What is the purpose of the vent pipes on both sides of the turbine (back-pressure type)?
Thread Content
What is the purpose of the vent pipes on both sides of the turbine (back-pressure type)? Is the steam leakage normal?
Turbocharger steam seal vent pipe? Check whether the steam seal air valve is operating properly?
It’s fine if it sticks out a little; it just looks a bit too much so
When shaft seal steam leaks, older units are equipped with two pipes that lead directly to the atmosphere, in order to monitor the leakage of the sealing steam. However, maintenance of such units is inadequate in China, and few technicians are able to keep the leakage from the labyrinth seal within acceptable levels. Therefore, condensers are now installed after the steam starts leaking; these condensers help to deal with the leaked steam and also enhance the sealing effectiveness of the sealing steam
We have one here that doesn’t produce steam anymore, and the manufacturer says it’s okay.
Shaft seal steam release. Theoretically, it’s best not to produce steam, but in practice, it’s sufficient to control it to a slight level of steam emission. The shaft seal of the turbine operates based on the principle shown in the diagram below, by controlling the pressures at points X and Y to ensure that the airflow in the shaft gap flows in the direction indicated by the arrows. In practice, an excessive amount of air flowing from the atmosphere to point Y can prevent a vacuum from being established, and it is difficult to control this amount (with some models not even detecting any air entering the unit); therefore, a small amount of steam leaking out is often considered normal.
This post was last edited by cuikk on 2022-10-25 at 22:26. This term “signal tube” requires a leakage rate: 1. Since it is an axial seal, medium flow is necessary in order to carry away the heat generated by friction； 2. Turbine air must not leak to the steam side; therefore, it must leak to the atmosphere ； 3. It is possible to determine whether the shaft seal is damaged by observing the leakage from the signal tube; the amount of leakage, whether small or large, flows into the atmospheric side.