منصور کلباسی

Spray dryers are one of the most important dryers and have many applications in the food, drug and chemical industries. In this investigation, a model Is suggested to predict the product temperature, drying time and the dryer height In order to evaluate the dryer performance in different operational conditions. To achieve this, knowledge of the drying kinetics and the transfer phenomenon are necessary. The main aim in this project is, modeling of the spray drying of Alumina Slurry in a co current dryer.In this modeling Mass, heat and momentum transfer equations on droplets and hot air have been written. By writing a computer program for the simultaneous solution of mass, energy and momentum balances, a mathematical model is introduced. In order to evaluate the accuracy of the model, the experimental data were used and results showed good agreement between the theory and the experiments. By using the results of the model, the change in the dryer input parameters and their effect on final product characterizations have been studied.

In this investigation, the mean drop size and the drop size distribution which are the most important factors in the liquid-liquid dispersions were studied over a wide range of phase ratio for four different non viscous dispersed phases (namely ethyl hexanoate, toluene, kerosene and phenetole) in water. The dispersed phases have been used at concentrations of 5 to 50 (% v/v) that were agitated by Rushton turbine impeller with the revolution speed varied from 300 to 700 rpm. Drop size distributions were measured by an endoscope technique. The drop size distributions in the agitated dispersions resulted from the dynamic equilibrium existing between the breaking and coalescing drops. Since the common modulated correlation, d32(1+const)We-0.6 estimate fairy inaccurate the Sauter mean diameter especially at high hold up ratios and the linearity dependence on hold up ratio is doubtful, in frame of the classical Hinze-Kolmogorov theory, a new two-parametric relation was established which correlated the Sauter mean drop diameter to the Weber number and to the volume phase fraction much more reliably. Also, in this work the linear normal distribution function in cumulative form was used to fit the experimental data with appropriate agreement. The variations of the related standard deviation were correlated to the Sauter drop diameter and to the phase ratios. For modeling drop size distribution, the population balance equation was solved by discrete formulation methods. Drop breakage and coalescence frequency were described by famous Coulaloglou and Tavlarides model and the parameters of the model were obtained by least squares error method. The results showed that if the parameters obtained for a specified revolution speed was used the experimental and simulated data agreed well, but since the parameter depended on the power input to the system, this model should be improved.

Powder detergent for spray drying, hot air with a gas such as food drops Nahmsv contact form is given. During the call transfer torque phenomena, heat and mass basis is performed simultaneously. The simulation model for predicting the operational parameters, time Khshkshdn tower height and provide the desired effect of various parameters on the performance of spray dryer has been studied. For this purpose, mass and energy balance equations and the torque around a small element of the tower and for both gas and particle phase, was written, and the numbers and the dimensionless heat and mass transfer coefficients were calculated. Then write a suitable computer, application and integration of momentum equations and Mvaznhhay mass and energy, and finite difference method to solve system of equations and a mathematical model was presented. The model profiles via a descending trend for temperatures for the gas and particle temperatures were predicted. Moisture profiles of gas and the particles were evaluated for particle reduction process and the process for increasing the gas humidity was obtained. The results indicate that the radial velocity of particles Atmsaz output at a fraction of seconds to zero, and the axial particle velocity also reaches a fixed value. Effect of particle diameter Atmsaz output has also been investigated. For testing the model of the data using a detergent powder dryer tower and a good agreement between theoretical and experimental results is observed. These results can be simulated in optimizing existing units, changing their operating conditions, and also used in the design of new units.

One of the chemicals formaldehyde and consumed values ​​in the petrochemical industry is always check and optimize its production processes a large part of the investigation is taken. The present partial oxidation of methanol in formaldehyde using a catalyst of iron oxide, molybdenum oxide in the temperature range $ ^ circ C $ 410-270 in a continuous reactive fluid bed has been studied. Catalyst needed for the process, a process during Hmrsvby of ammonium and nitrate solutions Polar Hptamvlybdat iron is produced. In order to increase the mechanical strength and resistance to catalyst synthesis, the action inoculated with bismuth nitrate on it and then taken up again by calcination reaction in order Bstrsyal useful. During the impact of various parameters such as reaction temperature, gas superficial velocity and the percentage of feed, the reaction rate and operational capacity has been studied reagent. Experimental results obtained with the results of the models presented for fluid bed reactors have been compared. Finally the best model based on reagent performance is marked.

In this project, a mathematical model used to study the process of calcium carbonate drying in a co-current spray dryer. In order to determine its performance, the drying kinetics equation obtained using the experimental data. The momentum equation on the suspending particle in air and the differential equations in three dimensions of the particle movement paths and the Reynolds number and the mass and heat transfer coefficients have been solved. Proportional to these relations, a computer program in MATLAB presented. The results obtained from this program predicted the experimental data very well.