Process for reducing or avoiding foam generation in chemical or physical substance converting processes and device for its realization

Reducing or preventing foaming in chemical and physical transformation processes in liquid media comprises carrying out the transformation in a buoyancy-free jet reactor with no baffles, which has a tapered lower part and is fitted with a gas injector in a position which facilitates circulation without buoyancy. The reactor contents are thoroughly mixed by gas injection. Also claimed is an apparatus for the above process, with a pipe connection for taking off a high-solids suspension and an inlet tube for a liquid medium above the gas injector, the outlet of this tube being located in the cloud of bubbles formed when the apparatus is working.