Problems with dry gas seals in Chengdu
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Our facility’s exhaust gas absorption tower is equipped with a bottom pump for such towers, manufactured by Suzhou Sulzer Pump Industry. The model of the pump is GSG 100-300 (E)(Bd)-6; the medium used is amine-rich liquid, the pressure in the sealing chamber is 0.12 MPa, and the temperature is 39°C. Auxiliary system: API PLANⅡ 72+75 system; the original pump manufacturer supplied Sichuan Nikki mechanical seals with the pumps, which were later replaced by Chengdu Yitong seals. After 8 months of operation with this seal in place, leakage occurred. Upon disassembly, it was found that the static and dynamic rings on the medium side of the seal were severely scaled, and the spring box on the dynamic ring side of the medium side was stuck and could not be moved manually. The dynamic ring compensation system was non-functional, and there were scratches on the circumferential surface of the dynamic ring’s sealing surface; the circumference appeared notched. The flushing port on the medium side was also severely blocked. However, the “O”-ring of the rotating and stationary ring seal is intact. The \"O\"-rings of the rotating and stationary rings in the dry gas side mechanical seal have hardened and failed; the sealing surface of the stationary ring shows uneven wear, but the surface is relatively clean. The image is as follows: Please, experts, help analyze this issue and suggest ways to address it; what are some good methods to solve the problem of spring failure on the medium side? How to address the issue of aging of the seal rings on the dry gas side?
Please ask the moderator to transfer me to the moving equipment section, thank you.
Is it possible that the first seal has leaked, causing the medium to solidify within the second sealing chamber? This leads to the failure of the sealing replenishment mechanism, and as a result, sealing leakage occurs.
The cause of failure in the medium-side sealing spring compensation mechanism appears to be coking – the accumulation of carbon particles leads to the failure of this compensation mechanism, resulting in leakage at the sealing surface. Since the amine-rich liquid in question contains hydrogen sulfide, it seems that there is a significant amount of such coking material. This is caused by high temperatures; factors such as lack of fluid and poor self-cleaning effects may also play a role. Is there a PLAN11 solution available? Is there a orifice plate in the flushing pipeline? Is the orifice plate clogged? Is the aperture size inappropriate? ) Second, is the pre-filter element clogged, resulting in insufficient inlet flow? Third, this sealing and flushing scheme is 72+75; what is the density of the medium? Is the official torch relay website accessible? Is the nitrogen flow rate meeting the design requirements? The O-ring has hardened due to high temperatures; it is estimated that the graphite ring has also changed color and cracked. Fourth, it is possible to ask the sealing manufacturer to analyze and make modifications, as this is a sporadic fault.
The coking of the rich and lean fluids is too severe; look for the causes in terms of the process media. I encountered a similar problem in a diesel hydrogenation unit before; it was a Calrit high-speed pump, under similar operating conditions. I hope this can be helpful to you.
If the original manufacturer’s Sichuan Nikki models have a longer lifespan, then switch back to them or provide one set to Chengdu for further research. If the lifespans of both types are similar, then regular maintenance is necessary, or alternative cleaning methods should be considered
The comparison method – this is an approach: victory:
Thank you for getting back to me; I just returned to the factory after the Spring Festival. This seal has a PLAN 11 system. I really didn’t pay attention to what size the throttle hole is. Regarding medium density, this needs to be asked of the process team.
People who work with mechanical equipment should have some knowledge of the manufacturing process, as it is very helpful for equipment maintenance