Abstract: Processes and devices for confining, retaining and sucking off vapors, fumes, dust or similar materials including dispersed or dissolved vapor particles in a fluid medium. In order to separate these pollution particles, a fluid boundary layer or front is generated by diverting a jet against a boundary surface. The curved jet forms a vortex flow retaining the particles and transports them to the suction surfaces. The process and device are especially useful for exhaust hoods in the kitchen field and in the field of clean rooms, furthermore, in those fields, where fluid media with different characteristics are to be separated, confined and suctioned off.