Corrosion issues in CO2 compressors
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In actual production, our piston-type CO2 compressors suffer from corrosion of the gas valves and the intake ports of the cylinder blocks in the high-pressure sections (mainly stages 4 and 5, with pressures of approximately 8.5 Mpa and 20.0 Mpa). Let’s analyze what the reasons are. Explanation: The water in CO2 is separated quite cleanly.
Our facility has several CO2 compressors, but we haven’t encountered the issue you mentioned. If there is no water present in the CO2, I suggest checking for H2S
H2S was analyzed; there was none. Such incidents mainly occurred after the compressor underwent an expansion upgrade; it may be related to this expansion, but it’s not possible to determine the exact cause.
After the compressor is modified, its coolers at each stage should also have been enlarged, right? What are the temperatures of grade 4 and grade 5 imported gases? There is definitely a small amount of water vapor in carbon dioxide gas, and corrosion that occurs is usually carbonic acid corrosion. I personally recommend trying to increase the inlet temperature by four or five levels.
It’s likely caused by hydrogen sulfide corrosion, or there are water molecules inside
I agree with the view from the fourth floor. Our company has encountered similar situations, where piston rings of grades 4 and 5 as well as cylinder liners have a short lifespan. Currently, the temperature in the five-stage system is controlled at around 50 degrees. It has improved.
:Handshake: I believe that the key to preventing corrosion in the high-pressure section of CO2 machines lies in strict control of relevant parameters; specifically, the inlet temperature at the five different stages of the machine must be kept above 38 degrees. 5 degrees – no matter how large the water cooling system in the front section is, it is essential to control this temperature value. Our factory has experienced situations similar to what the poster described. :handshake :handshake
The air valves in stages 4 and 5 of our CO2 compressors have a short service life, and there is corrosion in the air valve chamber, resulting in pitting