéà Khouribga (Maroc). Le four aété equipé d'instruments nécessaires pour la réalisation de mesures au cours de son fonctionnement. Les essais ont porté sur la détermination de l'humidité et de la température du produit le long du tube sécheur. Ils ont permis de valider le modèle mathématiqueélaboré et de vérifier les hypothèses simplificatrices introduites lors de son développement.

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The integration of phase change materials (PCMs) in the construction sector is very promising for the improvement of the thermal and energy performance of buildings. This multi-variable study aims to reveal the contribution of PCM plaster according to the type of masonry (single cement bricks or double clay bricks), the type of plaster (PCM or cement plaster) and its location (interior or exterior) to reduce indoor temperature fluctuations and energy consumption levels. Small-scale experimentation and dwelling dynamic modelling of several types of rooms have revealed that compared to cement plaster, PCM plaster on the interior surface of exposed walls reduces the indoor temperature fluctuation range by up to 2.5°C on winter days and by up to 2.6°C on summer days if it is applied on the exterior surface of the single-partition walls. In the case of double-partition walls, the reduction in the indoor temperature fluctuation range reaches 1°C on winter days and 1.3°C on summer days. Interior PCM plaster reduces the heating energy demand in winter by up to 25% for single partitions and 21% for double partitions. In summer, the reduction in cooling energy demand with exterior PCM plaster is up to 36% for single walls and 44% for double walls. Compared to cement plaster, although the thermal and energy reduction percentages of PCM plaster are greater for single-partition walls, the temperature fluctuations and energy consumption are lower for double-partition walls. Determination of the optimum melting temperature and thickness of PCM plaster would improve the performance obtained.

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