Abstract: An apparatus for treating, for example cleaning, sensitive, in particular highly contoured surfaces such as those of sculptures of wood, plaster, bronze and the like, comprises a mixing head (1) for mixing media supplied to the mixing head (1) and for spraying a treatment jet (50) formed therefrom. The mixing head (1) comprises a mixing chamber (30) into which under pressure a first jet with a liquid treating agent is introduced via a first supply conduit (10) through an inlet (12) and a second jet is introduced, the jet axis (22) of which is inclined at an angle (.gamma.) to the jet axis (11) of the first jet and extends eccentrically thereto. In this apparatus the inlet (12) for the first jet comprises an inlet opening (14) which is so formed and/or orientated that the jet axis (22) of the second jet intersects the first jet.

Abstract: The present invention relates to a method and an apparatus for cleaning surfaces, in particular sensitive surfaces contaminated and attacked by environmental influences, by means of a jet of fine grain blast material and air. A blast material is used which contains crystals and/or particles of at least one cleaning agent crystallized by cooling.