JP7144528B2 - Segmented perforated plate for fluid bed granulator or fluid bed cooler - Google Patents

Description

The present invention provides a fluid bed granulator system comprising a divided perforated plate, a corresponding fluid bed cooler system, a urea granulation plant comprising the respective inventive fluid bed granulator system and/or fluid bed cooler system and the use of the fluid bed granulator/cooler system of the present invention for producing fertilizer granules containing ammonia compounds.

As the world's population continues to grow, there is a constant need to provide reliable, easy-to-manufacture and inexpensive fertilizers. These conventional fertilizers may contain nitrogen, phosphate, sulfur, potassium or micronutrients.

Commonly and widely used fertilizers contain urea as their main component. Water-soluble urea decomposes rapidly in soil to produce ammonia and nitrate compounds. Based on the application, the fertilizer may contain urea alone or a combination of urea and one or more of the aforementioned ingredients such as phosphate, sulfur, potassium or micronutrients.

Urea can be produced on a large industrial scale by reacting ammonia and carbon dioxide via a (simplified) two-step reaction.

2NH ₃ +CO ₂ ⇔ H ₂ N-COONH ₄ (1)
H ₂ N-COONH ₄ ⇔ (NH ₂ ) ₂ CO + H ₂ O (2)
Light absorption of water due to the hygroscopic nature of urea easily leads to uncontrolled agglomeration, deterioration and caking of fine untreated urea particles. This process can adversely affect the solubility, bulk storage, durability or chemical stability of urea fertilizers. In addition, uncontrolled weight gain due to water absorption increases shipping weight and costs. Therefore, additional post-synthetic process steps are required to provide a transportable and storable urea fertilizer. Common technological processes include various granulation techniques such as prilling, drum granulation or fluid bed granulation. The prilling process in particular suffers from some serious drawbacks such as relatively soft particles and sometimes deformed and non-uniform particles.

These problems can be circumvented by using a fluid bed granulation process, resulting in firmer, more stable and uniform granules. The resulting particulate urea is particularly suitable for bulk blending operations. Furthermore, segregation or mechanical damage during mixing and transportation of urea-based fertilizers is reduced.

Examples of fluid bed granulation processes for urea are described in WO 2010/060535, e.g. paragraphs [0025]-[0035], Figure 1 or US Pat. It can be found in US Pat. No. 4,219,589.

Urea fertilizers can be combined with ammonium sulfate or elemental sulfur, thus providing both plant nutrients in one fertilizer. Ammonia sulfur can be used directly by plants, but elemental sulfur must be broken down by soil microorganisms, thus providing long-term plant nutrients. Examples of urea/sulfur granules can be found, for example, in US Pat. No. 4,330,319.

The fluid bed granulation process is based on providing granulation seeds that grow by imbibing very small droplets of a growth liquid. These small droplets can be provided via an "atomized" liquid urea melt. The term "atomized" as used in the description refers to the process of mixing a liquid urea melt (or other suitable fertilizer melt) with a pressurized medium such as air. This mixing process creates a liquid/gas emulsion or aerosol of small droplets. Therefore, the term "atomized" should not be confused with molecular separation processes on the atomic scale. The droplets produced can have a moderate size distribution from about 1 μm to about 200 μm. These small melt droplets are absorbed on the surface of the granulation seeds, thereby creating "growing" granulation particles. These fresh "in situ" produced granules can typically exhibit temperatures of about 100°C and are relatively soft. The particles are further cooled in the fluidized bed and/or separate cooling section of the granulator.

Since there is a constant demand to further increase the daily output of granulated urea, the size of newly designed fluid bed granulators or fluid bed coolers must also be increased. This increase in size is associated with larger components of the fluid bed granulator or fluid bed cooler.

However, the perforated plate size of a fluid bed granulator or fluid bed cooler cannot be increased indefinitely. Perforated plates are typically integrated into an unfinished fluid bed granulator or fluid bed cooler by crane during construction utilizing the open roof. However, damaged perforated plates cannot be replaced using the same method during the service life of the fluid bed granulator or fluid bed cooler. Depending on the size of the aperture plate element and the available openings, it may not be possible to replace and/or repair the aperture plate element without destroying it. Additionally, increasing the size of the aperture plate is associated with increasing the weight of the aperture plate. This weight increase increases the bending tendency of the perforated plate and prevents planar placement of very heavy perforated plates. This tortuosity can lead to non-uniform temperature and flow profiles in the fluid bed granulator, increased particle size distribution, and reduced product quality.

US Pat. No. 3,733,056 discloses a perforated plate in a fluidized bed for processing particulate material. The perforated plate comprises sections with various openings.

WO2013/165245 discloses a plant for the production of urea. The plant has conventional sections for synthesis and recovery, evaporation and condensation, urea finishing, and dust scrubbing.

GB2012030 discloses a fluidized bed apparatus for use with a coal-fired boiler.

WO2010/060535 U.S. Pat. No. 4,701,353 German Patent No. 3116778 U.S. Pat. No. 4,219,589 U.S. Pat. No. 4,330,319 U.S. Pat. No. 3,733,056 WO2013/165245 British Patent No. 2012030

The object of the present invention is therefore a fluidized bed granulator with perforated plates, the perforated plates exhibiting a low tendency to bend, in particular without destroying or damaging the perforated plates, during maintenance or repair. To provide a fluidized bed granulator that allows easy removal or replacement of elements.

The object of the present invention is solved by a fluid bed granulator according to claim 1. Preferred embodiments of the invention are the subject matter of the corresponding dependent claims.

In a further aspect, another object of the invention is that the perforated plate exhibits a low tendency to bend, in particular to allow easy removal or replacement of its elements during maintenance or repair without destroying or damaging the perforated plate. To provide a fluidized bed cooler that Preferred embodiments of the invention are the subject matter of the corresponding dependent claims.

The object of the invention is also solved by providing a urea granulation plant suitable for the preparation of urea-containing granules, according to claim 15.

In a further aspect, another object of the present invention is to provide the use of a fluid bed granulator system or a fluid bed cooler system for producing fertilizer granules.

The fluidized bed granulator system according to the present invention comprises at least a fluidized bed granulator with a perforated plate arranged inside the granulator space. Preferably, the fluid bed granulator system according to the invention is suitable for granulating urea and nitrogen-containing fertilizers. Said perforated plate comprises at least two inner perforated plates (2a, 2a'), which are connected via an intermediate bar and between the intermediate bar and the granulator ground floor. A central support tube is arranged in between. Undivided perforated plates with a length greater than 3000 mm have been found to be very difficult to handle (if at all). Furthermore, perforated plates with a length greater than 3000 mm are prone to bending, which adversely affects the performance of the perforated plate in the granulation process. Without being bound by theory, it is believed that the dead weight and size of large (as above) perforated plates prevent meaningful use. Said middle bar is arranged in the granulator space, oriented parallel to the flow direction of the granulated particles and preferably defined by the axis between the granulator seed inlet and the granulator outlet opening. in the main direction. The term "parallel" includes deviations from the exact parallel alignment of the middle bars. Preferably, the parallel deflection of the middle bar comprises a deflection of ±(plus/minus) 20° (degrees). The term "granular particle flow direction" refers to the direction starting at the granulator seed inlet, through the growth and cooling zones of the perforated plate, and ending near the granulator outlet opening. Intermediate bars should not be confused with connecting elements that link the single perforated plate elements that form the entire final perforated plate. These connecting elements are oriented at an orthogonal or near-orthogonal angle to the aforesaid flow direction of the granular particles and the axis between the granulation seed inlet and the granulator outlet opening. Preferably, the total perforated plate closing and sealing the space between the perforated plate and the granulator bed comprises 15 to 50 internal perforated plates.

A fluidized bed granulator system according to the present invention comprises at least a fluidized bed granulator having a granulator space inside the fluidized bed granulator. The fluid bed granulator further comprises a perforated plate located inside the granulator space and a spray nozzle located in, above or beside the perforated plate. Preferably, the spray nozzles are mounted above the perforated plate. A fluidizing air inlet, preferably located below the perforated plate, provides the necessary fluidizing air for the fluidized bed of fertilizer grains. The term "fluidizing air" includes air or inert gases such as _CO2 , nitrogen, argon or mixtures thereof. The spray nozzle is connected to a supply line for atomizing air and to a supply line for a liquid melt, preferably a liquid melt containing urea. It may be possible to combine these feed lines for air and melt into one line or two adjacent lines. Within the meaning of the invention, the term "line" includes hoses, tubes and pipes. Within the meaning of the present invention, the term "melt" means 50 wt. (weight)%, preferably 75 wt. % urea or nitrogen-containing fertilizer salts or compounds. Additionally, the fluid bed granulator is equipped with a granulation seed inlet. The term "granulated seed inlet" includes internal and external devices, lines and openings for introducing granular seeds such as urea or nitrogen-containing fertilizers. The term "internal" refers to the production of granular seeds within the granulator. The term "external" refers to providing or producing the particulate seed from outside the granulator, eg, through a screen or crusher external to the fluid bed granulator. Additionally, the fluidized bed granulator comprises a granulator outlet opening and a vent opening. The granulator space may comprise a separating wall with an integrated opening. These separating walls can further change and modify the velocity of the fluidized bed towards the granulator exit opening. Dust produced or released during the granulation process, eg urea dust, and chemical vapors such as ammonia are removed in a separate scrubber unit. Preferably, the scrubber unit comprises at least a dust removal scrubber and an ammonia removal scrubber. Examples of suitable scrubbers can be found in WO2005/032696 (Fig. 1) or WO2010/60535. As mentioned above, the perforated plate comprises at least two inner perforated plates (2a, 2a') connected via a middle bar, the middle bar and the granulator ground. A central support tube is placed between the floor. Undivided perforated plates with a length greater than 3000 mm have been found to be very difficult to handle (if at all). Furthermore, perforated plates with a length greater than 3000 mm are prone to bending, which adversely affects the performance of the perforated plate in the granulation process. Without being bound by theory, it is believed that the dead weight and size of large (as above) perforated plates prevent meaningful use. Said middle bar is arranged in the granulator space, oriented parallel to the flow direction of the granulated particles and preferably defined by the axis between the granulator seed inlet and the granulator outlet opening. in the main direction. The term "parallel" includes deviations from the exact parallel alignment of the middle bars. Preferably, the parallel deflection of the middle bar includes a maximum ±(plus/minus) 20° (degrees) deflection. The term "granular particle flow direction" refers to the direction starting at the granulator seed inlet, through the growth and cooling zones of the perforated plate, and ending near the granulator outlet opening. Intermediate bars should not be confused with connecting elements that link the single perforated plate elements that form the entire final perforated plate. These connecting elements are oriented at an orthogonal or near-orthogonal angle to the aforesaid flow direction of the granular particles and the axis between the granulation seed inlet and the granulator outlet opening. Preferably, the total perforated plate closing and sealing the space between the perforated plate and the granulator bed comprises 15 to 50 internal perforated plates.

Preferably, reinforcing tubes are arranged under the two internal perforated plates and/or under the intermediate bar. The reinforcing tubes increase the stability of the internal perforated plates and reduce the deflection between the connected adjacent perforated plates and the internal perforated plates.

Preferably, the internal perforated plates are arranged in two internal frames. The internal frame increases the stability of the internal perforated plate. Additionally, the internal frame reduces fluctuations, vibrations and rocking of the internal perforated plate within the granulator, especially during the granulation process.

In a further embodiment, a partition plate is arranged below and/or above the perforated plate. In addition to their general beneficial effects on the granulation process (eg on temperature and particle growth), the introduction of partition plates further increases the stability of the perforated plates.

Preferably, the reinforcing tube is connected to the partition plate to further increase the stability of the perforated plate and reduce the tendency of the perforated plate to vibrate.

In a further embodiment, the two internal perforated plates, intermediate bar, central support tube and/or tube support comprise metals and polymers, preferably steel, more preferably stainless steel.

Preferably, the two internal perforated plates have a width of 300mm to 1000mm, more preferably 400mm to 900mm, and a length of 1500mm to 2200mm, more preferably 1600mm to 2000mm.

In a preferred embodiment, the perforated plates comprise 15-50 internal perforated plates, more preferably 16-40 internal perforated plates.

The invention further includes a fluidized bed cooler system. The fluidized bed cooler system comprises at least a fluidized bed cooler having a cooler space inside the fluidized bed cooler and a perforated plate arranged inside the cooler space. A fluidizing air inlet, preferably located below the perforated plate, provides the necessary fluidizing air for the fluidized bed of fertilizer grains. Fertilizer granules are conveyed into the cooler through the product inlet. Cooled fertilizer granules exit the fluidized bed cooler through the cooler outlet opening. Furthermore, the fluidized bed cooler is provided with ventilation openings. Dust produced or released during the granulation process, eg urea dust, and chemical vapors such as ammonia are removed in the scrubber unit via the ventilation openings. Preferably, the scrubber unit comprises at least a dust removal scrubber and an ammonia removal scrubber. Examples of suitable scrubbers can be found in WO2005/032696 (Fig. 1) or WO2010/60535. Said perforated plate comprises at least two inner perforated plates (2a, 2a'), which are connected via an intermediate bar and between the intermediate bar and the granulator ground floor. A central support tube is arranged in between. The intermediate bar is positioned within the fluidized bed cooler space and oriented parallel to the flow direction of the particulate particles, preferably in the main direction defined by the axis between the product inlet and the cooler outlet opening. The term "parallel" includes deviations from the exact parallel alignment of the middle bars. Preferably, the parallel deflection of the middle bar comprises a deflection of ±(plus/minus) 20° (degrees). The term "granular particle flow direction" refers to the direction starting at the product inlet, passing through the cooling zone of the perforated plate, and ending near the cooler outlet opening. Intermediate bars should not be confused with connecting elements that link the single perforated plate elements that form the entire final perforated plate. These connecting elements are oriented at a perpendicular or near-perpendicular angle to the aforementioned particulate particle flow direction and at a perpendicular angle to the axis between the product inlet and the cooler outlet opening. Preferably, the entire perforated plate closing and sealing the space between the perforated plate and the cooler floor comprises 15 to 50 internal perforated plates.

Preferably, reinforcing tubes are arranged under the two internal perforated plates and/or under the intermediate bar. The reinforcing tubes increase the stability of the internal perforated plates and reduce the deflection between the connected adjacent perforated plates and the internal perforated plates.

Preferably, the internal perforated plates are arranged in two internal frames. The internal frame increases the stability of the internal perforated plate. Additionally, the internal frame reduces fluctuations, vibrations and rocking of the internal perforated plate within the granulator, especially during the granulation process.

In a further embodiment, a partition plate is arranged below and/or above the perforated plate. In addition to their general beneficial effects on the granulation process (eg on temperature and particle growth), the introduction of partition plates further increases the stability of the perforated plates.

Preferably, the reinforcing tube is connected to the partition plate to further increase the stability of the perforated plate and reduce the tendency of the perforated plate to vibrate.

In a further embodiment, the two internal perforated plates, intermediate bar, central support tube and/or tube support comprise metals and polymers, preferably steel, more preferably stainless steel.

Preferably, the two internal perforated plates have a width of 300mm to 1000mm, more preferably 400mm to 900mm, and a length of 1500mm to 2200mm, more preferably 1600mm to 2000mm.

In a preferred embodiment, the perforated plates comprise 15-50 internal perforated plates, more preferably 16-40 internal perforated plates.

The present invention further comprises a urea granulation plant comprising a fluid bed granulator according to the invention as described above and/or a fluid bed cooler as described above.

The present invention provides a method for producing fertilizer granules containing ammonia compounds, nitrates, phosphates, urea, elemental sulfur, ammonium sulfate, UAS (urea-ammonium sulfate) and/or mixtures thereof. It further comprises a fluid bed granulator system and/or a fluid bed cooler system as previously disclosed.

The invention is further illustrated in the following figures. The figures are intended for illustrative purposes only and are not intended to limit the scope of protection. Illustrations are not to scale.

1 shows a schematic diagram of a fluid bed granulator system; FIG. 1 shows a schematic diagram of a fluidized bed cooler system; FIG. 1 shows a schematic diagram of a perforated plate; FIG. Fig. 3 shows a schematic top view of a perforated plate;

FIG. 1 shows a fluidized bed granulator according to the invention comprising a fluidized bed granulator (9) with a granulator space (1) and a granulator ground floor (10) inside the fluidized bed granulator (9). 1 shows a schematic diagram of a granulator system; FIG. A perforated plate (2) is placed inside the granulator space (1). The spray nozzles (3) are placed on or above the perforated plate (2) and the fluidizing air inlets (11) are placed below the perforated plate (2). be. A plurality of feed lines (4) for atomizing air and feed lines (5) for the liquid melt are connected to the spray nozzle (3). It may be possible to combine these supply lines (4, 5) into one line. The fluidized bed granulator (9), preferably in conjunction with a product screen or crusher not shown, has a granulator seed inlet (6), a granulator outlet opening (7) and a vent opening (8). further provide. A fluidized bed (17) is formed by corresponding granular particles (16) utilizing fluidizing air from below the perforated plate (2). The fluidizing air flow is indicated by the arrow labeled (II) and the flow direction of the fluidized bed granules (16) is indicated by the arrow labeled (I). The fluidized bed (17) is preferably divided by one or more partitions (13). The structure of the perforated plate (2) is shown in FIG.

Figure 2 shows a fluidized bed cooler system for granulation, preferably of urea and nitrogen containing fertilizers, according to the invention. The fluidized bed cooler system comprises a fluidized bed cooler (14) having a cooler space (15) and a cooler grounded bed (12) inside the fluidized bed cooler (14) and a perforated space located inside the cooler space (15). It comprises at least a plate (2), a product inlet (19), a fluidizing air inlet (21), a cooler outlet opening (18) and a ventilation opening (20). A fluidized bed (17) is formed by corresponding granular particles (16) utilizing fluidizing air from below the perforated plate (2). The granule flow direction is indicated by (I) and the fluidizing air flow direction is indicated by (II). The structure of the perforated plate (2) is shown in detail in FIG.

FIG. 3 shows a schematic diagram of a perforated plate. FIG. 3 shows the lower part of the fluid bed granulator (9)/fluid bed cooler (14) from the granulator ground (10)/cooler ground (12) to the perforated plate 2. Fluid bed granulation machine (9) or fluidized bed cooler (14) cutout. For purposes of illustration only, FIG. 3 shows the elements of the invention in a ready state, showing a single partially unfinished element. A "minimal" element of the configuration of the present invention is shown in the area labeled (A). This inventive arrangement comprises at least two internal perforated plates (2a, 2a') connected via an intermediate bar (2c). A central support tube (2d) is located between the intermediate bar (2c) and the granulator ground floor (10)/cooler ground floor (12). The internal perforated plates (2a, 2a') are preferably arranged in two internal frames (2b, 2b'). The configuration with internal perforated plates is repeated along the middle bar (2c) forming and closing the final perforated plate (2) (not shown in Figure 3, see Figure 4). A reinforcing tube (2e) is placed under the two internal perforated plates (2a, 2a') and under the intermediate bar (2c). These reinforcing tubes (2e) increase stability. In addition, the stiffening tube (2e) reduces vibration and bending of the perforated plate (2). The reinforcing tube is connected to the partition plate (13), which further regulates the temperature and gas flow within the granulator.

FIG. 4 shows a schematic top view of an aperture plate. The configuration of the invention comprising two internal perforated plates (2a, 2a'), two internal frames (2b, 2b'), a middle bar (2c) and a central support tube (2d). The "minimum" element is shown in the area labeled (A). Reinforcing tubes (2e) are placed under the internal perforated plates (2a, 2a') and/or between the partition plate (13) and the perforated plate (2), the two internal perforated plates (2a, 2a') Further increasing the stability of the adjacent elements with 2a').

(1) Granulator space (2) Perforated plate (2a) Internal perforated plate (2a') Internal perforated plate (2b) Internal frame (2b') Internal frame (2c) Intermediate bar (2d) Central support Tube (2e) Reinforcing tube (3) Spray nozzle (4) Supply line for atomizing air (5) Supply line for liquid melt (6) Granulation seed inlet (7) Granulator outlet opening (8) Ventilation opening (9) fluid bed granulator (10) granulator ground floor (11) fluidizing air inlet (12) cooler ground floor (13) partition plate (14) fluid bed cooler (15) cooler space (16) Granular particles (17) Fluidized bed (18) Cooler outlet opening (19) Product inlet (20) Vent opening (fluidized bed cooler)
(21) Fluidizing Air Inlet (Fluidized Bed Cooler)
(I) flow direction of granules (II) flow direction of fluidizing air

Claims (22)

A fluidized bed granulator system comprising at least a fluidized bed granulator (9) with a perforated plate (2) arranged inside the granulator space (1),
Said perforated plate (2) comprises at least two inner perforated plates (2a, 2a'), said two inner perforated plates (2a, 2a') being connected via an intermediate bar (2c). and a central support tube (2d) is arranged between said intermediate bar (2c) and the granulator ground floor (10), said fluid bed granulator (9) is connected to said fluid bed granulator granulator space (1) inside (14), said perforated plate (2) located inside said granulator space (1), in, on or above said perforated plate (2) a laterally arranged spray nozzle (3), a fluidizing air inlet (11), a supply line (4) for atomizing air connected to said spray nozzle (3) and connected to said spray nozzle (3). A fluidized bed granulator system comprising a feed line (5) for a liquefied liquid melt, a granulation seed inlet (6), a granulator outlet opening (7) and a vent opening (8). 2. Fluid bed granulator according to claim 1, wherein reinforcing tubes (2e) are arranged under the two internal perforated plates (2a, 2a') and/or under the intermediate bar (2c). system. 3. A fluid bed granulator system according to any one of the preceding claims, wherein the internal perforated plates (2a, 2a') are arranged in two internal frames (2b, 2b'). Fluid bed granulator system according to any one of the preceding claims, wherein a partition plate (13) is arranged below and/or above said perforated plate (2). 5. The fluidized bed granulator system according to claim 4, wherein said reinforcing tube (2e) is connected to said partition plate (13). Claim 1, wherein the two internal perforated plates (2a, 2a'), the intermediate bar (2c), the central support tube (2d) and/or the tube support (2e) comprise metal and polymer . 6. The fluid bed granulator system according to any one of claims 1 to 5. 7. The claim 6, wherein the two internal perforated plates (2a, 2a'), the intermediate bar (2c), the central support tube (2d) and/or the tube support (2e) comprise steel. fluid bed granulator system. 7. According to claim 6, wherein the two internal perforated plates (2a, 2a'), the intermediate bar (2c), the central support tube (2d) and/or the tube support (2e) comprise stainless steel. A fluidized bed granulator system as described. Fluid bed granulator system according to any one of the preceding claims, wherein said two internal perforated plates (2a, 2a') have a width of 300 mm to 1000 mm and a length of 1500 mm to 2200 mm. . Fluid bed granulator system according to claim 9, wherein said two internal perforated plates (2a, 2a') have a width of 400 mm to 900 mm and a length of 1600 mm to 2000 mm. a fluidized bed cooler (14) having a cooler space (15) inside the fluidized bed cooler (14);
a perforated plate (2) disposed inside said cooler space (15);
a product inlet (19), a fluidizing air inlet (21), a cooler outlet opening (18) and a vent opening (20);
A fluidized bed cooler system comprising at least
Said perforated plate (2) comprises at least two inner perforated plates (2a, 2a'), said two inner perforated plates (2a, 2a') being connected via an intermediate bar (2c). and a central support tube (2d) is arranged between said intermediate bar (2c) and the cooler ground floor (12). 12. Fluidized bed cooler system according to claim 11 , wherein reinforcing tubes (2e) are arranged under the two internal perforated plates (2a, 2a') and/or under the intermediate bar (2c) . Fluidized bed cooler system according to claim 11 or 12, wherein said internal perforated plates (2a, 2a') are arranged in two internal frames (2b, 2b'). Fluidized bed cooler system according to any one of claims 11 to 13 , wherein a partition plate (13) is arranged below and/or above said perforated plate (2). 15. Fluidized bed cooler system according to claim 14 , wherein said reinforcing tube (2e) is connected to said partition plate (13). 11. Claim 11 , wherein the two internal perforated plates (2a, 2a'), the intermediate bar (2c), the central support tube (2d) and/or the tube support (2e) comprise metal and polymer . 16. A fluidized bed cooler system according to any one of claims 1 to 15 . 17. The claim 16, wherein the two internal perforated plates (2a, 2a'), the intermediate bar (2c), the central support tube (2d) and/or the tube support (2e) comprise steel. fluidized bed cooler system. 17. According to claim 16, wherein said two internal perforated plates (2a, 2a'), said intermediate bar (2c), said central support tube (2d) and/or said tube support (2e) comprise stainless steel. A fluidized bed cooler system as described. Fluidized bed cooler system according to any one of claims 11 to 18, wherein said two internal perforated plates (2a, 2a') have a width of 300 mm to 1000 mm and a length of 1500 mm to 2200 mm. Fluidized bed cooler system according to claim 19, wherein said two internal perforated plates (2a, 2a') have a width of 400 mm to 900 mm and a length of 1600 mm to 2000 mm. A urea granulation plant comprising a fluid bed granulator system according to any one of claims 1 to 10 and/or a fluid bed cooler system according to any one of claims 11 to 20 . Fertilizer granules containing ammonia compounds, nitrates, phosphates, urea, nitrogen-containing fertilizers, elemental sulfur, ammonium sulphate, UAS (urea-ammonium sulphate) and/or mixtures thereof according to any one of claims 1 to 10 21. Use of a fluid bed granulator system according to claim 10 or a fluid bed cooler system according to any one of claims 11 to 20 .

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