A pulsing device for packed-bed bioreactors: I. Hydrodynamic behaviour

This paper describes a new pulsing device which permits the insertion in pulsing form of a liquid phase fed into an equipment where a microbial or enzymatic transformation occurs. It also analyzes the modifications of the flow model caused by the pulsation generated by means of three kinds of pulsators: A hydropneumatic pulsator, a selfpropelled pulsator and a newly designed elastic membrane pulsator.The hydrodynamic behaviour of a packed-bed column, to which each of these pulsators has been connected is compared with the correspondent system without pulsation. The flow model is determined by the study of the curves of residence times distribution, obtained by using a stimulus-response technique. A computer programme has been used to determine the axial dispersion coefficients from the response curves. In all cases we worked within a wide range of Re _p(10–215).