The invention relates to a powder spreader device including a sealed tank (1) with a tapered bottom wall (5), a vessel (2) containing a pressurised spray gas connected to the tank (1) via a feed line (27), control means (20) connected to the vessel (1), and a powder dispensing nozzle (10) connected to the tank, wherein the elongate nozzle (10) includes at least two pressure relief stages (11, 12) for breaking up the dispensed powder jet and forming a uniform and homogenous jet with a relatively low flow rate.