Claims
- 1. Process for the continuous agglomeration of a powder in a fluidized bed which comprises the steps of
- (a) providing said powder, a granulating liquid and propellant air to a three-substance nozzle arranged axially at the bottom center of the fluidized bed granulator, comprising an outer tube and an inner tube which is concentrically arranged within the outer tube to form an annular channel between the outer and the inner tube,
- (b) supplying the powder together with propellant air to said annular channel and the granulating liquid to the inner tube,
- (c) discharging said powder, granulating liquid and propellant air out of said three-substance nozzle as a three-phase mixture of powder, granulating liquid and propellent air in the form of a spray cone,
- (d) spraying said three-phase mixture into the fluidized bed, and
- (e) discharging agglomerated product out of the fluidized bed through a gas classifier located at the base of the fluidized bed granulator and concentric to the fluidized bed nozzle.
- 2. Process according to claim 1, characterised in that the finished granular material is discharged out of the fluidised bed (13) through an intake weir (25) arranged concentrically to the three-substance nozzle (12) on the gas classifier (15).
- 3. Process according to claim 1, characterised in that the solids content of the fluidised bed (13) is kept constant by means of a control loop, wherein
- a) the pressure drop of the fluidising air in the fluidised bed (13) is used as measured variable, and
- b) the mass flow of the classifying air in the gas classifier (15) is used as correcting variable.
- 4. Process according to claim 1, characterised in that the solids content of the fluidised bed is kept constant by means of a control loop, wherein
- a) the pressure drop of the fluidising air in the fluidised bed is used as measured variable, and
- b) the inlet cross-section of the intake weir (25) on the gas classifier (15) is used as correcting variable.
- 5. Process according to claim 1, characterised in that a part of the solid to be granulated (4) is added in the finely divided form to the granulating liquid (3).
- 6. Process according to claim 1, characterised in that proportions of fines in the fluidised bed (13) are separated by an external dust filter (8) and recycled to the fluidised bed (13) via the solids-propellant air stream (5).
- 7. Process according to claim 1, characterised in that the product moisture content in the fluidised bed (13) is measured and controlled constantly by adjusting the quantity of granulating liquid or suspension metered into the fluidised bed.
Priority Claims (1)
Number |
Date |
Country |
Kind |
43 04 405.0 |
Feb 1993 |
DEX |
|
BACKGROUND OF THE INVENTION
This is a division of application Ser. No. 08/193,836, filed on Feb. 8, 1994 now U.S. Pat. No. 5,480,617.
US Referenced Citations (4)
Divisions (1)
|
Number |
Date |
Country |
Parent |
193836 |
Feb 1994 |
|