An experimental study of the catalytic hydorgenation of 2,4-dinitrotoluene (DNT) in a mini-installation with a continuously operated stirred three-phase slurry reactor and an evaporating solvent is discussed. Some characteristic properties of the reactor system and the influence of the operating parameters on the performance of the reactor are illustrated. The experimental results are compared with the predictions based on a mathematical model of the reactor system. The results indicated that the assumption of complete saturation with solvent vapors of the gas exit stream out of the reactor does not hold for our small laboratory reactor. It is concluded that, for the mini-installtion, the model describes well the operation and further the behavior of the reactor system, and that the model should be fully adequate for large industrial reactors. Further, it was concluded that the kinetics cannot be based on the overall hydrogen conversion determinations alone, and reevaluation of chemisorption constants by analysis of the reactor product composition also is required as soon as a new batch of catalyst is taken into use.