Compound fertilizer pellets granulation machines are used to produce NPK pellet fertilizer from powder. When it comes to investing in the best equipment for your production line, you need to understand the difference between the two main methods of producing fertilizer granules: dry granulation and wet granulation. With the dry method, extrusion force is used to mechanically press and compress NPK powder into pellets. With wet granulating, a liquid is added to fertilizer powder before it is added to a drum pelletizer. The liquid is needed to provide a binding agent for raw powders that have a low moisture content. Buying the right type of granulation pelletizing machinery for the raw materials you have access to is essential for the running of a profitable compound fertilizer production line.
Wet Granulating Technology
When using the wet granulation method, the fertilizer pellets produced have a high-moisture content, so they require drying, solidifying and cooling processes before packing. There are various machines that can be used for wet granulation including spray granulation machines, disc pan granulation machines, rotary drum granulators, and tow spray granulating equipment. The liquid to facilitate the formation of compound fertilizer granules from low-moisture content powder must be a good binding agent. It needs to be volatilizable and non-toxic. Some of the most common liquids used are ethyl alcohol and isopropanol. If the right liquid binding agent is not used, the end product will crumble and separate following the drying process.
Double Roller Press Granulator
A double roller press granulator uses extrusion forces to produce NPK fertilizer pellets. No drying processes are necessary with this type of machine. It can be used to produce fertilizer granules in a wide range of sizes and shapes. During the extrusion granulation process, powder fertilizer is vigorously aggregated at high pressure. The power is then forced through rollers to produce granules. Since no cooling, drying or solidifying processes are needed, double roller press granulators are perfect for small to mid-sized compound fertilizer plants that perhaps don’t have the floor space or funds to invest in industrial drying machinery.
Disc Pan Granulation Machine
One of the main benefits of a disc pan granulator is that the cost is much lower than that of a rotary drum granulator. Furthermore, the machine can be used for a multitude of applications. The disc pan is manufactured from reinforced iron to make it durable. Furthermore, the interior of the disc pan is coated with anti-corrosion plastic glass material, which is very easy to clean and maintain. During production, a disc pan granulator has a surprisingly low noise output and such granulators are loved around the world because of their reliability. Some of the fertilizer manufacturers already using disc pan graduations can produce over 50,000 tons of compound fertilizer granules annually.
Final Production Processes
During the final stages of compound fertilizer production, the pellets undergo screening and unqualified granules are routed back to the start of the production line. The screening equipment used depends on the unique sieving specifications of the manufacturer. After screening, the pellets are often coated to improve the physical characteristics of the end product.