Reasons for the flattening of high-tower compound fertilizer pellets
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Our company produces compound fertilizers with a nitrogen content of 26% for use in high towers; the pellets produced are always flat-shaped. We are seeking advice from experts.
May I ask what your company is, as well as the height and diameter of the tower? What is the granulation temperature? What is the hourly output?
The tower has a diameter of 14 meters and a height of 98 meters. The granulation temperature is 107 degrees, with a production rate of 18 tons per hour.
It’s not clear what raw materials are being used; the materials I have are of average quality, the temperature at the bottom of the tower is too high, and there are also issues with the raw materials themselves
Possible reasons include: 1. The granulation temperature is too high; the tower height is limited, resulting in a short solidification time, and the finished product deforms due to collision with the bottom of the tank； 2. Insufficient ventilation in the towers, resulting in inadequate cooling ； The production load is too high. In short, various reasons lead to incomplete curing of the particles, as well as deformation due to collision with the material collection equipment at the bottom of the pot.
I also think it’s a material issue, because no matter how much the roundness is adjusted, it never really becomes ideal
Different formulations have a significant impact on the curing speed of the particles; for certain formulations, under the same conditions, the particles produced are of much better quality
What does a flattened shape look like? A high granulation temperature can cause flattening, and issues with the raw materials also lead to flattening; there is some difference in the appearance of flattening in these cases. High-nitrogen products tend to cool poorly, which can result in flattened granules; you can lower the granulation temperature further. When solid crystals appear at the top of the granulator, the temperature is likely appropriate.
It’s a bit bun-shaped; both the larger and smaller particles are flattened, and with the exception of the very small particles, they are basically all flattened
When producing high-nitrogen products in the tall tower, the temperature of the secondary mixing tank should be kept low. It is possible to add as much material as possible to this tank in order to lower its temperature; at the same time, this helps to increase the consistency of the slurry in the tank, preventing it from becoming too thin and resulting in flat or broken particles!
For high-nitrogen products, the slurry should have good fluidity; in such cases, the temperature of the secondary mixing tank can be reduced. Of course, it is necessary to maintain appropriate fluidity. Additionally, the rotation speeds of the inner and outer rotors of the granulator should be adjusted based on the slurry’s flow properties – the difference between these rotation speeds can be increased slightly so that the particle size distribution of the particles exiting the tower corresponds to the desired size of the final product. This should resolve the issue. If problems still persist, the cause may lie in the emulsification effect of the slurry’s shear mechanism, the stirring speed, or the fineness of the raw materials