Analysis of the causes of jacket damage and thinning in coal pulverization pressurized gasification furnaces
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Recently, in a coal-to-gas project in Xinjiang, less than five months after it went into operation, leaks were detected in the jackets of more than 20 gasification units. Upon shutdown for inspection, it was found that the jackets were damaged and had thinned out, requiring shutdown for repairs – a process that will take approximately two months. Such damage to these gasification units has occurred in many projects; why hasn’t this problem been properly resolved yet? Was it taken into account during the engineering design phase to determine the causes (corrosion, abrasion, ablation)? Are there any countermeasures?
It seems that this issue has been resolved as being corrosion leakage of the jacket caused by metal ion corrosion. Recently, it is said that applying an anti-corrosion coating inside the furnace is used to prevent metal corrosion; as for its effectiveness, we’ll have to wait and see
In addition to alkali metals, it is necessary to consider whether other trace elements in the coal type are high, such as Cl, which can also cause corrosion.
The corrosion caused by Cl is relatively severe for austenitic materials, while it is not significant for other non-austenitic materials and can be essentially ignored. Currently, these fixed-bed furnaces are almost all made of non-austenitic materials; therefore, Cl corrosion is not considered as a major cause of corrosion, and is even not taken into account at all.