The present invention relates to a spraying nozzle, a spraying device including such a nozzle, and a spraying method implementing such a device. A nozzle for projecting powdery sold products for coating objects. The nozzle comprises a body having an essentially cylindrical shape and comprises at least two tunnels extending there through and insulated from each other. Each tunnel developing helically about a main axis of the nozzle. The tunnels are independently supplied with a fluid/powdery solid(s) mixture. The helical shape of the tunnels makes it possible to obtain a powerful jet with a conical shape capable of coating the inner surfaces of tubular objects.