NUMERICAL-SIMULATION AND PHYSICAL MODELING OF THE HYDRODYNAMICS IN ANAIRLIFT INTERNAL LOOP REACTOR

The main objective of the present paper is to propose a new model of t he hydrodynamics in an air-lift internal loop reactor. The model is ba sed on one-dimensional (1D) two-fluid mass and momentum balances. It r equires closure relations for the slip velocity of the gas bubbles and both friction factors and singular pressure drop coefficients. The wa y to propose reliable closure relations for these terms is based on th ree-dimensional (3D) numerical simulations, using the Computational Fl uid Dynamics software ASTRID developed by Edf (Chatou, France). The nu merical simulations are first validated with experiments acquired on a laboratory pilot plant. Then the numerical simulations are used to im prove a more global modeling of the air-lift internal loop reactor. In particular, one can space average the local 3D results to obtain clos ure relations for the simpler 1D model. (C) 1997 Elsevier Science Ltd.