Rotary drum granulator is a kind of granulator commonly used in the production of NPK compound fertilizer, biological fertilizer, controlled-release fertilizer and other fertilizers. It is suitable for the large-scale production of cold, hot granulation and high, medium and low concentration NPK fertilizer production line.
The new blended raw materials are fed into drum granulator at a uniform rate according to the balling rate. At the same time, the saturated steam is fed into the material layer as required, so that the granulation process can be granulated at a lower moisture content, which not only raises the temperature of the material, but also causes the material to be humidified, thereby reducing the drying load. But, it needs to depend on the granulation rate, if necessary, a small amount of water or fertilizer solution may be sprayed on the material to maintain the optimum liquid phase for the granulation of the material.
1. Steam is introduced into the material layer of the drum granulator to improve the temperature of the granulated material, so as to dissolve the salt of the granulated material, achieve the high liquid volume under the low moisture content to meet the liquid volume required for the material granulation, and reduce the evaporation water volume of the drying process.
2. Ammonia can be applied to the material layer in the drum as required to make the material react.
3. The inner wall of the rotary drum granulator is lined with a number of soft rubber plates or polypropylene plates, and the corresponding position of the cylinder is provided with air holes. When the inner lining changes from the bottom to the top of the cylinder, the inner lining will sag due to the self weight, so that the materials adhered to the inner lining will fall down due to the gravity, so as to achieve the function of automatic cleaning and agglomeration.
4. The raw material adaptability of NPK fertilizer production process by drum steam granulation is extensive: it can be used in combination with low solubility (procalcium chloride, calcium chloride, ammonium sulfate, potassium sulfate, potassium chloride, etc.) and high solubility (urea, ammonium nitrate, ammonium phosphate, etc.) according to the requirements, as well as some organic matter and medium and trace elements.