Causes of internal corrosion in the furnace cooling wall tubes of gas boilers
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Our company’s 75-ton sub-high pressure boiler has been in use for 5 years when it suddenly started leaking. Upon inspection, it was found that the cooling wall tubes of the boiler were leaking at a distance of less than 1 meter from the bottom of the furnace. These tubes were cut open for examination, and local corrosion was detected inside them; the diameter of the corroded areas ranged from 10 to 30 mm. There are a total of 64 such tubes on the cooling wall opposite the boiler’s gas nozzles, and so far 30 of them have been found to be corroded. What could be the cause of this? Is it due to improper operation of the deaerator, poor control of water pH, or something else? Please help analyze it. Thank you.
Check the water quality supervision reports, including the control of the pH value of the boiler water, the monitoring of the concentration of PO3 ions, and whether the boiler’s waste discharge procedures are being followed properly. Also, has proper maintenance been carried out after the boiler was shut down?
Spraying for wear and corrosion protection of water wall metal; hope to have the opportunity to cooperate!
This should send the tube to the electrical testing laboratory for microscopic analysis under an electron microscope to determine the mechanism of failure