engleski

Investigation of pipeline failure in a thermal power plant’s process wastewater

In this paper, abundant, compacted, dust-like, corrosion scales from the interior of a corrosion- damaged pipeline were analyzed to determine the main reason for leakage and flow damping in the process- wastewater distribution system in the thermal power plant Plomin. The chemical composition, morphology and microbiological activity of the corrosion deposits present on the inner pipe wall were investigated and the physical and chemical analyses of the purified boiler water was made. The results show the presence of iron-related bacteria (IRB) in the corrosion deposits as well as in the distribution system water. XRD analysis shows exclusively magnetite and goethite with no calcium carbonate present in the layers, therefore indicating that no protective carbonate scales, which would protect the pipeline steel, had initially formed. It was concluded that the primary causes of intense corrosion were iron-oxidizing bacteria, that through their metabolism, support the redox cycling process, the formation of large tubercles as well as irregular thinning of the pipeline wall with separated anodic and cathodic areas.

pipeline failure ; microbiologically influenced corrosion (MIC) ; process wastewater distribution system ; tubercles

nije evidentirano