Bibliographic Details
| Title: |
AGGLOMERATION APPARATUS AND METHOD FOR PRODUCING AGGLOMERATED PARTICLES |
| Document Number: |
20090091049 |
| Publication Date: |
April 9, 2009 |
| Appl. No: |
12/298662 |
| Application Filed: |
May 02, 2006 |
| Abstract: |
The invention relates to an agglomeration apparatus comprising a fluid bed, a source of descending particles, one or more nozzles for atomizing an agglomeration fluid and an outlet for discharging the agglomerated particles. In the fluid bed, the particles are guided towards the outlet and pass an outer and an inner zone. The apparatus provides for the production of an improved agglomerated particulate product with a low content of fine particles. |
| Inventors: |
Nielsen, Peter Schultz (Soborg, DK) |
| Assignees: |
NIRO A/S (Soborg, DK) |
| Claim: |
1. An agglomeration apparatus comprising: a fluid bed having a perforated plate and means for producing an upwardly directed fluidisation gas flow through the perforations of the plate for maintaining a fluidised particle layer above the plate, a source of descending particles to be agglomerated in the fluid bed, a nozzle for atomizing an agglomeration fluid, said nozzle being positioned below the surface of the fluidised particle layer and pointing in an upward direction, and an outlet for discharging the agglomerated particles, wherein the fluid bed is provided with an outer zone receiving the majority of descending particles and an inner zone connected to the outlet. |
| Claim: |
2. An agglomeration apparatus according to claim 1, wherein the fluid bed is provided with means establishing different fluidisation gas flow velocities in each zone. |
| Claim: |
3. The agglomeration apparatus according to claim 1, wherein the fluid bed comprises at least one partition wall provided in the fluidised particle layer. |
| Claim: |
4. The agglomeration apparatus according to claim 3, wherein the partition wall abuts the perforated plate of the fluid bed and extends essentially vertically upwards. |
| Claim: |
5. The agglomeration apparatus according to claim 1, wherein an at least partly cylindrical partition wall is provided co-axially in the fluid bed, thereby defining a plug-flow path for the fluidised particles between the interior circumference of the fluid bed and the partition wall. |
| Claim: |
6. The agglomeration apparatus according to claim 1, wherein the outlet for the agglomerated particles is positioned substantially in the centre of the fluid bed and a nozzle for atomizing an agglomeration fluid is provided at least in the outer zone. |
| Claim: |
7. The agglomeration apparatus according to claim 1, wherein the source of descending particles is selected from the group comprising a spray dryer, a filter unit, and a cyclone. |
| Claim: |
8. The agglomeration apparatus according to claim 1, wherein the source of descending particles is a spray dryer. |
| Claim: |
9. The agglomeration apparatus according to claim 1, wherein the fluid bed is provided in the lower part of a spray drying chamber, said fluid bed receiving the descending, partly dried, particles from the spray dryer. |
| Claim: |
10. The agglomeration apparatus according to claim 9, wherein the spray drying chamber comprises internally arranged filters. |
| Claim: |
11. The agglomeration apparatus according to claim 1, wherein two or more agglomeration nozzles are arranged along the plug-flow path of the fluidised particles. |
| Claim: |
12. The agglomeration apparatus according to claim 1, wherein the agglomeration nozzle further is provided with a tube arranged coaxially around the nozzle for supplying a secondary fluidization gas around the atomized fluid. |
| Claim: |
13. The agglomeration apparatus according to claim 12, wherein swirling means is provided in the supply line for the secondary fluidisation gas. |
| Claim: |
14. The agglomeration apparatus according to claim 1, wherein the agglomeration nozzle and/or the tube arranged co-axially around the agglomeration nozzle are adjustable in height. |
| Claim: |
15. A method for producing agglomerated particles, comprising the steps of: maintaining in a fluid bed a fluidised particle layer above a plate having perforations through which fluidisation gas flows, said fluid bed being divided into an inner and an outer zone. supplying the fluidised particle layer with descending particles to be agglomerated in the fluid bed, atomizing an agglomeration liquid in the fluidised layer of particles, guiding the fluidised particles in a plug-flow toward an outlet, wherein the outer zone receives the majority of the descending particles and the inner zone is connected to an outlet. |
| Claim: |
16. The method according to claim 15, wherein the fluidisation gas flow velocity of the inner zone most proximal to the outlet is higher than the fluidisation gas flow velocity in the outer zone. |
| Claim: |
17. The method according to claim 15, wherein at least a part of the path of the fluidised particles follows the circumference of the fluid bed walls. |
| Claim: |
18. The method according to claim 15, wherein the two zones are provided with at least one atomisation nozzle in each zone. |
| Claim: |
19. The method according to claim 15, wherein the fluidisation gas velocity in the inner zone most proximal to the outlet is at least 5% higher than the adjacent neighbouring zone in the fluid bed. |
| Claim: |
20. The method according to claim 15, wherein the mean particle size of the discharged particles is at least doubled compared to the incoming descending particles. |
| Claim: |
21. The method according to claim 15, wherein the bulk density of the discharged particles is substantially the same as the bulk density of the incoming descending particles. |
| Claim: |
22. The method according to claim 15, wherein the agglomeration fluid has essentially the same dry matter composition as the incoming descending particles. |
| Claim: |
23. The method according claim 20, wherein the mean particle size of the discharged particles is at least 200 microns. |
| Claim: |
24. The method according to claim 21, wherein the bulk density of the discharged particles is at least 0.30 g/ml. |
| Current U.S. Class: |
264/12 |
| Current International Class: |
29; 28 |
| Accession Number: |
edspap.20090091049 |
| Database: |
USPTO Patent Applications |
