Equipment system abnormalities are the primary cause of process failures. Uneven airflow distribution is one of the core issues. If the openings of the airflow distribution plate are not reasonable, blocked, or worn, it will lead to an imbalance in the fluidization state of the materials in the bed layer. Some areas may have excessive boiling and clumping of materials, while others may have insufficient fluidization and form a dead bed, resulting in uneven granulation effects. In addition, the failure of the spray system cannot be ignored. Nozzle blockage and unstable atomization pressure will cause poor atomization effect of the adhesive. Too large droplets will easily lead to particle agglomeration, while too small droplets will be difficult to form effective bonding, resulting in too many fine powders. The failure of the drying temperature control system is equally critical. If the temperature is too high, the surface of the material will quickly solidify, and the internal moisture cannot be discharged in a timely manner, resulting in the particles being easily brittle and cracked; If the temperature is too low, the drying will be poor, the moisture content of the particles will exceed the standard, and they are prone to deterioration during storage.

Insufficient adaptability of material characteristics can also lead to granulation failure. The physical properties such as particle size distribution, bulk density, and moisture absorption of materials directly affect the fluidization state and bonding effect. If the proportion of fine powder in the material is too high, it is easy to generate dust during fluidization, and the adhesive adsorption is uneven, making it difficult to form uniform particles; Excessive moisture absorption of materials can absorb moisture from the air during the granulation process, leading to excessive particle bonding and the formation of large chunks; Hydrophobic materials may have loose particles and be prone to disintegration due to poor compatibility with adhesives. In addition, improper selection and proportioning of adhesives are also important factors. Excessive concentration of adhesives can cause particles to excessively bond, while low concentration can result in insufficient bonding force, both of which can affect the quality of particle molding.

Improper control of operating parameters is the direct cause of process failure. Imbalance in fluidized air flow control is a common problem, as excessive air flow can cause material entrainment and loss, and particle collision can be too severe, leading to breakage; If the air volume is too small, good fluidization cannot be achieved, and materials are prone to sedimentation and agglomeration. The mismatch between the adhesive spray rate and the fluidization state is also critical. If the spray rate is too fast, the adhesive can not be dispersed in time, which may lead to excessive wetting and caking of local materials; The spray rate is too slow, the production efficiency is low, and the particle molding is not full. In addition, unreasonable settings of parameters such as material feeding rate and drying time can also disrupt the dynamic balance of the granulation process and lead to process failure.

The successful implementation of granulation technology requires precise matching of equipment systems, material characteristics, and operating parameters. During production, the equipment shall be overhauled regularly to ensure uniform airflow distribution and stable spray system; Evaluate material characteristics in advance, select adhesives reasonably, and optimize the ratio; Establish a dynamic equilibrium of the granulation process by optimizing operating parameters through experiments. Only by comprehensively controlling all key factors can we effectively avoid process failures and ensure the quality stability of granular products.