Pelletizing Die Troubleshooting Case Study

Problem

A major producer of polyethylene had problems with its pelletizing die producing pellets of poor quality. The problem was suspected to be either the pelletizing die or the process. The associated down time resulted in over $50,000 in losses each time the train was shut down. The client hired KHE to analyze its problem due our extensive  experience in analyzing many of the major name pelletizing dies.

Solution

KHE characterized the pellets and reviewed the train operation on site. KHE built a computational fluid dynamics (CFD) model of the die. The process was modeled and the response experienced by production was duplicated numerically. Proposed changes by KHE were also modeled to determine possible solutions. KHE determined that the vendor’s die was not ideally suitable for the application. However, KHE was able to recommend a change in the process which would produce an acceptable pellet until a new die could be put in service.

Results

The client implemented the recommended changes and was able to produce acceptable pellets until a new die could be obtained.