NPK fertilizer granules are produced using NPK granulation machines. When it comes to buying NPK fertilizer granulation equipment, it’s important to know that there are two different methods of granulating fertilizer: wet and dry. The dry method utilizes extrusion force to press dry powder into pellets. Meanwhile, when using wet drum pelletizers, liquids needs to be added to the raw materials to provide an adhesive force for granulating. A dry granulation pelletizer is one of the most important pieces of equipment in an NPK compound fertilizer production line.
Double Roller Press Machine
This type of machine produces organic fertilizer pellets using extrusion force and does not require any drying processes. The double roller press pellet machine can function at room temperature and can be used to manufacture fertilizer granules in a range of shapes and sizes. During extrusion granulation, all of the raw materials are vigorously aggregated under high pressure. The resulting powder is then squeezed between rollers to make granules. Since no drying or cooling of fertilizer granules is needed, double roller extrusion granulators are ideal for small to mid-sized organic fertilizer manufacturing plants who have limited funds for investment in equipment.
Wet Granulation Technology
Wet granulation results in fertilizer that has a higher moisture content, so the end product requires drying, cooling and solidifying processes. The four types of machines that can be used for wet granulation include rotary drum granulator, spray granulation machine, tower spray granulation machine, and disc pan granulation machine. Furthermore, the liquid added during the wet granulation process must be non-toxic and volatilizable. Common additives used are isopropanol and ethyl alcohol. The liquid needs to include binders otherwise the final product will separate during the drying process.
Disc Pan Granulation
The advantages of a disc pan granulator are that it is a lot cheaper than a rotary drum granulator and it has a wide range of applications. The disk is constructed from strong iron material, making it durable and stable. The inside of the pan is coated in an anti-corrosion plastic glass lining, which is easy to maintain. During operation, the machine produces little noise and is known for its reliability. Disc pan granulators are used in compound fertilizer production lines that manufacture over 50,000 tons of fertilizer pellets each year.
After granulation, there are additional processes required to complete NPK fertilizer production. If a wet granulating machine was used to produce the pellets, drying and cooling processes are needed. You can buy drying machines specifically designed for drying and cooling NPK fertilizer granules.
The next stage is the screening process. During that process, unqualified pellets are removed and sent back to the crushing section of the production line. You can buy different screeners based on your sieving specifications.
The coating process follows the screening process and is used to give fertilizer granules a smoother finish as well as improving their physical characteristics. The packing process is the final stage of production. To increase production efficiency, many companies invest in automatic weighing and bagging machines.