BAFFLES IN A FLUIDIZED BED COOLER

Abstract

A fluidized bed cooler for cooling a urea-containing granular material may include a cooler chamber having a product inlet opening, a product outlet opening, a perforated plate disposed in the cooler chamber, and at least one cooling medium entry opening disposed beneath the perforated plate. The product inlet opening may be disposed above the perforated plate, and a baffle plate may be disposed between the product inlet opening and the perforated plate. A distributor plate may be disposed between the baffle plate and the perforated plate. An area of the distributor plate may be 10% to 50% greater than an area of the baffle plate.

Claims

1.-17. (canceled)

18. A fluidized bed cooler for cooling a granular material that contains urea, the fluidized bed cooler comprising: a cooling chamber having a product inlet opening; a product outlet opening; a perforated plate disposed in the cooler chamber, wherein the product inlet opening is disposed above the perforated plate; a cooling medium entry opening disposed beneath the perforated plate; and a baffle plate disposed between the product inlet opening and the perforated plate.

19. The fluidized bed cooler of claim 18 comprising a distributor plate disposed between the baffle plate and the perforated plate.

20. The fluidized bed cooler of claim 19 wherein an area of the distributor plate is 10% to 50% greater than an area of the baffle plate.

21. The fluidized bed cooler of claim 19 wherein the baffle plate is planar or curved so as to be roof-shaped, trapezium-shaped, saddle-shaped, concentric, or three-dimensional Gaussian.

22. The fluidized bed cooler of claim 19 wherein at least one of the distributor plate or the baffle plate is configured as perforated plates.

23. The fluidized bed cooler of claim 19 wherein at least one of the baffle plate or the distributor plate comprises metals, metal alloys, composite materials, and/or plastics.

24. The fluidized bed cooler of claim 19 wherein at least one of the distributor plate or the baffle plate has openings with an average diameter of 10 mm to 50 mm.

25. The fluidized bed cooler of claim 19 wherein the distributor plate comprises borders.

26. The fluidized bed cooler of claim 19 wherein at least one of the distributor plate or the baffle plate has a reinforcement with the product inlet opening.

27. The fluidized bed cooler of claim 18 wherein the baffle plate has less than 10% of an area of the perforated plate.

28. The fluidized bed cooler of claim 18 wherein the baffle plate is disposed parallel to the perforated plate.

29. A method of cooling a granular fertilizer, the method comprising: introducing a granular material from a fluidized bed granulator or granulation promoter in the fluidized bed cooler of claim 18.

30. A fluidized bed granulation plant for production of a granular fertilizer, the fluidized bed granulation plant comprising: a fluidized bed granulator having a perforated granulator plate, a seed grain inlet, a fluidization gas inlet, and a melt nozzle with an atomization gas inlet; a first fluidized bed cooler; granulation promoters; sieves; crushers; and product coolers, wherein at least one of the first fluidized bed cooler or one or more of the product coolers includes: a cooling chamber having a product inlet opening; a product outlet opening; a perforated plate disposed in the cooler chamber, wherein the product inlet opening is disposed above the perforated plate; a cooling medium entry opening disposed beneath the perforated plate; and a baffle plate disposed between the product inlet opening and the perforated plate.

31. The fluidized bed granulation plant of claim 30 wherein at least one of the fluidized bed granulator, the product coolers, or the first fluidized bed cooler is connected to a waste air treatment unit.

32. The fluidized bed granulation plant of claim 31 wherein the waste air treatment unit comprises at least one of a scrubber or an acidic scrubber.

33. The fluidized bed granulation plant of claim 30 configured for the production of the granular fertilizer containing ammonium compounds, nitrates, phosphates, urea, elemental sulfur, ammonium sulfate, urea ammonium sulfate (UAS), or combinations thereof.

34. The fluidized bed granulation plant of claim 30 configured for the production of the granular fertilizer containing urea.

Description

[0037] The figures show:

[0038] FIG. 1 a schematic cross section through a fluidized bed cooler according to the prior art,

[0039] FIG. 2 a schematic cross section through a fluidized bed cooler of the invention,

[0040] FIG. 3 an enlarged schematic cross section of a fluidized bed cooler of the invention in the region of the product inlet, and

[0041] FIG. 4 an enlarged schematic cross section of a preferred embodiment of the fluidized bed cooler of the invention in the region of the product inlet.

[0042] FIG. 1 shows a schematic cross section through a fluidized bed cooler according to the prior art. The fluidized bed cooler comprises a cooler chamber (1) into which the product (22) is introduced via a product inlet opening (2). The product (22), for example a urea-containing granular material, arrives in a non-attenuated manner in the fluidized product (22) already present on a perforated plate. Beneath the perforated plate (4) is disposed a cooling medium entry opening (7) that generates a gas stream (II) indicated by the black arrows. The gas stream (II) used is generally air; according to the substance to be granulated, it is alternatively also possible to introduce an inert gas. The product (22) present on the perforated plate in the cooler chamber (1), as a fluidized medium, moves in the direction of the product outlet opening (3) in the product stream (I). Removal of air from the cooler chamber is possible via an air removal opening (21).

[0043] FIG. 2 shows a schematic cross section through a fluidized bed cooler of the invention. The basic setup of the fluidized bed cooler corresponds to the setup described above for FIG. 1. By contrast with the fluidized bed cooler according to the prior art as described in FIG. 1, a baffle plate (5) and a distributor plate (6) are disposed between the product inlet opening (2) and the perforated plate (4). The baffle plate (5) enables attenuation of the incoming product (22) without noticeable destruction or deformation of the granular form of the product (22). The distributor plate (6) enables further attenuation and more homogeneous introduction of the product (22) flowing in in direction (I). The inventive arrangement of baffle plate (5) and preferably the distributor plate (6) reduces the accumulation of product beneath the perforated plate and hence extends the service life of the fluidized bed cooler. At the same time, there is a drop in the costs for the cleaning of the product cooler and the associated shutdown time of the fluidized bed granulation plant.

[0044] FIG. 3 shows an enlarged schematic cross section of a fluidized bed cooler of the invention in the region of the product inlet. The baffle plate (5) and the distributor plate (6) are disposed between the product inlet opening (2) and the perforated plate (4). The distributor plate, in an optional configuration, has openings (8). The baffle plate (5), as described above, reduces the velocity and hence the kinetic energy of the incoming product (22). The distributor plate (6) results in homogeneous introduction of the product (22) over a larger area into the fluidized bed (23) composed of fluid granule particles.

[0045] FIG. 4 shows an enlarged schematic cross section of a preferred embodiment of the fluidized bed cooler of the invention in the region of the product inlet. Apart from the baffle plate (5), the setup corresponds to that described in FIG. 3. The baffle plate (5) is preferably curved, and in the present example is in roof-shaped form. The curved basic shape surprisingly increases the stability and durability of the baffle plate (5) in the product stream (I) and distributes the product (22) more uniformly over the distributor plate (6).

LIST OF REFERENCE NUMERALS

[0046] (1) cooler chamber [0047] (2) product inlet opening [0048] (3) product outlet opening [0049] (4) perforated plate [0050] (5) baffle plate [0051] (6) distributor plate [0052] (7) cooling medium entry opening [0053] (8) openings [0054] (21) air removal opening [0055] (22) product (granular material) [0056] (23) fluidized bed [0057] (I) flow direction of the granulation product/product stream [0058] (II) gas stream