Abu Dhabi Gas Liquefaction Company Ltd Job Training Mechanical Technician Course Module 9 Compressors
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- Figure 5.24
- Labyrinth seals
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5.1.6 Compressor
Seals There must always be clearance between the stationary and rotating parts in a machine. In a centrifugal compressor it is very important to stop, or at least reduce to a minimum, the leakage of gas from high to low pressure through these clearances. Different types of seals are used wherever leakage of gas is possible. They are located between: • impellers and diaphragms • rotor shaft and casing These locations are shown in red in Figure 5.24. This figure does not show bearings. Figure 5.24: Seal Locations Suction nozzle Discharge nozzle Diaphragm seals Shaft seal Shaft seal Personnel & Training Division Job Training—Mechanical Technician Compressors/Rev. 0.0 Page 66 of 90 The four main types of compressor seals are: • labyrinth • carbon ring • mechanical • liquid film Labyrinth seals are the most common type used for sealing diaphragms. A labyrinth seal is shown in Figure 5.25. These seals leave a large number of very small gaps for the gas to pass through. There is a lot of fluid friction as the gas squeezes through each gap. This friction loss results in a pressure loss. By the time the gas reaches the outside its pressure has dropped so much that it is no higher than the outside pressure and it can not flow out. Figure 5.25: Labyrinth Seal Personnel & Training Division Job Training—Mechanical Technician Compressors/Rev. 0.0 Page 67 of 90 Rings Oil in Oil out Oil out Labyrinth seal Labyrinth seal Gas pressure side Atmospheric pressure side Download 0.5 Mb. Do'stlaringiz bilan baham: 
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