Compressor dry gas seal nitrogen
Thread Content
The flow rate of the secondary gas (nitrogen) for the compressor’s dry gas seal is 1 m3/h at the inlet side and 0.7 m3/h at the outlet side. I’m not sure if this is normal; I think the flow rates should be the same on both sides. If it’s not normal, what could be the reason?
Thank you. I’d like to ask what could cause the flow rates on both sides to be different, and what are the effects of either too low or too high nitrogen flow rates?
It should be normal. Sealing cannot achieve 100% tightness
Differences in dry gas seal leakage at the high and low pressure ends, pressure drops caused by piping, as well as varying back pressures, can all result in different flow rates of the secondary seal gas
If the piping does not change diameter, it is a minor leak~
It’s quite normal; varying degrees of seal damage, as well as occasional deviations in the flow meter, can all lead to such results. The labyrinth and mechanical seals on the drive side and the non-drive side may exhibit varying levels of leakage, which can range from mild to severe; slight deviations are considered normal.
It’s okay; consult the manufacturer. If there is a trend of increase, then it’s necessary to investigate the reason.
First of all, I’m not sure if you are using a series sealing arrangement with an intermediate labyrinth. If that’s the case, then the flow rate of the secondary seal will equal the leakage rate of the secondary seal (which is what you refer to as the flow rate at the outlet) plus the leakage rate through the intermediate labyrinth (whose main function is to dilute the process gas that leaks out from the primary seal, thereby ensuring effective isolation between the process gas and the environment). In such a situation, it’s inevitable that the flow rate at the outlet will be less than the flow rate at the inlet. In fact, as long as the flow rate and pressure of the flare at the primary stage are normal, there is no need to worry at all, as these are the most basic indicators for determining whether the seal has failed or not.