Level control for a fluidized bed
AssigneeCarbomedics, Inc.
InventorLionel H. Brooks
Life of this patent
Estimating the term…
Abstract
Fluidized bed apparatus for use in applying a coating, having a relatively lesser density, to particles, having relatively greater densities by causing passage of a gaseous atmosphere through a bed of the particles. The apparatus includes an enclosure holding a bed of the particles and means for causing flowing of the gaseous atmosphere carrying a material for forming the coating through the bed of particles to be fluidized. The apparatus further includes means for adding seed particles to the bed and weir tube means removing coated particles from the bed when the contents of the bed achieves a predetermined level. Finally, the apparatus includes discharge means receiving the coated particles from the tube means and conveying them to a collection location remote from the enclosure.
Claims10
Fluidized bed apparatus for use in applying a coating, having a relatively lesser density, to particles, having relatively greater densities, by causing passage of a gaseous atmosphere through a bed of said particles, said apparatus comprising:
- an enclosure for holding a bed of said particles;
- means for causing flow of said gaseous atmosphere carrying a material for forming said coating upward through said bed of particles to fluidize said particles;
- and
- a weir tube defined by a sidewall and having a spillover entrance hole for defining a maximum particle level for said bed by receiving and removing particles having substantial coatings from said bed but not removing substantial quantities of uncoated or lightly coated particles when the contents of said bed achieves said level, whereby the relatively less dense coated particles levitate to the top of said bed where they are removed from said bed through said weir tube entrance hole.
A method of providing level control in fluidized bed apparatus of the type for applying a coating to particles having greater densities than that of said coating by flowing a gaseous atmosphere through a bed of said particles, said apparatus comprising an enclosure for holding said bed of particles, means for causing flowing of said gaseous atmosphere carrying a material for forming said coating through said bed of particles to fluidize them, and means for adding seed particles to said bed;
- said level control method comprising:
- (a) providing a substantially vertical weir tube so it extends through a portion of said bed and thereabove adjacent a side of said bed;
- (b) providing a spillover hole in a sidewall of said tube extending through said sidewall and disposed to define a predetermined level of said bed;
- (c) positioning said hole angularly so that it faces away from a central portion of said bed;
- and
- (d) covering the upper end of said tube.
Dependencies are inferred from the claim text.