FIELD: process engineering.
SUBSTANCE: invention relates to granulation of powder materials by rolling, namely such products as dry milk, instant coffee, cacao, sugar powder etc. Proposed method comprises producing centrifugal field in inner cylindrical chamber with vertical axis of symmetry generated by air upflow and down flows, swirled in one direction. Toroidal suspended swirled dust layer of initial food product is created between aforesaid flows, while, in axial section of aforesaid chamber, a total common outlet flow is created cleaned of dusty fraction. Note here that said initial dust food product is fed to top boundary of suspended swirled layer. Note here also that upflow represents humid water vapor fed in several swirled separate flows. The latter are used to swirl along trajectories in flow volume, the number of layer swirls corresponding to the number of fed separate flows that make upflow. Mind that major initial particles are rolled by minor powder particles in humid medium of upflow vapor to allow growth of round granules to preset diametre limited by upflow rate that ensured minor diametre granule holding force. Positive effect of proposed method consists in feeding humid water vapor upflow to swirled layer to efficiently coagulate initial particles of feed product, for example instant coffee, and to allow coagulation of food product initial particles and their granulation by rolling with the help of minor particles.
EFFECT: improved storage and transportation properties.
1 dwg
