How to prevent corrosion on the inner wall of the flue gas induced draft fan casing of the oil refining unit?
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How to prevent corrosion on the inner wall of the induced draft fan casing of the oil refining unit? The entrance of the induced draft fan of the oil refining unit is the flue gas from the outlet of the heat pipe heater. The general temperature is about 160°C. Since the flue gas contains a large amount of sulfur dioxide gas, the casing and impeller of the induced draft fan are severely corroded. In less than half a year of use, pitting corrosion and large-area thinning occurred in the casing, and in less than a year of use, the casing was scrapped.
Judging from the scene, it should be made of stainless steel, right? Also, can you consider inserting an elbow at the bottom of the chimney and extending the extension pipe upward (higher than the smoke inlet) to connect a blower to blow air into the chimney, using the high flow rate of air to generate negative pressure to bring the smoke out. Although the efficiency will be reduced, the problem of fan corrosion can be solved. Just thinking, for reference: lol
When corrosion is inevitable, should we consider using the sacrificial principle to reduce corrosion to the exhaust fan?
Sacrificial anodes are not appropriate, they are for environments with water. Under this condition, there is no water and no corrosive circuit can be formed.
Mr. Wang, you have learned a lesson! :handshake
I don’t know if the high-temperature resistant coating can delay corrosion.
The appropriate anti-corrosion coating referred to here is not only able to withstand temperatures below 200 degrees, but also has resistance to the acidic corrosion of flue gas. This will delay corrosion on the metal surface.
I wonder if a product similar to Belzona 1591 is feasible.
It can be used if it can withstand the temperature and flue gas corrosion conditions.
This post was last posted by lcmqh@163.com Edited on 2019-7-23 14:13 If it is a high-temperature fan, 1. Consider the fan shell insulation, and the carbon steel part of the fan outer wall should not be lower than the SO2 dew point temperature ； 2. The oxygen content in the exhaust gas is not high ； 3. The part of the chimney whose temperature is lower than the dew point should be made of corrosion-resistant materials. ； 4. Use S316 for the drainage pipe at the bottom of the fan to drain the condensate in time to prevent circulation in the casing. Paying attention to the above issues should reduce corrosion and allow normal use.
Spray temperature-resistant and corrosion-resistant paint on the inside of the fan housing. If this is the current actual situation, we can discuss cooperation.