Improvement in properties of nanocomposite materials by temperature control

185-190Polystyrene/nano-SiO2 composites with different silica contents have been prepared by using nano-silica particles of 10 nm and polystyrene obtained in batch jacketed reactor with self-tuning PID (STPID) temperature control. The relationship between final properties of nanocomposite material and polymer matrix properties with control has been studied and the composites thus prepared are characterized by means of differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), scanning electron microscope (SEM) and hardness tests. It is observed that higher mechanical and thermal properties of nanocomposites could be obtained using polystyrene produced with STPID temperature control under optimal conditions which are precalculated for average number of molecular weight of 52000 and monomer conversion of 50%. It is also found that hardness and thermal stability of nanocomposite materials increase with increasing nano-silica contents, as expected. The same thermal stability increase is observed in DSC thermograms

Application of Fuzzy Control in a Wireless Liquid Level Simulator

WOS: 000490015900014Liquid level control has great proposition in terms of chemical processes. It is important to make the level measurement in the tanks filled with industrial liquids with accurate and reliable equipment and to keep the liquid level at a certain level. In the studies conducted, wireless liquid level control was performed in a process control simulator system. For all computation and data processing procedures, the MATLAB program is used on-line connected to the system where the liquid level system is located. Then, the behavior of the output variable is examined by giving various effects to the liquid level valve opening selected as the setting variable. Fuzzy control of the system was performed by using the most suitable model found in the operating conditions obtained in dynamic studies. Wireless on-line computer control systems are used for this. The best control efficiency was obtained when the values were 4 dm

Application of self-tuning PID control with genetic algorithm to a semi-batch polystyrene reactor

356-365In semi-batch polymerization reactors, due to changing monomer concentration, the reaction rate varies non-linearly with the time. The heat transfer characteristics change by the large changes in the viscosity of the polymer solution over the reaction and by the environmental conditions like temperature. These factors complicate the automatic control of polymerization processes. In this study, considering operational constraints, optimum reactor temperature for the desired conversion and molecular weight in minimum time was tried to track using self-tuning PID controller. Tuning parameters of controller were obtained by using Genetic Algorithm. The fitness function for GA was chosen to be the integral of the absolute value of the error (IAE). The results show that STPID controller with genetic algorithm controls the temperature of the semi-batch polymerization reactor very well