Patent ID: 6499979
Filing Date: 2002-12-31
Classification: B01J,C10C,C10L,Y02E

Abstract:
A pelletizer for making spherical pellets from a normally solid feed material that can be made molten at an elevated temperature, comprising:an upright pelletizing vessel having an upper prilling zone, a sphere-forming zone below the prilling zone, a cooling zone below the sphere-forming zone, and a lower cooling bath below the cooling zone; a centrally disposed prilling head in the prilling zone rotatable along a vertical axis and having a plurality of discharge orifices for throwing the feed material radially outwardly, wherein a throw-away diameter of the prilling head is less than an inside diameter of the pelletizing vessel; a prilling head assembly comprising a rotary union including a housing, a feed inlet, a rotatable pipe depending from the housing, a flow path between the feed inlet and an upper end of the pipe disposed within the housing and a fluid tight seal between an exterior surface of the pipe and an opening in the housing; a lower end of the rotatable pipe connected to the prilling head having a flow passage in fluid communication between an outlet from the lower end of the rotatable pipe and the plurality of discharge orifices wherein the discharge orifices are radially offset from an axis of the rotatabe pipe; a support housing having a mount for attachment to the pelletizing vessel and upper and lower bearings adjacent respective upper and lower ends of the support housing for rotatably receiving the rotatable pipe; a drive wheel secured to the rotatable pipe; a first line for supplying the molten feed material to the feed inlet of the prilling head assembly; a vertical height of the sphere-forming zone sufficient to allow material discharged from the prilling head to form substantially spherical liquid pellets; nozzles for spraying a liquid cooling medium inwardly into the cooling zone to cool and at least partially solidify the liquid pellets to be collected in the bath; a second line for supplying cooling medium to the nozzles and the bath to maintain a depth of the bath in the pelletizing vessel; and a third line for withdrawing a slurry of the pellets in the cooling medium.