(210f) Troubleshooting Anomalous Behaviour in a Solid-State Reaction Process

A novel solid-state process for increasing molecular weight of a polymer powder was scaled-up to 3 m3 tumble dryer before going to full-scale production. The pilot plant process occasionally showed damaged internals, which eventually ended in serious damage to the reactor. A full-blown root cause analysis, including analysis of the powder properties before and after the incidents, did not reveal an explanation. Only after further detailed analysis of the plant signals around the incident and an understanding of the underlying physics of the process, the root cause was revealed. The full-scale process was started up with operating parameters based on the new findings and still runs smoothly today. However, a one-time error in operation of the full-scale process indeed reproduced bent internals, proving that the solution found is at the heart of the problem and that it protects the full-scale process from damage and mechanical failure.