NPK fertilizer production steam drum granulation process
Brief introduction of NPK fertilizer production drum granulation process:
1) Deliver qualified raw materials such as nitrogen, phosphorus, potassium and fillers to each relevant weighing equipment.
2) The weighed raw material is transferred to the mixer and stirred evenly.
3) Transported into the drum fertilizer granulator machine, and at the same time pass saturated steam, the material forms a rolling material by the friction generated by the rotation of the drum granulator, and the pressing force generated by the rolling causes the materials to agglomerate into small particles. The small particles become the core and adhere to the surrounding powder to form qualified particles.
4) Transfer to the rotary dryer for heat exchange with heat from the hot air oven.
5) The screened semi-finished granules are transported to a rotary chiller to cool the fertilizer by natural cold air or strong cooling air. The large particles are pulverized by the pulverizer and returned to the drum granulator to continue to participate in the ball formation.
6) Transfer to the sieving machine to sort the granules. The fine granules are directly returned to the drum granulator machine, and as the core continue to participate in the adhesion of the granules into balls.
7) The qualified products after screening are transported to the coating machine for coating.
8) Transfer to the fully automatic packaging scale for weighing, packaging and storage.
The production of compound fertilizer by drum granulation has the following advantages
1. Steam is introduced into the material layer in the drum to increase the temperature of the granulated material, dissolve the salt of the granulated material, and obtain a high liquid phase at a low moisture content to satisfy the liquid phase required for granulation of the material, while reducing the amount of evaporated water in the drying process.
2. Ammonia can be passed through the layer in the drum as needed to allow the material to react.
3. The inner wall of the drum is lined with soft rubber sheets or polypropylene sheets. Ventilation holes are opened at corresponding positions on the cylinder. When the inner liner moves from the bottom to the top at the same time, the inner lining hangs due to its own weight, thus the material adhering to the inner lining falls due to gravity and achieves automatic cleaning.
4. During the fertilizer manufacturing process, the operator can observe the material into the ball at any time, and take corresponding measures as needed to ensure the normal operation of the system.
5. Wide range of adaptability of raw materials: low solubility (calcium, calcium chloride, ammonium sulfate, potassium sulfate, potassium chloride, etc.) and high solubility (urea, ammonium nitrate, ammonium phosphate, etc.) can be arbitrarily matched according to requirements. It can also be used with some organic and medium trace elements.