Failure analysis of a large coal chemical reactor exhibiting bulging and cracking

Reactors represent the core components of coal chemical plants. Reactor failures can lead to significant operational hurdles, substantial financial losses, and potential casualties. Given these critical implications of reactor failures, thorough failure analyses of failed reactors are essential. This study investigated a failure incident involving bulging and cracking of a large coal chemical plant reactor. The failure analysis relied on several techniques, including macroscopic inspection, wall thickness measurement, mechanical property testing, hardness testing, metallographic analysis, and scanning electron microscopy analysis. The investigation confirmed that the failure of the reactor was caused by local overheating, which triggered high-temperature short-term creep, ultimately leading to bulging and cracking. To identify the factors responsible for this local overheating, a process analysis involving flow field and structural numerical simulations under abnormal working conditions was performed. The results of the flow field simulation, combined with field investigation data, revealed that the local overheating resulted from deposition or clogging of the distributor disk. Additionally, the extent of overheating was determined through the structural numerical simulation. In this paper, physical and chemical inspection, numerical modeling, and other means are comprehensively used to deduce the failure position through numerical simulation, to find out the failure reason, and to deduce the temperature range of failure. Overall, we hope that the results of this comprehensive failure analysis will provide valuable and experiential insights into the operation and maintenance of coal chemical plant reactors.