The thermal power plant uses an ammonia-based desulfurization process; the chimney lining is corroded and covered with ammonium sulfate. Please all...
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The thermal power plant uses an ammonia-based desulfurization process; after operating for a period of time, the lining of the power plant’s chimney corrodes, and ammonium sulfate accumulates on it. Dear experts, where does the problem lie? Is it a process operation issue? Is it still a problem with the quality of the chimney lining construction?
Liner corrosion is ultimately a result of construction quality issues； However, the attachment of sulfuric acid an is due to process design issues or operational problems. If the sulfuric acid concentration in the tower is too high, or if the solid-liquid ratio of the sulfuric acid slurry is too high, crystallization will occur and accumulate in areas such as corners and beam supports, where it can continue to grow. Controlling the solid-liquid ratio of the slurry and regularly cleaning those areas prone to accumulation can be effective.
Is there a demister on the equipment? What is the type of demister? What is the spacing between the demisters? The efficiency of the demister is too low； In terms of the process: whether the flue gas flow rate is too high is greatly influenced by factors such as the pressure and duration of the water used for cleaning the demister. What I encountered was that the demister wasn’t cleaned for an extended period of time, which resulted in a reduced spacing between the corrugated plates of the demister. As a result, the flow velocity of the flue gas became too high; the flue gas exiting the desulfurization tower contained large amounts of sulfuric acid, sulfurous acid, and ammonium bisulfite. Not only was there sulfur ammonium adhering to the inner walls of the chimney, but there were also sulfur crystals throughout the area surrounding the desulfurization unit.
1. There is a problem with the design of the demister in the desulfurization tower; the pressure of the water used to wash the demister is too low, or the number of nozzles is insufficient. 2. There may be an issue with the operation; the cleaning interval for the demister is too long – it should be cleaned once every hour. An electromagnetic valve is used to control the flushing water valve, and a clock controller is employed to enable automatic flushing.
Which unit are you from? Leave your contact information; it can be resolved. The desulfurization process must be modified, as it’s caused by the aerosols specific to ammonia-based desulfurization – your flue gas must have a very long tail.
There are reasons from both aspects. :)