Apparatus and method for producing pellets by layering powder onto particles.

摘要

The apparatus for layering powder (157) onto particles (191) has a vessel (1) in which a rotor (21) is mounted rotatable around a vertical axis (3). The rotor (21) comprises a disc (23) with a supporting surface (23a) for supporting particles (191). The apparatus also has feeding means (67) with a substantially horizontal introducing member (71) protruding slightly into the vessel (1) above the disc (23). The introducing member (71) limits a liquid outlet and an annular powder outlet encompassing the liquid outlet. During a layering operation, the introducing member (71) protrudes into a bed of particles (191) lying on the rotating disc (23) and moved by the latter. There can then be sprayed liquid (129) and powder (157) simultaneously by one and the same introducing member (71) onto the particles (191) passing in proximity of said outlets. This enables layering powder (157) onto particles (191) and to produce thereby pellets having sizes lying in a narrow range, wherein the pellets can be produced by using only a small amount of liquid and in short time. <IMAGE>