Discussion on problems with this waste boiler equipment
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As shown in the figure above: In this vertical waste heat boiler (with crude gas on the tube side and boiler water on the shell side), after operating for a long period of time (about 20,000 hours), problems such as the detachment of the tube sheet at the joints with the heat exchange tubes as well as abrasion of those tubes occurred, with these issues being most severe near the top end. Please analyze the reasons; there will be rewards for those who contribute!
Consider the following points. 1: Has it ever run dry due to a water outage? 2: Is there regular maintenance to remove scale and other impurities? 3: Are the water quality parameters within the range required by the boiler? For example, chloride ions/PH, etc. 4: Does the boiler have high-temperature protection?
Are there any design requirements for the waste heat boiler, as well as specifications regarding the way in which the heat exchange tubes are connected to the tube sheet? Is the tube sheet a flexible one?
From the photo, it seems to be a support tube sheet? If corrosion occurs at the gap between the heat exchange tube and the upper tube sheet, it may be due to improper expansion fitting, which leads to gap corrosion.
What is the mechanism of intergranular corrosion? Thank you
Could there be an erosion problem caused by vibration of the heat exchange tubes? Is there any software for analyzing vibrations in heat exchange equipment?
The gasket plate is the main cause caused by vibration, with wear and corrosion being secondary causes; additionally, there may be an issue with the material temperature selection
What could be the reasons for vibration in the heat exchanger tube sheet?
First, whether the water has been purified and whether it contains chloride ions, as chloride ions have a strong tendency to cause intergranular corrosion. Secondly, was magnesium anode electrochemical protection used? Finally, it is crucial to determine whether it is external corrosion or internal corrosion.