Industry Info

Process design of NPK fertilizer production line

2023/06/26
 

The production process of NPK compound fertilizer equipment mainly involves mixing organic solid waste with a moisture content of less than 60%, auxiliary materials (such as plant straw), microbial fermentation agents, etc. Evenly, and using pool type aerobic continuous fermentation to fully decompose, sterilize, deodorize, and remove water. The moisture content of the decomposed material is generally 30-35%. After screening and magnetic separation, it can be directly used for pelletizing to produce spherical Manure, or further drying to produce powdery organic fertilizer.

The NPK composite fertilizer production process consists of multiple processes: raw material measurement, raw material crushing, granulation, drying, cooling, screening, coating, and packaging. Each process has strict indicator control, and none is indispensable. Firstly, technical personnel develop corresponding fertilizer production formulas based on market needs or customer needs, combined with the market situation of raw materials, and refine them into the input amount of raw materials.

NPK Fertilizer Production Line Process Design Description:

1. Compound fertilizer ingredient process:

The operators strictly follow the technical personnel's requirements for the amount of each raw material added, and add various raw materials such as N, P, K, and additives to the electronic belt scale. The addition process of raw materials requires that the raw materials be in powder or granular form without agglomeration, and the material flow should be uniform without intermittent operation. Otherwise, it will affect the measurement accuracy and control of the granulation process, as well as affect the product content. The measured material flows into the raw material crusher and enters the next section.

2. Compound fertilizer crushing process:

The mixed fertilizer that is proportioned according to the design requirements is transported to the raw material crusher for raw material crushing, with the aim of crushing various raw materials to a certain degree of fineness, basically ensuring that the particle size of the raw materials is less than 1mm, which is conducive to rolling the materials into balls that meet the standards in the granulator.

3. Compound fertilizer granulation process:

The crushed raw materials enter the conveyor belt conveyor and are transported to the drum granulator for granulation. The solid fertilizer powder to be granulated will rise with the help of the rotation of the cylinder and roll down under the action of gravity. At the same time, Adhesive will be added according to the proportion of raw materials for granulation. The material is wrapped layer by layer on the surface of the granulation nucleus, thickening layer by layer, and gradually granulating. Under the action of the above forces, the material gradually forms a core until it meets the granulation requirements and enters the drying section.

4. Compound fertilizer drying process:

The dryer adopts a cylinder edge drive, flange connection, and direct heat transfer method, suitable for drying compound fertilizers after granulation. The materials that need to be dried enter the sheet drying area equipped with a special combination. Due to the tilting movement of the body and sheet, the materials are continuously lifted by the sheet for sufficient scattering and longitudinal movement. At the same time, they undergo sufficient heat exchange with the high-temperature furnace gas from the hot air furnace, evaporate water, and dry the materials. Materials and flue gas need to be dried and operated in a forward flow and micro negative pressure manner.

The dryer is equipped with a secondary granulation area, which can perform secondary granulation on some non granulated materials, which is beneficial for improving the granulation rate of the system. During the drying process, it is necessary to monitor at all times and adjust the temperature of the dryer head and tail according to the process requirements by adjusting the temperature of the hot air stove and the air volume of the exhaust fan, so as to achieve the drying target of the dried material. The materials that have completed the drying operation are transported by a belt conveyor to the fifth section.

5. Composite fertilizer cooling process:

The rotary cooling machine is mainly used for cooling composite fertilizer products after drying, which can quickly cool hot granular materials to near room temperature. The material entering the cooling machine continuously moves forward under the rotation and tilting action of the body, while the induced draft fan introduces air from the tail of the cooling machine to the head and meets the material countercurrent, taking away the heat of the material. During the cooling process, the cold air also carries some moisture away.

The cooled material is easy to pack in a timely and fast manner to prevent clumping during storage. This machine adopts micro negative pressure operation, reducing pollution and improving the working environment. It has the characteristics of reasonable structure, stable operation, and strong adaptability. The cooled material is transported by a belt conveyor to the sixth section.

6. Compound fertilizer screening and large particle crushing process:

The screening section mainly separates fine powder, finished products, and large particle materials from the materials. Firstly, separate the fine powder in the semi-finished product, and then separate the large particles.

The separated large particles are crushed by a large particle crusher and together with the separated fine powder, they enter the return belt and return to the granulator for granulation. The finished product enters the seventh section.

7. Composite fertilizer packaging process:

The finished product is lifted by a leather elevator to the material bin on the packaging machine, unloaded into the measuring scale and automatically weighed according to the set weight. The weighed material enters the sewing and packaging section through a conveyor for sewing and packaging operations and enters the finished product warehouse.

The complete set of NPK fertilizer equipment includes: automatic batching system, new vertical crusher, rotary granulator, drum screening machine, dryer, cooling machine, packaging scale, etc. The volume size and yield of the compound fertilizer production line equipment vary to some extent, so the price of the compound fertilizer production line equipment naturally varies. The higher the yield, the slightly higher the price.