Views: 8 Author: Site Editor Publish Time: 2023-12-22 Origin: Site
The conventional granulation plant for the fertilizer process includes the following main items:
• A rotary drum granulator, in which the ammonium nitrate solution is sprayed over a bed of recycled product consisting of fines, dust (collected from equipment cleaning), coarse ground grains, some recycled final products, filler (most often limestone or dolomite) and solid raw material if required (ammonium sulphate or calcium sulphate)
• At the outlet of the drum granulator the granules fall through a chute into a rotary dryer meeting a hot, co-current air flow coming from a dedicated heater. The residence time in the dryer is such to completely dry the AN product, which at the exit contains about 0.2 % H2O
• The product is then sent to a screen where it is divided into three parts: undersize, oversize and on-size product. Oversize granules are crushed, mixed with undersize ones and fed back to the granulator together with a portion of the marketable product in order to maintain a constant recycle flowrate.
Most fertilizers need to be dried and cooled after the granulation process, such as drum granulators, organic fertilizer granulators, and disc granulators. roller compactor granulation has the advantages of short process flow, convenient operation, easy-to-realize production automation control, and improved production efficiency. There are no special requirements for the properties and particle size distribution of raw materials, so the sources of raw materials are relatively wide.
The dry extrusion granulation process of a double roller compactor granulator is widely used in powder particle processing. The characteristic of this process is that the particles can be treated directly without humidification or heating. It can be used as fertilizer production machinery to process organic fertilizer, inorganic fertilizer particles, and chemical particles, such as NPK fertilizer, Potassium chloride, and potassium sulfate.
One major field for the application of roller press compactors is the fertilizer industry. By compaction, a fine grain material is compacted into the so-called flake, a ribbon of defined thickness. The flake is crushed and screened to produce a coarse-grain material. A typical use of compaction is the production of agricultural fertilizers. Fertilizer is granulated to avoid dust during dispersion onto the ground and for better (reduced) solubility. When mined in large quantities potassium chloride (MOP) and other salts have particle sizes below 1 mm after concentration. With progressing mechanization and the use of bulk blending techniques the agricultural industry is demanding coarser grain sizes between 1 and 4 mm, or 2 to 4 mm as of late. NPK granules can also be produced by the compaction technology. A mixture of the nutrient carriers for nitrogen (N), phosphate (P), and potassium (K) is compacted into a flake. Here as well the flake is crushed, and the desired fraction is screened out. In contrast to conventional wet methods, the granulation of fertilizers by compaction uses dry feed materials from an almost unlimited number of sources and without special requirements on particle size or distribution, this technology is gaining increasing importance in the industry in particular with the rising energy costs (which is a major factor in wet granulation.
1). Batching system: Use belt scales to weigh each raw material according to the formula.
2). Powder mixer: Use a powder mixer to the raw material for more uniform feeding.
3). Bucket elevator and Silo: Use a bucket elevator to lift the material up to the silo.
4). The DG series comptactor compresses the raw material with double rollers, it mainly depends on the mechanical pressure to compress the dry powder, so the hardness of the granular is very high. DG series roller compactor (including three parts: dosage screw feeder, forced feeder, and flaking machine.)
5). Then we get the bar shape products.
6). Crusher (you can decide the size of granules, we will design the size of crusher mesh.)
: So we need a crusher to crush the bar shape products into 2-4mm irregular granules.
7). Rotary Screen: Finally, we will use the rotary screen to sieve the final products, the unqualified products, such as dust, big granular, and very small granules will be recycled for the next time granulation process. You will get the qualified 2-4mm irregular shape granules successfully.
8). Second Time Rotary Screen: Next we use the second-time rotary screen, the purpose is we want to get better results of irregular shape granules after the second time screening, so the appearance of irregular shape granulars will look more beautiful.
9). Coating machine: After the second sieve, the granule enters into the rotary drum for coating. You can spray some liquid or powder on the surface of the particles to avoid clumping.
9). Packing machine: This packing machine will help you pack the final granular into bags. You can choose a 25-50kg/bag Packaging Machine or a TON-package machine(800-1000kg/bag)
10). Dust collecting process: Workshop dusts mainly come from the crusher, screening, and discharging port of the bucket elevator, to effectively remove the dust, this process uses two stages of dust removal. A cyclone dust collector is used to remove the larger particles of dust, and then the bag dust filter is used to remove the residual dust. The dust from the dust collector will return to the granulation process by the scraper conveyor.
1. Extrusion granulation does not need heating and humidifying materials, saving investment and energy. It is also suitable for the granulation of heat-sensitive materials such as ammonium bicarbonate and some organic fertilizers.
2. There is no waste water and waste gas discharge in the production process, which does not pollute the environment.
3. Extrusion granulation has the advantages of short process flow, convenient operation, easy-to-realize production automation control, and improved production efficiency. The double roll extrusion granulator is suitable for the processing technology of small chemical fertilizer production machinery.
4. There are no special requirements for the properties and particle size distribution of raw materials, and there is a wide range of raw materials.
5. The fertilizer production is flexible, and the raw material formula can be changed at any time, which is conducive to the small batch production of special fertilizer.
6. The particle size distribution of the product is uniform without segregation and agglomeration.
7. The shape of extrusion granulation products is uniform, oval, and non-circular. Generally, if rounder particles are needed, a round machine needs to be added to the fertilizer production line to further shape the particles.
Dry Extrusion Granulation
Dry Extrusion Granulator
Dry Comptactor Granulation
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