Apparatus and process for coating, granulating and/or drying particles
AssigneeG. D. Searle & Co.
InventorsVictor Golant, David Hsia, William Taylor, Jr.
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Abstract
A fluidized bed apparatus and method are disclosed for coating, granulating and/or drying particles. The particles are circulated within a chamber by means of circumferential air flow. A first gas stream moves upwardly through the chamber. A second gas stream enters the chamber through openings in the side wall of the chamber. The openings extend generally horizontally and tangential to the side wall so that the second gas is directed circumferentially in the chamber for three-dimensional rotation and circulation of the particles.
Claims12
An apparatus for coating particles comprising a vertically extending round tower having a side wall extending between a top end and a bottom end,
- means for moving a flow of a first gas into the bottom end of said tower and generally vertically and upwardly through the tower,
- means for releasing particles to be coated into said moving flow of said first gas for suspending the particles in said flow,
- means for feeding into said tower a coating material containing a liquid for coating the particles,
- said side wall defining a plurality of openings that extend generally horizontally and generally tangential to said side wall, said side wall having at least some of said openings spaced from said bottom end,
- moving means for moving said particles circumferentially in said tower for three-dimensional rotation and circulation of substantially all of said particles and for evaporating same of said liquid from the coating material on substantially all of said particles, for maintaining substantially all of said particles suspended in said tower above said bottom end, and for dispersing said coating material,
- said moving means comprising means for introducing a second gas into said tower through said openings in said side wall generally horizontally and generally tangentially to said side wall.
A process for coating particles, comprising the steps of providing a stationary vertically extending round tower having a side wall extending between a top end and a bottom end,
- introducing a first gas into the bottom end of the tower,
- flowing said first gas generally vertically and upwardly through said tower,
- introducing particles into said tower for coating, said particles being suspended in the flow of said first gas,
- feeding a coating material containing a liquid into said tower for coating the particles,
- introducing a second gas into said tower through said side wall from a plurality of locations with at least some of said locations spaced above said bottom end,
- directing said second gas into said tower generally horizontally and circumferentially,
- dispersing said coating material by means of said second gas,
- rotating substantially all of said particles three-dimensionally and circulating substantially all of said particles by means of said second gas to evenly coat said particles with said coating material, and
- evaporating some of the liquid from the coating material on substantially all of said particles by means of said second gas.
Dependencies are inferred from the claim text.