A, LAURENT, C.The scaling of the experimental data carried out in a gas-liquid laboratory scale reactor up to the pilot or industrial scale is an important problem, Indeed, the determination of the solubility and the diffusivity of one or several solutes in a reacting solution with sometimes unknown or complicated kinetics is very often a challenging problem. Moreover, it is not always possible to experiment in reactors of continuously increasing sizes because of time and/or equipment cost. These difficulties have justified the idea of making relatively simple laboratory models with well-defined interfacial areas and gas and liquid phase contact times (Charpentier and Laurent, 1974;Laurent and Charpentier, 1977) and carrying out experiments to obtain information in a form that could be directly applicable to design. The aim is thus to predict the effect of the chemical reaction in an industrial absorber from tests in the laboratory model with the same gas-liquid reactants, or to predict the reactor length for a specified duty using data from the laboratory model, even though the means of agitating both phases in the two types of equipment is quite different. This promising technique, that is, the simulation, has been intensively developed these last years but only in the case of the packed columns, where either a laboratory scale stirred cell can simulate a point in the column, that is, the differential simulation ( Danckwerts and Gillham, 1966;Laurent et al., 1974;Danckwerts and Alper, 1975), or a laboratory scale string of spheres can simulate the behavior of the full sized equipment, that is, the integral simulation (Alper and Danckwerts, 1976).The purpose of this note is to present the use of the simulation in the case of a quite different pilot equipment that is a turbulent Venturi jet scrubber by a laboratory laminar jet used as an integral model. This technique usually requires the equality of two or more of the follow-