Dry gas seal of centrifugal compressors
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This post was last edited by Lost Boy on 2018-11-10 22:22 :handshake:) In the dry gas seal of a centrifugal compressor, which has a higher pressure – the pressure of the isolation gas or that of the lubricating oil? The parameters that our factory has adjusted currently are: the pressure of the isolation gas is 0.02 MPa, while the pressure of the lubricating oil is 0.15 MPa. Won’t this allow the lubricating oil to enter the sealing chamber? I think the pressure of the isolation gas should be slightly higher than that of the lubricating oil, right? I hope the experts here can help me figure this out!
The pressure of the isolation gas is high; the lubricating oil pressure is 0.15, and in fact there is almost no pressure on the side of the sealed atmosphere
The seal of a centrifuge is usually a labyrinth seal; the pressure of the lubricating oil decreases gradually as it moves toward the gas seal side. As long as the pressure of the sealing gas is higher than the pressure of the lubricating oil at the gas seal side, no leakage will occur
In my understanding, the pressure of the lubricating oil for personnel refers to the pressure at the outlet of the lubricating oil pump. However, each bearing housing of the compressor is equipped with a breather cap, keeping the pressure at near atmospheric levels. The purpose of having pressure in the lubricating oil pump is simply to ensure that the lubricating oil can be smoothly delivered from the lubricating oil tank to the corresponding bearings in the bearing housings. Therefore, as long as the isolation gas maintains a slight positive pressure, lubricant leakage into the dry gas seal can be completely prevented.