Defects in the installation and operation of the underwater pelletizer
The temperature of the pelletizing template or the heating cylinder is out of control (too high):
Due to accidents, such as the template or the thermocouple of the heating cylinder is damaged or not placed in place, the system misjudgment and raises the actual temperature of the heating cylinder or the pelletizing template very high.
Even close to 300°C, excessive carbides (scaling) will adhere to individual parts of the feeding cavity, diameter reduction hole, and discharge hole wall within a short period of time, resulting in different sizes of granulated particles.
This phenomenon often occurs in major overhauls or When replacing a new template.
At the same time, the performance of additives is not stable: due to the differences in matching requirements between some additives and existing processes, some process needs to be changed.
It is characterized by low opening rate, different material particle sizes, and reduced product qualification rate.
The material cavity of the granulation template and the inner wall of the discharge hole are carbonized and polluted.
Solution: Check whether the thermocouple of the heating cylinder and the template is in place and whether it is invalid. In addition, adjust the process, remove the template, and ask professional manufacturers to repair it.
Quote-[1] Yang Zhongbo. Causes and optimization of the failure of the underwater pelletizer for polypropylene technology [J]. Petrochemical Technology, 2017, 024(010): 26-27
