The process flow of complete sets of equipment in npk production line can usually be divided into: raw material batching, raw material mixing, raw material granulation, particle drying, particle cooling, particle classification, finished product coating, and final finished product packaging.
Then the material in the equipment (drum granulator) how long can reach the expected quality, residence time is the amount of time the material is processed in the given equipment. In most npk fertilizer manufacturing process Settings, the manufacturer must be able to reach a specific retention time to achieve its desired goal.
While retention time seems simple in theory, it gets complicated when using continuous procedures. In a continuous production run, there are no batches and no real boundaries between “start” and “end”; Material is constantly in and out of the drum at the same time, so it is difficult to determine the true length of time to process a given part of the material.
1. Introduce tracers
Tracers such as dyes or chemicals are not always allowed due to product composition or contamination issues. However, when allowed, tracers can be a very useful tool for determining retention time; The average retention time can be determined by measuring where the tracer begins to flow out of the drum and where the tracer is no longer seen.
2. Measure the drum volume
Retention time can also be defined by measuring the volume of material in the drum or the weight of material in the drum when the process is in a steady state. In a steady state, the material is fed and discharged at the same rate. Average retention time can be determined by dividing the material bed volume or material bed weight by the volume flow rate or mass flow rate. It is important to understand that the retention time is always an average across successive Settings.
In the npk production line, we have encountered two situations due to the different friction between the material and the cylinder wall of the granulator. The internal surface finish of the granulator is large, which reduces the friction between the material and the cylinder wall and weakens the upward movement force of the material. If the material does not roll, it will not produce particles. In view of this situation, we can solve it by adjusting the rotating speed of the granulator and installing a small board inside.