Analysis on the Seal Performance of Aerostatic Gas Lubricating Mechanical Seal

The influences of the orifice diameter,process gas pressure,supplying gas pressure on the seal performances of external pressurized aerostatic gas lubricating mechanical seal(or called aerostatic dry gas seal) were analyzed by analytical method.The results show that the opening force is increased with the increasing of orifice diameter,process gas pressure and supplying gas pressure.Smaller orifice diameter can result in higher gas film stiffness when the work gas film is small;the leakage to the process fluid is increased with the increasing of orifice diameter at the same supplying gas pressure.Both the gas film stiffness and the leakage to the process fluid are decreased with the increasing of process gas pressure.The gas film stiffness is increased by raising the supplying gas pressure.When the gas film thickness is 4~6μm,the gas film stiffness increase is large and there is a maximum value.Both the leakages to the process fluid and to the atmosphere are increased with the increasing of supplying gas pressure.The high stiffness of the seal can be ensured and the operation stability can be improved by selecting smaller orifice diameter,decreasing process gas pressure and raising supplying gas pressure.