I’m a newcomer – why is the liquid level in the seal tank of the methanol pump kept rising?
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The equipment is a bit outdated; the liquid level in the methanol storage tank used for sealing with the methanol pump tends to keep rising in some pumps, requiring manual drainage on a regular basis. In other pumps, the level keeps dropping, necessitating manual addition of methanol. I’m not quite sure what’s going on. I asked some colleagues, but their explanations didn’t seem very convincing. I’m hoping to get a reliable explanation – please help!
Intuitively, it seems like there’s an increase in volume, as the medium inside the pump has leaked into the sealing tank； It’s because the liquid in the sealed tank has leaked into the environment.
Are the sealed tanks of the same type? Are they all pressure-free? If there is pressure, it leaks into the pump ； In the absence of pressure, it leaks into the sealed tank. Additionally, the outer seal leaks to the environment. Frequent additions indicate that the seal needs to be replaced.
There is a problem with the mechanical seal; it’s possible that the seal fluid and the medium have mixed together
If the storage tank is not under pressure, an increase in liquid level indicates a leak in the primary seal, while a decrease in liquid level indicates a leak in the secondary seal. If the storage tank is under pressure and the liquid level rises, it indicates that the pressure is not as high as in the sealing chamber, meaning the main seal has leaked ； The liquid level has dropped due to a leak in the primary or secondary seal
No, there was no leakage of methanol; the liquid level in the tank dropped from 2/3 to the point where it could no longer be seen. It took about 6 hours for that to happen, which is quite fast. We had to add more methanol manually. But it’s unlikely that the methanol leaked back into the pump – the pressure inside the pump is so high. A rise in pressure might be understandable, but what about a drop? Anyway, the machine pump has been in use for a long time, so it’s quite worn out
Well, I guess so too; the mechanical seal is broken.
But why do some pumps keep rising while others keep falling? I’m new, so I might ask some “basic” questions.
Have you had similar situations there? How to handle it?
This depends on whether there is pressure inside the tank; if there is pressure and it is greater than that in the sealing chamber, then it is an internal leak. It’s normal to replenish it every 20 days or so. If there is a lot of leakage, it indicates that the mechanical seal has failed and needs to be replaced