| 主权项 |
1. A process for continuously coating pellets comprising:
feeding pellets continuously into a linearly elongated trough, said trough having a concave trough bottom wall extending laterally from a first longitudinal side edge to an opposite second longitudinal side edge, said pellets being introduced into the trough at a first location along the length of the trough, and thereby maintaining a bed of pellets continuously moving longitudinally in the trough; directing a spray of liquefied pellet coating material toward the bed of pellets in the trough at least at one intermediate location along the length of the trough; causing reciprocating rotational vibration of the trough about a pivot axis parallel to the direction of elongation of the trough but laterally offset from a longitudinal centerline of the trough, said centerline being positioned above a location on said concave trough bottom midway between said first and second longitudinal side edges by applying impulse components to the trough as moments about said pivot axis, said reciprocating rotational vibration having sufficient intensity substantially to fluidize the bed of pellets disposed in said trough, thereby causing the pellets in said bed to circulate, substantially continuously and in the same direction, in a loop-shaped path transverse to the direction of elongation of the trough, as they move longitudinally in the trough, so that substantially all of the pellets are exposed to the spray at times during their travel along the trough; and collecting coated pellets discharged over a weir in the trough at a discharge location longitudinally spaced from the first location, the at least one intermediate location at which the spray is directed toward the bed of pellets being between the first location and the discharge location. |
