Let’s discuss dry gas seals.

Dry gas seals serve the same purpose as ordinary mechanical seals: that is, to convert axial leakage into radial leakage. Mechanical seals achieve sealing through friction between the rotating and stationary rings, and are generally used for liquid media with relatively high molecular weights. But this does not work for gas media with a low molecular weight. This leads to dry-sealing. In a dry gas seal, the dynamic and static rings are sealed by a high-pressure gas film created by the sealing gas; there is no direct contact between them. Mechanical seals typically use the high-pressure medium at the pump outlet to flush and cool the leakage, which is then returned to the pump body; whereas dry gas seals use nitrogen or the medium at the compressor outlet to dilute the leakage and carry it away for discharge. Let’s discuss to improve together. Our cyclohydrogen compressor has been in trial operation these past few days, and its final sealing will be carried out tomorrow.

When the rotating dynamic ring, which has hydrodynamic grooves (2.5–10 µm) on its outer surface, rotates, these grooves pump the high-pressure gas on the outer diameter side (referred to as the upstream side) into the space between the sealing surfaces. The pressure of the air film increases from the outer diameter toward the groove diameter, while it decreases from the groove diameter toward the inner diameter. The increased pressure on the sealing surfaces results in a force that overcomes the closing force acting on the sealing ring, thereby creating a very thin air film (1–3 µm) between the frictioning surfaces, allowing the seal to function in a non-contact manner. The formed gas film completely blocks the leakage path for the relatively low-pressure sealing medium, achieving zero leakage or zero escape of the sealing medium.

The primary buffer gas is vented to the flare, the secondary buffer gas is vented at a higher altitude, and the isolation gas is released directly into the atmosphere. The primary and secondary buffer gases are process gases, while the isolation gas is N2.

What zhangjx 19831 said is simple, but it covers all the key points; I think it’s quite good! !

Thanks for the compliment from above. When communicating, use simple language and just explain the points clearly. Don’t be too fixated on theory. Many people these days are stuck in this pattern, adhering to conventions without any drive for progress or spirit of innovation. I used to work in automation; after switching to operations for 4 years, I noticed that many operators, including some technical staff working with process equipment, lack a proactive attitude. They always rely on others’ experience, even though much of that experience is incorrect, but they don’t bother to think for themselves. Even experience must conform to theoretical inferences. Thinking more and doubting more will surely deepen understanding, help clarify the principles, and enable thorough theoretical analysis; this will allow one to handle tasks with ease and flexibility in practical applications, rather than merely following procedures mechanically and functioning like a simple machine. Maybe a bit arrogant. It might hurt people

For discussion threads dedicated to dry gas seals, please go to the expert discussion forum!