ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Comparison of Residence Time Distributions of Liquid for Different Types of Input Signal Using a Stimulus-Response Technique

J. Čermáková, N. Siyakatshana, F. Šilar, V. Kudrna, M. Jahoda, and V. Machoň

Department of Chemical Engineering, Faculty of Chemical Engineering, Prague Institute of Chemical Technology, CZ-166 28 Prague

E-mail: cermakoj@vscht.cz

Received: 1 April 2003

Abstract: A stimulus-response technique was used for measuring residence timedistribution of liquid phase. The evaluation of experiments depended on thetype of stimulus signal. Three types of input signals were tested: the _ -impulse,general pulse, and a general pulse in a recycle. The dispersion model was usedfor the interpretation of response curves for all stimuli. The model was basedon the diffusion with bulk flow equation solved with the Danckwert's boundaryconditions for a closed system. The analytical solution by the Fourier methodcontained the input stimulus function as a function of the time and initialdistribution of concentration inside the vessel. The liquid-phase differential distributionfunction was measured in a one-impeller atypical vessel with the volume of36.35 dm³ . The results of the experimental stimulus-response technique wereindependent of the shape of the stimulus signal. The differences and advantagesof individual stimuli under the same experimental conditions were presented.

Chemical Papers 57 (6) 427–431 (2003)