Abu Dhabi Gas Liquefaction Company Ltd Job Training Mechanical Technician Course Module 9 Compressors

The propane compressor has a single, horizontally-split casing. It has three 
compressor process stages that receive propane vapour at high, medium and low 
pressures from different chillers. It compresses this vapour before it is cooled and 
returned to the chillers.  Figure 5.20 shows the compressor arrangement. 
Note 1: In Train III the propane chillers are all located in the cold box. In Trains I and 
II they are at different locations in the plant. 
The propane compressors are driven by steam turbines. 

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Compressors/Rev. 0.0 
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MCR from 
cryogenic 
exchanger 
Return to cryogenic 
exchanger after 
cooling 
Casing 
Intercooler 
Figure 5.21: MCR Compressor
 
 
 
Note 2: Propane chillers are also used to cool MCR after compression, as well as 
other products from the plant. 
Each MCR compressor has a single, horizontally-split casing. It receives MCR 
vapour from the cryogenic exchanger. It compresses the vapour before it is cooled 
and returned to the cryogenic exchanger. Each compressor has two compressor 
process stages to allow the MCR to be cooled between stages as shown in Figure 
5.21. It is driven by a steam turbine. 
Note 3: All compressors on the plant have intercoolers. These have not been shown 
on earlier compressor diagrams for simplicity. They are described in
 Section 6.1
of 
this module. 
Note 4: There are other small refrigeration compressors in the Utilities Nitrogen 
Plant. 
Figure 5.20: Propane Compressor 
From low-
pressure 
chillers 
Return to chillers 
after cooling 
From medium
-pressure 
chillers
From high-
pressure 
chillers
Casing 

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Compressors/Rev. 0.0 
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Air Compressors
These are located in the Utilities areas of the plant. They supply air to all areas except 
the Sulphur STOREX area. 
Air from Utilities is used for: 
• process—Trains I, II and III 
• instrumentation—pneumatically controlled valves, etc. 
• service—air hoses in workshops, etc. 
• Nitrogen Plant 
Centrifugal compressors provide a continuous supply of air for normal operation.
There is one reciprocating air compressor in the Utilities area that is used for 
emergency instrument air. This was described in