The nozzle scrubber is a wet separator simple in design and robust in operation. Hence, it is well suited for installation in existing plants and, generally, a more powerful fan can be forgone since the energy needed to disperse the scrubbing liquid is not delivered by the crude gas (as in the case with venturi scrubbers). All parameters relevant for operation such as specific water consumption, residence time and specific energy consumption have been investigated in detail, and different pneumatic atomizing nozzles (with internal and external mixing of both phases) in various geometrical arrays are examined. The design criteria for the use of the nozzle have been worked out. The effect of particle generation by vaporizing liquid droplets, has for the first time been examined and quantitatively proven on a technical wet scrubber. The results plainly refute the assumption that the concentration of particles realized by the evaporation effect is negligibly low. Possibly contaminations with mass concentrations up to some mg/m(3) are emitted at which the median of mass density distribution (x(50,3)) amounts to 0.05 mu m.