Abstract
Experimental investigations were carried out on hydrodynamical modes of a falling thin film along a vertical wall under the influence of viscous-gravitational forces with and without generation of a second liquid film from the gas phase. Experiments were performed in a special installation, where the main element was a reactor, accompanied by measuring equipment. The average thickness of the film was calculated by means of the "hold-up" method. The process of sulphuric acid alkylation of isobutanes with butenes was studied where a second organic film was formed by the obtained liquid product, which flows upon the film of sulphuric acid (catalyst) flowing along the wall.