Heat treatments of alloys in fluidized bed reactors have been carried out for more than twentyfive years. More recently this technology has been used for carrying out nitriding, carburizing and similar surface treatments. This technology offers certain advantages over other traditional methods for Surface Engineering. These advantages include a more precise process control, greater flexibility and more efficient mass and heat transfer control during the process. In this paper we present a design of a fluidized bed reactor capable for carrying out single, and multilayer surface coatings.