Modélisation et simulation en régime stationnaire d'ateliers d'évaporation de sucreries à l'aide de l'équation d'état de Peng-Robinson

In this work the Peng-Robinson equation of state, previously adapted in our laboratory to predict physical and vapor-liquid equilibrium properties of sugar juices caracterised by the pseudo-components: sugar, amino acid ,carboxylic acid and cinders in aquesus solution, was tested in the modeling and simulation of the steady-state behaviour of multiple effect evaporation plants in sugar factory. The results of simulation has been compared to the real average measurements in the SUNABEL(Sucrerie Nationale de Betterave de Loukkos,Maroc) sugar factory, and showed that the Peng-Robinson equation of state can be used to predict, with a sufficient precision, of the steady-state behaviour of multiple effect evaporation plants in sugar factory. The originality of the model in comparison with the published others models consist in takening account of purity and natural of impurity in the juice. The simultanious modular approach is used in steady state process simulation.

Experimental Investigation of Thermal Conductivity and Specific Heat of the Calcium Phosphate Ore for a Drying Application

This paper discusses an experimental investigation to determine regression models for thermal properties of phosphate particles and to analyze the performances of the phosphate flash dryer. For this purpose, the specific heat capacity and thermal conductivity of phosphate particles were experimentally determined by the modulated differential scanning calorimetry (MDSC) and the modified transient plane source method (MTPS), respectively. Multiple regression models were developed to correlate the specific heat and thermal conductivity to moisture content, particle size, and temperature. Experimental results showed that the measured thermal conductivity and dry specific heat were found in the range of 0.07–0.61 W/m K and 510–630 J/kg·K, respectively. Furthermore, the specific heat increased almost linearly with temperature but decreased with particle size, while the thermal conductivity increased with moisture content and temperature but decreased with particle size. These correlations were integrated to the phosphate flash dryer mathematical model and used to analyze the thermal behavior of phosphate drying. Simulation results were compared to experimental data obtained on a bench-scale dryer, where the model exhibits an average error of 2% and 4% for moisture content and air temperature estimation, showing good fitting for practical data